BioMed Research International: Biomaterials The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Ordinary and Activated Bone Grafts: Applied Classification and the Main Features Sun, 15 Nov 2015 12:13:28 +0000 Bone grafts are medical devices that are in high demand in clinical practice for substitution of bone defects and recovery of atrophic bone regions. Based on the analysis of the modern groups of bone grafts, the particularities of their composition, the mechanisms of their biological effects, and their therapeutic indications, applicable classification was proposed that separates the bone substitutes into “ordinary” and “activated.” The main differential criterion is the presence of biologically active components in the material that are standardized by qualitative and quantitative parameters: growth factors, cells, or gene constructions encoding growth factors. The pronounced osteoinductive and (or) osteogenic properties of activated osteoplastic materials allow drawing upon their efficacy in the substitution of large bone defects. R. V. Deev, A. Y. Drobyshev, I. Y. Bozo, and A. A. Isaev Copyright © 2015 R. V. Deev et al. All rights reserved. Increased Mesenchymal Stem Cell Response and Decreased Staphylococcus aureus Adhesion on Titania Nanotubes without Pharmaceuticals Tue, 10 Nov 2015 12:22:43 +0000 Titanium (Ti) implants with enhanced biocompatibility and antibacterial property are highly desirable and characterized by improved success rates. In this study, titania nanotubes (TNTs) with various tube diameters were fabricated on Ti surfaces through electrochemical anodization at 10, 30, and 60 V (denoted as NT10, NT30, and NT60, resp.). Ti was also investigated and used as a control. NT10 with a diameter of 30 nm could promote the adhesion and proliferation of bone marrow mesenchymal stem cells (BMSCs) without noticeable differentiation. NT30 with a diameter of 100 nm could support the adhesion and proliferation of BMSCs and induce osteogenesis. NT60 with a diameter of 200 nm demonstrated the best ability to promote cell spreading and osteogenic differentiation; however, it clearly impaired cell adhesion and proliferation. As the tube diameter increased, bacterial adhesion on the TNTs decreased and reached the lowest value on NT60. Therefore, NT30 without pharmaceuticals could be used to increase mesenchymal stem cell response and decrease Staphylococcus aureus adhesion and thus should be further studied for improving the efficacy of Ti-based orthopedic implants. Zhiqiang Xu, Yingzhen Lai, Dong Wu, Wenxiu Huang, Sijia Huang, Lin Zhou, and Jiang Chen Copyright © 2015 Zhiqiang Xu et al. All rights reserved. Long-Term In Vitro Degradation of a High-Strength Brushite Cement in Water, PBS, and Serum Solution Mon, 26 Oct 2015 07:43:29 +0000 Bone loss and fractures may call for the use of bone substituting materials, such as calcium phosphate cements (CPCs). CPCs can be degradable, and, to determine their limitations in terms of applications, their mechanical as well as chemical properties need to be evaluated over longer periods of time, under physiological conditions. However, there is lack of data on how the in vitro degradation affects high-strength brushite CPCs over longer periods of time, that is, longer than it takes for a bone fracture to heal. This study aimed at evaluating the long-term in vitro degradation properties of a high-strength brushite CPC in three different solutions: water, phosphate buffered saline, and a serum solution. Microcomputed tomography was used to evaluate the degradation nondestructively, complemented with gravimetric analysis. The compressive strength, chemical composition, and microstructure were also evaluated. Major changes from 10 weeks onwards were seen, in terms of formation of a porous outer layer of octacalcium phosphate on the specimens with a concomitant change in phase composition, increased porosity, decrease in object volume, and mechanical properties. This study illustrates the importance of long-term evaluation of similar cement compositions to be able to predict the material’s physical changes over a relevant time frame. Ingrid Ajaxon, Caroline Öhman, and Cecilia Persson Copyright © 2015 Ingrid Ajaxon et al. All rights reserved. Dental Implants Fatigue as a Possible Failure of Implantologic Treatment: The Importance of Randomness in Fatigue Behaviour Sun, 25 Oct 2015 12:35:39 +0000 Objective. To show how random variables concern fatigue behaviour by a probabilistic finite element method. Methods. Uncertainties on material properties due to the existence of defects that cause material elastic constant are not the same in the whole dental implant the dimensions of the structural element and load history have a decisive influence on the fatigue process and therefore on the life of a dental implant. In order to measure these uncertainties, we used a method based on Markoff chains, Bogdanoff and Kozin cumulative damage model, and probabilistic finite elements method. Results. The results have been obtained by conventional and probabilistic methods. Mathematical models obtained the same result regarding fatigue life; however, the probabilistic model obtained a greater mean life but with more information because of the cumulative probability function. Conclusions. The present paper introduces an improved procedure to study fatigue behaviour in order to know statistics of the fatigue life (mean and variance) and its probability of failure (fatigue life versus probability of failure). María Prados-Privado, Juan Carlos Prados-Frutos, Ángel Manchón, Rosa Rojo, Pietro Felice, and José Antonio Bea Copyright © 2015 María Prados-Privado et al. All rights reserved. Quantitative Evaluation of Tissue Surface Adaption of CAD-Designed and 3D Printed Wax Pattern of Maxillary Complete Denture Sun, 25 Oct 2015 09:48:58 +0000 Objective. To quantitatively evaluate the tissue surface adaption of a maxillary complete denture wax pattern produced by CAD and 3DP. Methods. A standard edentulous maxilla plaster cast model was used, for which a wax pattern of complete denture was designed using CAD software developed in our previous study and printed using a 3D wax printer, while another wax pattern was manufactured by the traditional manual method. The cast model and the two wax patterns were scanned in the 3D scanner as “DataModel,” “DataWaxRP,” and “DataWaxManual.” After setting each wax pattern on the plaster cast, the whole model was scanned for registration. After registration, the deviations of tissue surface between “DataModel” and “DataWaxRP” and between “DataModel” and “DataWaxManual” were measured. The data was analyzed by paired t-test. Results. For both wax patterns produced by the CAD&RP method and the manual method, scanning data of tissue surface and cast surface showed a good fit in the majority. No statistically significant () difference was observed between the CAD&RP method and the manual method. Conclusions. Wax pattern of maxillary complete denture produced by the CAD&3DP method is comparable with traditional manual method in the adaption to the edentulous cast model. Hu Chen, Han Wang, Peijun Lv, Yong Wang, and Yuchun Sun Copyright © 2015 Hu Chen et al. All rights reserved. Biological Behaviour and Enhanced Anticorrosive Performance of the Nitrided Superelastic Ti-23Nb-0.7Ta-2Zr-0.5N Alloy Sun, 25 Oct 2015 09:43:31 +0000 The influence of gas nitriding surface treatment on the superelastic Ti-23Nb-0.7Ta-2Zr-0.5N alloy was evaluated. A thorough characterization of bare and nitrided Ti-based alloy and pure Ti was performed in terms of surface film composition and morphology, electrochemical behaviour, and short term osteoblast response. XPS analysis showed that the nitriding treatment strongly influenced the composition (nitrides and oxynitrides) and surface properties both of the substrate and of the bulk alloy. SEM images revealed that the nitrided surface appears as a similar dotted pattern caused by the formation of N-rich domains coexisting with less nitrided domains, while before treatment only topographical features could be observed. All the electrochemical results confirmed the high chemical stability of the nitride and oxynitride coating and the superiority of the applied treatment. The values of the corrosion parameters ascertained the excellent corrosion resistance of the coated alloy in the real functional conditions from the human body. Cell culture experiments with MG63 osteoblasts demonstrated that the studied biomaterials do not elicit any toxic effects and support cell adhesion and enhanced cell proliferation. Altogether, these data indicate that the nitrided Ti-23Nb-0.7Ta-2Zr-0.5N alloy is the most suitable substrate for application in bone implantology. Valentina Mitran, Cora Vasilescu, Silviu Iulian Drob, Petre Osiceanu, Jose Maria Calderon-Moreno, Mariana-Cristina Tabirca, Doina-Margareta Gordin, Thierry Gloriant, and Anisoara Cimpean Copyright © 2015 Valentina Mitran et al. All rights reserved. An Overview of the Mechanical Integrity of Dental Implants Sun, 25 Oct 2015 09:22:36 +0000 With the growing use of dental implants, the incidence of implants’ failures grows. Late treatment complications, after reaching full osseointegration and functionality, include mechanical failures, such as fracture of the implant and its components. Those complications are deemed severe in dentistry, albeit being usually considered as rare, and therefore seldom addressed in the clinical literature. The introduction of dental implants into clinical practice fostered a wealth of research on their biological aspects. By contrast, mechanical strength and reliability issues were seldom investigated in the open literature, so that most of the information to date remains essentially with the manufacturers. Over the years, implants have gone through major changes regarding the material, the design, and the surface characteristics aimed at improving osseointegration. Did those changes improve the implants’ mechanical performance? This review article surveys the state-of-the-art literature about implants’ mechanical reliability, identifying the known causes for fracture, while outlining the current knowledge-gaps. Recent results on various aspects of the mechanical integrity and failure of implants are presented and discussed next. The paper ends by a general discussion and suggestions for future research, outlining the importance of mechanical considerations for the improvement of their future performance. Keren Shemtov-Yona and Daniel Rittel Copyright © 2015 Keren Shemtov-Yona and Daniel Rittel. All rights reserved. Hexosamine-Induced TGF-β Signaling and Osteogenic Differentiation of Dental Pulp Stem Cells Are Dependent on N-Acetylglucosaminyltransferase V Sun, 25 Oct 2015 07:20:53 +0000 Glycans of cell surface glycoproteins are involved in the regulation of cell migration, growth, and differentiation. N-acetyl-glucosaminyltransferase V (GnT-V) transfers N-acetyl-d-glucosamine to form β1,6-branched N-glycans, thus playing a crucial role in the biosynthesis of glycoproteins. This study reveals the distinct expression of GnT-V in STRO-1 and CD-146 double-positive dental pulp stem cells (DPSCs). Furthermore, we investigated three types of hexosamines and their N-acetyl derivatives for possible effects on the osteogenic differentiation potential of DPSCs. Our results showed that exogenous d-glucosamine (GlcN), N-acetyl-d-glucosamine (GlcNAc), d-mannosamine (ManN), and acetyl-d-mannosamine (ManNAc) promoted DPSCs’ early osteogenic differentiation in the absence of osteogenic supplements, but d-galactosamine (GalN) or N-acetyl-galactosamine (GalNAc) did not. Effects include the increased level of TGF-β receptor type I, activation of TGF-β signaling, and increased mRNA expression of osteogenic differentiation marker genes. The hexosamine-treated DPSCs showed an increased mineralized matrix deposition in the presence of osteogenic supplements. Moreover, the level of TGF-β receptor type I and early osteogenic differentiation were abolished in the DPSCs transfected with siRNA for GnT-V knockdown. These results suggest that GnT-V plays a critical role in the hexosamine-induced activation of TGF-β signaling and subsequent osteogenic differentiation of DPSCs. Yi-Jane Chen, Chung-Chen Yao, Chien-Hsun Huang, Hao-Hueng Chang, and Tai-Horng Young Copyright © 2015 Yi-Jane Chen et al. All rights reserved. Photocatalytical Antibacterial Activity of Mixed-Phase TiO2 Nanocomposite Thin Films against Aggregatibacter actinomycetemcomitans Wed, 21 Oct 2015 13:52:13 +0000 Mixed-phase nanocomposite thin films consisting of anatase and rutile prepared on commercially pure Ti sheets via the electrochemical anodization and annealing treatments were investigated in terms of their photocatalytic activity for antibacterial use around dental implants. The resulting films were characterized by scanning electron microscopy (SEM), and X-ray diffraction (XRD). The topology was assessed by White Light Optical Profiling (WLOP) in the Vertical Scanning Interferometer (VSI) mode. Representative height descriptive parameters of roughness and were calculated. The photocatalytic activity of the resulting films was evaluated by the photodegradation of Rhodamine B (RhB) dye solution. The antibacterial ability of the photocatalyst was examined by  Aggregatibacter actinomycetemcomitans suspensions in a colony-forming assay. XRD showed that anatase/rutile mixed-phase thin films were predominantly in anatase and rutile that were 54.6 wt% and 41.9 wt%, respectively. Craters (2–5 µm) and protruding hills (10–50 µm) on Ti substrates were produced after electrochemical anodization with higher and surface roughness values. Anatase/rutile mixed-phase thin films showed 26% photocatalytic decolorization toward RhB dye solution. The number of colonizing bacteria on anatase/rutile mixed-phase thin films was decreased significantly in vitro. The photocatalyst was effective against A. actinomycetemcomitans colonization. Sinem Yeniyol, Ilven Mutlu, Zhiming He, Behiye Yüksel, Robert Joseph Boylan, Mustafa Ürgen, Zihni Cüneyt Karabuda, Cansu Basegmez, and John Lawrence Ricci Copyright © 2015 Sinem Yeniyol et al. All rights reserved. Fracture Strength of Aged Monolithic and Bilayer Zirconia-Based Crowns Wed, 21 Oct 2015 11:57:00 +0000 The purpose of this study was to evaluate the effect of design and surface finishing on fracture strength of yttria-tetragonal zirconia polycrystal (Y-TZP) crowns in monolithic (1.5 mm thickness) and bilayer (0.8 mm zirconia coping and 0.7 mm porcelain veneer) configuration after artificial aging. Bovine incisors received crown preparation and Y-TZP crowns were manufactured using CAD/CAM technique, according to the following groups (): Polished monolithic zirconia crowns (PM); Glazed monolithic zirconia crowns (GM); Bi-layer crowns (BL). Crowns were cemented with resin cement, submitted to artificial aging in a chewing simulator (2.5 million cycles/80 N/artificial saliva/37°C), and tested for fracture strength. Two remaining crowns referring to PM and GM groups were submitted to a chemical composition analysis to measure the level of yttrium after aging. One-way ANOVA and Tukey’s test () indicated that monolithic zirconia crowns presented similar fracture strength ( N ± 791.7;  N ± 991.6), which was higher than bilayer crowns (2060.4 N ± 810.6). There was no difference in the yttrium content among the three surfaces evaluated in the monolithic crowns. Thus, monolithic zirconia crowns present higher fracture strength than bilayer veneered zirconia after artificial aging and surface finishing does not affect their fracture strength. Deborah Pacheco Lameira, Wilkens Aurélio Buarque e Silva, Frederico Andrade e Silva, and Grace M. De Souza Copyright © 2015 Deborah Pacheco Lameira et al. All rights reserved. Comparison of Conventional Methods and Laser-Assisted Rapid Prototyping for Manufacturing Fixed Dental Prostheses: An In Vitro Study Wed, 21 Oct 2015 09:00:09 +0000 This study assessed whether there are differences in marginal fit between laser-fusion and conventional techniques to produce fixed dental prostheses (FDPs). A master steel die with 2 abutments was produced to receive a posterior 4-unit FDPs and single copings. These experimental models were divided into three groups (/group) manufactured: group 1, Ni-Cr alloy, with a lost-wax casting technique; group 2, Co-Cr alloy, with selective laser melting (SLM); and group 3, yttria-tetragonal zirconia polycrystal (Y-TZP), with a milling system. All specimens were cut along the longitudinal axis and their adaptation was measured at the marginal and shoulder areas on the right and left sides of each abutment. Measurements were made using a stereomicroscope (×60 magnification) and a scanning electron microscope (×800 magnification). The data were analyzed using one-way analysis of variance and the Bonferroni post hoc test, with a significance cutoff of 5%. Significant differences () were observed between group 3 and the other groups. The marginal opening was smallest with Co-Cr alloy substructures, while the shoulder opening was smallest with Ni-Cr alloy substructures. Within the limitations of this study, the marginal fit of an FDP is better with rapid prototyping (RP) via SLM than conventional manufacturing systems. Giorgio Pompa, Stefano Di Carlo, Francesca De Angelis, Maria Paola Cristalli, and Susanna Annibali Copyright © 2015 Giorgio Pompa et al. All rights reserved. 3D Surface Profile and Color Stability of Tooth Colored Filling Materials after Bleaching Mon, 19 Oct 2015 09:40:31 +0000 This study aims to evaluate the effects of vital tooth bleaching with carbamide peroxide home bleaching and in-office bleaching on the color stability and 3D surface profile of dental restorative filling materials. Thirty discs () measure 6 mm in diameter and 2 mm thick for each of three restorative materials. These are nanofilled composite Filtek Z350 XT, the submicron composite Estelite Quick, and nanofilled glass ionomer Ketac N100 nanoionomer and were fabricated in shade A2. Each group was further divided into three subgroups (): subgroup A (Opalescence PF), subgroup B (Opalescence Boost in-office bleaching), and subgroup C (distilled water) serving as control. Samples were bleached according to the manufacturer’s instructions for a period of two weeks. The Commission Internationale de L’Eclairage (CIE , , ) system was chosen for image processing, while 3D surface profile was tested with atomic force microscopy (AFM). Statistical analyses were performed with the Mann-Whitney tests and Krusal-Wallis with a value of ≤0.05. The three restorative materials showed significant color changes (); . In diminishing order, the mean color changes recorded were Estelite (3.82 ± 1.6) > Ketac Nano (2.97 ± 1.2) > Filtek Z350 XT (2.25 ± 1.0). However, none of the tested materials showed statistically significant changes in surface roughness; . Bryant Anthony Irawan, Stacey Natalie Irawan, Sam’an Malik Masudi, Ninin Sukminingrum, and Mohammad Khursheed Alam Copyright © 2015 Bryant Anthony Irawan et al. All rights reserved. Cementation of Glass-Ceramic Posterior Restorations: A Systematic Review Sun, 18 Oct 2015 13:35:28 +0000 Aim. The aim of this comprehensive review is to systematically organize the current knowledge regarding the cementation of glass-ceramic materials and restorations, with an additional focus on the benefits of Immediate Dentin Sealing (IDS). Materials and Methods. An extensive literature search concerning the cementation of single-unit glass-ceramic posterior restorations was conducted in the databases of MEDLINE (Pubmed), CENTRAL (Cochrane Central Register of Controlled Trials), and EMBASE. To be considered for inclusion, in vitro and in vivo studies should compare different cementation regimes involving a “glass-ceramic/cement/human tooth” complex. Results and Conclusions. 88 studies were included in total. The in vitro data were organized according to the following topics: (micro)shear and (micro)tensile bond strength, fracture strength, and marginal gap and integrity. For in vivo studies survival and quality of survival were considered. In vitro studies showed that adhesive systems (3-step, etch-and-rinse) result in the best (micro)shear bond strength values compared to self-adhesive and self-etch systems when luting glass-ceramic substrates to human dentin. The highest fracture strength is obtained with adhesive cements in particular. No marked clinical preference for one specific procedure could be demonstrated on the basis of the reviewed literature. The possible merits of IDS are most convincingly illustrated by the favorable microtensile bond strengths. No clinical studies regarding IDS were found. Carline R. G. van den Breemer, Marco M. M. Gresnigt, and Marco S. Cune Copyright © 2015 Carline R. G. van den Breemer et al. All rights reserved. Real-Time Analysis of Temperature Changes in Composite Increments and Pulp Chamber during Photopolymerization Sun, 18 Oct 2015 12:28:51 +0000 Objective. The aim of this study was to evaluate the temperature change at various sites within the composite and on the pulpal side of dentin during polymerization of two composite increments. Materials and Methods. Class I cavities prepared in third molars were restored in two composite increments (). Temperatures were measured for 110 s using eight thermocouples: bottom center of cavity (BC), top center of 1st increment (MC), top center of 2nd increment (TC), bottom corner of cavity (BE), top corner of 1st increment (ME), top corner of 2nd increment (TE), pulpal side of dentin (PD), and center of curing light guide tip (CL). Results. Maximum temperature values (°C) measured during polymerization of 1st increment were MC (59.8); BC (52.8); ME (51.3); CL (50.7); BE (48.4); and PD (39.8). Maximum temperature values during polymerization of 2nd increment were TC 58.5; TE (52.6); MC (51.7); CL (50.0); ME (48.0); BC (46.7); BE (44.5); and PD (38.8). Conclusion. Temperature at the floor of the cavity was significantly higher during polymerization of 1st increment compared to 2nd increment. Temperature rise was higher at the center than at the corner and at the top surface than at the bottom surface of each increment. Ryan Jin-Young Kim, In-Bog Lee, Jin-Young Yoo, Su-Jung Park, Sin-Young Kim, Young-Ah Yi, Ji-Yun Hwang, and Deog-Gyu Seo Copyright © 2015 Ryan Jin-Young Kim et al. All rights reserved. Effects of Computer-Aided Manufacturing Technology on Precision of Clinical Metal-Free Restorations Sun, 18 Oct 2015 12:09:58 +0000 Purpose. The purpose of this study was to investigate the marginal fit of metal-free crowns made by three different computer-aided design/computer-aided manufacturing (CAD/CAM) systems. Materials and Methods. The maxillary left first premolar of a dentiform was prepared for all-ceramic crown restoration. Thirty all-ceramic premolar crowns were made, ten each manufactured by the Lava system, Cercon, and Cerec. Ten metal ceramic gold (MCG) crowns served as control. The marginal gap of each sample was measured under a stereoscopic microscope at 75x magnification after cementation. One-way ANOVA and the Duncan’s post hoc test were used for data analysis at the significance level of 0.05. Results. The mean (standard deviation) marginal gaps were 70.5 (34.4) μm for the MCG crowns, 87.2 (22.8) μm for Lava, 58.5 (17.6) μm for Cercon, and 72.3 (30.8) μm for Cerec. There were no significant differences in the marginal fit among the groups except that the Cercon crowns had significantly smaller marginal gaps than the Lava crowns .  Conclusions. Within the limitation of this study, all the metal-free restorations made by the digital CAD/CAM systems had clinically acceptable marginal accuracy. Ki-Hong Lee, In-Sung Yeo, Benjamin M. Wu, Jae-Ho Yang, Jung-Suk Han, Sung-Hun Kim, Yang-Jin Yi, and Taek-Ka Kwon Copyright © 2015 Ki-Hong Lee et al. All rights reserved. Analysis of Self-Adhesive Resin Cement Microshear Bond Strength on Leucite-Reinforced Glass-Ceramic with/without Pure Silane Primer or Universal Adhesive Surface Treatment Sun, 18 Oct 2015 12:06:16 +0000 Objective. To evaluate the microshear bond strength (μSBS) of self-adhesive resin (SA) cement on leucite-reinforced glass-ceramic using silane or universal adhesive. Materials and Methods. Ceramic blocks were etched with 9.5% hydrofluoric acid and divided into three groups (): (1) negative control (NC) without treatment; (2) Single Bond Universal (SBU); (3) RelyX Ceramic Primer as positive control (PC). RelyX Unicem resin cement was light-cured, and μSBS was evaluated with/without thermocycling. The μSBS was analyzed using one-way analysis of variance. The fractured surfaces were examined using stereomicroscopy and scanning electron microscopy (SEM). Results. Without thermocycling, μSBS was highest for PC (30.50 MPa ± 3.40), followed by SBU (27.33 MPa ± 2.81) and NC (20.18 MPa ± 2.01) (). Thermocycling significantly reduced μSBS in SBU (22.49 MPa ± 4.11) (), but not in NC (20.68 MPa ± 4.60) and PC (28.77 MPa ± 3.52) (). PC and NC predominantly fractured by cohesive failure within the ceramic and mixed failure, respectively. Conclusion. SBU treatment improves μSBS between SA cement and glass ceramics, but to a lower value than PC, and the improvement is eradicated by thermocycling. NC exhibited the lowest μSBS, which remained unchanged after thermocycling. Yoon Lee, Jae-Hoon Kim, Jung-Soo Woo, Young-Ah Yi, Ji-Yun Hwang, and Deog-Gyu Seo Copyright © 2015 Yoon Lee et al. All rights reserved. Bone Regeneration by Nanohydroxyapatite/Chitosan/Poly(lactide-co-glycolide) Scaffolds Seeded with Human Umbilical Cord Mesenchymal Stem Cells in the Calvarial Defects of the Nude Mice Tue, 13 Oct 2015 12:54:57 +0000 In the preliminary study, we have found an excellent osteogenic property of nanohydroxyapatite/chitosan/poly(lactide-co-glycolide) (nHA/CS/PLGA) scaffolds seeded with human umbilical cord mesenchymal stem cells (hUCMSCs) in vitro and subcutaneously in the nude mice. The aim of this study was to further evaluate the osteogenic capacity of nHA/CS/PLGA scaffolds seeded with hUCMSCs in the calvarial defects of the nude mice. Totally 108 nude mice were included and divided into 6 groups: PLGA scaffolds + hUCMSCs; nHA/PLGA scaffolds + hUCMSCs; CS/PLGA scaffolds + hUCMSCs; nHA/CS/PLGA scaffolds + hUCMSCs; nHA/CS/PLGA scaffolds without seeding; the control group (no scaffolds) (). The scaffolds were implanted into the calvarial defects of nude mice. The amount of new bones was evaluated by fluorescence labeling, H&E staining, and Van Gieson staining at 4 and 8 weeks, respectively. The results demonstrated that the amount of new bones was significantly increased in the group of nHA/CS/PLGA scaffolds seeded with hUCMSCs (). On the basis of previous studies in vitro and in subcutaneous implantation of the nude mice, the results revealed that the nHA and CS also enhanced the bone regeneration by nHA/CS/PLGA scaffolds seeded with hUCMSCs in the calvarial defects of the nude mice at early stage. Fei Wang, Xiao-Xia Su, Yu-Cheng Guo, Ang Li, Yin-Cheng Zhang, Hong Zhou, Hu Qiao, Li-Min Guan, Min Zou, and Xin-Qin Si Copyright © 2015 Fei Wang et al. All rights reserved. Shear Bond Strength of MDP-Containing Self-Adhesive Resin Cement and Y-TZP Ceramics: Effect of Phosphate Monomer-Containing Primers Sun, 11 Oct 2015 13:47:45 +0000 Purpose. This study was conducted to evaluate the effects of different phosphate monomer-containing primers on the shear bond strength between yttria-tetragonal zirconia polycrystal (Y-TZP) ceramics and MDP-containing self-adhesive resin cement. Materials and Methods. Y-TZP ceramic surfaces were ground flat with #600-grit SiC paper and divided into six groups (). They were treated as follows: untreated (control), Metal/Zirconia Primer, Z-PRIME Plus, air abrasion, Metal/Zirconia Primer with air abrasion, and Z-PRIME Plus with air abrasion. MDP-containing self-adhesive resin cement was applied to the surface-treated Y-TZP specimens. After thermocycling, a shear bond strength test was performed. The surfaces of the Y-TZP specimens were analyzed under a scanning electron microscope. The bond strength values were statistically analyzed using one-way analysis of variance and the Student–Newman–Keuls multiple comparison test (). Results. The Z-PRIME Plus treatment combined with air abrasion produced the highest bond strength, followed by Z-PRIME Plus application, Metal/Zirconia Primer combined with air abrasion, air abrasion alone, and, lastly, Metal/Zirconia Primer application. The control group yielded the lowest results (). Conclusion. The application of MDP-containing primer resulted in increased bond strength between Y-TZP ceramics and MDP-containing self-adhesive resin cements. Jin-Soo Ahn, Young-Ah Yi, Yoon Lee, and Deog-Gyu Seo Copyright © 2015 Jin-Soo Ahn et al. All rights reserved. Direct Tensile Strength and Characteristics of Dentin Restored with All-Ceramic, Resin-Composite, and Cast Metal Prostheses Cemented with Resin Adhesives Sun, 11 Oct 2015 13:36:47 +0000 A dentin-cement-prosthesis complex restored with either all-porcelain, cured resin-composite, or cast base metal alloy and cemented with either of the different resin cements was trimmed into a mini-dumbbell shape for tensile testing. The fractured surfaces and characterization of the dentin-cement interface of bonded specimens were investigated using a Scanning Electron Microscope. A significantly higher tensile strength of all-porcelain (12.5 ± 2.2 MPa) than that of cast metal (9.2 ± 3.5 MPa) restorations was revealed with cohesive failure in the cement and failure at the prosthesis-cement interface in Super-Bond C&B group. No significant difference in tensile strength was found among the types of restorations using the other three cements with adhesive failure on the dentin side and cohesive failure in the cured resin. SEM micrographs demonstrated the consistent hybridized dentin in Super-Bond C&B specimens that could resist degradation when immersed in hydrochloric acid followed by NaOCl solutions whereas a detached and degraded interfacial layer was found for the other cements. The results suggest that when complete hybridization of resin into dentin occurs tensile strength at the dentin-cement is higher than at the cement-prosthesis interfaces. The impermeable hybridized dentin can protect the underlying dentin and pulp from acid demineralization, even if detachment of the prosthesis has occurred. Morakot Piemjai and Nobuo Nakabayashi Copyright © 2015 Morakot Piemjai and Nobuo Nakabayashi. All rights reserved. In Vitro Behavior of Human Adipose Tissue-Derived Stem Cells on Poly(ε-caprolactone) Film for Bone Tissue Engineering Applications Thu, 08 Oct 2015 13:54:43 +0000 Bone tissue engineering is an emerging field, representing one of the most exciting challenges for scientists and clinicians. The possibility of combining mesenchymal stem cells and scaffolds to create engineered tissues has brought attention to a large variety of biomaterials in combination with osteoprogenitor cells able to promote and regenerate bone tissue. Human adipose tissue is officially recognized as an easily accessible source of mesenchymal stem cells (AMSCs), a significant factor for use in tissue regenerative medicine. In this study, we analyze the behavior of a clonal finite cell line derived from human adipose tissue seeded on poly(ε-caprolactone) (PCL) film, prepared by solvent casting. PCL polymer is chosen for its good biocompatibility, biodegradability, and mechanical properties. We observe that AMSCs are able to adhere to the biomaterial and remain viable for the entire experimental period. Moreover, we show that the proliferation process and osteogenic activity of AMSCs are maintained on the biofilm, demonstrating that the selected biomaterial ensures cell colonization and the development of an extracellular mineralized matrix. The results of this study highlight that AMSCs and PCL film can be used as a suitable model to support regeneration of new bone for future tissue engineering strategies. Cecilia Romagnoli, Roberto Zonefrati, Gianna Galli, Dario Puppi, Alessandro Pirosa, Federica Chiellini, Francesco Saverio Martelli, Annalisa Tanini, and Maria Luisa Brandi Copyright © 2015 Cecilia Romagnoli et al. All rights reserved. New Biomaterials in Drug Delivery and Wound Care Wed, 07 Oct 2015 07:26:21 +0000 Šeila Selimović, Francesco Piraino, Robert Gauvin, and Hojae Bae Copyright © 2015 Šeila Selimović et al. All rights reserved. Macrophage-Targeting Gene Delivery Using a Micelle Composed of Mannose-Modified Lipid with Triazole Ring and Dioleoyl Trimethylammonium Propane Mon, 05 Oct 2015 09:35:15 +0000 Gene carriers with cell specific ligand molecules are needed for the treatment of several diseases. Mannose is known to be recognized and incorporated into the cells through mannose recognition lectins that are exclusively expressed on macrophages. In this study, we synthesized two types of mannose-modified lipids with different stereoisomer (α-mannose and β-mannose). To make a complex with plasmid DNA (pDNA), termed “lipoplex,” we prepared a two-component micelle made from cationic lipid; dioleoyltrimethylammoniumpropane (DOTAP); and mannose-modified lipid (D/α-Man or D/β-Man). The prepared D/α-Man lipoplexes were able to bind to one of the α-mannose lectins concanavalin A (ConA) immobilized on gold substrate in the quartz-crystal microbalance sensor cell. D/β-Man lipoplexes did not show any frequency changes. These results indicate that the mannose residues were exposed on the lipoplexes, leading to not only the binding to ConA but also the prevention of nonspecific interactions with proteins. Both lipoplexes showed high transfection efficiencies to RAW264.7 cells which have several kinds of mannose lectins. This delivery system to macrophages may overcome the problems for gene therapy and may be used for the treatment of immune diseases involved in macrophages. Ichiki Fukuda, Shinichi Mochizuki, and Kazuo Sakurai Copyright © 2015 Ichiki Fukuda et al. All rights reserved. A Current View of Functional Biomaterials for Wound Care, Molecular and Cellular Therapies Mon, 05 Oct 2015 08:38:15 +0000 The intricate process of wound healing involves activation of biological pathways that work in concert to regenerate a tissue microenvironment consisting of cells and external cellular matrix (ECM) with enzymes, cytokines, and growth factors. Distinct stages characterize the mammalian response to tissue injury: hemostasis, inflammation, new tissue formation, and tissue remodeling. Hemostasis and inflammation start right after the injury, while the formation of new tissue, along with migration and proliferation of cells within the wound site, occurs during the first week to ten days after the injury. In this review paper, we discuss approaches in tissue engineering and regenerative medicine to address each of these processes through the application of biomaterials, either as support to the native microenvironment or as delivery vehicles for functional hemostatic, antibacterial, or anti-inflammatory agents. Molecular therapies are also discussed with particular attention to drug delivery methods and gene therapies. Finally, cellular treatments are reviewed, and an outlook on the future of drug delivery and wound care biomaterials is provided. Francesco Piraino and Šeila Selimović Copyright © 2015 Francesco Piraino and Šeila Selimović. All rights reserved. Biologic Agents for Periodontal Regeneration and Implant Site Development Mon, 05 Oct 2015 08:27:39 +0000 The advancement of molecular mediators or biologic agents has increased tremendously during the last decade in periodontology and dental implantology. Implant site development and reconstruction of the lost periodontium represent main fields in which these molecular mediators have been employed and investigated. Different growth factors trigger different reactions in the tissues of the periodontium at various cellular levels. Proliferation, migration, and differentiation constitute the main target areas of these molecular mediators. It was the purpose of this comprehensive review to describe the origin and rationale, evidence, and the most current understanding of the following biologic agents: Recombinant Human Platelet-Derived Growth Factor-BB (rhPDGF-BB), Enamel Matrix Derivate (EMD), Platelet-Rich Plasma (PRP) and Platelet-Rich Fibrin (PRF), Recombinant Human Fibroblast Growth Factor-2 (rhFGF-2), Bone Morphogenic Proteins (BMPs, BMP-2 and BMP-7), Teriparatide PTH, and Growth Differential Factor-5 (GDF-5). Fernando Suárez-López del Amo, Alberto Monje, Miguel Padial-Molina, ZhiHui Tang, and Hom-Lay Wang Copyright © 2015 Fernando Suárez-López del Amo et al. All rights reserved. Bone Regeneration from PLGA Micro-Nanoparticles Mon, 05 Oct 2015 08:23:55 +0000 Poly-lactic-co-glycolic acid (PLGA) is one of the most widely used synthetic polymers for development of delivery systems for drugs and therapeutic biomolecules and as component of tissue engineering applications. Its properties and versatility allow it to be a reference polymer in manufacturing of nano- and microparticles to encapsulate and deliver a wide variety of hydrophobic and hydrophilic molecules. It additionally facilitates and extends its use to encapsulate biomolecules such as proteins or nucleic acids that can be released in a controlled way. This review focuses on the use of nano/microparticles of PLGA as a delivery system of one of the most commonly used growth factors in bone tissue engineering, the bone morphogenetic protein 2 (BMP2). Thus, all the needed requirements to reach a controlled delivery of BMP2 using PLGA particles as a main component have been examined. The problems and solutions for the adequate development of this system with a great potential in cell differentiation and proliferation processes under a bone regenerative point of view are discussed. Inmaculada Ortega-Oller, Miguel Padial-Molina, Pablo Galindo-Moreno, Francisco O’Valle, Ana Belén Jódar-Reyes, and Jose Manuel Peula-García Copyright © 2015 Inmaculada Ortega-Oller et al. All rights reserved. Effects of P-15 Peptide Coated Hydroxyapatite on Tibial Defect Repair In Vivo in Normal and Osteoporotic Rats Mon, 05 Oct 2015 08:02:03 +0000 This study assessed the efficacy of anorganic bone mineral coated with P-15 peptide (ABM/P-15) on tibia defect repair longitudinally in both normal and osteoporotic rats in vivo. A paired design was used. 24 Norwegian brown rats were divided into normal and osteoporotic groups. 48 cylindrical defects were created in proximal tibias bilaterally. Defects were filled with ABM/P-15 or left empty. Osteoporotic status was assessed by microarchitectural analysis. Microarchitectural properties of proximal tibial defects were evaluated at 4 time points. 21 days after surgery, tibias were harvested for histology and histomorphometry. Significantly increased bone volume fraction, surface density, and connectivity were seen in all groups at days 14 and 21 compared with day 0. Moreover, the structure type of ABM/P-15 group was changed toward typical plate-like structure. Microarchitectural properties of ABM/P-15 treated newly formed bones at 21 days were similar in normal and osteoporotic rats. Histologically, significant bone formation was seen in all groups. Interestingly, significantly increased bone formation was seen in osteoporotic rats treated with ABM/P-15 indicating optimized healing potential. Empty defects showed lower healing potential in osteoporotic bone. In conclusion, ABM/P-15 accelerated bone regeneration in osteoporotic rats but did not enhance bone regeneration in normal rats. Rasmus Hestehave Pedersen, Marina Rasmussen, Søren Overgaard, and Ming Ding Copyright © 2015 Rasmus Hestehave Pedersen et al. All rights reserved. Naturally Occurring Extracellular Matrix Scaffolds for Dermal Regeneration: Do They Really Need Cells? Mon, 05 Oct 2015 07:55:49 +0000 The pronounced effect of extracellular matrix (ECM) scaffolds in supporting tissue regeneration is related mainly to their maintained 3D structure and their bioactive components. These decellularized matrix scaffolds could be revitalized before grafting via adding stem cells, fibroblasts, or keratinocytes to promote wound healing. We reviewed the online published literature in the last five years for the studies that performed ECM revitalization and discussed the results of these studies and the related literature. Eighteen articles met the search criteria. Twelve studies included adding cells to acellular dermal matrix (ADM), 3 studies were on small intestinal mucosa (SIS), one study was on urinary bladder matrix (UBM), one study was on amniotic membrane, and one study included both SIS and ADM loaded constructs. We believe that, in chronic and difficult-to-heal wounds, revitalizing the ECM scaffolds would be beneficial to overcome the defective host tissue interaction. This belief still has to be verified by high quality randomised clinical trials, which are still lacking in literature. A. M. Eweida and M. K. Marei Copyright © 2015 A. M. Eweida and M. K. Marei. All rights reserved. Custom-Made Antibiotic Cement Nails in Orthopaedic Trauma: Review of Outcomes, New Approaches, and Perspectives Mon, 05 Oct 2015 07:12:44 +0000 Since the first description in 2002 by Paley and Herzenberg, antibiotic bone cement nails (ACNs) have become an effective tool in the orthopaedic trauma surgeons’ hands. They simultaneously elute high amounts of antibiotics into medullary canal dead space and provide limited stability to the debrided long bone. In this paper, we perform a systematic review of current evidence on ACNs in orthopaedic trauma and provide an up-to-date review of the indications, operative technique, failure mechanisms, complications, outcomes, and outlooks for the ACNs use in long bone infection. Marcin K. Wasko and Rafal Kaminski Copyright © 2015 Marcin K. Wasko and Rafal Kaminski. All rights reserved. Twelve-Month Results of a Single or Multiple Dexamethasone Intravitreal Implant for Macular Edema following Uncomplicated Phacoemulsification Mon, 05 Oct 2015 07:10:16 +0000 The clinical efficacy of one or two intravitreal injections of a continued deliverance dexamethasone 700 μg implant in ten patients with persistent macular edema following uncomplicated phacoemulsification was evaluated. Complete ophthalmological examination and spectral domain optical coherence tomography were carried out. Follow-up was at day 7 and months 1, 2, 4, 6, 8, and 12. At baseline mean best corrected visual acuity was 62 Early Treatment Diabetic Retinopathy Study Chart letters, which showed statistically significant improvement at each follow-up, except at month 6, to reach 79 letters at month 12 (). Prior to treatment mean central foveal thickness was 622 μm, which showed statistically significant improvement at each follow-up to reach a mean value of 282 μm () at month 12. Five patients received a second dexamethasone implant at month 7. Two patients were excluded from the study at months 4 and 8. Intraocular pressure remained stable during the study period with the exception of mild increase in two patients requiring topical therapy. In conclusion there was statistically significant improvement of best corrected visual acuity and mean central foveal thickness with one or two intravitreal dexamethasone implants over 12 months. Solmaz Abdolrahimzadeh, Vito Fenicia, Maurizio Maurizi Enrici, Pasquale Plateroti, Dora Cianfrone, and Santi Maria Recupero Copyright © 2015 Solmaz Abdolrahimzadeh et al. All rights reserved. Microstereolithography-Based Fabrication of Anatomically Shaped Beta-Tricalcium Phosphate Scaffolds for Bone Tissue Engineering Sun, 04 Oct 2015 14:00:49 +0000 Porous ceramic scaffolds with shapes matching the bone defects may result in more efficient grafting and healing than the ones with simple geometries. Using computer-assisted microstereolithography (MSTL), we have developed a novel gelcasting indirect MSTL technology and successfully fabricated two scaffolds according to CT images of rabbit femur. Negative resin molds with outer 3D dimensions conforming to the femur and an internal structure consisting of stacked meshes with uniform interconnecting struts, 0.5 mm in diameter, were fabricated by MSTL. The second mold type was designed for cortical bone formation. A ceramic slurry of beta-tricalcium phosphate (-TCP) with room temperature vulcanization (RTV) silicone as binder was cast into the molds. After the RTV silicone was completely cured, the composite was sintered at 1500°C for 5 h. Both gross anatomical shape and the interpenetrating internal network were preserved after sintering. Even cortical structure could be introduced into the customized scaffolds, which resulted in enhanced strength. Biocompatibility was confirmed by vital staining of rabbit bone marrow mesenchymal stromal cells cultured on the customized scaffolds for 5 days. This fabrication method could be useful for constructing bone substitutes specifically designed according to local anatomical defects. Dajiang Du, Teruo Asaoka, Makoto Shinohara, Tomonori Kageyama, Takashi Ushida, and Katsuko Sakai Furukawa Copyright © 2015 Dajiang Du et al. All rights reserved. Collagen/Beta-Tricalcium Phosphate Based Synthetic Bone Grafts via Dehydrothermal Processing Sun, 04 Oct 2015 13:24:51 +0000 Millions of patients worldwide remain inadequately treated for bone defects related to factors such as disease or trauma. The drawbacks of metallic implant and autograft/allograft use have steered therapeutic approaches towards tissue engineering solutions involving tissue regeneration scaffolds. This study proposes a composite scaffold with properties tailored to address the macro- and microenvironmental conditions deemed necessary for successful regeneration of bone in defect areas. The biodegradable scaffold composed of porous beta-tricalcium phosphate particles and collagen type I fibers is prepared from a mixture of collagen type-I and β-tricalcium phosphate (β-TCP) particles via lyophilization, followed by dehydrothermal (DHT) processing. The effects of both sterilization via gamma radiation and the use of DHT processing to achieve cross-linking were investigated. The impact of the chosen fabrication methods on scaffold microstructure and β-TCP particle-collagen fiber combinations were analyzed using X-ray diffractometry (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and microcomputerized tomography (µ-CT). Electron spinning resonance (ESR) analysis was used to investigate free radicals formation following sterilization. Results revealed that the highly porous (65% porosity at an average of 100 µm pore size), mechanically adequate, and biocompatible scaffolds can be utilized for bone defect repairs. Burcu Sarikaya and Halil Murat Aydin Copyright © 2015 Burcu Sarikaya and Halil Murat Aydin. All rights reserved. Cutaneous and Labyrinthine Tolerance of Bioactive Glass S53P4 in Mastoid and Epitympanic Obliteration Surgery: Prospective Clinical Study Sun, 04 Oct 2015 13:19:35 +0000 Objective. To evaluate the cutaneous and the inner ear tolerance of bioactive glass S53P4 when used in the mastoid and epitympanic obliteration for chronic otitis surgery. Material and Methods. Forty-one cases have been included in this prospective study. Cutaneous tolerance was clinically evaluated 1 week, 1 month, and 3 months after surgery with a physical examination of the retroauricular and external auditory canal (EAC) skin and the presence of otalgia; the inner ear tolerance was assessed by bone-conduction hearing threshold 1 day after surgery and by the presence of vertigo or imbalance. Results. All surgeries but 1 were uneventful: all patients maintained the preoperative bone-conduction hearing threshold except for one case in which the round window membrane was opened during the dissection of the cholesteatoma in the hypotympanum and this led to a dead ear. No dizziness or vertigo was reported. Three months after surgery, healing was achieved in all cases with a healthy painless skin. No cases of revision surgery for removal of the granules occurred in this study. Conclusion. The bioactive glass S53P4 is a well-tolerated biomaterial for primary or revision chronic otitis surgery, as shown by the local skin reaction which lasted less than 3 months and by the absence of labyrinthine complications. Daniele Bernardeschi, Yann Nguyen, Francesca Yoshie Russo, Isabelle Mosnier, Evelyne Ferrary, and Olivier Sterkers Copyright © 2015 Daniele Bernardeschi et al. All rights reserved. In Vivo Osseointegration Performance of Titanium Dioxide Coating Modified Polyetheretherketone Using Arc Ion Plating for Spinal Implant Application Sun, 04 Oct 2015 12:52:03 +0000 Polyetheretherketone (PEEK), which has biomechanical performance similar to that of human cancellous bone, is used widely as a spinal implant material. However, its bioinertness and hydrophobic surface properties result in poor osseointegration. This study applies a novel modification method, arc ion plating (AIP), that produces a highly osteoblast compatible titanium dioxide (TiO2) coatings on a PEEK substrate. This PEEK with TiO2 coating (TiO2/PEEK) was implanted into the femurs of New Zealand white male rabbits to evaluate its in vivo performance by the push-out test and histological observation. Analytical results show that AIP can prepare TiO2 coatings on bullet-shaped PEEK substrates as implant materials. After prolonged implantation in rabbits, no signs of inflammation existed. Newly regenerated bone formed more prominently with the TiO2/PEEK implant by histological observation. The shear strength of the bone/implant interface increases as implantation period increases. Most importantly, bone bonding performance of the TiO2/PEEK implant was superior to that of bare PEEK. The rutile-TiO2 coatings achieved better osseointegration than the anatase-TiO2 coatings. Therefore, AIP-TiO2 can serve as a novel surface modification method on PEEK for spinal interbody fusion cages. Hsi-Kai Tsou, Meng-Hui Chi, Yi-Wen Hung, Chi-Jen Chung, and Ju-Liang He Copyright © 2015 Hsi-Kai Tsou et al. All rights reserved. Chitosan and Its Potential Use as a Scaffold for Tissue Engineering in Regenerative Medicine Sun, 04 Oct 2015 11:42:32 +0000 Tissue engineering is an important therapeutic strategy to be used in regenerative medicine in the present and in the future. Functional biomaterials research is focused on the development and improvement of scaffolding, which can be used to repair or regenerate an organ or tissue. Scaffolds are one of the crucial factors for tissue engineering. Scaffolds consisting of natural polymers have recently been developed more quickly and have gained more popularity. These include chitosan, a copolymer derived from the alkaline deacetylation of chitin. Expectations for use of these scaffolds are increasing as the knowledge regarding their chemical and biological properties expands, and new biomedical applications are investigated. Due to their different biological properties such as being biocompatible, biodegradable, and bioactive, they have given the pattern for use in tissue engineering for repair and/or regeneration of different tissues including skin, bone, cartilage, nerves, liver, and muscle. In this review, we focus on the intrinsic properties offered by chitosan and its use in tissue engineering, considering it as a promising alternative for regenerative medicine as a bioactive polymer. Martin Rodríguez-Vázquez, Brenda Vega-Ruiz, Rodrigo Ramos-Zúñiga, Daniel Alexander Saldaña-Koppel, and Luis Fernando Quiñones-Olvera Copyright © 2015 Martin Rodríguez-Vázquez et al. All rights reserved. A Comparison of the Process of Remodeling of Hydroxyapatite/Poly-D/L-Lactide and Beta-Tricalcium Phosphate in a Loading Site Sun, 04 Oct 2015 11:40:06 +0000 Currently, the most commonly used bioresorbable scaffold is made of beta-tricalcium phosphate (β-TCP); it is hoped that scaffolds made of a mixture of hydroxyapatite (HA) and poly-D/L-lactide (PDLLA) will be able to act as novel bioresorbable scaffolds. The aim of this study was to evaluate the utility of a HA/PDLLA scaffold compared to β-TCP, at a loading site. Dogs underwent surgery to replace a section of tibial bone with a bioresorbable scaffold. After the follow-up period, the scaffold was subjected to histological analysis. The HA/PDLLA scaffold showed similar bone formation and superior cell and tissue infiltration compared to the β-TCP scaffold, as seen after Villanueva Goldner staining. Moreover, silver staining and immunohistochemistry for Von Willebrand factor and cathepsin K demonstrated better cell infiltration in the HA/PDLLA scaffold. The fibrous tissue and cells that had infiltrated into the HA/PDLLA scaffold tested positive for collagen type I and RUNX2, respectively, indicating that the tissue and cells that had infiltrated into the HA/PDLLA scaffold had the potential to differentiate into bone. The HA/PDLLA scaffold is therefore likely to find clinical application as a new bioresorbable scaffold. Hiroyuki Akagi, Hiroki Ochi, Satoshi Soeta, Nobuo Kanno, Megumi Yoshihara, Kenshi Okazaki, Takuya Yogo, Yasuji Harada, Hajime Amasaki, and Yasushi Hara Copyright © 2015 Hiroyuki Akagi et al. All rights reserved. Histological Comparison in Rats between Carbonate Apatite Fabricated from Gypsum and Sintered Hydroxyapatite on Bone Remodeling Sun, 04 Oct 2015 11:29:53 +0000 Carbonate apatite (CO3Ap), the form of apatite found in bone, has recently attracted attention. The purpose of the present study was to histologically evaluate the tissue/cellular response toward the low-crystalline CO3Ap fabricated using a dissolution-precipitation reaction with set gypsum as a precursor. When set gypsum was immersed in a 100°C 1 mol/L Na3PO4 aqueous solution for 24 h, the set gypsum transformed into CO3Ap. Both CO3Ap and sintered hydroxyapatite (s-HAp), which was used as a control, were implanted into surgically created tibial bone defects of rats for histological evaluation. Two and 4 weeks after the implantation, histological sections were created and observed using light microscopy. The CO3Ap granules revealed both direct apposition of the bone matrix by osteoblasts and osteoclastic resorption. In contrast, the s-HAp granules maintained their contour even after 4 weeks following implantation which implied that there was a lack of replacement into the bone. The s-HAp granules were sometimes encapsulated with fibrous tissue, and macrophage polykaryon was occasionally observed directly apposed to the implanted granules. From the viewpoint of bone remodeling, the CO3Ap granules mimicked the bone matrix, suggesting that CO3Ap may be an appropriate bone substitute. Yasunori Ayukawa, Yumiko Suzuki, Kanji Tsuru, Kiyoshi Koyano, and Kunio Ishikawa Copyright © 2015 Yasunori Ayukawa et al. All rights reserved. Alginate/Poly(γ-glutamic Acid) Base Biocompatible Gel for Bone Tissue Engineering Sun, 04 Oct 2015 11:05:19 +0000 A technique for synthesizing biocompatible hydrogels by cross-linking calcium-form poly(γ-glutamic acid), alginate sodium, and Pluronic F-127 was created, in which alginate can be cross-linked by Ca2+ from Ca–γ-PGA directly and γ-PGA molecules introduced into the alginate matrix to provide pH sensitivity and hemostasis. Mechanical properties, swelling behavior, and blood compatibility were investigated for each hydrogel compared with alginate and for γ-PGA hydrogel with the sodium form only. Adding F-127 improves mechanical properties efficiently and influences the temperature-sensitive swelling of the hydrogels but also has a minor effect on pH-sensitive swelling and promotes anticoagulation. MG-63 cells were used to test biocompatibility. Gelation occurred gradually through change in the elastic modulus as the release of calcium ions increased over time and caused ionic cross-linking, which promotes the elasticity of gel. In addition, the growth of MG-63 cells in the gel reflected nontoxicity. These results showed that this biocompatible scaffold has potential for application in bone materials. Wing P. Chan, Fu-Chen Kung, Yu-Lin Kuo, Ming-Chen Yang, and Wen-Fu Thomas Lai Copyright © 2015 Wing P. Chan et al. All rights reserved. Potential of Newborn and Adult Stem Cells for the Production of Vascular Constructs Using the Living Tissue Sheet Approach Sun, 04 Oct 2015 10:13:54 +0000 Bypass surgeries using native vessels rely on the availability of autologous veins and arteries. An alternative to those vessels could be tissue-engineered vascular constructs made by self-organized tissue sheets. This paper intends to evaluate the potential use of mesenchymal stem cells (MSCs) isolated from two different sources: (1) bone marrow-derived MSCs and (2) umbilical cord blood-derived MSCs. When cultured in vitro, a proportion of those cells differentiated into smooth muscle cell- (SMC-) like cells and expressed contraction associated proteins. Moreover, these cells assembled into manipulable tissue sheets when cultured in presence of ascorbic acid. Tubular vessels were then produced by rolling those tissue sheets on a mandrel. The architecture, contractility, and mechanical resistance of reconstructed vessels were compared with tissue-engineered media and adventitia produced from SMCs and dermal fibroblasts, respectively. Histology revealed a collagenous extracellular matrix and the contractile responses measured for these vessels were stronger than dermal fibroblasts derived constructs although weaker than SMCs-derived constructs. The burst pressure of bone marrow-derived vessels was higher than SMCs-derived ones. These results reinforce the versatility of the self-organization approach since they demonstrate that it is possible to recapitulate a contractile media layer from MSCs without the need of exogenous scaffolding material. Jean-Michel Bourget, Robert Gauvin, David Duchesneau, Murielle Remy, François A. Auger, and Lucie Germain Copyright © 2015 Jean-Michel Bourget et al. All rights reserved. Titanium-Based Hip Stems with Drug Delivery Functionality through Additive Manufacturing Sun, 04 Oct 2015 09:23:58 +0000 Postoperative infections are a major concern in patients that receive implants. These infections generally occur in areas with poor blood flow and pathogens do not always respond to antibiotic treatment. With the latest developments in nanotechnology, the incorporation of antibiotics into prosthetic implants may soon become a standard procedure. The success will, however, depend on the ability to control the release of antibiotics at concentrations high enough to prevent the development of antibiotic-resistant strains. Through additive manufacturing, antibiotics can be incorporated into cementless femoral stems to produce prosthetic devices with antimicrobial properties. With the emerging increase in resistance to antibiotics, the incorporation of antimicrobial compounds other than antibiotics, preferably drugs with a broader spectrum of antimicrobial activity, will have to be explored. This review highlights the microorganisms associated with total hip arthroplasty (THA), discusses the advantages and disadvantages of the latest materials used in hip implants, compares different antimicrobial agents that could be incorporated, and addresses novel ideas for future research. Martin B. Bezuidenhout, Dimitar M. Dimitrov, Anton D. van Staden, Gert A. Oosthuizen, and Leon M. T. Dicks Copyright © 2015 Martin B. Bezuidenhout et al. All rights reserved. In Vitro Evaluation of Scaffolds for the Delivery of Mesenchymal Stem Cells to Wounds Sun, 04 Oct 2015 09:18:25 +0000 Mesenchymal stem cells (MSCs) have been shown to improve tissue regeneration in several preclinical and clinical trials. These cells have been used in combination with three-dimensional scaffolds as a promising approach in the field of regenerative medicine. We compare the behavior of human adipose-derived MSCs (AdMSCs) on four different biomaterials that are awaiting or have already received FDA approval to determine a suitable regenerative scaffold for delivering these cells to dermal wounds and increasing healing potential. AdMSCs were isolated, characterized, and seeded onto scaffolds based on chitosan, fibrin, bovine collagen, and decellularized porcine dermis. In vitro results demonstrated that the scaffolds strongly influence key parameters, such as seeding efficiency, cellular distribution, attachment, survival, metabolic activity, and paracrine release. Chick chorioallantoic membrane assays revealed that the scaffold composition similarly influences the angiogenic potential of AdMSCs in vivo. The wound healing potential of scaffolds increases by means of a synergistic relationship between AdMSCs and biomaterial resulting in the release of proangiogenic and cytokine factors, which is currently lacking when a scaffold alone is utilized. Furthermore, the methods used herein can be utilized to test other scaffold materials to increase their wound healing potential with AdMSCs. Elizabeth A. Wahl, Fernando A. Fierro, Thomas R. Peavy, Ursula Hopfner, Julian F. Dye, Hans-Günther Machens, José T. Egaña, and Thilo L. Schenck Copyright © 2015 Elizabeth A. Wahl et al. All rights reserved. Antimicrobial Activity Evaluation on Silver Doped Hydroxyapatite/Polydimethylsiloxane Composite Layer Sun, 04 Oct 2015 09:12:49 +0000 The goal of this study was the preparation, physicochemical characterization, and microbiological evaluation of novel hydroxyapatite doped with silver/polydimethylsiloxane (Ag:HAp-PDMS) composite layers. In the first stage, the deposition of polydimethylsiloxane (PDMS) polymer layer on commercially pure Si disks has been produced in atmospheric pressure corona discharges. Finally, the new silver doped hydroxyapatite/polydimethylsiloxane composite layer has been obtained by the thermal evaporation technique. The Ag:HAp-PDMS composite layers were characterized by various techniques, such as Scanning Electron Microscopy (SEM), Glow Discharge Optical Emission Spectroscopy (GDOES), and X-ray photoelectron spectroscopy (XPS). The antimicrobial activity of the Ag:HAp-PDMS composite layer was assessed against Candida albicans ATCC 10231 (ATCC—American Type Culture Collection) by culture based and confirmed by SEM and Confocal Laser Scanning Microscopy (CLSM) methods. This is the first study reporting the antimicrobial effect of the Ag:HAp-PDMS composite layer, which proved to be active against Candida albicans biofilm embedded cells. C. S. Ciobanu, A. Groza, S. L. Iconaru, C. L. Popa, P. Chapon, M. C. Chifiriuc, R. Hristu, G. A. Stanciu, C. C. Negrila, R. V. Ghita, M. Ganciu, and D. Predoi Copyright © 2015 C. S. Ciobanu et al. All rights reserved. Clinical Applications of S53P4 Bioactive Glass in Bone Healing and Osteomyelitic Treatment: A Literature Review Sun, 04 Oct 2015 09:09:38 +0000 Nowadays, S53P4 bioactive glass is indicated as a bone graft substitute in various clinical applications. This review provides an overview of the current published clinical results on indications such as craniofacial procedures, grafting of benign bone tumour defects, instrumental spondylodesis, and the treatment of osteomyelitis. Given the reported results that are based on examinations, such as clinical examinations by the surgeons, radiographs, CT, and MRI images, S53P4 bioactive glass may be beneficial in the various reported applications. Especially in craniofacial reconstructions like mastoid obliteration and orbital floor reconstructions, in grafting bone tumour defects, and in the treatment of osteomyelitis very promising results are obtained. Randomized clinical trials need to be performed in order to determine whether bioactive glass would be able to replace the current golden standard of autologous bone usage or with the use of antibiotic containing PMMA beads (in the case of osteomyelitis). N. A. P. van Gestel, J. Geurts, D. J. W. Hulsen, B. van Rietbergen, S. Hofmann, and J. J. Arts Copyright © 2015 N. A. P. van Gestel et al. All rights reserved. Effects of rhBMP-2 on Sandblasted and Acid Etched Titanium Implant Surfaces on Bone Regeneration and Osseointegration: Spilt-Mouth Designed Pilot Study Sun, 04 Oct 2015 08:42:16 +0000 This study was conducted to evaluate effects of rhBMP-2 applied at different concentrations to sandblasted and acid etched (SLA) implants on osseointegration and bone regeneration in a bone defect of beagle dogs as pilot study using split-mouth design. Methods. For experimental groups, SLA implants were coated with different concentrations of rhBMP-2 (0.1, 0.5, and 1 mg/mL). After assessment of surface characteristics and rhBMP-2 releasing profile, the experimental groups and untreated control groups (n = 6 in each group, two animals in each group) were placed in split-mouth designed animal models with buccal open defect. At 8 weeks after implant placement, implant stability quotients (ISQ) values were recorded and vertical bone height (VBH, mm), bone-to-implant contact ratio (BIC, %), and bone volume (BV, %) in the upper 3 mm defect areas were measured. Results. The ISQ values were highest in the 1.0 group. Mean values of VBH (mm), BIC (%), and BV (%) were greater in the 0.5 mg/mL and 1.0 mg/mL groups than those in 0.1 and control groups in buccal defect areas. Conclusion. In the open defect area surrounding the SLA implant, coating with 0.5 and 1.0 mg/mL concentrations of rhBMP-2 was more effective, compared with untreated group, in promoting bone regeneration and osseointegration. Nam-Ho Kim, So-Hyoun Lee, Jae-Jun Ryu, Kyung-Hee Choi, and Jung-Bo Huh Copyright © 2015 Nam-Ho Kim et al. All rights reserved. Anodisation Increases Integration of Unloaded Titanium Implants in Sheep Mandible Tue, 08 Sep 2015 13:27:12 +0000 Spark discharge anodic oxidation forms porous TiO2 films on titanium implant surfaces. This increases surface roughness and concentration of calcium and phosphate ions and may enhance early osseointegration. To test this, forty 3.75 mm × 13 mm titanium implants (Megagen, Korea) were placed into healed mandibular postextraction ridges of 10 sheep. There were 10 implants per group: RBM surface (control), RBM + anodised, RBM + anodised + fluoride, and titanium alloy + anodised surface. Resonant frequency analysis (RFA) was measured in implant stability quotient (ISQ) at surgery and at sacrifice after 1-month unloaded healing. Mean bone-implant contact (% BIC) was measured in undemineralised ground sections for the best three consecutive threads. One of 40 implants showed evidence of failure. RFA differed between groups at surgery but not after 1 month. RFA values increased nonsignificantly for all implants after 1 month, except for controls. There was a marked difference in BIC after 1-month healing, with higher values for alloy implants, followed by anodised + fluoride and anodised implants. Anodisation increased early osseointegration of rough-surfaced implants by 50–80%. RFA testing lacked sufficient resolution to detect this improvement. Whether this gain in early bone-implant contact is clinically significant is the subject of future experiments. Warwick J. Duncan, Min-Ho Lee, Tae-Sung Bae, Sook-Jeong Lee, Jennifer Gay, and Carolina Loch Copyright © 2015 Warwick J. Duncan et al. All rights reserved. Efficacy Study of Broken Rice Maltodextrin in In Vitro Wound Healing Assay Tue, 08 Sep 2015 13:06:25 +0000 Maltodextrins that contain both simple sugars and polymers of saccharides have been widely used as ingredients in food products and pharmaceutical delivery systems. To date, no much work has been reported on the applications of maltodextrin from broken rice (RB) sources. Therefore, the objective of this work was to investigate the in vitro wound healing efficacy of RB maltodextrin at different conditions. Wounds treated with lower dextrose equivalent (DE) range (DE 10–14) of maltodextrins at a concentration of 10% obtained from RB were found to be able to heal the wounds significantly faster () than maltodextrin with higher DE ranges (DE 15–19 and DE 20–24) and concentrations of 5% and 20%. The findings from both BrdU and MTT assay further confirmed its wound healing properties as the NIH 3T3 fibroblast wounded cells were able to proliferate without causing cytotoxic effect when wounded cell was treated with maltodextrin. All these findings indicated that the RB maltodextrin could perform better than the commercial maltodextrin at the same DE range. This study showed that RB maltodextrins had better functionality properties than other maltodextrin sources and played a beneficial role in wound healing application. Zahiah Mohamed Amin, Soo Peng Koh, Swee Keong Yeap, Nur Syazwani Abdul Hamid, Chin Ping Tan, and Kamariah Long Copyright © 2015 Zahiah Mohamed Amin et al. All rights reserved. The Effect of Covalently Immobilized FGF-2 on Biphasic Calcium Phosphate Bone Substitute on Enhanced Biological Compatibility and Activity Mon, 07 Sep 2015 09:55:24 +0000 The purpose of this research was to covalently graft fibroblast growth factor 2 (FGF-2) onto biphasic calcium phosphate (BCP) via a bifunctional cross-linker technique and to estimate the optimal dose of FGF-2 resulting in the best osteogenic differentiation of human mesenchymal stem cells (hMSCs). SEM observation revealed that the surface of the 100 ng FGF-2 coated BCP was completely covered with the nanoparticles expected to be from the silane coupling agent. XRD, FT-IR, and XPS analysis showed that silane treatment, bifunctional cross-linker coating, and FGF-2 covalent grafts were conducted successfully without deforming the crystalline structure of BCP. An MTT assay demonstrated that FGF-2 coated BCP had good biocompatibility, regardless of the concentration of FGF-2, after 24 or 48 h of incubation. An alkaline phosphatase (ALP) activity assay (14 days of incubation) and the ALP gene expression level of real-time PCR analysis (7 days of incubation) revealed that 50, 100, and 200 ng FGF-2 coated BCP induced the highest activities among all experimental groups and control group (). Thus, low concentrations of FGF-2 facilitated excellent osteogenesis and were effective at enhancing osteogenic potential. Also, the bifunctional cross-linker technique is expected to be a more feasible way to induce osteogenic differentiation while minimizing the risk of FGF-2 overdose. Kyung-Suk Moon, Eun-Joo Choi, Seunghan Oh, and Sungtae Kim Copyright © 2015 Kyung-Suk Moon et al. All rights reserved. Efficacy of Biodentine as an Apical Plug in Nonvital Permanent Teeth with Open Apices: An In Vitro Study Mon, 07 Sep 2015 09:44:31 +0000 The aim of this study was to evaluate the apical microleakage of Biodentine and MTA orthograde apical plugs and to compare the effect of thickness of these biomaterials on their sealing ability. A total of eighty maxillary anterior teeth were used. The apices were removed by cutting with a diamond disc (Jota, Germany) 2 mm from the apical root end in an attempt to standardize the working length of all specimens to 15 ± 1 mm. Both materials were placed in 1–4 mm thickness as apical plugs root canal. Root canal leakage was evaluated by the fluid filtration technique. One-way ANOVA was used in order to determine normality of dispersal distribution of parameters; thereafter, results were analyzed by Kolmogorov-Smirnov test. Overall, between microleakage values of MTA and Biodentine regardless of apical plug thickness, no difference was observed. In terms of plug thickness, a statistically significant difference was observed between the subgroups of MTA and Biodentine (). The apical sealing ability of Biodentine was comparable to MTA at any apical plug thickness. Mehmet Bani, Elif Sungurtekin-Ekçi, and Mesut Enes Odabaş Copyright © 2015 Mehmet Bani et al. All rights reserved. Surface Modifications and Their Effects on Titanium Dental Implants Mon, 07 Sep 2015 09:39:38 +0000 This review covers several basic methodologies of surface treatment and their effects on titanium (Ti) implants. The importance of each treatment and its effects will be discussed in detail in order to compare their effectiveness in promoting osseointegration. Published literature for the last 18 years was selected with the use of keywords like titanium dental implant, surface roughness, coating, and osseointegration. Significant surface roughness played an important role in providing effective surface for bone implant contact, cell proliferation, and removal torque, despite having good mechanical properties. Overall, published studies indicated that an acid etched surface-modified and a coating application on commercial pure titanium implant was most preferable in producing the good surface roughness. Thus, a combination of a good surface roughness and mechanical properties of titanium could lead to successful dental implants. A. Jemat, M. J. Ghazali, M. Razali, and Y. Otsuka Copyright © 2015 A. Jemat et al. All rights reserved. Cholesteryl Pullulan Encapsulated TNF-α Nanoparticles Are an Effective Mucosal Vaccine Adjuvant against Influenza Virus Tue, 01 Sep 2015 06:12:31 +0000 We encapsulated tumor necrosis factor-α (TNF-α), a major proinflammatory cytokine, into cholesteryl pullulan (CHP) to prepare TNF/CHP nanoparticles. In this report, we describe the immune-enhancing capability of the nanoparticles to act as a vaccine adjuvant. TNF/CHP nanoparticles showed excellent storage stability and enhanced host immune responses to external immunogens. The nanoparticles were effective via the nasal route of administration for inducing systemic IgG1 as well as mucosal IgA. We applied the nanoparticles in a model experimental influenza virus infection to investigate their adjuvant ability. TNF/CHP nanoparticles combined with a conventional split vaccine protected mice via nasal administration against a lethal challenge of A/PR/8/34 (H1N1) influenza virus. Mechanistic studies showed that the nanoparticles enhanced antigen uptake by dendritic cells (DCs) and moderately induced the expression of inflammation-related genes in nasopharynx lymphoid tissue (NALT), leading to the activation of both B and T cells. Preliminary safety study revealed no severe toxicity to TNF/CHP nanoparticles. Slight-to-moderate influences in nasal mucosa were observed only in the repeated administration and they seemed to be reversible. Our data show that TNF/CHP nanoparticles effectively enhance both humoral and cellular immunity and could be a potential adjuvant for vaccines against infectious diseases, especially in the mucosa. Daiki Nagatomo, Madoka Taniai, Harumi Ariyasu, Mutsuko Taniguchi, Miho Aga, Toshio Ariyasu, Tsunetaka Ohta, and Shigeharu Fukuda Copyright © 2015 Daiki Nagatomo et al. All rights reserved. Corrigendum to “Characterization of Bone Marrow Mononuclear Cells on Biomaterials for Bone Tissue Engineering In Vitro” Mon, 31 Aug 2015 12:02:36 +0000 Dirk Henrich, René Verboket, Alexander Schaible, Kerstin Kontradowitz, Elsie Oppermann, Jan C. Brune, Christoph Nau, Simon Meier, Halvard Bonig, Ingo Marzi, and Caroline Seebach Copyright © 2015 Dirk Henrich et al. All rights reserved. In Vitro and In Vivo Response to Low-Modulus PMMA-Based Bone Cement Thu, 20 Aug 2015 16:17:29 +0000 The high stiffness of acrylic bone cements has been hypothesized to contribute to the increased number of fractures encountered after vertebroplasty, which has led to the development of low-modulus cements. However, there is no data available on the in vivo biocompatibility of any low-modulus cement. In this study, the in vitro cytotoxicity and in vivo biocompatibility of two types of low-modulus acrylic cements, one modified with castor oil and one with linoleic acid, were evaluated using human osteoblast-like cells and a rodent model, respectively. While the in vitro cytotoxicity appeared somewhat affected by the castor oil and linoleic acid additions, no difference could be found in the in vivo response to these cements in comparison to the base, commercially available cement, in terms of histology and flow cytometry analysis of the presence of immune cells. Furthermore, the in vivo radiopacity of the cements appeared unaltered. While these results are promising, the mechanical behavior of these cements in vivo remains to be investigated. Elin Carlsson, Gemma Mestres, Kiatnida Treerattrakoon, Alejandro López, Marjam Karlsson Ott, Sune Larsson, and Cecilia Persson Copyright © 2015 Elin Carlsson et al. All rights reserved. Synthesis and Properties of pH-, Thermo-, and Salt-Sensitive Modified Poly(aspartic acid)/Poly(vinyl alcohol) IPN Hydrogel and Its Drug Controlled Release Thu, 13 Aug 2015 14:00:08 +0000 Modified poly(aspartic acid)/poly(vinyl alcohol) interpenetrating polymer network (KPAsp/PVA IPN) hydrogel for drug controlled release was synthesized by a simple one-step method in aqueous system using poly(aspartic acid) grafting 3-aminopropyltriethoxysilane (KH-550) and poly(vinyl alcohol) (PVA) as materials. The hydrogel surface morphology and composition were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The thermal stability was analyzed by thermogravimetric analysis (TGA). The swelling properties and pH, temperature, and salt sensitivities of KPAsp, KPAsp/PVA semi-interpenetrating polymer network (semi-IPN), and KPAsp/PVA IPN hydrogels were also investigated. All of the three hydrogels showed ampholytic pH-responsive properties, and swelling behavior was also extremely sensitive to the temperature, ionic strength, and cationic species. Finally, the drug controlled release properties of the three hydrogels were evaluated and results indicated that three hydrogels could control drug release by external surroundings stimuli. The drug controlled release properties of KPAsp/PVA IPN hydrogel are the most outstanding, and the correlative measured release profiles of salicylic acid at 37°C were 32.6 wt% at pH = 1.2 (simulated gastric fluid) and 62.5 wt% at pH = 7.4 (simulated intestinal fluid), respectively. These results indicated that KPAsp/PVA IPN hydrogels are a promising carrier system for controlled drug delivery. Jingqiong Lu, Yinhui Li, Deng Hu, Xiaoling Chen, Yongmei Liu, Liping Wang, and Yansheng Zhao Copyright © 2015 Jingqiong Lu et al. All rights reserved. Research Advances in Tissue Engineering Materials for Sustained Release of Growth Factors Tue, 11 Aug 2015 05:50:26 +0000 Growth factors are a class of cytokines that stimulate cell growth and are widely used in clinical practice, such as wound healing, revascularization, bone repair, and nervous system disease. However, free growth factors have a short half-life and are instable in vivo. Therefore, the search of excellent carriers to enhance sustained release of growth factors in vivo has become an area of intense research interest. The development of controlled-release systems that protect the recombinant growth factors from enzymatic degradation and provide sustained delivery at the injury site during healing should enhance the growth factor’s application in tissue regeneration. Thus, this study reviews current research on commonly used carriers for sustained release of growth factors and their sustained release effects for preservation of their bioactivity and their accomplishment in tissue engineering approaches. Hai-yang Zhao, Jiang Wu, Jing-jing Zhu, Ze-cong Xiao, Chao-chao He, Hong-xue Shi, Xiao-kun Li, Shu-lin Yang, and Jian Xiao Copyright © 2015 Hai-yang Zhao et al. All rights reserved. Erratum to “Localized and Sustained Delivery of Erythropoietin from PLGA Microspheres Promotes Functional Recovery and Nerve Regeneration in Peripheral Nerve Injury” Tue, 28 Jul 2015 11:22:45 +0000 Wei Zhang, Yuan Gao, Yan Zhou, Jianheng Liu, Licheng Zhang, Anhua Long, Lihai Zhang, and Peifu Tang Copyright © 2015 Wei Zhang et al. All rights reserved. New Biomaterials and Regenerative Medicine Strategies in Periodontology, Oral Surgery, Esthetic and Implant Dentistry Mon, 27 Jul 2015 15:01:11 +0000 David M. Dohan Ehrenfest, Hom-Lay Wang, Jean-Pierre Bernard, and Gilberto Sammartino Copyright © 2015 David M. Dohan Ehrenfest et al. All rights reserved. Histological and Histomorphometric Human Results of HA-Beta-TCP 30/70 Compared to Three Different Biomaterials in Maxillary Sinus Augmentation at 6 Months: A Preliminary Report Sun, 26 Jul 2015 13:04:59 +0000 Objective. The aim of this investigation was to examine the bone regenerative potential of newly biphasic calcium phosphate ceramics (HA-β-TCP 30/70), by assessing histological and histomorphometric results of human specimens retrieved from sinuses augmented with HA-β-TCP 30/70, and comparing them to anorganic bovine bone (ABB), mineralized solvent-dehydrated bone allograft (MSDBA), and equine bone (EB), after a healing period of 6 months. Materials and Methods. Four consecutive patients with edentulous atrophic posterior maxilla were included in this report. A two-stage procedure was carried out for sinus augmentation with HA-β-TCP 30/70, ABB, MSDBA, and EB. After 6 months, specimens were retrieved at the time of implant placement and processed for histological and histomorphometric analyses. Results. At histological examination, all biomaterials were in close contact with the newly formed bone and showed the same pattern of bone formation; the grafted granules were surrounded by a bridge-like network of newly formed bone. A limited number of ABB particles were partially covered by connective tissue. The histomorphometric analysis revealed 30.2% newly formed bone for Ha-β-TCP 30/70, 20.1% for ABB, 16.4% for MSDBA, and 21.9% for EB. Conclusions. Within the limitations of the present investigation, these results support the successful use of HA-β-TCP 30/70 for sinus augmentation. Susanna Annibali, Giovanna Iezzi, Gian Luca Sfasciotti, Maria Paola Cristalli, Iole Vozza, Carlo Mangano, Gerardo La Monaca, and Antonella Polimeni Copyright © 2015 Susanna Annibali et al. All rights reserved. Oral Streptococci Biofilm Formation on Different Implant Surface Topographies Sun, 26 Jul 2015 08:47:31 +0000 The establishment of the subgingival microbiota is dependent on successive colonization of the implant surface by bacterial species. Different implant surface topographies could influence the bacterial adsorption and therefore jeopardize the implant survival. This study evaluated the biofilm formation capacity of five oral streptococci species on two titanium surface topographies. In vitro biofilm formation was induced on 30 titanium discs divided in two groups: sandblasted acid-etched (SAE- ) and as-machined (M- ) surface. The specimens were immersed in sterilized whole human unstimulated saliva and then in fresh bacterial culture with five oral streptococci species: Streptococcus sanguinis, Streptococcus salivarius, Streptococcus mutans, Streptococcus sobrinus, and Streptococcus cricetus. The specimens were fixed and stained and the adsorbed dye was measured. Surface characterization was performed by atomic force and scanning electron microscopy. Surface and microbiologic data were analyzed by Student’s -test and two-way ANOVA, respectively (). S. cricetus, S. mutans, and S. sobrinus exhibited higher biofilm formation and no differences were observed between surfaces analyzed within each species (). S. sanguinis exhibited similar behavior to form biofilm on both implant surface topographies, while S. salivarius showed the lowest ability to form biofilm. It was concluded that biofilm formation on titanium surfaces depends on surface topography and species involved. Pedro Paulo Cardoso Pita, José Augusto Rodrigues, Claudia Ota-Tsuzuki, Tatiane Ferreira Miato, Elton G. Zenobio, Gabriela Giro, Luciene C. Figueiredo, Cristiane Gonçalves, Sergio A. Gehrke, Alessandra Cassoni, and Jamil Awad Shibli Copyright © 2015 Pedro Paulo Cardoso Pita et al. All rights reserved. Influence of Leukocyte- and Platelet-Rich Fibrin (L-PRF) in the Healing of Simple Postextraction Sockets: A Split-Mouth Study Sun, 26 Jul 2015 08:17:48 +0000 The aim of this study was to evaluate the effects of leukocyte- and platelet-rich fibrin (L-PRF) on the pain and soft tissue healing after tooth extractions. Twenty-six patients (9 males and 17 females) were treated with multiple extractions (2 to 8), with a total of 108 extractions. This was an exploratory single blinded randomized clinical trial with a split-mouth design. The pain after the surgery was assessed in each patient by the VAS scale (1 to 10) at intervals of 24-48-72-96 hours. The soft tissue healing was clinically evaluated at 3, 7, 14, and 21 days after surgery by the same examiner surgeon, using the modified Healing Index (4 to 12). The mean value of postextraction pain was 3.2 ± 0.3 in the experimental sides and 4.1 ± 0.1 in the control sides. After 7 days from the extractions, the values of modified Healing Index in the experimental and control groups were, respectively, 4.8 ± 0.6 and 5.1 ± 0.9. The use of L-PRF in postextraction sockets filling can be proposed as a useful procedure in order to manage the postoperative pain and to promote the soft tissue healing process, reducing the early adverse effects of the inflammation. Gaetano Marenzi, Francesco Riccitiello, Mariano Tia, Alessandro di Lauro, and Gilberto Sammartino Copyright © 2015 Gaetano Marenzi et al. All rights reserved. Innate Immunity and Biomaterials at the Nexus: Friends or Foes Sun, 12 Jul 2015 11:12:45 +0000 Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestation of the biomaterial-induced foreign body response are different for each biomaterial, with cases of incompatibility often associated with loss of function. However, unravelling the mechanisms that progress to the formation of the fibrotic capsule highlights the tightly intertwined nature of immunological responses to a seemingly noncanonical “antigen.” In this review, we detail the pathways associated with the foreign body response and describe possible mechanisms of immune involvement that can be targeted. We also discuss methods of modulating the immune response by altering the physiochemical surface properties of the biomaterial prior to implantation. Developments in these areas are reliant on reproducible and effective animal models and may allow a “combined” immunomodulatory approach of adapting surface properties of biomaterials, as well as treating key immune pathways to ultimately reduce the negative consequences of biomaterial implantation. Susan N. Christo, Kerrilyn R. Diener, Akash Bachhuka, Krasimir Vasilev, and John D. Hayball Copyright © 2015 Susan N. Christo et al. All rights reserved. Nanostructures Control the Hepatocellular Responses to a Cytotoxic Agent “Cisplatin” Sun, 12 Jul 2015 10:53:32 +0000 In drug discovery programs, the alteration between in vivo and in vitro cellular responses to drug represents one of the main challenges. Since the variation in the native extracellular matrix (ECM) between in vivo and 2D in vitro conditions is one of the key reasons for such discrepancies, thus the utilization of substrate that likely mimics ECM characteristics (topography, stiffness, and chemical composition) is needed to overcome such problem. Here, we investigated the role of substrate nanotopography as one of the major determinants of hepatic cellular responses to a chemotherapeutic agent “cisplatin.” We studied the substratum induced variations in cisplatin cytotoxicity; a higher cytotoxic response to cisplatin was observed for cells cultured on the nanopattern relative to a flat substrate. Moreover, the nanofeatures with grating shapes that mimic the topography of major ECM protein constituents (collagen) induced alterations in the cellular orientation and chromatin condensation compared to flat surfaces. Accordingly, the developments of biomimetic substrates with a particular topography could have potentials in drug development analyses to reflect more physiological mimicry conditions in vitro. Shimaa A. Abdellatef, Riho Tange, Takeshi Sato, Akihiko Ohi, Toshihide Nabatame, and Akiyoshi Taniguchi Copyright © 2015 Shimaa A. Abdellatef et al. All rights reserved. Gold Nanoparticles Promote Oxidant-Mediated Activation of NF-κB and 53BP1 Recruitment-Based Adaptive Response in Human Astrocytes Tue, 23 Jun 2015 13:31:42 +0000 Nanogold-based materials are promising candidate tools for nanobased medicine. Nevertheless, no conclusive information on their cytotoxicity is available. In the present study, we investigated the effects of gold nanoparticles (AuNPs) on human astrocytes in vitro. Nanogold treatment in a wide range of concentrations did not result in cytotoxicity. In contrast, nanogold provoked changes in the astrocyte cell cycle and induced senescence-associated β-galactosidase activity. AuNPs promoted oxidative stress and caused activation of NF-κB pathway. After nanogold treatment, an inverse correlation between the formation of 53BP1 foci and micronuclei generation was observed. The robust 53BP1 recruitment resulted in reduced micronuclei production. Thus, nanogold treatment stimulated an adaptive response in a human astrocyte cell. Jennifer Mytych, Anna Lewinska, Jacek Zebrowski, and Maciej Wnuk Copyright © 2015 Jennifer Mytych et al. All rights reserved. Dental Stem Cell Migration on Pulp Ceiling Cavities Filled with MTA, Dentin Chips, or Bio-Oss Wed, 03 Jun 2015 08:03:51 +0000 MTA, Bio-Oss, and dentin chips have been successfully used in endodontics. The aim of this study was to assess the adhesion and migration of dental stem cells on human pulp ceiling cavities filled with these endodontic materials in an experimental model, which mimics the clinical conditions of regenerative endodontics. Cavities were formed, by a homemade mold, on untouched third molars, filled with endodontic materials, and observed with electron microscopy. Cells were seeded on cavities’ surface and their morphology and number were analysed. The phenomenon of tropism was assessed in a migration assay. All three materials demonstrated appropriate microstructures for cell attachment. Cells grew on all reagents, but they showed a differential morphology. Moreover, variations were observed when comparing cells numbers on cavity’s filling versus the surrounding dentine disc. The highest number of cells was recorded on dentin chips whereas the opposite was true for Bio-Oss. This was confirmed in the migration assay where a statistically significant lower number of cells migrated towards Bio-Oss as compared to MTA and dentin chips. This study highlights that MTA and dentin chips have a greater potential compared to Bio-Oss regarding the attraction of dental stem cells and are good candidates for bioengineered pulp regeneration. Stefania Lymperi, Vasiliki Taraslia, Ioannis N. Tsatsoulis, Athina Samara, Athanasios D. Velentzas, Anastasia Agrafioti, Ema Anastasiadou, and Evangelos Kontakiotis Copyright © 2015 Stefania Lymperi et al. All rights reserved. A Novel Injectable Magnesium/Calcium Sulfate Hemihydrate Composite Cement for Bone Regeneration Sun, 31 May 2015 11:37:51 +0000 Objective. A novel injectable magnesium/calcium sulfate hemihydrate (Mg/CSH) composite with improved properties was reported here. Methods. Composition, setting time, injectability, compressive strength, and bioactivity in simulated body fluid (SBF) of the Mg/CSH composite were evaluated. Furthermore, the cellular responses of canine bone marrow stromal cells (cBMSCs) and bone formation capacity after the implantation of Mg/CSH in tibia defects of canine were investigated. Results. Mg/CSH possessed a prolonged setting time and markedly improved injectability and mechanical property . Mg/CSH samples showed better degradability than CSH in SBF after 21 days of soaking . Moreover, the degrees of cell attachment, proliferation, and capability of osteogenic differentiation on the Mg/CSH specimens were higher than those on CSH, without significant cytotoxicity and with the increased proliferation index, ALP activity, and expression levels of integrin β1 and Coll I in cBMSCs . Mg/CSH enhanced the efficiency of new bone formation at the tibia defect area, including the significantly elevated bone mineral density, bone area fraction, and Coll I expression level . Conclusions. The results implied that this new injectable bone scaffold exhibited promising prospects for bone repair and had a great potential in bone tissue engineering. Shanchuan Zhang, Ke Yang, Fuzhai Cui, Yi Jiang, Lingling E, Baohua Xu, and Hongchen Liu Copyright © 2015 Shanchuan Zhang et al. All rights reserved. The Use of Natural Polysaccharides as Biomaterials Mon, 25 May 2015 08:53:48 +0000 Paola Laurienzo, João C. Fernandes, Sylvia Colliec-Jouault, and J. Helen Fitton Copyright © 2015 Paola Laurienzo et al. All rights reserved. Prevention of Polyglycolic Acid-Induced Peritoneal Adhesions Using Alginate in a Rat Model Thu, 21 May 2015 14:18:05 +0000 Postoperative intra-abdominal or intrathoracic adhesions sometimes cause significant morbidity. We have designed three types of alginate-based treatments using strongly cross-linked (SL), weakly cross-linked (WL), and non-cross-linked (NL) alginate with calcium gluconate. In rat experiments, we compared the antiadhesive effects of the three types of alginate-based treatments, fibrin glue treatment (a standard treatment), and no treatment against adhesions caused by polyglycolic acid (PGA) mesh (PGA-induced adhesions). The antiadhesive materials were set on the PGA sheet fixed on the parietal peritoneum of the abdomen. Fifty-six days later, the adhesions were evaluated macroscopically by the adhesion scores and microscopically by hematoxylin-eosin staining and immunostaining. We also tested the fibroblast growth on the surface of the antiadhesive materials in vitro. The antiadhesive effects of WL and NL were superior to the no treatment and fibrin glue treatment. A microscopic evaluation confirmed that the PGA sheet was covered by a peritoneal layer constructed of well-differentiated mesothelial cells, and the inflammation was most improved in the NL and WL. The fibroblast growth was inhibited most on the surfaces of the NL and WL. These results suggest that either the WL or NL treatments are suitable for preventing PGA-induced adhesions compared to SL or the conventional treatment. Mari Matoba, Ayumi Hashimoto, Ayumi Tanzawa, Taichi Orikasa, Junki Ikeda, Yoshizumi Iwame, Yuki Ozamoto, Rie Abe, Hiroe Miyamoto, Chiko Yoshida, Toru Hashimoto, Hiroko Torii, Hideki Takamori, Shinichiro Morita, Hiroyuki Tsujimoto, and Akeo Hagiwara Copyright © 2015 Mari Matoba et al. All rights reserved. Insights in Behavior of Variably Formulated Alginate-Based Microcapsules for Cell Transplantation Wed, 20 May 2015 10:00:35 +0000 Alginate-based microencapsulation of live cells may offer the opportunity to treat chronic and degenerative disorders. So far, a thorough assessment of physical-chemical behavior of alginate-based microbeads remains cloudy. A disputed issue is which divalent cation to choose for a high performing alginate gelling process. Having selected, in our system, high mannuronic (M) enriched alginates, we studied different gelling cations and their combinations to determine their eventual influence on physical-chemical properties of the final microcapsules preparation, in vitro and in vivo. We have shown that used of ultrapure alginate allows for high biocompatibility of the formed microcapsules, regardless of gelation agents, while use of different gelling cations is associated with corresponding variable effects on the capsules’ basic architecture, as originally reported in this work. However, only the final application which the capsules are destined to will ultimately guide the selection of the ideal, specific gelling divalent cations, since in principle there are no capsules that are better than others. Pia Montanucci, Silvia Terenzi, Claudio Santi, Ilaria Pennoni, Vittorio Bini, Teresa Pescara, Giuseppe Basta, and Riccardo Calafiore Copyright © 2015 Pia Montanucci et al. All rights reserved. Preparation of Porous Chitosan-Siloxane Hybrids Coated with Hydroxyapatite Particles Wed, 20 May 2015 08:07:02 +0000 This paper describes the apatite deposition of chitosan-silicate porous hybrids derived from chitosan and γ-glycidoxypropyltrimethoxysilane (GPTMS) in alkaline phosphate solution. The preparation of porous hybrids with needle-like apatite on their surfaces is described. Following apatite deposition the porous hybrids maintained high porosity. The enzymatic degradation rate was low even after 6 months and the porous hybrids were very flexible and cut easily using surgical scissors. Yuki Shirosaki, Kohei Okamoto, Satoshi Hayakawa, Akiyoshi Osaka, and Takuji Asano Copyright © 2015 Yuki Shirosaki et al. All rights reserved. Preliminary Study on Biosynthesis of Bacterial Nanocellulose Tubes in a Novel Double-Silicone-Tube Bioreactor for Potential Vascular Prosthesis Tue, 19 May 2015 14:30:38 +0000 Bacterial nanocellulose (BNC) has demonstrated a tempting prospect for applications in substitute of small blood vessels. However, present technology is inefficient in production and BNC tubes have a layered structure that may bring danger after implanting. Double oxygen-permeable silicone tubes in different diameters were therefore used as a tube-shape mold and also as oxygenated supports to construct a novel bioreactor for production of the tubular BNC materials. Double cannula technology was used to produce tubular BNC via cultivations with Acetobacter xylinum, and Kombucha, a symbiosis of acetic acid bacteria and yeasts. The results indicated that Kombucha gave higher yield and productivity of BNC than A. xylinum. Bacterial nanocellulose was simultaneously synthesized both on the inner surface of the outer silicone tube and on the outer surface of the inner silicone tube. Finally, the nano BNC fibrils from two directions formed a BNC tube with good structural integrity. Scanning electron microscopy inspection showed that the tubular BNC had a multilayer structure in the beginning but finally it disappeared and an intact BNC tube formed. The mechanical properties of BNC tubes were comparable with the reported value in literatures, demonstrating a great potential in vascular implants or in functional substitutes in biomedicine. Feng Hong, Bin Wei, and Lin Chen Copyright © 2015 Feng Hong et al. All rights reserved. Polysaccharide-Coated Magnetic Nanoparticles for Imaging and Gene Therapy Tue, 19 May 2015 13:59:23 +0000 Today, nanotechnology plays a vital role in biomedical applications, especially for the diagnosis and treatment of various diseases. Among the many different types of fabricated nanoparticles, magnetic metal oxide nanoparticles stand out as unique and useful tools for biomedical applications, because of their imaging characteristics and therapeutic properties such as drug and gene carriers. Polymer-coated magnetic particles are currently of particular interest to investigators in the fields of nanobiomedicine and fundamental biomaterials. Theranostic magnetic nanoparticles that are encapsulated or coated with polymers not only exhibit imaging properties in response to stimuli, but also can efficiently deliver various drugs and therapeutic genes. Even though a large number of polymer-coated magnetic nanoparticles have been fabricated over the last decade, most of these have only been used for imaging purposes. The focus of this review is on polysaccharide-coated magnetic nanoparticles used for imaging and gene delivery. Saji Uthaman, Sang Joon Lee, Kondareddy Cherukula, Chong-Su Cho, and In-Kyu Park Copyright © 2015 Saji Uthaman et al. All rights reserved. Recombinant Phage Coated 1D Al2O3 Nanostructures for Controlling the Adhesion and Proliferation of Endothelial Cells Tue, 19 May 2015 13:48:34 +0000 A novel synthesis of a nanostructured cell adhesive surface is investigated for future stent developments. One-dimensional (1D) Al2O3 nanostructures were prepared by chemical vapor deposition of a single source precursor. Afterwards, recombinant filamentous bacteriophages which display a short binding motif with a cell adhesive peptide (RGD) on p3 and p8 proteins were immobilized on these 1D Al2O3 nanostructures by a simple dip-coating process to study the cellular response of human endothelial EA hy.926. While the cell density decreased on as-deposited 1D Al2O3 nanostructures, we observed enhanced cell proliferation and cell-cell interaction on recombinant phage overcoated 1D Al2O3 nanostructures. The recombinant phage overcoating also supports an isotropic cell spreading rather than elongated cell morphology as we observed on as-deposited Al2O3 1D nanostructures. Juseok Lee, Hojeong Jeon, Ayman Haidar, Hashim Abdul-Khaliq, Michael Veith, Cenk Aktas, and Youngjun Kim Copyright © 2015 Juseok Lee et al. All rights reserved. A Direct Sulfation Process of a Marine Polysaccharide in Ionic Liquid Tue, 19 May 2015 13:43:45 +0000 GY785 is an exopolysaccharide produced by a mesophilic bacterial strain Alteromonas infernus discovered in the deep-sea hydrothermal vents. GY785 highly sulfated derivative (GY785 DRS) was previously demonstrated to be a promising molecule driving the efficient mesenchymal stem cell chondrogenesis for cartilage repair. This glycosaminoglycan- (GAG-) like compound was modified in a classical solvent (N,N′-dimethylformamide). However, the use of classical solvents limits the polysaccharide solubility and causes the backbone degradation. In the present study, a one-step efficient sulfation process devoid of side effects (e.g., polysaccharide depolymerization and/or degradation) was developed to produce GAG-like derivatives. The sulfation of GY785 derivative (GY785 DR) was carried out using ionic liquid as a reaction medium. The successful sulfation of this anionic and highly branched heteropolysaccharide performed in ionic liquid would facilitate the production of new molecules of high specificity for biological targets such as tissue engineering or regenerative medicine. Nathalie Chopin, Corinne Sinquin, Jacqueline Ratiskol, Agata Zykwinska, Pierre Weiss, Stéphane Cérantola, Jean Le Bideau, and Sylvia Colliec-Jouault Copyright © 2015 Nathalie Chopin et al. All rights reserved. Comparison and Characterisation of Regenerated Chitosan from 1-Butyl-3-methylimidazolium Chloride and Chitosan from Crab Shells Tue, 19 May 2015 13:37:27 +0000 Chitosan is a biopolymer derived from chitin which is naturally occurring in the exoskeleton of crustaceans. This paper reports dissolution and regeneration of chitosan by directly dissolving in an ionic liquid solvent, 1-butyl-3-methylimidazolium chloride (BMIMCl). This will provide an ideal platform to solubilise these kinds of polymers to achieve the dissolution. The current study dissolved chitosan from crab shell utilising BMIMCl as a solvent and characterised the resultant regenerated polymer. The regenerated chitosan showed increased hydrogen bonding when characterised by Fourier transform infrared (FTIR) spectral analysis. In addition, the study also compared the characteristics of regenerated and generic chitosan. The regenerated chitosan was also evaluated for antimicrobial properties and showed to possess antibacterial features similar to the commercial grade. This method can be utilised in future for blending of polymers with chitosan in a dissolved phase. Saniyat Islam, Lyndon Arnold, and Rajiv Padhye Copyright © 2015 Saniyat Islam et al. All rights reserved. 3D Bioprinting of Carboxymethylated-Periodate Oxidized Nanocellulose Constructs for Wound Dressing Applications Tue, 19 May 2015 13:35:35 +0000 Nanocellulose has a variety of advantages, which make the material most suitable for use in biomedical devices such as wound dressings. The material is strong, allows for production of transparent films, provides a moist wound healing environment, and can form elastic gels with bioresponsive characteristics. In this study, we explore the application of nanocellulose as a bioink for modifying film surfaces by a bioprinting process. Two different nanocelluloses were used, prepared with TEMPO mediated oxidation and a combination of carboxymethylation and periodate oxidation. The combination of carboxymethylation and periodate oxidation produced a homogeneous material with short nanofibrils, having widths <20 nm and lengths <200 nm. The small dimensions of the nanofibrils reduced the viscosity of the nanocellulose, thus yielding a material with good rheological properties for use as a bioink. The nanocellulose bioink was thus used for printing 3D porous structures, which is exemplified in this study. We also demonstrated that both nanocelluloses did not support bacterial growth, which is an interesting property of these novel materials. Adam Rees, Lydia C. Powell, Gary Chinga-Carrasco, David T. Gethin, Kristin Syverud, Katja E. Hill, and David W. Thomas Copyright © 2015 Adam Rees et al. All rights reserved. Hyaluronic Acid Based Hydrogels for Regenerative Medicine Applications Tue, 19 May 2015 12:45:39 +0000 Hyaluronic acid (HA) hydrogels, obtained by cross-linking HA molecules with divinyl sulfone (DVS) based on a simple, reproducible, and safe process that does not employ any organic solvents, were developed. Owing to an innovative preparation method the resulting homogeneous hydrogels do not contain any detectable residual cross-linking agent and are easier to inject through a fine needle. HA hydrogels were characterized in terms of degradation and biological properties, viscoelasticity, injectability, and network structural parameters. They exhibit a rheological behaviour typical of strong gels and show improved viscoelastic properties by increasing HA concentration and decreasing HA/DVS weight ratio. Furthermore, it was demonstrated that processes such as sterilization and extrusion through clinical needles do not imply significant alteration of viscoelastic properties. Both SANS and rheological tests indicated that the cross-links appear to compact the network, resulting in a reduction of the mesh size by increasing the cross-linker amount. In vitro degradation tests of the HA hydrogels demonstrated that these new hydrogels show a good stability against enzymatic degradation, which increases by increasing HA concentration and decreasing HA/DVS weight ratio. Finally, the hydrogels show a good biocompatibility confirmed by in vitro tests. Assunta Borzacchiello, Luisa Russo, Birgitte M. Malle, Khadija Schwach-Abdellaoui, and Luigi Ambrosio Copyright © 2015 Assunta Borzacchiello et al. All rights reserved. Preparation, Optimization, and Screening of the Effect of Processing Variables on Agar Nanospheres Loaded with Bupropion HCl by a D-Optimal Design Tue, 19 May 2015 12:39:39 +0000 Bupropion is an atypical antidepressant drug. Fluctuating in its serum levels following oral administration of immediate release dosage forms leads to occasional seizure. The aim of the present work was designing of sustained release bupropion HCl nanospheres suited for pulmonary delivery. Agar nanospheres were prepared by transferring the w/o emulsion to solid in oil (s/o) suspension. Calcium chloride was used as cross-linking agent and hydroxypropyl β-cyclodextrin (HPβCD) was used as permeability enhancer. A response surface D-optimal design was used for optimization of nanospheres. Independent factors included in the design were calcium chloride percent, speed of homogenization, agar percent, and HPβCD percent. Optimum condition was predicted to be achieved when the calcium chloride was set at 7.19%, homogenization speed at 8500 rpm, agar content at 2%, and HPβCD at 0.12%. The optimized nanoparticles showed particle size of 587 nm, zeta potential of −30.9 mV, drug loading efficiency of 38.6%, and release efficiency of 51% until 5 h. The nanospheres showed high degree of bioadhesiveness. D-optimal response surface method is a satisfactory design to optimize the fabrication of bupropion HCl loaded agar nanospheres and these nanospheres can be successively exploited to deliver bupropion in a controlled manner for a sufficiently extended period. Jaleh Varshosaz, Mohammad Reza Zaki, Mohsen Minaiyan, and Jaafar Banoozadeh Copyright © 2015 Jaleh Varshosaz et al. All rights reserved. Assessment of Atmospheric Pressure Plasma Treatment for Implant Osseointegration Tue, 19 May 2015 10:10:11 +0000 This study assessed the osseointegrative effects of atmospheric pressure plasma (APP) surface treatment for implants in a canine model. Control surfaces were untreated textured titanium (Ti) and calcium phosphate (CaP). Experimental surfaces were their 80-second air-based APP-treated counterparts. Physicochemical characterization was performed to assess topography, surface energy, and chemical composition. One implant from each control and experimental group (four in total) was placed in one radius of each of the seven male beagles for three weeks, and one implant from each group was placed in the contralateral radius for six weeks. After sacrifice, bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were assessed. X-ray photoelectron spectroscopy showed decreased surface levels of carbon and increased Ti and oxygen, and calcium and oxygen, posttreatment for Ti and CaP surfaces, respectively. There was a significant increase in BIC for APP-treated textured Ti surfaces at six weeks but not at three weeks or for CaP surfaces. There were no significant differences for BAFO between treated and untreated surfaces for either material at either time point. This suggests that air-based APP surface treatment may improve osseointegration of textured Ti surfaces but not CaP surfaces. Studies optimizing APP parameters and applications are warranted. Natalie R. Danna, Bryan G. Beutel, Nick Tovar, Lukasz Witek, Charles Marin, Estevam A. Bonfante, Rodrigo Granato, Marcelo Suzuki, and Paulo G. Coelho Copyright © 2015 Natalie R. Danna et al. All rights reserved. Antibacterial Effects and Biocompatibility of Titania Nanotubes with Octenidine Dihydrochloride/Poly(lactic-co-glycolic acid) Tue, 19 May 2015 09:52:35 +0000 Titanium (Ti) implants with long-term antibacterial ability and good biocompatibility are highly desirable materials that can be used to prevent implant-associated infections. In this study, titania nanotubes (TNTs) were synthesized on Ti surfaces through electrochemical anodization. Octenidine dihydrochloride (OCT)/poly(lactic-co-glycolic acid) (PLGA) was infiltrated into TNTs using a simple solvent-casting technique. OCT/PLGA-TNTs demonstrated sustained drug release and maintained the characteristic hollow structures of TNTs. TNTs (200 nm in diameter) alone exhibited slight antibacterial effect and good osteogenic activity but also evidently impaired adhesion and proliferation of bone marrow mesenchymal stem cells (BMSCs). OCT/PLGA-TNTs (100 nm in diameter) supported BMSC adhesion and proliferation and showed good osteogenesis-inducing ability. OCT/PLGA-TNTs also exhibited good long-term antibacterial ability within the observation period of 7 d. The synthesized drug carrier with relatively long-term antibacterial ability and enhanced excellent biocompatibility demonstrated significant potential in bone implant applications. Zhiqiang Xu, Yingzhen Lai, Dong Wu, Wenxiu Huang, Sijia Huang, Lin Zhou, and Jiang Chen Copyright © 2015 Zhiqiang Xu et al. All rights reserved. Clinical Application of Mesenchymal Stem Cells and Novel Supportive Therapies for Oral Bone Regeneration Tue, 12 May 2015 09:02:38 +0000 Bone regeneration is often needed prior to dental implant treatment due to the lack of adequate quantity and quality of the bone after infectious diseases, trauma, tumor, or congenital conditions. In these situations, cell transplantation technologies may help to overcome the limitations of autografts, xenografts, allografts, and alloplastic materials. A database search was conducted to include human clinical trials (randomized or controlled) and case reports/series describing the clinical use of mesenchymal stem cells (MSCs) in the oral cavity for bone regeneration only specifically excluding periodontal regeneration. Additionally, novel advances in related technologies are also described. 190 records were identified. 51 articles were selected for full-text assessment, and only 28 met the inclusion criteria: 9 case series, 10 case reports, and 9 randomized controlled clinical trials. Collectively, they evaluate the use of MSCs in a total of 290 patients in 342 interventions. The current published literature is very diverse in methodology and measurement of outcomes. Moreover, the clinical significance is limited. Therefore, the use of these techniques should be further studied in more challenging clinical scenarios with well-designed and standardized RCTs, potentially in combination with new scaffolding techniques and bioactive molecules to improve the final outcomes. Miguel Padial-Molina, Francisco O’Valle, Alejandro Lanis, Francisco Mesa, David M. Dohan Ehrenfest, Hom-Lay Wang, and Pablo Galindo-Moreno Copyright © 2015 Miguel Padial-Molina et al. All rights reserved. Biomechanical Stability of Dental Implants in Augmented Maxillary Sites: Results of a Randomized Clinical Study with Four Different Biomaterials and PRF and a Biological View on Guided Bone Regeneration Sun, 12 Apr 2015 11:49:48 +0000 Introduction. Bone regenerates mainly by periosteal and endosteal humoral and cellular activity, which is given only little concern in surgical techniques and choice of bone grafts for guided bone regeneration. This study investigates on a clinical level the biomechanical stability of augmented sites in maxillary bone when a new class of moldable, self-hardening calcium-phosphate biomaterials (SHB) is used with and without the addition of Platelet Rich Fibrin (aPRF) in the Piezotome-enhanced subperiosteal tunnel-technique (PeSPTT). Material and Methods. 82 patients with horizontal atrophy of anterior maxillary crest were treated with PeSPTT and randomly assigned biphasic (60% HA/40% bTCP) or monophasic (100% bTCP) SHB without or with addition of aPRF. 109 implants were inserted into the augmented sites after 8.3 months and the insertion-torque-value (ITV) measured as clinical expression of the (bio)mechanical stability of the augmented bone and compared to ITVs of a prior study in sinus lifting. Results. Significant better results of (bio)mechanical stability almost by two-fold, expressed by higher ITVs compared to native bone, were achieved with the used biomaterials and more constant results with the addition of aPRF. Conclusion. The use of SHB alone or combined with aPRF seems to be favourable to achieve a superior (bio)mechanical stable restored alveolar bone. Troedhan Angelo, Wainwright Marcel, Kurrek Andreas, and Schlichting Izabela Copyright © 2015 Troedhan Angelo et al. All rights reserved. Osteogenic Biomaterials in Contemporary Dentistry Wed, 08 Apr 2015 06:59:28 +0000 Seong-Hun Kim, Jae-Pyung Ahn, Homayoun H. Zadeh, and Eric J. W. Liou Copyright © 2015 Seong-Hun Kim et al. All rights reserved. An Alumina Toughened Zirconia Composite for Dental Implant Application: In Vivo Animal Results Mon, 06 Apr 2015 12:03:53 +0000 Ceramic materials are widely used for biomedical applications because of their remarkable biological and mechanical properties. Composites made of alumina and zirconia are particularly interesting owing to their higher toughness with respect to the monolithic materials. On this basis, the present study is focused on the in vivo behavior of alumina toughened zirconia (ATZ) dental implants treated with a hydrothermal process. A minipig model was implemented to assess the bone healing through histology and mRNA expression at different time points (8, 14, 28, and 56 days). The novel ATZ implant was compared to a titanium clinical standard. The implants were analyzed in terms of microstructure and surface roughness before in vivo tests. The most interesting result deals with a statistically significant higher digital histology index for ATZ implants with respect to titanium standard at 56 days, which is an unprecedented finding, to the authors’ knowledge. Even if further investigations are needed before proposing the clinical use in humans, the tested material proved to be a promising candidate among the possible ceramic dental implants. Gianmario Schierano, Federico Mussano, Maria Giulia Faga, Giulio Menicucci, Carlo Manzella, Cristian Sabione, Tullio Genova, Mitzy Mauthe von Degerfeld, Bruno Peirone, Adele Cassenti, Paola Cassoni, and Stefano Carossa Copyright © 2015 Gianmario Schierano et al. All rights reserved. Regulation of Osteoblast Differentiation by Acid-Etched and/or Grit-Blasted Titanium Substrate Topography Is Enhanced by 1,25(OH)2D3 in a Sex-Dependent Manner Mon, 06 Apr 2015 08:13:39 +0000 This study assessed contributions of micron-scale topography on clinically relevant titanium (Ti) to differentiation of osteoprogenitor cells and osteoblasts; the interaction of this effect with 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3); and if the effects are sex-dependent. Male and female rat bone marrow cells (BMCs) were cultured on acid-etched (A,  μm), grit-blasted (GB,  μm), or grit-blasted/acid-etched (SLA,  μm) Ti. BMCs were sensitive to surface topography and underwent osteoblast differentiation. This was greatest on SLA; acid etching and grit blasting contributed additively. Primary osteoblasts were also sensitive to SLA, with less effect from individual structural components, demonstrated by enhanced local factor production. Sex-dependent responses of BMCs to topography varied with parameter whereas male and female osteoblasts responded similarly to surface treatment. 1α,25(OH)2D3 enhanced cell responses on all surfaces similarly. Effects were sex-dependent and male cells grown on a complex microstructured surface were much more sensitive than female cells. These results indicate that effects of the complex SLA topography are greater than acid etching or grit blasting alone on multipotent BMCs and committed osteoblasts and that individual parameters are sex-specific. The effect of 1α,25(OH)2D3 was sex dependent. The results also suggest that levels of 1α,25(OH)2D3 in the patient may be important in osseointegration. Rene Olivares-Navarrete, Sharon L. Hyzy, Barbara D. Boyan, and Zvi Schwartz Copyright © 2015 Rene Olivares-Navarrete et al. All rights reserved. Optimizing Perfusion-Decellularization Methods of Porcine Livers for Clinical-Scale Whole-Organ Bioengineering Tue, 31 Mar 2015 06:37:14 +0000 Aim. To refine the decellularization protocol of whole porcine liver, which holds great promise for liver tissue engineering. Methods. Three decellularization methods for porcine livers (1% sodium dodecyl sulfate (SDS), 1% Triton X-100 + 1% sodium dodecyl sulfate, and 1% sodium deoxycholate + 1% sodium dodecyl sulfate) were studied. The obtained liver scaffolds were processed for histology, residual cellular content analysis, and extracellular matrix (ECM) components evaluation to investigate decellularization efficiency and ECM preservation. Rat primary hepatocytes were seeded into three kinds of scaffold to detect the biocompatibility. Results. The whole liver decellularization was successfully achieved following all three kinds of treatment. SDS combined with Triton had a high efficacy of cellular removal and caused minimal disruption of essential ECM components; it was also the most biocompatible procedure for primary hepatocytes. Conclusion. We have refined a novel, standardized, time-efficient, and reproducible protocol for the decellularization of whole liver which can be further adapted to liver tissue engineering. Qiong Wu, Ji Bao, Yong-jie Zhou, Yu-jia Wang, Zheng-gui Du, Yu-jun Shi, Li Li, and Hong Bu Copyright © 2015 Qiong Wu et al. All rights reserved. Advances in Gene Delivery Systems Mon, 30 Mar 2015 06:49:34 +0000 Surendra Nimesh, Sabina Halappanavar, Nagendra K. Kaushik, and Pradeep Kumar Copyright © 2015 Surendra Nimesh et al. All rights reserved. Delivery of Nucleic Acids and Nanomaterials by Cell-Penetrating Peptides: Opportunities and Challenges Thu, 26 Mar 2015 12:27:11 +0000 Many viral and nonviral systems have been developed to aid delivery of biologically active molecules into cells. Among these, cell-penetrating peptides (CPPs) have received increasing attention in the past two decades for biomedical applications. In this review, we focus on opportunities and challenges associated with CPP delivery of nucleic acids and nanomaterials. We first describe the nature of versatile CPPs and their interactions with various types of cargoes. We then discuss in vivo and in vitro delivery of nucleic acids and nanomaterials by CPPs. Studies on the mechanisms of cellular entry and limitations in the methods used are detailed. Yue-Wern Huang, Han-Jung Lee, Larry M. Tolliver, and Robert S. Aronstam Copyright © 2015 Yue-Wern Huang et al. All rights reserved. Biotribology in Knee Arthroplasty Thu, 26 Mar 2015 12:26:06 +0000 Thomas M. Grupp, Sandra Utzschneider, and Markus A. Wimmer Copyright © 2015 Thomas M. Grupp et al. All rights reserved. Biomaterial Hypersensitivity: Is It Real? Supportive Evidence and Approach Considerations for Metal Allergic Patients following Total Knee Arthroplasty Wed, 25 Mar 2015 09:15:31 +0000 The prospect of biomaterial hypersensitivity developing in response to joint implant materials was first presented more than 30 years ago. Many studies have established probable causation between first-generation metal-on-metal hip implants and hypersensitivity reactions. In a limited patient population, implant failure may ultimately be related to metal hypersensitivity. The examination of hypersensitivity reactions in current-generation metal-on-metal knee implants is comparatively limited. The purpose of this study is to summarize all available literature regarding biomaterial hypersensitivity after total knee arthroplasty, elucidate overall trends about this topic in the current literature, and provide a foundation for clinical approach considerations when biomaterial hypersensitivity is suspected. Andrew J. Mitchelson, Craig J. Wilson, William M. Mihalko, Thomas M. Grupp, Blaine T. Manning, Douglas A. Dennis, Stuart B. Goodman, Tony H. Tzeng, Sonia Vasdev, and Khaled J. Saleh Copyright © 2015 Andrew J. Mitchelson et al. All rights reserved. Rapid Prototyping for In Vitro Knee Rig Investigations of Prosthetized Knee Biomechanics: Comparison with Cobalt-Chromium Alloy Implant Material Tue, 24 Mar 2015 06:33:49 +0000 Retropatellar complications after total knee arthroplasty (TKA) such as anterior knee pain and subluxations might be related to altered patellofemoral biomechanics, in particular to trochlear design and femorotibial joint positioning. A method was developed to test femorotibial and patellofemoral joint modifications separately with 3D-rapid prototyped components for in vitro tests, but material differences may further influence results. This pilot study aims at validating the use of prostheses made of photopolymerized rapid prototype material (RPM) by measuring the sliding friction with a ring-on-disc setup as well as knee kinematics and retropatellar pressure on a knee rig. Cobalt-chromium alloy (standard prosthesis material, SPM) prostheses served as validation standard. Friction coefficients between these materials and polytetrafluoroethylene (PTFE) were additionally tested as this latter material is commonly used to protect pressure sensors in experiments. No statistical differences were found between friction coefficients of both materials to PTFE. UHMWPE shows higher friction coefficient at low axial loads for RPM, a difference that disappears at higher load. No measurable statistical differences were found in knee kinematics and retropatellar pressure distribution. This suggests that using polymer prototypes may be a valid alternative to original components for in vitro TKA studies and future investigations on knee biomechanics. Christian Schröder, Arnd Steinbrück, Tatjana Müller, Matthias Woiczinski, Yan Chevalier, Patrick Weber, Peter E. Müller, and Volkmar Jansson Copyright © 2015 Christian Schröder et al. All rights reserved. Patients with Intolerance Reactions to Total Knee Replacement: Combined Assessment of Allergy Diagnostics, Periprosthetic Histology, and Peri-implant Cytokine Expression Pattern Thu, 19 Mar 2015 13:17:22 +0000 We performed a combined approach to identify suspected allergy to knee arthroplasty (TKR): patch test (PT), lymphocyte transformation test (LTT), histopathology (overall grading; T- and B-lymphocytes, macrophages, and neutrophils), and semiquantitative Real-time-PCR-based periprosthetic inflammatory mediator analysis (IFNγ, TNFα, IL1-β, IL-2, IL-6, IL-8, IL-10, IL17, and TGFβ). We analyzed 25 TKR patients with yet unexplained complications like pain, effusion, and reduced range of motion. They consisted of 20 patients with proven metal sensitization (11 with PT reactions; 9 with only LTT reactivity). Control specimens were from 5 complicated TKR patients without metal sensitization, 12 OA patients before arthroplasty, and 8 PT patients without arthroplasty. Lymphocytic infiltrates were seen and fibrotic (Type IV membrane) tissue response was most frequent in the metal sensitive patients, for example, in 81% of the PT positive patients. The latter also had marked periprosthetic IFNγ expression. 8/9 patients with revision surgery using Ti-coated/oxinium based implants reported symptom relief. Our findings demonstrate that combining allergy diagnostics with histopathology and periprosthetic cytokine assessment could allow us to design better diagnostic strategies. Peter Thomas, Christine von der Helm, Christoph Schopf, Farhad Mazoochian, Lars Frommelt, Hans Gollwitzer, Josef Schneider, Michael Flaig, Veit Krenn, Benjamin Thomas, and Burkhard Summer Copyright © 2015 Peter Thomas et al. All rights reserved. PMMA Third-Body Wear after Unicondylar Knee Arthroplasty Decuples the UHMWPE Wear Particle Generation In Vitro Thu, 19 Mar 2015 09:46:07 +0000 Introduction. Overlooked polymethylmethacrylate after unicondylar knee arthroplasty can be a potential problem, since this might influence the generated wear particle size and morphology. The aim of this study was the analysis of polyethylene wear in a knee wear simulator for changes in size, morphology, and particle number after the addition of third-bodies. Material and Methods. Fixed bearing unicondylar knee prostheses (UKA) were tested in a knee simulator for 5.0 million cycles. Following bone particles were added for 1.5 million cycles, followed by 1.5 million cycles with PMMA particles. A particle analysis by scanning electron microscopy of the lubricant after the cycles was performed. Size and morphology of the generated wear were characterized. Further, the number of particles per 1 million cycles was calculated for each group. Results. The particles of all groups were similar in size and shape. The number of particles in the PMMA group showed 10-fold higher values than in the bone and control group (PMMA: 12; bone: 12; control: 12). Conclusion. The addition of bone or PMMA particles in terms of a third-body wear results in no change of particle size and morphology. PMMA third-bodies generated tenfold elevated particle numbers. This could favor an early aseptic loosening. Alexander Christoph Paulus, Manja Franke, Michael Kraxenberger, Christian Schröder, Volkmar Jansson, and Sandra Utzschneider Copyright © 2015 Alexander Christoph Paulus et al. All rights reserved. Variability of TKR Knee Kinematics and Relationship with Gait Kinetics: Implications for Total Knee Wear Thu, 19 Mar 2015 08:28:18 +0000 Several factors, including compressive load and knee kinematics, have been shown to influence wear. External knee moments (a surrogate for load) have recently been correlated with the medial and lateral wear scar areas of an unconstrained, PCL retaining knee design. Therefore, the purpose of this study was to determine whether differences in kinetics during level walking are accompanied by specific differences in relative knee kinematics. Thirty TKR patients were gait tested using the point cluster technique to obtain 3D motions of the knee. External knee moments were calculated from ground reaction forces recorded with a multicomponent force plate. The subjects were separated into two distinct anteroposterior (AP) motion categories: a low motion group and a high motion group. Similarly, the low and high motion groups for internal-external (IE) rotation were also identified. For the IE motion, there was no significant difference between the transverse internal rotation moments between the two IE motion groups. However for the AP motion groups, a higher external peak flexion moment was found for the group displaying less AP motion. These observations suggest that subjects with higher joint moments execute smaller ranges of AP motion and thus are likely to incur less wear. Valentina Ngai and Markus A. Wimmer Copyright © 2015 Valentina Ngai and Markus A. Wimmer. All rights reserved. Localized and Sustained Delivery of Erythropoietin from PLGA Microspheres Promotes Functional Recovery and Nerve Regeneration in Peripheral Nerve Injury Tue, 03 Mar 2015 09:16:11 +0000 Erythropoietin (EPO) has been demonstrated to exert neuroprotective effects on peripheral nerve injury recovery. Though daily intraperitoneal injection of EPO during a long period of time was effective, it was a tedious procedure. In addition, only limited amount of EPO could reach the injury sites by general administration, and free EPO is easily degraded in vivo. In this study, we encapsulated EPO in poly(lactide-co-glycolide) (PLGA) microspheres. Both in vitro and in vivo release assays showed that the EPO-PLGA microspheres allowed sustained release of EPO within a period of two weeks. After administration of such EPO-PLGA microspheres, the peripheral nerve injured rats had significantly better recovery compared with those which received daily intraperitoneal injection of EPO, empty PLGA microspheres, or saline treatments. This was supported by the functional, electrophysiological, and histological evaluations of the recovery done at week 8 postoperatively. We conclude that sustained delivery of EPO could be achieved by using EPO-PLGA microspheres, and such delivery method could further enhance the recovery function of EPO in nerve injury recovery. Wei Zhang, Yuan Gao, Yan Zhou, Jianheng Liu, Licheng Zhang, Anhua Long, Lihai Zhang, and Peifu Tang Copyright © 2015 Wei Zhang et al. All rights reserved. Characterization of Bone Marrow Mononuclear Cells on Biomaterials for Bone Tissue Engineering In Vitro Mon, 23 Feb 2015 10:05:13 +0000 Bone marrow mononuclear cells (BMCs) are suitable for bone tissue engineering. Comparative data regarding the needs of BMC for the adhesion on biomaterials and biocompatibility to various biomaterials are lacking to a large extent. Therefore, we evaluated whether a surface coating would enhance BMC adhesion and analyze the biocompatibility of three different kinds of biomaterials. BMCs were purified from human bone marrow aspirate samples. Beta tricalcium phosphate (β-TCP, without coating or coated with fibronectin or human plasma), demineralized bone matrix (DBM), and bovine cancellous bone (BS) were assessed. Seeding efficacy on β-TCP was 95% regardless of the surface coating. BMC demonstrated a significantly increased initial adhesion on DBM and β-TCP compared to BS. On day 14, metabolic activity was significantly increased in BMC seeded on DBM in comparison to BMC seeded on BS. Likewise increased VEGF-synthesis was observed on day 2 in BMC seeded on DBM when compared to BMC seeded on BS. The seeding efficacy of BMC on uncoated biomaterials is generally high although there are differences between these biomaterials. Beta-TCP and DBM were similar and both superior to BS, suggesting either as suitable materials for spatial restriction of BMC used for regenerative medicine purposes in vivo. Dirk Henrich, René Verboket, Alexander Schaible, Kerstin Kontradowitz, Elsie Oppermann, Jan C. Brune, Christoph Nau, Simon Meier, Halvard Bonig, Ingo Marzi, and Caroline Seebach Copyright © 2015 Dirk Henrich et al. All rights reserved. Cellular Responses Evoked by Different Surface Characteristics of Intraosseous Titanium Implants Thu, 12 Feb 2015 12:24:36 +0000 The properties of biomaterials, including their surface microstructural topography and their surface chemistry or surface energy/wettability, affect cellular responses such as cell adhesion, proliferation, and migration. The nanotopography of moderately rough implant surfaces enhances the production of biological mediators in the peri-implant microenvironment with consequent recruitment of differentiating osteogenic cells to the implant surface and stimulates osteogenic maturation. Implant surfaces with moderately rough topography and with high surface energy promote osteogenesis, increase the ratio of bone-to-implant contact, and increase the bonding strength of the bone to the implant at the interface. Certain features of implant surface chemistry are also important in enhancing peri-implant bone wound healing. It is the purpose of this paper to review some of the more important features of titanium implant surfaces which have an impact on osseointegration. Liviu Feller, Yusuf Jadwat, Razia A. G. Khammissa, Robin Meyerov, Israel Schechter, and Johan Lemmer Copyright © 2015 Liviu Feller et al. All rights reserved. Gene Profiling of Bone around Orthodontic Mini-Implants by RNA-Sequencing Analysis Wed, 11 Feb 2015 12:21:21 +0000 This study aimed to evaluate the genes that were expressed in the healing bones around SLA-treated titanium orthodontic mini-implants in a beagle at early (1-week) and late (4-week) stages with RNA-sequencing (RNA-Seq). Samples from sites of surgical defects were used as controls. Total RNA was extracted from the tissue around the implants, and an RNA-Seq analysis was performed with Illumina TruSeq. In the 1-week group, genes in the gene ontology (GO) categories of cell growth and the extracellular matrix (ECM) were upregulated, while genes in the categories of the oxidation-reduction process, intermediate filaments, and structural molecule activity were downregulated. In the 4-week group, the genes upregulated included ECM binding, stem cell fate specification, and intramembranous ossification, while genes in the oxidation-reduction process category were downregulated. GO analysis revealed an upregulation of genes that were related to significant mechanisms, including those with roles in cell proliferation, the ECM, growth factors, and osteogenic-related pathways, which are associated with bone formation. From these results, implant-induced bone formation progressed considerably during the times examined in this study. The upregulation or downregulation of selected genes was confirmed with real-time reverse transcription polymerase chain reaction. The RNA-Seq strategy was useful for defining the biological responses to orthodontic mini-implants and identifying the specific genetic networks for targeted evaluations of successful peri-implant bone remodeling. Kyung-Yen Nahm, Jung Sun Heo, Jae-Hyung Lee, Dong-Yeol Lee, Kyu-Rhim Chung, Hyo-Won Ahn, and Seong-Hun Kim Copyright © 2015 Kyung-Yen Nahm et al. All rights reserved. Resistance to Fracture of Dental Roots Obturated with Different Materials Sun, 08 Feb 2015 08:54:44 +0000 The aim of this study was to compare the vertical fracture resistance of roots obturated with different root canal filling materials and sealers. Crowns of 55 extracted mandibular premolar teeth were removed to provide root lengths of 13 mm. Five roots were saved as negative control group (canals unprepared and unfilled). Fifty root canals were instrumented and then five roots were saved as positive control group (canals prepared but unfilled). The remaining 45 roots were randomly divided into three experimental groups ( root/group) and obturated with the following procedures: in group 1, glass ionomer-based sealer and cone (ActiV GP obturation system); in group 2, bioceramic sealer and cone (EndoSequence BC obturation system); and in group 3, roots were filled with bioceramic sealer and cone (Smartpaste bio obturation system). All specimens were tested in a universal testing machine for measuring fracture resistance. For each root, the force at the time of fracture was recorded in Newtons. The statistical analysis was performed by using Kruskal-Wallis and post hoc test. There were no significant differences between the three experimental groups. The fracture values of three experimental and negative control groups were significantly higher than the positive control group. Within the limitations of this study, all materials increased the fracture resistance of instrumented roots. Berkan Celikten, Ceren Feriha Uzuntas, and Kamran Gulsahi Copyright © 2015 Berkan Celikten et al. All rights reserved. The Osteogenic Properties of Multipotent Mesenchymal Stromal Cells in Cultures on TiO2 Sol-Gel-Derived Biomaterial Sun, 01 Feb 2015 13:22:16 +0000 The biocompatibility of the bone implants is a crucial factor determining the successful tissue regeneration. The aim of this work was to compare cellular behavior and osteogenic properties of rat adipose-derived multipotent stromal cells (ASCs) and bone marrow multipotent stromal cells (BMSCs) cultured on metallic substrate covered with TiO2 sol-gel-derived nanolayer. The morphology, proliferation rate, and osteogenic differentiation potential of both ASCs and BMSCs propagated on the biomaterials were examined. The potential for osteogenic differentiation of ASCs and BMSCs was determined based on the presence of specific markers of osteogenesis, that is, alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OCL). Additionally, the concentration of calcium and phosphorus in extracellular matrix was determined using energy-dispersive X-ray spectroscopy (SEM-EDX). Obtained results showed that TiO2 layer influenced proliferation activity of ASCs, which manifested by shortening of population doubling time and increase of OPN secretion. However, characteristic features of cells morphology and growth pattern of cultures prompted us to conclude that ultrathin TiO2 layer might also enhance osteodifferentiation of BMSCs. Therefore in our opinion, both populations of MSCs should be used for biological evaluation of biomaterials compatibility, such results may enhance the area of investigations related to regenerative medicine. Krzysztof Marycz, Agnieszka Śmieszek, Jakub Grzesiak, Anna Siudzińska, Monika Marędziak, Anna Donesz-Sikorska, and Justyna Krzak Copyright © 2015 Krzysztof Marycz et al. All rights reserved. The Biocompatibility of Degradable Magnesium Interference Screws: An Experimental Study with Sheep Sat, 31 Jan 2015 10:06:19 +0000 Screws for ligament reconstruction are nowadays mostly made of poly-L-lactide (PLLA). However, magnesium-based biomaterials are gathering increased interest in this research field because of their good mechanical property and osteoanabolic influence on bone metabolism. The aim of this pilot study was to evaluate the biocompatibility of an interference screw for ligament reconstruction made of magnesium alloy W4 by diecasting and milling and using different PEO-coatings with calcium phosphates. PLLA and titanium screws were used as control samples. The screws were implanted in the femur condyle of the hind leg of a merino sheep. The observation period was six and twelve weeks and one year. Histomorphometric, immunohistochemical, immunofluorescence, and molecular biological evaluation were conducted. Further TEM analysis was done. In all magnesium screws a clinically relevant gas formation in the vicinity of the biomaterial was observed. Except for the PLLA and titanium control samples, no screw was fully integrated in the surrounding bone tissue. Regarding the fabrication process, milling seems to produce less gas liberation and has a better influence on bone metabolism than diecasting. Coating by PEO with calcium phosphates could not reduce the initial gas liberation but rather reduced the bone metabolism in the vicinity of the biomaterial. Ulrich Thormann, Volker Alt, Lydia Heimann, Cyrille Gasquere, Christian Heiss, Gabor Szalay, Jörg Franke, Reinhard Schnettler, and Katrin Susanne Lips Copyright © 2015 Ulrich Thormann et al. All rights reserved. Application of AMOR in Craniofacial Rabbit Bone Bioengineering Thu, 29 Jan 2015 12:15:47 +0000 Endogenous molecular and cellular mediators modulate tissue repair and regeneration. We have recently described antibody mediated osseous regeneration (AMOR) as a novel strategy for bioengineering bone in rat calvarial defect. This entails application of anti-BMP-2 antibodies capable of in vivo capturing of endogenous osteogenic BMPs (BMP-2, BMP-4, and BMP-7). The present study sought to investigate the feasibility of AMOR in other animal models. To that end, we examined the efficacy of a panel of anti-BMP-2 monoclonal antibodies (mAbs) and a polyclonal Ab immobilized on absorbable collagen sponge (ACS) to mediate bone regeneration within rabbit calvarial critical size defects. After 6 weeks, de novo bone formation was demonstrated by micro-CT imaging, histology, and histomorphometric analysis. Only certain anti-BMP-2 mAb clones mediated significant in vivo bone regeneration, suggesting that the epitopes with which anti-BMP-2 mAbs react are critical to AMOR. Increased localization of BMP-2 protein and expression of osteocalcin were observed within defects, suggesting accumulation of endogenous BMP-2 and/or increased de novo expression of BMP-2 protein within sites undergoing bone repair by AMOR. Considering the ultimate objective of translation of this therapeutic strategy in humans, preclinical studies will be necessary to demonstrate the feasibility of AMOR in progressively larger animal models. Marcelo Freire, Jeong-Ho Choi, Anthony Nguyen, Young Deok Chee, Joong-Ki Kook, Hyung-Keun You, and Homayoun H. Zadeh Copyright © 2015 Marcelo Freire et al. All rights reserved. Insight into Bone-Derived Biological Apatite: Ultrastructure and Effect of Thermal Treatment Wed, 28 Jan 2015 14:07:01 +0000 Objectives. This study aims at examining the ultrastructure of bone-derived biological apatite (BAp) from a series of small vertebrates and the effect of thermal treatment on its physiochemical properties. Materials and Methods. Femurs/fin rays and vertebral bodies of 5 kinds of small vertebrates were firstly analyzed with X-ray microtomography. Subsequently, BAp was obtained with thermal treatment and low power plasma ashing, respectively. The properties of BAp, including morphology, functional groups, and crystal characteristics were then analyzed. Results. The bones of grouper and hairtail were mainly composed of condensed bone. Spongy bone showed different distribution in the bones from frog, rat, and pigeon. No significant difference was found in bone mineral density of condensed bone and trabecular thickness of spongy bone. Only platelet-like crystals were observed for BAp obtained by plasma ashing, while rod-like and irregular crystals were both harvested from the bones treated by sintering. A much higher degree of crystallinity and larger crystal size but a lower content of carbonate were detected in the latter. Conclusion. Platelet-like BAp is the common inorganic component of vertebrate bones. BAp distributing in condensed and spongy bone may exhibit differing thermal reactivity. Thermal treatment may alter BAp’s in vivo structure and composition. Quan Liu, Haobo Pan, Zhuofan Chen, and Jukka Pekka Matinlinna Copyright © 2015 Quan Liu et al. All rights reserved. Prediction of Local Ultimate Strain and Toughness of Trabecular Bone Tissue by Raman Material Composition Analysis Wed, 28 Jan 2015 09:48:59 +0000 Clinical studies indicate that bone mineral density correlates with fracture risk at the population level but does not correlate with individual fracture risk well. Current research aims to better understand the failure mechanism of bone and to identify key determinants of bone quality, thus improving fracture risk prediction. To get a better understanding of bone strength, it is important to analyze tissue-level properties not influenced by macro- or microarchitectural factors. The aim of this pilot study was to identify whether and to what extent material properties are correlated with mechanical properties at the tissue level. The influence of macro- or microarchitectural factors was excluded by testing individual trabeculae. Previously reported data of mechanical parameters measured in single trabeculae under tension and bending and its compositional properties measured by Raman spectroscopy was evaluated. Linear and multivariate regressions show that bone matrix quality but not quantity was significantly and independently correlated with the tissue-level ultimate strain and postyield work . Principal component analysis extracted three independent components explaining 86% of the total variance, representing elastic, yield, and ultimate components according to the included mechanical parameters. Some matrix parameters were both included in the ultimate component, indicating that the variation in ultimate strain and postyield work could be largely explained by Raman-derived compositional parameters. Roberto Carretta, Edgar Stüssi, Ralph Müller, and Silvio Lorenzetti Copyright © 2015 Roberto Carretta et al. All rights reserved. Dragging Human Mesenchymal Stem Cells with the Aid of Supramolecular Assemblies of Single-Walled Carbon Nanotubes, Molecular Magnets, and Peptides in a Magnetic Field Mon, 26 Jan 2015 11:03:16 +0000 Human adipose-derived stem cells (hASCs) are an attractive cell source for therapeutic applicability in diverse fields for the repair and regeneration of damaged or malfunctioning tissues and organs. There is a growing number of cell therapies using stem cells due to their characteristics of modulation of immune system and reduction of acute rejection. So a challenge in stem cells therapy is the delivery of cells to the organ of interest, a specific site. The aim of this paper was to investigate the effects of a supramolecular assembly composed of single-walled carbon nanotubes (SWCNT), molecular magnets (lawsone-Co-phenanthroline), and a synthetic peptide (FWYANHYWFHNAFWYANHYWFHNA) in the hASCs cultures. The hASCs were isolated, characterized, expanded, and cultured with the SWCNT supramolecular assembly (SWCNT-MA). The assembly developed did not impair the cell characteristics, viability, or proliferation. During growth, the cells were strongly attached to the assembly and they could be dragged by an applied magnetic field of less than 0.3 T. These assemblies were narrower than their related allotropic forms, that is, multiwalled carbon nanotubes, and they could therefore be used to guide cells through thin blood capillaries within the human body. This strategy seems to be useful as noninvasive and nontoxic stem cells delivery/guidance and tracking during cell therapy. Ana Cláudia C. de Paula, Gustavo A. M. Sáfar, Alfredo M. Góes, Marcelo P. Bemquerer, Marcos A. Ribeiro, and Humberto O. Stumpf Copyright © 2015 Ana Cláudia C. de Paula et al. All rights reserved. Bone Regeneration of Hydroxyapatite/Alumina Bilayered Scaffold with 3 mm Passage-Like Medullary Canal in Canine Tibia Model Mon, 26 Jan 2015 06:40:44 +0000 The aim of this study was to evaluate the bone regeneration of hydroxyapatite (HA)/alumina bilayered scaffold with a 3 mm passage-like medullary canal in a beagle tibia model. A porous HA/alumina scaffold was fabricated using a polymeric template-coating technique. HA/alumina scaffold dimensions were 10 mm in outer diameter, 20 mm in length, and with either a 3 mm passage or no passage. A 20 mm segmental defect was induced using an oscillating saw through the diaphysis of the beagle tibia. The defects of six beagles were filled with HA/alumina bilayered scaffolds with a 3 mm passage or without. The segmental defect was fixated using one bone plate and six screws. Bone regeneration within the HA/alumina scaffolds was observed at eight weeks after implantation. The evaluation of bone regeneration within the scaffolds after implantation in a beagle tibia was performed using radiography, computerized tomography (CT), micro-CT, and fluorescence microscopy. New bone successfully formed in the tibia defects treated with 3 mm passage HA/alumina scaffolds compared to without-passage HA/alumina scaffolds. It was concluded that the HA/alumina bilayered scaffold with 3 mm passage-like medullary canal was instrumental in inducing host-scaffold engraftment of the defect as well as distributing the newly formed bone throughout the scaffold at 8 weeks after implantation. Jong Min Kim, Jun Sik Son, Seong Soo Kang, Gonhyung Kim, and Seok Hwa Choi Copyright © 2015 Jong Min Kim et al. All rights reserved. Nanoscale Bonding between Human Bone and Titanium Surfaces: Osseohybridization Thu, 15 Jan 2015 10:14:28 +0000 Until now, the chemical bonding between titanium and bone has been examined only through a few mechanical detachment tests. Therefore, in this study, a sandblasted and acid-etched titanium mini-implant was removed from a human patient after 2 months of placement in order to identify the chemical integration mechanism for nanoscale osseointegration of titanium implants. To prepare a transmission electron microscopy (TEM) specimen, the natural state was preserved as much as possible by cryofixation and scanning electron microscope/focused ion beam (SEM-FIB) milling without any chemical treatment. High-resolution TEM (HRTEM), energy dispersive X-ray spectroscopy (EDS), and scanning TEM (STEM)/electron energy loss spectroscopic analysis (EELS) were used to investigate the chemical composition and structure at the interface between the titanium and bone tissue. HRTEM and EDS data showed evidence of crystalline hydroxyapatite and intermixing of bone with the oxide layer of the implant. The STEM/EELS experiment provided particularly interesting results: carbon existed in polysaccharides, calcium and phosphorus existed as tricalcium phosphate (TCP), and titanium existed as oxidized titanium. In addition, the oxygen energy loss near edge structures (ELNESs) showed a possibility of the presence of CaTiO3. These STEM/EELS results can be explained by structures either with or without a chemical reaction layer. The possible existence of the osseohybridization area and the form of the carbon suggest that reconsideration of the standard definition of osseointegration is necessary. Jun-Sik Kim, Seok-Man Kang, Kyung-Won Seo, Kyung-Yen Nahm, Kyu-Rhim Chung, Seong-Hun Kim, and Jae-Pyeong Ahn Copyright © 2015 Jun-Sik Kim et al. All rights reserved. Increase in the Tibial Slope Reduces Wear after Medial Unicompartmental Fixed-Bearing Arthroplasty of the Knee Thu, 15 Jan 2015 08:07:42 +0000 Introduction. Unicompartmental arthroplasty of the knee in patients with isolated medial osteoarthritis gives good results, but survival is inferior to that of total knee prosthesis. Knees may fail because positioning of the prosthesis has been suboptimal. The aim of this study was to investigate the influence of the tibial slope on the rate of wear of a medial fixed-bearing unicompartmental knee arthroplasty. Materials and Methods. We simulated wear on a medial fixed-bearing unicompartmental knee prosthesis (Univation) in vitro with a customised, four-station, and servohydraulic knee wear simulator, which exactly reproduced the walking cycle (International Organisation for Standardisation (ISO) 14243-1:2002(E)). The medial prostheses were inserted with 3 different posterior tibial slopes: 0°, 4°, and 8° (n = 3 in each group). Results. The wear rate decreased significantly between 0° and 4° slope from 10.4 (SD 0.62) mg/million cycles to 3.22 (SD 1.71) mg/million cycles. Increasing the tibial slope to 8° did not significantly change the wear rate. Discussion. As an increase in the tibial slope reduced the wear rate in a fixed-bearing prosthesis, a higher tibial slope should be recommended. However, other factors that are influenced by the tibial slope (e.g., the tension of the ligament) must also be considered. Patrick Weber, Christian Schröder, Jens Schwiesau, Sandra Utzschneider, Arnd Steinbrück, Matthias F. Pietschmann, Volkmar Jansson, and Peter E. Müller Copyright © 2015 Patrick Weber et al. All rights reserved. Acute and Chronic Local Inflammatory Reaction after Implantation of Different Extracellular Porcine Dermis Collagen Matrices in Rats Wed, 14 Jan 2015 13:54:32 +0000 Two cross-linked acellular porcine dermal collagen matrices (Permacol and NRX) were implanted into rats and the acute and chronic local inflammatory tissue reactions were investigated after 7, 14, 28, and 112 days. Both membranes were stable in vivo for up to 112 days. All investigated immune cell populations (CD68+ macrophages, CD163+ macrophages, T lymphocytes, MHC class II positive cells, mast cells, and NK cells) were present. Their amount decreased significantly over time compared to day 7 after implantation. A change from an acute to a chronic inflammation and an associated shift from proinflammatory M1-like to anti-inflammatory M2-like macrophages were observed. In the early phase there was a significant correlation of T cells to CD68+ (M1-like) macrophages, whereas in the chronic phase T lymphocytes were positively correlated with CD163+ (M2-like) macrophages. The material NRX showed an enhanced inflammatory reaction in comparison to Permacol possibly caused by material characteristics such as a twofold higher thickness of the membrane, roughness, and water absorption capacity. Nevertheless, a more pronounced regenerative process as, for example, indicated by nestin expression demonstrated its possible suitability for applications as wound repair material. Silke Lucke, Andreas Hoene, Uwe Walschus, Anette Kob, Jens-Wolfgang Pissarek, and Michael Schlosser Copyright © 2015 Silke Lucke et al. All rights reserved. CR TKA UHMWPE Wear Tested after Artificial Aging of the Vitamin E Treated Gliding Component by Simulating Daily Patient Activities Thu, 20 Nov 2014 10:06:53 +0000 The wear behaviour of total knee arthroplasty (TKA) is dominated by two wear mechanisms: the abrasive wear and the delamination of the gliding components, where the second is strongly linked to aging processes and stress concentration in the material. The addition of vitamin E to the bulk material is a potential way to reduce the aging processes. This study evaluates the wear behaviour and delamination susceptibility of the gliding components of a vitamin E blended, ultra-high molecular weight polyethylene (UHMWPE) cruciate retaining (CR) total knee arthroplasty. Daily activities such as level walking, ascending and descending stairs, bending of the knee, and sitting and rising from a chair were simulated with a data set received from an instrumented knee prosthesis. After 5 million test cycles no structural failure of the gliding components was observed. The wear rate was with  mg/million cycles falling within the limit of previous reports for established wear test methods. Jens Schwiesau, Bernhard Fritz, Ines Kutzner, Georg Bergmann, and Thomas M. Grupp Copyright © 2014 Jens Schwiesau et al. All rights reserved. Differences in Anatomy and Kinematics in Asian and Caucasian TKA Patients: Influence on Implant Positioning and Subsequent Loading Conditions in Mobile Bearing Knees Thu, 20 Nov 2014 09:58:28 +0000 The objective of our study was to determine the mechanical stress conditions under tibiofemoral loading with an overlay of knee kinematics in deep flexion on two different mobile bearing designs in comparison to in vivo failure modes. This study investigates the seldom but severe complication of fatigue failure of polyethylene components at mobile bearing total knee arthroplasty designs. Assuming a combination of a floor-based lifestyle and tibial malrotation as a possible reason for a higher failure rate in Asian countries we developed a simplified finite element model considering a tibiofemoral roll-back angle of 22° and the range of rotational motion of a clinically established floating platform design (e.motion FP) at a knee flexion angle of 120° in order to compare our results to failure modes found in retrieved implants. Compared to the failure mode observed in the clinical retrievals the locations of the occurring stress maxima as well as the tensile stress distribution show analogies. From our observations, we conclude that the newly introduced finite element model with an overlay of deep knee flexion (lateral roll-back) and considerable internally rotated tibia implant positioning is an appropriate analysis for knee design optimizations and a suitable method to predict clinical failure modes. Allan Maas, Tae Kyun Kim, Rolf K. Miehlke, Thomas Hagen, and Thomas M. Grupp Copyright © 2014 Allan Maas et al. All rights reserved. Influence of Orthotropy on Biomechanics of Peri-Implant Bone in Complete Mandible Model with Full Dentition Mon, 03 Nov 2014 14:01:07 +0000 Objective. The study was to investigate the impact of orthotropic material on the biomechanics of dental implant, based on a detailed mandible with high geometric and mechanical similarity. Materials and Methods. Multiple data sources were used to elaborate detailed biological structures and implant CAD models. In addition, an extended orthotropic material assignment methodology based on harmonic fields was used to handle the alveolar ridge region to generate compatible orthotropic fields. The influence of orthotropic material was compared with the commonly used isotropic model and simplified orthotropic model. Results. The simulation results showed that the values of stress and strain on the implant-bone interface almost increased in the orthotropic model compared to the isotropic case, especially for the cancellous bone. However, the local stress concentration was more obvious in the isotropic case compared to that in orthotropic case. The simple orthotropic model revealed irregular stress and strain distribution, compared to the isotropic model and the real orthotropic model. The influence of orthotropy was little on the implant, periodontal ligament, tooth enamel, and dentin. Conclusion. The orthotropic material has significant effect on stress and strain of implant-bone interface in the mandible, compared with the isotropic simulation. Real orthotropic mechanical properties of mandible should be emphasized in biomechanical studies of dental implants. Xi Ding, Sheng-Hui Liao, Xing-Hao Zhu, and Hui-Ming Wang Copyright © 2014 Xi Ding et al. All rights reserved. Elastin-Coated Biodegradable Photopolymer Scaffolds for Tissue Engineering Applications Thu, 23 Oct 2014 12:45:58 +0000 One of the main open issues in modern vascular surgery is the nonbiodegradability of implants used for stent interventions, which can lead to small caliber-related thrombosis and neointimal hyperplasia. Some new, resorbable polymeric materials have been proposed to substitute traditional stainless-steel stents, but so far they were affected by poor mechanical properties and low biocompatibility. In this respect, a new material, polypropylene fumarate (PPF), may be considered as a promising candidate to implement the development of next generation stents, due to its complete biodegradability, and excellent mechanical properties and the ease to be precisely patterned. Besides all these benefits, PPF has not been tested yet for vascular prosthesis, mainly because it proved to be almost inert, while the ability to elicit a specific biological function would be of paramount importance in such critical surgery applications. Here, we propose a biomimetic functionalization process, aimed at obtaining specific bioactivation and thus improved cell-polymer interaction. Porous PPF-based scaffolds produced by deep-UV photocuring were coated by elastin and the functionalized scaffolds were extensively characterized, revealing a stable bound between the protein and the polymer surface. Both 3T3 and HUVEC cell lines were used for in vitro tests displaying an enhancement of cells adhesion and proliferation on the functionalized scaffolds. Rossella Barenghi, Szabolcs Beke, Ilaria Romano, Paola Gavazzo, Balázs Farkas, Massimo Vassalli, Fernando Brandi, and Silvia Scaglione Copyright © 2014 Rossella Barenghi et al. All rights reserved. Surface Modifications of Dental Ceramic Implants with Different Glass Solder Matrices: In Vitro Analyses with Human Primary Osteoblasts and Epithelial Cells Sun, 14 Sep 2014 00:00:00 +0000 Ceramic materials show excellent esthetic behavior, along with an absence of hypersensitivity, making them a possible alternative implant material in dental surgery. However, their surface properties enable only limited osseointegration compared to titanium implants. Within this study, a novel surface coating technique for enhanced osseointegration was investigated biologically and mechanically. Specimens of tetragonal zirconia polycrystal (TZP) and aluminum toughened zirconia (ATZ) were modified with glass solder matrices in two configurations which mainly consisted of SiO2, Al2O3, K2O, and Na2O. The influence on human osteoblastic and epithelial cell viability was examined by means of a WST-1 assay as well as live/dead staining. A C1CP-ELISA was carried out to verify procollagen type I production. Uncoated/sandblasted ceramic specimens and sandblasted titanium surfaces were investigated as a reference. Furthermore, mechanical investigations of bilaterally coated pellets were conducted with respect to surface roughness and adhesive strength of the different coatings. These tests could demonstrate a mechanically stable implant coating with glass solder matrices. The coated ceramic specimens show enhanced osteoblastic and partly epithelial viability and matrix production compared to the titanium control. Hence, the new glass solder matrix coating could improve bone cell growth as a prerequisite for enhanced osseointegration of ceramic implants. Jana Markhoff, Enrico Mick, Aurica Mitrovic, Juliane Pasold, Katharina Wegner, and Rainer Bader Copyright © 2014 Jana Markhoff et al. All rights reserved. Can Pin-on-Disk Testing Be Used to Assess the Wear Performance of Retrieved UHMWPE Components for Total Joint Arthroplasty? Thu, 11 Sep 2014 08:19:13 +0000 The objective of this study was to assess the suitability of using multidirectional pin-on-disk (POD) testing to characterize wear behavior of retrieved ultrahigh molecular weight polyethylene (UHMWPE). The POD wear behavior of 25 UHMWPE components, retrieved after 10 years in vivo, was compared with 25 that were shelf aged for 10–15 years in their original packaging. Components were gamma sterilized (25–40 kGy) in an air or reduced oxygen (inert) package. 9 mm diameter pins were fabricated from each component and evaluated against CoCr disks using a super-CTPOD with 100 stations under physiologically relevant, multidirectional loading conditions. Bovine serum (20 g/L protein concentration) was used as lubricant. Volumetric wear rates were found to vary based on the aging environment, as well as sterilization environment. Volumetric wear rates were the lowest for the pins in the gamma inert, shelf aged cohort. These results support the utility of using modern, multidirectional POD testing with a physiologic lubricant as a novel method for evaluating wear properties of retrieved UHMWPE components. The data also supported the hypothesis that wear rates of gamma-inert liners were lower than gamma-air liners for both retrieved and shelf aging conditions. However, this difference was not statistically significant for the retrieved condition. Steven M. Kurtz, Daniel W. MacDonald, Sevi Kocagöz, Mariya Tohfafarosh, and Doruk Baykal Copyright © 2014 Steven M. Kurtz et al. All rights reserved. Effects of Soft Denture Liners on L929 Fibroblasts, HaCaT Keratinocytes, and RAW 264.7 Macrophages Thu, 11 Sep 2014 06:30:56 +0000 The effects of six soft liners (Ufi Gel P (UG), Sofreliner S (SR), Durabase Soft (D), Trusoft (T), Coe Comfort (CC), and Softone (ST)) on L929, HaCat, and RAW 264.7 cells were investigated. Eluates (24 and 48 h) from the materials were applied on the cells and the viability, type of cell death, and morphology were evaluated. Cells were also seeded on the specimens’ surfaces (direct contact) and incubated (24 or 48 h), and viability was analyzed. Controls were cells in culture medium without eluates or specimens. For cell viability, no significant differences were found among materials or between extraction periods, and the liners were noncytotoxic or slightly cytotoxic. Morphology of RAW 264.7 cells was altered by the 24 h eluates from CC and D and the 48 h eluates from SR, CC, and D. The 24 and 48 h eluates from all materials (except T) increased the percentages of L929 necrotic cells. For direct contact tests, the lowest cytotoxicity was observed for UG and SR. Although eluates did not reduce viability, morphology alterations and increase in necrosis were seen. Moreover, in the direct contact, effects on viability were more pronounced, particularly for D, T, CC and ST. Thus, the use of UG and SR might reduce the risk of adverse effects. Carolina de Andrade Lima Chaves, Carlos Alberto de Souza Costa, Carlos Eduardo Vergani, Pedro Paulo Chaves de Souza, and Ana Lucia Machado Copyright © 2014 Carolina de Andrade Lima Chaves et al. All rights reserved. On the Feasibility of Utilizing Allogeneic Bone Blocks for Atrophic Maxillary Augmentation Thu, 11 Sep 2014 00:00:00 +0000 Purpose. This systematic review was aimed at assessing the feasibility by means of survival rate, histologic analysis, and causes of failure of allogeneic block grafts for augmenting the atrophic maxilla. Material and Methods. A literature search was conducted by one reviewer in several databases. Articles were included in this systematic review if they were human clinical trials in which outcomes of allogeneic bone block grafts were studied by means of survival rate. In addition other factors were extracted in order to assess their influence upon graft failure. Results. Fifteen articles fulfilled the inclusion criteria and subsequently were analyzed in this systematic review. A total of 361 block grafts could be followed 4 to 9 months after the surgery, of which 9 (2.4%) failed within 1 month to 2 months after the surgery. Additionally, a weighed mean 4.79 mm (95% CI: 4.51–5.08) horizontal bone gain was computed from 119 grafted sites in 5 studies. Regarding implant cumulative survival rate, the weighed mean was 96.9% (95% CI: 92.8–98.7%), computed from 228 implants over a mean follow-up period of 23.9 months. Histologic analysis showed that allogeneic block grafts behave differently in the early stages of healing when compared to autogenous block grafts. Conclusion. Atrophied maxillary reconstruction with allogeneic bone block grafts represents a reliable option as shown by low block graft failure rate, minimal resorption, and high implant survival rate. Alberto Monje, Michael A. Pikos, Hsun-Liang Chan, Fernando Suarez, Jordi Gargallo-Albiol, Federico Hernández-Alfaro, Pablo Galindo-Moreno, and Hom-Lay Wang Copyright © 2014 Alberto Monje et al. All rights reserved. Wear Behavior of an Unstable Knee: Stabilization via Implant Design? Tue, 09 Sep 2014 11:23:20 +0000 Background. Wear-related failures and instabilities are frequent failure mechanisms of total knee replacements. High-conforming designs may provide additional stability for the joint. This study analyzes the effects of a ligamentous insufficiency on the stability and the wear behavior of a high-conforming knee design. Methods. Two simulator wear tests were performed on a high-conforming total knee replacement design. In the first, a ligamentous-stable knee replacement with a sacrificed anterior cruciate ligament was simulated. In the second, a ligamentous-unstable knee with additionally insufficient posterior cruciate ligament and medial collateral ligament was simulated. Wear was determined gravimetrically and wear particles were analyzed. Implant kinematics was recorded during simulation. Results. Significantly higher wear rates () were observed for the unstable knee ( mg/106 cycles) compared to the stable knee ( mg/106 cycles). A higher number of wear particles with only small differences in wear particle characteristics were observed. Under unstable knee conditions, kinematics increased significantly for translations and rotations (). This increase was mainly attributed to higher tibial posterior translation and internal rotations. Conclusion. Higher kinematics under unstable test conditions is a result of insufficient stabilization via implant design. Due to the higher kinematics, increased wear was observed in this study. Jörn Reinders, Robert Sonntag, and Jan Philippe Kretzer Copyright © 2014 Jörn Reinders et al. All rights reserved. Periodontal Responses to Augmented Corticotomy with Collagen Membrane Application during Orthodontic Buccal Tipping in Dogs Tue, 09 Sep 2014 00:00:00 +0000 This prospective randomized split-mouth study was performed to examine the effects of absorbable collagen membrane (ACM) application in augmented corticotomy using deproteinized bovine bone mineral (DBBM), during orthodontic buccal tipping movement in the dog. After buccal circumscribing corticotomy and DBBM grafting into the decorticated area, flaps were repositioned and sutured on control sides. ACM was overlaid and secured with membrane tacks, on test sides only, and the flaps were repositioned and sutured. Closed coil springs were used to apply 200 g orthodontic force in the buccolingual direction on the second and third premolars, immediately after primary flap closure. The buccal tipping angles were ° and ° on the control and test sides, respectively. A mean of % of the buccal bone wall was replaced by new bone on the control side, and on the test side % was replaced. ACM application promoted an even bone surface. In conclusion, ACM application in augmented corticotomy using DBBM might stimulate periodontal tissue reestablishment, which is useful for rapid orthodontic treatment or guided bone regeneration. In particular, ACM could control the formation of mesenchymal matrix, facilitating an even bone surface. Dong-Yeol Lee, Hyo-Won Ahn, Yeek Herr, Young-Hyuk Kwon, Seong-Hun Kim, and Eun-Cheol Kim Copyright © 2014 Dong-Yeol Lee et al. All rights reserved. Clinical Evaluation of the Regenerative Potential of EMD and NanoHA in Periodontal Infrabony Defects: A 2-Year Follow-Up Mon, 08 Sep 2014 08:47:51 +0000 Introduction. The aim of this retrospective study was to compare the clinical efficacy of four different surgical techniques in promoting periodontal regeneration in patients with infrabony defects: open flap debridement, application of enamel matrix derivatives (EMD), nanohydroxyapatite (nanoHA) application, and combined nanoHA and EMD application. Probing attachment level (PAL), pocket depth (PD), and position of gingival margin at completion of therapy (REC) were measured. Materials and Methods. Data were collected from 64 healthy patients (34 women and 30 men, mean age 37,7 years). Clinical indices were measured by a calibrated examiner at baseline and at 12, 18, and 24 months. The values obtained for each treatment were compared using nonparametric tests. Results. All treatments resulted in a tendency toward PD reduction over time, with improvements in REC and PAL. The differences in PD, REC, and PAL values at baseline compared with values after 12, 18, and 24 months were statistically significant for all treatments. Statistically significant differences in PAL and PD were detected between nanoHA and nanoHA + EMD at 12, 18, and 24 months. Conclusion. In this study, EMD and nanoHA used together in patients with infrabony periodontal lesions had better clinical efficacy than nanoHA alone, EMD alone, or open flap debridement. Andrea Pilloni, Matteo Saccucci, Gabriele Di Carlo, Blerina Zeza, Marco Ambrosca, Michele Paolantonio, Gilberto Sammartino, Claudio Mongardini, and Antonella Polimeni Copyright © 2014 Andrea Pilloni et al. All rights reserved. Serum Metal Ion Concentrations in Paediatric Patients following Total Knee Arthroplasty Using Megaprostheses Mon, 08 Sep 2014 06:38:39 +0000 The purpose of this study was to determine the concentrations of cobalt, chromium, and molybdenum in the serum of paediatric tumour patients after fixed hinge total knee arthroplasty. Further, these metal ion levels were compared with serum metal ion levels of patients with other orthopaedic devices such as hip and knee prostheses with metal-on-metal or metal-on-polyethylene articulation to find differences between anatomical locations, abrasion characteristics, and bearing surfaces. After an average follow-up of 108 months (range: 67 to 163) of 11 paediatric patients with fixed hinge total knee arthroplasty, the mean concentrations for Co and Cr were significantly increased while Mo was within the limits compared to the upper values from the reference laboratory. Furthermore, these serum concentrations were significantly higher compared to patients with a standard rotating hinge device ( and ) and preoperative controls . On the other hand, the serum levels of patients following MoM THA or rotating hinge arthroplasty using megaprostheses were higher. Therefore, periodic long-term follow-ups are recommended due to the rising concerns about systemic metal ion exposure in the literature. Upon the occurrence of adverse reactions to metal debris the revision of the fixed hinge implant should be considered. Jörg Friesenbichler, Patrick Sadoghi, Werner Maurer-Ertl, Joanna Szkandera, Mathias Glehr, Kathrin Ogris, Matthias Wolf, Christian Weger, and Andreas Leithner Copyright © 2014 Jörg Friesenbichler et al. All rights reserved. Dynamic Contact Angle Analysis of Protein Adsorption on Polysaccharide Multilayer’s Films for Biomaterial Reendothelialization Mon, 08 Sep 2014 00:00:00 +0000 Atherosclerosis is a major cardiovascular disease. One of the side effects is restenosis. The aim of this work was to study the coating of stents by dextran derivates based polyelectrolyte’s multilayer (PEM) films in order to increase endothelialization of injured arterial wall after stent implantation. Films were composed with diethylaminoethyl dextran (DEAE) as polycation and dextran sulphate (DS) as polyanion. One film was composed with 4 bilayers of (DEAE-DS)4 and was labeled D−. The other film was the same as D− but with an added terminal layer of DEAE polycation: (DEAE-DS)4-DEAE (labeled D+). The dynamic adsorption/desorption of proteins on the films were characterized by dynamic contact angle (DCA) and atomic force microscopy (AFM). Human endothelial cell (HUVEC) adhesion and proliferation were quantified and correlated to protein adsorption analyzed by DCA for fibronectin, vitronectin, and bovine serum albumin (BSA). Our results showed that the endothelial cell response was optimal for films composed of DS as external layer. Fibronectin was found to be the only protein to exhibit a reversible change in conformation after desorption test. This behavior was only observed for (DEAE-DS)4 films. (DEAE-DS)4 films could enhance HUVEC proliferation in agreement with fibronectin ability to easily change from conformation. Safiya Benni, Thierry Avramoglou, Hanna Hlawaty, and Laurence Mora Copyright © 2014 Safiya Benni et al. All rights reserved. In Vitro Bioactivity and Antimicrobial Tuning of Bioactive Glass Nanoparticles Added with Neem (Azadirachta indica) Leaf Powder Sun, 07 Sep 2014 07:45:09 +0000 Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique. In vitro bioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity against Staphylococcus aureus and Escherichia coli and less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications. M. Prabhu, S. Ruby Priscilla, K. Kavitha, P. Manivasakan, V. Rajendran, and P. Kulandaivelu Copyright © 2014 M. Prabhu et al. All rights reserved. Dynamics of Alloplastic Bone Grafts on an Early Stage of Corticotomy-Facilitated Orthodontic Tooth Movement in Beagle Dogs Wed, 03 Sep 2014 00:00:00 +0000 Alveolar augmented corticotomy is effective in accelerating orthodontic tooth movement, but the effect only lasts for a relatively short time. Therefore, the purpose of this study was to investigate the underlying biology of the immediate periodontal response to orthodontic tooth movement after a corticotomy with alloplastic bone grafts. The results demonstrated that measurable tooth movement began as early as 3 days after the intervention in beagle dogs. Based on the results and histological findings, augmented corticotomy-facilitated orthodontic tooth movement might enhance the condition of the periodontal tissue and the stability of the outcomes of orthodontic treatment. Hyung-Joo Choi, Dong-Yeol Lee, and Tae-Woo Kim Copyright © 2014 Hyung-Joo Choi et al. All rights reserved. Systemic Treatment with Strontium Ranelate Accelerates the Filling of a Bone Defect and Improves the Material Level Properties of the Healing Bone Thu, 28 Aug 2014 00:00:00 +0000 Rapid bone defect filling with normal bone is a challenge in orthopaedics and dentistry. Strontium ranelate (SrRan) has been shown to in vitro decrease bone resorption and increase bone formation, and represents a potential agent with the capacity to accelerate bone defect filling. In this study, bone tibial defects of 2.5 mm in diameter were created in 6-month-old female rats orally fed SrRan (625 mg/kg/d; 5/7 days) or vehicle for 4, 8, or 12 weeks (10 rats per group per time point) from the time of surgery. Tibias were removed. Micro-architecture was determined by micro-computed tomography (µCT) and material level properties by nanoindentation analysis. µCT analysis showed that SrRan administration significantly improved microarchitecture of trabecular bone growing into the defect after 8 and 12 weeks of treatment compared to vehicle. SrRan treatment also accelerated the growth of cortical bone over the defect, but with different kinetics compared to trabecular bone, as the effects were already significant after 4 weeks. Nanoindentation analysis demonstrated that SrRan treatment significantly increased material level properties of both trabecular bone and cortical bone filling the defect compared to vehicle. SrRan accelerates the filling of bone defect by improving cortical and trabecular bone microarchitecture both quantitatively and qualitatively. Giovanna Zacchetti, Romain Dayer, René Rizzoli, and Patrick Ammann Copyright © 2014 Giovanna Zacchetti et al. All rights reserved. Recent Trends of Polymer Mediated Liposomal Gene Delivery System Wed, 27 Aug 2014 12:12:01 +0000 Advancement in the gene delivery system have resulted in clinical successes in gene therapy for patients with several genetic diseases, such as immunodeficiency diseases, X-linked adrenoleukodystrophy (X-ALD) blindness, thalassemia, and many more. Among various delivery systems, liposomal mediated gene delivery route is offering great promises for gene therapy. This review is an attempt to depict a portrait about the polymer based liposomal gene delivery systems and their future applications. Herein, we have discussed in detail the characteristics of liposome, importance of polymer for liposome formulation, gene delivery, and future direction of liposome based gene delivery as a whole. Shyamal Kumar Kundu, Ashish Ranjan Sharma, Sang-Soo Lee, Garima Sharma, C. George Priya Doss, Shin Yagihara, Do-Young Kim, Ju-Suk Nam, and Chiranjib Chakraborty Copyright © 2014 Shyamal Kumar Kundu et al. All rights reserved. TolC Promotes ExPEC Biofilm Formation and Curli Production in Response to Medium Osmolarity Wed, 27 Aug 2014 09:19:58 +0000 While a high osmolarity medium activates Cpx signaling and causes CpxR to repress csgD expression, and efflux protein TolC protein plays an important role in biofilm formation in Escherichia coli, whether TolC also responds to an osmolarity change to regulate biofilm formation in extraintestinal pathogenic E. coli (ExPEC) remains unknown. In this study, we constructed ΔtolC mutant and complement ExPEC strains to investigate the role of TolC in the retention of biofilm formation and curli production capability under different osmotic conditions. The ΔtolC mutant showed significantly decreased biofilm formation and lost the ability to produce curli fimbriae compared to its parent ExPEC strain PPECC42 when cultured in M9 medium or 1/2 M9 medium of increased osmolarity with NaCl or sucrose at 28°C. However, biofilm formation and curli production levels were restored to wild-type levels in the ΔtolC mutant in 1/2 M9 medium. We propose for the first time that TolC protein is able to form biofilm even under high osmotic stress. Our findings reveal an interplay between the role of TolC in ExPEC biofilm formation and the osmolarity of the surrounding environment, thus providing guidance for the development of a treatment for ExPEC biofilm formation. Bo Hou, Xian-Rong Meng, Li-Yuan Zhang, Chen Tan, Hui Jin, Rui Zhou, Jian-Feng Gao, Bin Wu, Zi-Li Li, Mei Liu, Huan-Chun Chen, Ding-Ren Bi, and Shao-Wen Li Copyright © 2014 Bo Hou et al. All rights reserved. Adsorption of the Inflammatory Mediator High-Mobility Group Box 1 by Polymers with Different Charge and Porosity Wed, 27 Aug 2014 09:06:54 +0000 High-mobility group box 1 protein (HMGB1) is a conserved protein with a variety of biological functions inside as well as outside the cell. When released by activated immune cells, it acts as a proinflammatory cytokine. Its delayed release has sparked the interest in HMGB1 as a potential therapeutic target. Here, we studied the adsorption of HMGB1 to anionic methacrylate-based polymers as well as to neutral polystyrene-divinylbenzene copolymers. Both groups of adsorbents exhibited efficient binding of recombinant HMGB1 and of HMGB1 derived from lipopolysaccharide-stimulated peripheral blood mononuclear cells. The adsorption characteristics depended on particle size, porosity, accessibility of the pores, and charge of the polymers. In addition to these physicochemical parameters of the adsorbents, modifications of the molecule itself (e.g., acetylation, phosphorylation, and oxidation), interaction with other plasma proteins or anticoagulants (e.g., heparin), or association with extracellular microvesicles may influence the binding of HMGB1 to adsorbents and lead to preferential depletion of HMGB1 subsets with different biological activity. Carla Tripisciano, Tanja Eichhorn, Stephan Harm, and Viktoria Weber Copyright © 2014 Carla Tripisciano et al. All rights reserved. Tooth Movement out of the Bony Wall Using Augmented Corticotomy with Nonautogenous Graft Materials for Bone Regeneration Wed, 27 Aug 2014 00:00:00 +0000 This prospective randomized split-mouth study was performed to compare the effects of augmented corticotomy with those of different nonautogenous bone graft materials combined with orthodontic tooth movement in dogs. Decortication was performed on the buccal bone surface of 6 male beagle dogs that were randomly assigned to receive grafts of deproteinized bovine bone mineral, irradiated cortical bone, or synthetic bone. Immediate orthodontic force was applied to the second and third premolars for buccal tipping for 6 weeks. The pocket depth and width of keratinized tissue (WKT) were measured. Histologic and histomorphometric analyses were performed. The probing depth, WKT, and ratio of the area of new bone to that of total bone on the buccal side were not significantly different between groups. All groups had considerable new bone formation on the pressure side. New bone formation on the buccal side and buccal plate formation in the coronal direction along the root surfaces were induced by the bone-derived and PDL-derived mesenchymal matrix, respectively. The angular change between groups was significantly different (P < 0.001). Augmented corticotomy using nonautogenous graft materials facilitated tooth movement without fenestrations and accelerated new bone formation on the pressure side. Kye-Bok Lee, Dong-Yeol Lee, Hyo-Won Ahn, Seong-Hun Kim, Eun-Cheol Kim, and Igor Roitman Copyright © 2014 Kye-Bok Lee et al. All rights reserved. Scaffolds Reinforced by Fibers or Tubes for Tissue Repair Mon, 18 Aug 2014 05:14:09 +0000 Xiaoming Li, Nicholas Dunne, Xiaowei Li, and Katerina E. Aifantis Copyright © 2014 Xiaoming Li et al. All rights reserved. Adhesion and Proliferation of Human Periodontal Ligament Cells on Poly(2-methoxyethyl acrylate) Wed, 06 Aug 2014 12:02:45 +0000 Human periodontal ligament (PDL) cells obtained from extracted teeth are a potential cell source for tissue engineering. We previously reported that poly(2-methoxyethyl acrylate) (PMEA) is highly biocompatible with human blood cells. In this study, we investigated the adhesion, morphology, and proliferation of PDL cells on PMEA and other types of polymers to design an appropriate scaffold for tissue engineering. PDL cells adhered and proliferated on all investigated polymer surfaces except for poly(2-hydroxyethyl methacrylate) and poly[(2-methacryloyloxyethyl phosphorylcholine)-co-(n-butyl methacrylate)]. The initial adhesion of the PDL cells on PMEA was comparable with that on polyethylene terephthalate (PET). In addition, the PDL cells on PMEA spread well and exhibited proliferation behavior similar to that observed on PET. In contrast, platelets hardly adhered to PMEA. PMEA is therefore expected to be an excellent scaffold for tissue engineering and for culturing tissue-derived cells in a blood-rich environment. Erika Kitakami, Makiko Aoki, Chikako Sato, Hiroshi Ishihata, and Masaru Tanaka Copyright © 2014 Erika Kitakami et al. All rights reserved. Proteomics and Metabolomics for In Situ Monitoring of Wound Healing Mon, 04 Aug 2014 09:59:46 +0000 Wound healing of soft tissue and bone defects is a complex process in which cellular differentiation and adaption are regulated by internal and external factors, among them are many different proteins. In contrast to insights into the significance of various single proteins based on model systems, the knowledge about the processes at the actual site of wound healing is still limited. This is caused by a general lack of methods that allow sampling of extracellular factors, metabolites, and proteins in situ. Sampling of wound fluids in combination with proteomics and metabolomics is one of the promising approaches to gain comprehensive and time resolved data on effector molecules. Here, we describe an approach to sample metabolites by microdialysis and to extract proteins simultaneously by adsorption. With this approach it is possible (i) to collect, enrich, and purify proteins for a comprehensive proteome analysis; (ii) to detect more than 600 proteins in different defects including more than 100 secreted proteins, of which many proteins have previously been demonstrated to have diagnostic or predictive power for the wound healing state; and (iii) to combine continuous sampling of cytokines and metabolites and discontinuous sampling of larger proteins to gain complementary information of the same defect. Stefan Kalkhof, Yvonne Förster, Johannes Schmidt, Matthias C. Schulz, Sven Baumann, Anne Weißflog, Wenling Gao, Ute Hempel, Uwe Eckelt, Stefan Rammelt, and Martin von Bergen Copyright © 2014 Stefan Kalkhof et al. All rights reserved. Mercury and Other Biomedical Waste Management Practices among Dental Practitioners in India Mon, 04 Aug 2014 07:16:31 +0000 Objectives. The objective of the study was to assess the awareness and performance towards dental waste including mercury management policy and practices among the dental practitioners in North India. Materials and Methods. An epidemiologic survey was conducted among 200 private dental practitioners. The survey form was composed of 29 self-administered questions frame based on knowledge, attitude, and those regarding the practices of dentists in relation to dental health-care waste management. The resulting data were coded and a statistical analysis was done. Results and Discussion. About 63.7% of the dentists were not aware of the different categories of biomedical waste generated in their clinics. Only 31.9% of the dentists correctly said that outdated and contaminated drugs come under cytotoxic waste. 46.2% said they break the needle and dispose of it and only 21.9% use needle burner to destroy it. 45.0% of the dentists dispose of the developer and fixer solutions by letting them into the sewer, 49.4% of them dilute the solutions and let them into sewer and only 5.6% return them to the supplier. About 40.6% of the dentists dispose of excess silver amalgam by throwing it into common bin. Conclusion. It was concluded that not all dentists were aware of the risks they were exposed to and only half of them observe infection control practices. Raghuwar D. Singh, Sunit K. Jurel, Shuchi Tripathi, Kaushal K. Agrawal, and Reema Kumari Copyright © 2014 Raghuwar D. Singh et al. All rights reserved. Characterization of Morphology and Composition of Inorganic Fillers in Dental Alginates Thu, 24 Jul 2014 11:38:31 +0000 Energy dispersive X-ray spectroscopy microanalysis (EDX), scanning electron microscopy (SEM), and Archimedes’ Principle were used to determine the characteristics of inorganic filler particles in five dental alginates, including Cavex ColorChange (C), Hydrogum 5 (H5), Hydrogum (H), Orthoprint (O), and Jeltrate Plus (JP). The different alginate powders (0.5 mg) were fixed on plastic stubs and sputter coated with carbon for EDX analysis, then coated with gold, and observed using SEM. Volume fractions were determined by weighing a sample of each material in water before and after calcining at 450°C for 3 h. The alginate materials were mainly composed of silicon (Si) by weight (C—81.59%, H—79.89%, O—78.87%, H5—77.95%, JP—66.88%, wt). The filler fractions in volume (vt) were as follows: H5—84.85%, JP—74.76%, H—70.03%, O—68.31%, and C—56.10%. The tested materials demonstrated important differences in the inorganic elemental composition, filler fraction, and particle morphology. Ricardo Danil Guiraldo, Sandrine Bittencourt Berger, Rafael Leonardo Xediek Consani, Simonides Consani, Rodrigo Varella de Carvalho, Murilo Baena Lopes, Luciana Lira Meneghel, Fabiane Borges da Silva, and Mário Alexandre Coelho Sinhoreti Copyright © 2014 Ricardo Danil Guiraldo et al. All rights reserved. Cationic Polyene Phospholipids as DNA Carriers for Ocular Gene Therapy Thu, 24 Jul 2014 08:54:19 +0000 Recent success in the treatment of congenital blindness demonstrates the potential of ocular gene therapy as a therapeutic approach. The eye is a good target due to its small size, minimal diffusion of therapeutic agent to the systemic circulation, and low immune and inflammatory responses. Currently, most approaches are based on viral vectors, but efforts continue towards the synthesis and evaluation of new nonviral carriers to improve nucleic acid delivery. Our objective is to evaluate the efficiency of novel cationic retinoic and carotenoic glycol phospholipids, designated C20-18, C20-20, and C30-20, to deliver DNA to human retinal pigmented epithelium (RPE) cells. Liposomes were produced by solvent evaporation of ethanolic mixtures of the polyene compounds and coformulated with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) or cholesterol (Chol). Addition of DNA to the liposomes formed lipoplexes, which were characterized for binding, size, biocompatibility, and transgene efficiency. Lipoplex formulations of suitable size and biocompatibility were assayed for DNA delivery, both qualitatively and quantitatively, using RPE cells and a GFP-encoding plasmid. The retinoic lipoplex formulation with DOPE revealed a transfection efficiency comparable to the known lipid references 3β-[N-(N′,N′-dimethylaminoethane)-carbamoyl]-cholesterol (DC-Chol) and 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (EPC) and GeneJuice. The results demonstrate that cationic polyene phospholipids have potential as DNA carriers for ocular gene therapy. Susana Machado, Sofia Calado, Diogo Bitoque, Ana Vanessa Oliveira, Christer L. Øpstad, Muhammad Zeeshan, Hans-Richard Sliwka, Vassilia Partali, Michael D. Pungente, and Gabriela A. Silva Copyright © 2014 Susana Machado et al. All rights reserved. Immobilization of Murine Anti-BMP-2 Monoclonal Antibody on Various Biomaterials for Bone Tissue Engineering Wed, 23 Jul 2014 11:09:49 +0000 Biomaterials are widely used as scaffolds for tissue engineering. We have developed a strategy for bone tissue engineering that entails application of immobilized anti-BMP-2 monoclonal antibodies (mAbs) to capture endogenous BMPs in vivo and promote antibody-mediated osseous regeneration (AMOR). The purpose of the current study was to compare the efficacy of immobilization of a specific murine anti-BMP-2 mAb on three different types of biomaterials and to evaluate their suitability as scaffolds for AMOR. Anti-BMP-2 mAb or isotype control mAb was immobilized on titanium (Ti) microbeads, alginate hydrogel, and ACS. The treated biomaterials were surgically implanted in rat critical-sized calvarial defects. After 8 weeks, de novo bone formation was assessed using micro-CT and histomorphometric analyses. Results showed de novo bone regeneration with all three scaffolds with immobilized anti-BMP-2 mAb, but not isotype control mAb. Ti microbeads showed the highest volume of bone regeneration, followed by ACS. Alginate showed the lowest volume of bone. Localization of BMP-2, -4, and -7 antigens was detected on all 3 scaffolds with immobilized anti-BMP-2 mAb implanted in calvarial defects. Altogether, these data suggested a potential mechanism for bone regeneration through entrapment of endogenous BMP-2, -4, and -7 proteins leading to bone formation using different types of scaffolds via AMOR. Sahar Ansari, Marcelo O. Freire, Eun-Kyoung Pang, Alaa I. Abdelhamid, Mohammad Almohaimeed, and Homayoun H. Zadeh Copyright © 2014 Sahar Ansari et al. All rights reserved. Modified Titanium Implant as a Gateway to the Human Body: The Implant Mediated Drug Delivery System Tue, 22 Jul 2014 11:25:44 +0000 The aim of this study was to investigate the efficacy of a proposed new implant mediated drug delivery system (IMDDS) in rabbits. The drug delivery system is applied through a modified titanium implant that is configured to be implanted into bone. The implant is hollow and has multiple microholes that can continuously deliver therapeutic agents into the systematic body. To examine the efficacy and feasibility of the IMDDS, we investigated the pharmacokinetic behavior of dexamethasone in plasma after a single dose was delivered via the modified implant placed in the rabbit tibia. After measuring the plasma concentration, the areas under the curve showed that the IMDDS provided a sustained release for a relatively long period. The result suggests that the IMDDS can deliver a sustained release of certain drug components with a high bioavailability. Accordingly, the IMDDS may provide the basis for a novel approach to treating patients with chronic diseases. Young-Seok Park, Joo-Youn Cho, Shin-Jae Lee, and Chee Il Hwang Copyright © 2014 Young-Seok Park et al. All rights reserved. Gene Delivery Potential of Biofunctional Carbonate Apatite Nanoparticles in Lungs Mon, 21 Jul 2014 07:07:57 +0000 Existing nonviral gene delivery systems to lungs are inefficient and associated with dose limiting toxicity in mammalian cells. Therefore, carbonate apatite (CO3Ap) nanoparticles were examined as an alternative strategy for effective gene delivery to the lungs. This study aimed to (1) assess the gene delivery efficiency of CO3Ap in vitro and in mouse lungs, (2) evaluate the cytotoxicity effect of CO3Ap/pDNA in vitro, and (3) characterize the CO3Ap/pDNA complex formulations. A significantly high level of reporter gene expression was detected from the lung cell line transfected with CO3Ap/pDNA complex prepared in both serum and serum-free medium. Cytotoxicity analysis revealed that the percentage of the viable cells treated with CO3Ap to be almost similar to the untreated cells. Characterization analyses showed that the CO3Ap/pDNA complexes are in a nanometer range with aggregated spherical structures and tended to be more negatively charged. In the lung of mice, highest level of transgene expression was observed when CO3Ap (8 μL) was complexed with 40 μg of pDNA at day 1 after administration. Although massive reduction of gene expression was seen beyond day 1 post administration, the level of expression remained significant throughout the study period. Suleiman Yusuf Alhaji, Ezharul Houque Chowdhury, Rozita Rosli, Fatma Hassan, and Syahril Abdullah Copyright © 2014 Suleiman Yusuf Alhaji et al. All rights reserved. Effect of Glass Fiber Incorporation on Flexural Properties of Experimental Composites Thu, 17 Jul 2014 08:41:53 +0000 This study evaluated the effect of fiber addiction in flexural properties of 30 wt% silica filled BisGMA resin (FR) or unfilled Bis-GMA (UR). Ten groups were created () varying the resin (FR or UR) and quantity of glass fibers (wt%: 0, 10, 15, 20, and 30). Samples (10 × 2 × 1 mm) were submitted to flexural strength test following SEM examination. Data were analyzed by two-way ANOVA, Tukey, and Student -test (). Results for flexural strength (MPa) were FR-groups: 0% , 10% , 15% , 20% , 30% ; UR-groups: 0% , 10% , 15% , 20% , and 30% , and for flexural modulus (GPa) FR-groups: 0% , 10% , 15% , 20% , and 30% ; UR-groups: 0% , 10% , 15% , 20% , and 30% . Fiber addiction in BisGMA resin increases flexural properties, and the interaction between resin and fibers seems better in the absence of inorganic fillers increasing flexural properties. Rodrigo Borges Fonseca, Aline Silva Marques, Karina de Oliveira Bernades, Hugo Lemes Carlo, and Lucas Zago Naves Copyright © 2014 Rodrigo Borges Fonseca et al. All rights reserved. Next Generation Delivery System for Proteins and Genes of Therapeutic Purpose: Why and How? Tue, 15 Jul 2014 00:00:00 +0000 Proteins and genes of therapeutic interests in conjunction with different delivery systems are growing towards new heights. “Next generation delivery systems” may provide more efficient platform for delivery of proteins and genes. In the present review, snapshots about the benefits of proteins or gene therapy, general procedures for therapeutic protein or gene delivery system, and different next generation delivery system such as liposome, PEGylation, HESylation, and nanoparticle based delivery have been depicted with their detailed explanation. Ashish Ranjan Sharma, Shyamal Kumar Kundu, Ju-Suk Nam, Garima Sharma, C. George Priya Doss, Sang-Soo Lee, and Chiranjib Chakraborty Copyright © 2014 Ashish Ranjan Sharma et al. All rights reserved. Antidiabetic Activity of Acacia tortilis (Forsk.) Hayne ssp. raddiana Polysaccharide on Streptozotocin-Nicotinamide Induced Diabetic Rats Wed, 09 Jul 2014 11:03:35 +0000 The present study was designed to investigate the antidiabetic activity of aqueous extract of Acacia tortilis polysaccharide (AEATP) from gum exudates and its role in comorbidities associated with diabetes in STZ-nicotinamide induced diabetic rats. Male albino Wistar rats were divided into control, diabetic control, glimepiride treated (10 mg/kg), and diabetic rats treated with 250, 500, and 1000 mg/kg dose of AEATP groups and fasting blood glucose, glycated hemoglobin, total cholesterol, triglyceride, LDL, VLDL, HDL, SGOT, and SGPT levels were measured. STZ significantly increased fasting blood glucose level, glycated hemoglobin, total cholesterol, triglyceride, LDL, VLDL, SGOT, and SGPT levels, whereas HDL level was reduced as compared to control group. After 7 days of administration, 500 and 1000 mg/kg dose of AEATP showed significant reduction in fasting blood glucose level compared to diabetic control. AEATP has also reduced total cholesterol, triglyceride, LDL, VLDL, SGOT, and SGPT levels and improved HDL level as compared to diabetic control group. Our study is the first to report the normalization of fasting blood glucose level, lipid profile, and liver enzyme in AEATP treated diabetic rats. Thus, it can be concluded that AEATP may have potentials for the treatment of T2DM and its comorbidities. Pradeep Kumar Bhateja and Randhir Singh Copyright © 2014 Pradeep Kumar Bhateja and Randhir Singh. All rights reserved. Physicochemical Characteristics of Bone Substitutes Used in Oral Surgery in Comparison to Autogenous Bone Tue, 08 Jul 2014 08:17:17 +0000 Bone substitutes used in oral surgery include allografts, xenografts, and synthetic materials that are frequently used to compensate bone loss or to reinforce repaired bone, but little is currently known about their physicochemical characteristics. The aim of this study was to evaluate a number of physical and chemical properties in a variety of granulated mineral-based biomaterials used in dentistry and to compare them with those of autogenous bone. Autogenous bone and eight commercial biomaterials of human, bovine, and synthetic origins were studied by high-resolution X-ray diffraction, atomic absorption spectrometry, and laser diffraction to determine their chemical composition, calcium release concentration, crystallinity, and granulation size. The highest calcium release concentration was 24. 94 mg/g for Puros and the lowest one was 2.83 mg/g for Ingenios β-TCP compared to 20.15 mg/g for natural bone. The range of particles sizes, in terms of median size D50, varied between 1.32 μm for BioOss and 902.41 μm for OsteoSponge, compared to 282.1 μm for natural bone. All samples displayed a similar hexagonal shape as bone, except Ingenios β-TCP, Macrobone, and OsteoSponge, which showed rhomboid and triclinic shapes, respectively. Commercial bone substitutes significantly differ in terms of calcium concentration, particle size, and crystallinity, which may affect their in vivo performance. Antoine Berberi, Antoine Samarani, Nabih Nader, Ziad Noujeim, Maroun Dagher, Wasfi Kanj, Rita Mearawi, Ziad Salemeh, and Bassam Badran Copyright © 2014 Antoine Berberi et al. All rights reserved. Development of New Method for Simultaneous Analysis of Piracetam and Levetiracetam in Pharmaceuticals and Biological Fluids: Application in Stability Studies Tue, 08 Jul 2014 06:33:50 +0000 RP-HPLC ultraviolet detection simultaneous quantification of piracetam and levetiracetam has been developed and validated. The chromatography was obtained on a Nucleosil C18 column of , 10 m, dimension. The mobile phase was a (70 : 30 v/v) mixture of 0.1 g/L of triethylamine and acetonitrile. Smooth flow of mobile phase at 1 mL/min was set and 205 nm wavelength was selected. Results were evaluated through statistical parameters which qualify the method reproducibility and selectivity for the quantification of piracetam, levetiracetam, and their impurities hence proving stability-indicating properties. The proposed method is significantly important, permitting the separation of the main constituent piracetam from levetiracetam. Linear behavior was observed between 20 ng/mL and 10000 ng/mL for both drugs. The proposed method was checked in bulk drugs, dosage formulations, physiological condition, and clinical investigations and excellent outcome was witnessed. Farhan Ahmed Siddiqui, Nawab Sher, Nighat Shafi, Alisha Wafa Sial, Mansoor Ahmad, Mehjebeen, and Huma Naseem Copyright © 2014 Farhan Ahmed Siddiqui et al. All rights reserved. Influence of Thread Pitch, Helix Angle, and Compactness on Micromotion of Immediately Loaded Implants in Three Types of Bone Quality: A Three-Dimensional Finite Element Analysis Tue, 08 Jul 2014 00:00:00 +0000 This study investigated the influence of thread pitch, helix angle, and compactness on micromotion in immediately loaded implants in bone of varying density (D2, D3, and D4). Five models of the three-dimensional finite element (0.8 mm pitch, 1.6 mm pitch, 2.4 mm pitch, double-threaded, and triple-threaded implants) in three types of bone were created using Pro/E, Hypermesh, and ABAQUS software. The study had three groups: Group 1, different pitches (Pitch Group); Group 2, same compactness but different helix angles (Angle Group); and Group 3, same helix angle but different compactness (Compact Group). Implant micromotion was assessed as the comprehensive relative displacement. We found that vertical relative displacement was affected by thread pitch, helix angle, and compactness. Under vertical loading, displacement was positively correlated with thread pitch and helix angle but negatively with compactness. Under horizontal loading in D2, the influence of pitch, helix angle, and compactness on implant stability was limited; however, in D3 and D4, the influence of pitch, helix angle, and compactness on implant stability is increased. The additional evidence was provided that trabecular bone density has less effect on implant micromotion than cortical bone thickness. Bone type amplifies the influence of thread pattern on displacement. Pan Ma, Wei Xiong, Baosheng Tan, Wei Geng, Jiaqiang Liu, Weihong Li, and Dehua Li Copyright © 2014 Pan Ma et al. All rights reserved. Development and Characterization of Novel Porous 3D Alginate-Cockle Shell Powder Nanobiocomposite Bone Scaffold Mon, 07 Jul 2014 12:20:01 +0000 A novel porous three-dimensional bone scaffold was developed using a natural polymer (alginate/Alg) in combination with a naturally obtained biomineral (nano cockle shell powder/nCP) through lyophilization techniques. The scaffold was developed in varying composition mixture of Alg-nCP and characterized using various evaluation techniques as well as preliminary in vitro studies on MG63 human osteoblast cells. Morphological observations using SEM revealed variations in structures with the use of different Alg-nCP composition ratios. All the developed scaffolds showed a porous structure with pore sizes ideal for facilitating new bone growth; however, not all combination mixtures showed subsequent favorable characteristics to be used for biological applications. Scaffolds produced using the combination mixture of 40% Alg and 60% nCP produced significantly promising results in terms of mechanical strength, degradation rate, and increased cell proliferation rates making it potentially the optimum composition mixture of Alg-nCP with future application prospects. B. Hemabarathy Bharatham, Md. Zuki Abu Bakar, Enoch Kumar Perimal, Loqman Mohamed Yusof, and Muhajir Hamid Copyright © 2014 B. Hemabarathy Bharatham et al. All rights reserved. Biomaterials: Chitosan and Collagen for Regenerative Medicine Tue, 01 Jul 2014 08:47:24 +0000 Yoshihiko Hayashi, Mitsuo Yamauchi, Se-Kwon Kim, and Hideo Kusaoke Copyright © 2014 Yoshihiko Hayashi et al. All rights reserved. Initial Sliding Wear Kinetics of Two Types of Glass Ionomer Cement: A Tribological Study Sun, 29 Jun 2014 11:34:38 +0000 The aim of this work was to characterize the initial wear kinetics of two different types of glass ionomer cement used in dentistry (the conventional glass ionomer cement and the resin-modified glass ionomer cement) under sliding friction after 28-day storing in distilled water or Ringer’s solution. Sliding friction was applied through a pin-on-disk tribometer, in sphere-on-plane contact conditions, under 5 N normal load and 120 rotations per minute. The test lasted 7500 cycles and replicas were performed at 2500, 5000 and 7500 cycles. A profilometer was used to evaluate the wear volume. Data were analysed using Student’s -test at a significant level of 5%. There is no statistical significant difference between the results obtained for a given material with the maturation media (). However, for a given maturation medium, there are significant statistical differences between the data obtained for the two materials at each measurement (). The wear rates of both materials decrease continuously during the running-in period between 0 and 2500 cycles. After 2500 cycles, the wear rate becomes constant and equal for both materials. The resin matrix contained in the resin-modified glass ionomer cement weakens the tribological behaviour of this material. Cyril Villat, Pierre Ponthiaux, Nelly Pradelle-Plasse, Brigitte Grosgogeat, and Pierre Colon Copyright © 2014 Cyril Villat et al. All rights reserved. Biological Assessment of a Calcium Silicate Incorporated Hydroxyapatite-Gelatin Nanocomposite: A Comparison to Decellularized Bone Matrix Thu, 26 Jun 2014 09:22:06 +0000 Our laboratory utilized biomimicry to develop a synthetic bone scaffold based on hydroxyapatite-gelatin-calcium silicate (HGCS). Here, we evaluated the potential of HGCS scaffold in bone formation in vivo using the rat calvarial critical-sized defect (CSD). Twelve Sprague-Dawley rats were randomized to four groups: control (defect only), decellularized bone matrix (DECBM), and HGCS with and without multipotent adult progenitor cells (MAPCs). DECBM was prepared by removing all the cells using SDS and NH4OH. After 12 weeks, the CSD specimens were harvested to evaluate radiographical, histological, and histomorphometrical outcomes. The in vitro osteogenic effects of the materials were studied by focal adhesion, MTS, and alizarin red. Micro-CT analysis indicated that the DECBM and the HGCS scaffold groups developed greater radiopaque areas than the other groups. Bone regeneration, assessed using histological analysis and fluorochrome labeling, was the highest in the HGCS scaffold seeded with MAPCs. The DECBM group showed limited osteoinductivity, causing a gap between the implant and host tissue. The group grafted with HGCS+MAPCs resulting in twice as much new bone formation seems to indicate a role for effective bone regeneration. In conclusion, the novel HGCS scaffold could improve bone regeneration and is a promising carrier for stem cell-mediated bone regeneration. Dong Joon Lee, Ricardo Padilla, He Zhang, Wei-Shou Hu, and Ching-Chang Ko Copyright © 2014 Dong Joon Lee et al. All rights reserved. Early Results of a New Rotating Hinge Knee Implant Wed, 25 Jun 2014 12:19:24 +0000 Background. Indication for rotating hinge (RH) total knee arthroplasty (TKA) includes primary and revision cases, with contradictory results. The aim of this study was to report prospective early results of a new modular rotating hinge TKA (EnduRo). For this implant several new design features and a new bearing material (carbon-fiber reinforced poly-ether-ether-ketone) have been developed. Furthermore, we tried to establish a new classification of failure modes for revision TKA. Methods. 152 EnduRo rotating-hinge prostheses were implanted in two centers. In 90 patients a primary implantation has been performed and 62 patients were revision cases. Knee Society Score (KSS), Western Ontario and McMaster Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), and Range of motion (ROM) were assessed before surgery, 3 months postoperatively, 12 months postoperatively, and annually thereafter. We defined 3 types of complications: Type 1, infection; type 2, periprosthetic complications; type 3, implant failures. Results. KSS, WOMAC, OKS, and ROM revealed significant improvements between the preoperative and the follow-up investigations. There were 14 complications (9.2%) leading to revision surgery, predominantly type 2. Conclusion. Our study shows excellent clinical results of the EnduRo TKA. Furthermore, no premature material failure or unusual biological response to the new bearing material could be detected. Alexander Giurea, Hans-Joachim Neuhaus, Rolf Miehlke, Reinhard Schuh, Richard Lass, Bernd Kubista, and Reinhard Windhager Copyright © 2014 Alexander Giurea et al. All rights reserved. Differential Expression of Osteo-Modulatory Molecules in Periodontal Ligament Stem Cells in Response to Modified Titanium Surfaces Wed, 25 Jun 2014 07:36:37 +0000 This study assessed differential gene expression of signaling molecules involved in osteogenic differentiation of periodontal ligament stem cells (PDLSCs) subjected to different titanium (Ti) surface types. PDLSCs were cultured on tissue culture polystyrene (TCPS), and four types of Ti discs (PT, SLA, hydrophilic PT (pmodPT), and hydrophilic SLA (modSLA)) with no osteoinductive factor and then osteogenic activity, including alkaline phosphatase (ALP) activity, mRNA expression of runt-related gene 2, osterix, FOSB, FRA1, and protein levels of osteopontin and collagen type IA, were examined. The highest osteogenic activity appeared in PDLSCs cultured on SLA, compared with the TCPS and other Ti surfaces. The role of surface properties in affecting signaling molecules to modulate PDLSC behavior was determined by examining the regulation of Wnt pathways. mRNA expression of the canonical Wnt signaling molecules, Wnt3a and β-catenin, was higher on SLA and modSLA than on smooth surfaces, but gene expression of the calcium-dependent Wnt signaling molecules Wnt5a, calmodulin, and NFATc1 was increased significantly on PT and pmodPT. Moreover, integrin α2/β1, sonic hedgehog, and Notch signaling molecules were affected differently by each surface modification. In conclusion, surface roughness and hydrophilicity can affect differential Wnt pathways and signaling molecules, targeting the osteogenic differentiation of PDLSCs. So Yeon Kim, Ji-Yeon Yoo, Joo-Young Ohe, Jung-Woo Lee, Ji-Hoi Moon, Yong-Dae Kwon, and Jung Sun Heo Copyright © 2014 So Yeon Kim et al. All rights reserved. Development and Characterization of In Situ Oral Gel of Spiramycin Tue, 24 Jun 2014 00:00:00 +0000 The present investigation deals with the optimization, formulation, and characterization of oral in situ gel of spiramycin. Sodium alginate and hydroxypropyl methylcellulose were used as cross-linking and viscosifying agents, respectively. Sodium bicarbonate was used as a floating agent. In preformulation studies, the melting point, pH, and partition coefficient were found to be 133°C, 9.5, and 0.193, respectively. The drug had retention time at around 2.65 minutes in high performance liquid chromatography (HPLC). During compatibility studies of drug with all polymers, we observed that there were no changes in the FTIR spectra of a mixture of drug and polymers. All the formulations showed good pourability. Floating time and total floating time were 30 sec and >12 hours, respectively. During in vitro drug release studies, the drug was released from the formulation around 80–100% for 12–16 hrs. In TEM analysis, we found that the drug molecules were well entrapped in the polymer and the drug was released slowly for up to 12 hrs. In these studies, we found that the concentration of sodium alginate and HPMC had significant influence on floating lag time, gelling capacity, and cumulative percentage drug release. During antimicrobial studies, we found that the formulation containing spiramycin showed good zone of inhibition against different microbial strains (Staphylococcus aureus and Escherichia coli). Avinash Sharma, Jyoti Sharma, Rupinder Kaur, and Vinay Saini Copyright © 2014 Avinash Sharma et al. All rights reserved. Biological Width around One- and Two-Piece Implants Retrieved from Human Jaws Mon, 23 Jun 2014 08:20:20 +0000 Several histologic studies regarding peri-implant soft tissues and biological width around dental implants have been done in animals. However, these findings in human peri-implant soft tissues are very scarce. Therefore, the aim of this case series was to compare the biological width around unloaded one- and two-piece implants retrieved from human jaws. Eight partially edentulous patients received 2 test implants in the posterior mandible: one-piece (solid implants that comprise implant and abutment in one piece) and two-piece (external hexagon with a healing abutment) implants. After 4 months of healing, the implants and surrounding tissue were removed for histologic analysis. The retrieved implants showed healthy peri-implant bone and exhibited early stages of maturation. Marginal bone loss, gaps, and fibrous tissue were not present around retrieved specimens. The biologic width dimension ranged between 2.55 ± 0.16 and 3.26 ± 0.15 to one- and two-piece implants, respectively (). This difference was influenced by the connective tissue attachment, while sulcus depth and epithelial junction presented the same dimension for both groups (). Within the limits of this study, it could be shown that two-piece implants resulted in the thickening of the connective tissue attachment, resulting in the increase of the biological width, when compared to one-piece implants. Ricardo Judgar, Gabriela Giro, Elton Zenobio, Paulo G. Coelho, Magda Feres, Jose A. Rodrigues, Carlo Mangano, Giovanna Iezzi, Adriano Piattelli, and Jamil Awad Shibli Copyright © 2014 Ricardo Judgar et al. All rights reserved. Osteoblast-Like Cell Behavior on Porous Scaffolds Based on Poly(styrene) Fibers Thu, 19 Jun 2014 11:02:22 +0000 Scaffolds of nonresorbable biomaterials can represent an interesting alternative for replacing large bone defects in some particular clinical cases with massive bone loss. Poly(styrene) microfibers were prepared by a dry spinning method. They were partially melted to provide 3D porous scaffolds. The quality of the material was assessed by Raman spectroscopy. Surface roughness was determined by atomic force microscopy and vertical interference microscopy. Saos-2 osteoblast-like cells were seeded on the surface of the fibers and left to proliferate. Cell morphology, evaluated by scanning electron microscopy, revealed that they can spread and elongate on the rough microfiber surface. Porous 3D scaffolds made of nonresorbable poly(styrene) fibers are cytocompatible biomaterials mimicking allogenic bone trabeculae and allowing the growth and development of osteoblast-like cells in vitro. Andrada Serafim, Romain Mallet, Florence Pascaretti-Grizon, Izabela-Cristina Stancu, and Daniel Chappard Copyright © 2014 Andrada Serafim et al. All rights reserved. Vegetable Oil Derived Solvent, and Catalyst Free “Click Chemistry” Thermoplastic Polytriazoles Tue, 17 Jun 2014 08:01:13 +0000 Azide-alkyne Huisgen “click” chemistry provides new synthetic routes for making thermoplastic polytriazole polymers—without solvent or catalyst. This method was used to polymerize three diester dialkyne monomers with a lipid derived 18 carbon diazide to produce a series of polymers (labelled C18C18, C18C9, and C18C4 based on monomer chain lengths) free of residual solvent and catalyst. Three diester dialkyne monomers were synthesized with ester chain lengths of 4, 9, and 18 carbons from renewable sources. Significant differences in thermal and mechanical properties were observed between C18C9 and the two other polymers. C18C9 presented a lower melting temperature, higher elongation at break, and reduced Young’s modulus compared to C18C4 and C18C18. This was due to the “odd-even” effect induced by the number of carbon atoms in the monomers which resulted in orientation of the ester linkages of C18C9 in the same direction, thereby reducing hydrogen bonding. The thermoplastic polytriazoles presented are novel polymers derived from vegetable oil with favourable mechanical and thermal properties suitable for a large range of applications where no residual solvent or catalyst can be tolerated. Their added potential biocompatibility and biodegradability make them ideal for applications in the medical and pharmaceutical industries. Michael C. Floros, Alcides Lopes Leão, and Suresh S. Narine Copyright © 2014 Michael C. Floros et al. All rights reserved. A Review on Biodentine, a Contemporary Dentine Replacement and Repair Material Mon, 16 Jun 2014 00:00:00 +0000 Biodentine is a calcium-silicate based material that has drawn attention in recent years and has been advocated to be used in various clinical applications, such as root perforations, apexification, resorptions, retrograde fillings, pulp capping procedures, and dentine replacement. There has been considerable research performed on this material since its launching; however, there is scarce number of review articles that collates information and data obtained from these studies. Therefore, this review article was prepared to provide the reader with a general picture regarding the findings about various characteristics of the material. The results of a PubMed search were classified and presented along with some critical comments where necessary. The review initially focuses on various physical properties of the material with subheadings and continues with biocompatibility. Another section includes the review of studies on Biodentine as a vital pulp treatment material and the article is finalized with the summary of some case reports where the material has been used. Özlem Malkondu, Meriç Karapinar Kazandağ, and Ender Kazazoğlu Copyright © 2014 Özlem Malkondu et al. All rights reserved. Nanofibrous Chitosan-Polyethylene Oxide Engineered Scaffolds: A Comparative Study between Simulated Structural Characteristics and Cells Viability Wed, 04 Jun 2014 09:50:01 +0000 3D nanofibrous chitosan-polyethylene oxide (PEO) scaffolds were fabricated by electrospinning at different processing parameters. The structural characteristics, such as pore size, overall porosity, pore interconnectivity, and scaffold percolative efficiency (SPE), were simulated by a robust image analysis. Mouse fibroblast cells (L929) were cultured in RPMI for 2 days in the presence of various samples of nanofibrous chitosan/PEO scaffolds. Cell attachments and corresponding mean viability were enhanced from 50% to 110% compared to that belonging to a control even at packed morphologies of scaffolds constituted from pores with nanoscale diameter. To elucidate the correlation between structural characteristics within the depth of the scaffolds’ profile and cell viability, a comparative analysis was proposed. This analysis revealed that larger fiber diameters and pore sizes can enhance cell viability. On the contrary, increasing the other structural elements such as overall porosity and interconnectivity due to a simultaneous reduction in fiber diameter and pore size through the electrospinning process can reduce the viability of cells. In addition, it was found that manipulation of the processing parameters in electrospinning can compensate for the effects of packed morphologies of nanofibrous scaffolds and can thus potentially improve the infiltration and viability of cells. Mohammad Kazemi Pilehrood, Mandana Dilamian, Mina Mirian, Hojjat Sadeghi-Aliabadi, Laleh Maleknia, Pertti Nousiainen, and Ali Harlin Copyright © 2014 Mohammad Kazemi Pilehrood et al. All rights reserved. Tissue Extracellular Matrix Nanoparticle Presentation in Electrospun Nanofibers Thu, 29 May 2014 09:13:30 +0000 Biomaterials derived from the decellularization of mature tissues retain biological and architectural features that profoundly influence cellular activity. However, the clinical utility of such materials remains limited as the shape and physical properties are difficult to control. In contrast, scaffolds based on synthetic polymers can be engineered to exhibit specific physical properties, yet often suffer from limited biological functionality. This study characterizes composite materials that present decellularized extracellular matrix (DECM) particles in combination with synthetic nanofibers and examines the ability of these materials to influence stem cell differentiation. Mechanical processing of decellularized tissues yielded particles with diameters ranging from 71 to 334 nm. Nanofiber scaffolds containing up to 10% DECM particles (wt/wt) derived from six different tissues were engineered and evaluated to confirm DECM particle incorporation and to measure bioactivity. Scaffolds containing bone, cartilage, and fat promoted osteogenesis at 1 and 3 weeks compared to controls. In contrast, spleen and lung DECM significantly reduced osteogenic outcomes compared to controls. These findings highlight the potential to incorporate appropriate source DECM nanoparticles within nanofiber composites to design a scaffold with bioactivity targeted to specific applications. Matt Gibson, Vince Beachley, Jeannine Coburn, Pierre Alain Bandinelli, Hai-Quan Mao, and Jennifer Elisseeff Copyright © 2014 Matt Gibson et al. All rights reserved. Insights into the Alteration of Osteoblast Mechanical Properties upon Adhesion on Chitosan Thu, 29 May 2014 05:53:15 +0000 Cell adhesion on substrates is accompanied by significant changes in shape and cytoskeleton organization, which affect subsequent cellular and tissue responses, determining the long-term success of an implant. Alterations in osteoblast stiffness upon adhesion on orthopaedic implants with different surface chemical composition and topography are, thus, of central interest in the field of bone implant research. This work aimed to study the mechanical response of osteoblasts upon adhesion on chitosan-coated glass surfaces and to investigate possible correlations with the level of adhesion, spreading, and cytoskeleton reorganization. Using the micropipette aspiration technique, the osteoblast elastic modulus was found higher on chitosan-coated than on uncoated control substrates, and it was found to increase in the course of spreading for both substrates. The cell-surface contact area was measured throughout several time points of adhesion to quantify cell spreading kinetics. Significant differences were found between chitosan and control surfaces regarding the response of cell spreading, while both groups displayed a sigmoidal kinetical behavior with an initially elevated spreading rate which stabilizes in the second hour of attachment. Actin filament structural changes were confirmed after observation with confocal microscope. Biomaterial surface modification can enhance osteoblast mechanical response and induce favorable structural organization for the implant integration. Antonia G. Moutzouri and George M. Athanassiou Copyright © 2014 Antonia G. Moutzouri and George M. Athanassiou. All rights reserved. Effect of Low-Level Laser on Bone Defects Treated with Bovine or Autogenous Bone Grafts: In Vivo Study in Rat Calvaria Wed, 28 May 2014 10:34:15 +0000 Objective. The purpose of this study was to histologically evaluate the effect of low-level laser (LLL) on the healing of critical size defects (CSD) in rat calvaria, filled with autogenous or inorganic bovine bone grafts. Methods. Sixty rats were divided into 6 groups : C (control—filled with blood clot), LLL (low-level laser—GaAlAs, 780 nm, 100 mW, 210 J/cm2, 0.05 cm2; 6 J/point), AB (autogenous bone), ABL (autogenous bone + low-level laser), OB (inorganic bovine bone), and OBL (inorganic bovine bone + LLL). Material and Methods. The animals were killed after 30 days. Histological and histometric analyses were performed by light microscopy. Results. The groups irradiated with laser, LLL (47.67% ± 8.66%), ABL (39.15% ± 16.72%), and OBL (48.57% ± 28.22%), presented greater area of new bone formation than groups C (9.96% ± 4.50%), AB (30.98% ± 16.59%), and OB (11.36% ± 7.89%), which were not irradiated. Moreover, they were significantly better than group C (Kruskal-Wallis test followed by Dunn test, . Conclusion. The laser accelerated the healing of bone defects and the resorption of particles of the graft material. Mércia J. S. Cunha, Luis A. Esper, Michyele C. Sbrana, Paula G. F. P. de Oliveira, Accácio L. do Valle, and Ana Lúcia P. F. de Almeida Copyright © 2014 Mércia J. S. Cunha et al. All rights reserved. Nano-/Microfabrication of Biomaterials Tue, 27 May 2014 09:45:18 +0000 Inn-Kyu Kang, Yoshihiro Ito, and Oh Hyeong Kwon Copyright © 2014 Inn-Kyu Kang et al. All rights reserved. Improvement of the Digestibility of Sulfated Hyaluronans by Bovine Testicular Hyaluronidase: A UV Spectroscopic and Mass Spectrometric Study Tue, 27 May 2014 08:53:28 +0000 Glycosaminoglycans (GAGs) such as hyaluronan (HA) and chondroitin sulfate (CS) are important, natural polysaccharides which occur in biological (connective) tissues and have various biotechnological and medical applications. Additionally, there is increasing evidence that chemically (over)sulfated GAGs possess promising properties and are useful as implant coatings. Unfortunately, a detailed characterization of these GAGs is challenging: although mass spectrometry (MS) is one of the most powerful tools to elucidate the structures of (poly)saccharides, MS is not applicable to high mass polysaccharides, but characteristic oligosaccharides are needed. These oligosaccharides are normally generated by enzymatic digestion. However, chemically modified (particularly sulfated) GAGs are extremely refractive to enzymatic digestion. This study focuses on the investigation of the digestibility of GAGs with different degrees of sulfation by bovine testicular hyaluronidase (BTH). It will be shown by using an adapted spectrophotometric assay that all investigated GAGs can be basically digested if the reaction conditions are carefully adjusted. However, the oligosaccharide yield correlates reciprocally with the number of sulfate residues per polymer repeating unit. Finally, matrix-laser desorption and ionization (MALDI) MS will be used to study the released oligosaccharides and their sulfation patterns. Katharina Lemmnitzer, Jürgen Schiller, Jana Becher, Stephanie Möller, and Matthias Schnabelrauch Copyright © 2014 Katharina Lemmnitzer et al. All rights reserved. Resin Composites Reinforced by Nanoscaled Fibers or Tubes for Dental Regeneration Tue, 27 May 2014 00:00:00 +0000 It has been stated clearly that nanofillers could make an enhancement on the mechanical performances of dental composites. In order to address current shortage of traditional dental composites, fillers in forms of nanofibers or nanotubes are broadly regarded as ideal candidates to greatly increase mechanical performances of dental composites with low content of fillers. In this review, the efforts using nanofibers and nanotubes to reinforce mechanical performances of dental composites, including polymeric nanofibers, metallic nanofibers or nanotubes, and inorganic nanofibers or nanotubes, as well as their researches related, are demonstrated in sequence. The first purpose of current paper was to confirm the enhancement of nanofibers or nanotubes’ reinforcement on the mechanical performances of dental restorative composite. The second purpose was to make a general description about the reinforcement mechanism of nanofibers and nanotubes, especially, the impact of formation of interphase boundary interaction and nanofibers themselves on the advanced mechanical behaviors of the dental composites. By means of the formation of interface interaction and poststretching nanofibers, reinforced effect of dental composites by sorts of nanofibers/nanotubes has been successfully obtained. Xiaoming Li, Wei Liu, Lianwen Sun, Katerina E. Aifantis, Bo Yu, Yubo Fan, Qingling Feng, Fuzhai Cui, and Fumio Watari Copyright © 2014 Xiaoming Li et al. All rights reserved. Reliable Assessment and Quantification of the Fluorescence-Labeled Antisense Oligonucleotides In Vivo Sun, 25 May 2014 10:58:41 +0000 The availability of fluorescent dyes and the advances in the optical systems for in vivo imaging have stimulated an increasing interest in developing new methodologies to study and quantify the biodistribution of labeled agents. However, despite these great achievements, we are facing significant challenges in determining if the observed fluorescence does correspond to the quantity of the dye in the tissues. In fact, although the far-red and near-infrared lights can propagate through several centimetres of tissue, they diffuse within a few millimetres as consequence of the elastic scattering of photons. In addition, when dye-labeled oligonucleotides form stable complex with cationic carriers, a large change in the fluorescence intensity of the dye is observed. Therefore, the measured fluorescence intensity is altered by the tissue heterogeneity and by the fluctuation of dye intensity. Hence, in this study a quantification strategy for fluorescence-labeled oligonucleotides was developed to solve these disadvantageous effects. Our results proved that upon efficient homogenization and dilution with chaotropic agents, such as guanidinium thiocyanate, it is possible to achieve a complete fluorescence intensity recovery. Furthermore, we demonstrated that this method has the advantage of good sensitivity and reproducibility, as well as easy handling of the tissue samples. Maria Chiara Munisso and Tetsuji Yamaoka Copyright © 2014 Maria Chiara Munisso and Tetsuji Yamaoka. All rights reserved. Potency of Fish Collagen as a Scaffold for Regenerative Medicine Sun, 25 May 2014 08:03:51 +0000 Cells, growth factors, and scaffold are the crucial factors for tissue engineering. Recently, scaffolds consisting of natural polymers, such as collagen and gelatin, bioabsorbable synthetic polymers, such as polylactic acid and polyglycolic acid, and inorganic materials, such as hydroxyapatite, as well as composite materials have been rapidly developed. In particular, collagen is the most promising material for tissue engineering due to its biocompatibility and biodegradability. Collagen contains specific cell adhesion domains, including the arginine-glycine-aspartic acid (RGD) motif. After the integrin receptor on the cell surface binds to the RGD motif on the collagen molecule, cell adhesion is actively induced. This interaction contributes to the promotion of cell growth and differentiation and the regulation of various cell functions. However, it is difficult to use a pure collagen scaffold as a tissue engineering material due to its low mechanical strength. In order to make up for this disadvantage, collagen scaffolds are often modified using a cross-linker, such as gamma irradiation and carbodiimide. Taking into account the possibility of zoonosis, a variety of recent reports have been documented using fish collagen scaffolds. We herein review the potency of fish collagen scaffolds as well as associated problems to be addressed for use in regenerative medicine. Shizuka Yamada, Kohei Yamamoto, Takeshi Ikeda, Kajiro Yanagiguchi, and Yoshihiko Hayashi Copyright © 2014 Shizuka Yamada et al. All rights reserved. Histologic Changes of Implanted Gore Bio-A in an Experimental Animal Model Wed, 21 May 2014 06:16:00 +0000 Gore Bio-A has been reported to be an ideal synthetic bioabsorbable scaffold material for hernia repair. The purpose of this study was to determine the effectiveness of Gore Bio-A in soft tissue augmentation. Six New Zealand white rabbits were used in the study. Five subcutaneous pockets were created on the back of the rabbit, and  mm sized square shaped Gore Bio-A sheets, each 1.5 mm, 3 mm, 4.5 mm, 6 mm, and 7.5 mm in thickness, were implanted into each pocket (1 layer to 5 layers). To analyze the morphologic and histologic changes, the implants were harvested 1, 3, and 6 months after implantation. Following the gross analysis, absorption rate was accelerated with increased implant duration and decreased thickness. Histological analysis of the implants demonstrated progressive neovascularization, fibroblast infiltration, and neocollagenation over time. Six months after implantation, Gore Bio-A was almost absorbed and degenerated, not maintaining its volume. Based on this study, Gore Bio-A was revealed as a biocompatible material; however, it is not suitable for soft tissue augmentation because it is absorbed in the process of changing into soft tissue without maintaining its own volume. Therefore, this material is incomplete and needs more study to overcome this limitation. Kwan Koo Yeo, Tae Hwan Park, Jin Hyuk Park, Choong Hyun Chang, June-kyu Kim, and Sang Won Seo Copyright © 2014 Kwan Koo Yeo et al. All rights reserved. Reinforcement of Dental Methacrylate with Glass Fiber after Heated Silane Application Tue, 20 May 2014 00:00:00 +0000 This study evaluated the influence of silane heat treatment and glass fiber fabrication type, industrially treated (I) or pure (P), on flexural and compressive strength of methacrylate resin bars (BISGMA/TEGDMA, 50/50%). Six groups were created: I-sil: I/silanated; P-sil: P-silanated; I-sil/heat: I/silanated heated to 100°; P-sil/heat: P/silanated heated to 100°; (I: I/not silanated; and P: P/not silanated. Specimens were prepared for flexural strength and for compressive strength ) and tested at 0.5 mm/min. Statistical analysis demonstrated the following for flexural strength : I-sil: ; P-sil: ; I-sil/heat: ; P-sil/heat: ; I: . For compressive strength, the following are demonstrated: I-sil: ; P-sil: ; I-sil/heat: ; P-sil/heat: ; and I: . Due to the impossibility of incorporating the stipulated amount of fiber, P group was excluded. Glass fiber treatment with heated silane enhanced flexural and compressive strength of a reinforced dental methacrylate. Rodrigo Borges Fonseca, Marcella Silva de Paula, Isabella Negro Favarão, Amanda Vessoni Barbosa Kasuya, Letícia Nunes de Almeida, Gustavo Adolfo Martins Mendes, and Hugo Lemes Carlo Copyright © 2014 Rodrigo Borges Fonseca et al. All rights reserved. Immunomodulation of Nanoparticles in Nanomedicine Applications Tue, 20 May 2014 00:00:00 +0000 Nanoparticles (NPs) have promising applications in medicine. Immune system is an important protective system to defend organisms from non-self matters. NPs interact with the immune system and modulate its function, leading to immunosuppression or immunostimulation. These modulating effects may bring benefits or danger. Compositions, sizes, and surface chemistry, and so forth, affect these immunomodulations. Here we give an overview of the relationship between the physicochemical properties of NPs, which are candidates to be applied in medicine, and their immunomodulation properties. Qing Jiao, Liwen Li, Qingxin Mu, and Qiu Zhang Copyright © 2014 Qing Jiao et al. All rights reserved. Spider Silk as Guiding Biomaterial for Human Model Neurons Sun, 18 May 2014 06:46:46 +0000 Over the last years, a number of therapeutic strategies have emerged to promote axonal regeneration. An attractive strategy is the implantation of biodegradable and nonimmunogenic artificial scaffolds into injured peripheral nerves. In previous studies, transplantation of decellularized veins filled with spider silk for bridging critical size nerve defects resulted in axonal regeneration and remyelination by invading endogenous Schwann cells. Detailed interaction of elongating neurons and the spider silk as guidance material is unknown. To visualize direct cellular interactions between spider silk and neurons in vitro, we developed an in vitro crossed silk fiber array. Here, we describe in detail for the first time that human (NT2) model neurons attach to silk scaffolds. Extending neurites can bridge gaps between single silk fibers and elongate afterwards on the neighboring fiber. Culturing human neurons on the silk arrays led to an increasing migration and adhesion of neuronal cell bodies to the spider silk fibers. Within three to four weeks, clustered somata and extending neurites formed ganglion-like cell structures. Microscopic imaging of human neurons on the crossed fiber arrays in vitro will allow for a more efficient development of methods to maximize cell adhesion and neurite growth on spider silk prior to transplantation studies. Frank Roloff, Sarah Strauß, Peter M. Vogt, Gerd Bicker, and Christine Radtke Copyright © 2014 Frank Roloff et al. All rights reserved. Enhanced Blood Compatibility of Metallocene Polyethylene Subjected to Hydrochloric Acid Treatment for Cardiovascular Implants Thu, 15 May 2014 00:00:00 +0000 Blood compatibility of metallocene polyethylene (mPE) was investigated after modifying the surface using hydrochloric acid. Contact angle of the mPE exposed to HCl poses a decrease in its value which indicates increasing wettability and better blood compatibility. Surface of mPE analyzed by using FTIR revealed no significant changes in its functional groups after treatment. Furthermore, scanning electron microscope images supported the increasing wettability through the modifications like pit formations and etching on the acid rendered surface. To evaluate the effect of acid treatment on the coagulation cascade, prothrombin time (PT) and activated partial thromboplastin time (APTT) were measured. Both PT and APTT were delayed significantly () after 60 min exposure implying improved blood compatibility of the surfaces. Hemolysis assay of the treated surface showed a remarkable decrease in the percentage of lysis of red blood cells when compared with untreated surface. Moreover, platelet adhesion assay demonstrated that HCl exposed surfaces deter the attachment of platelets and thereby reduce the chances of activation of blood coagulation cascade. These results confirmed the enhanced blood compatibility of mPE after HCl exposure which can be utilized for cardiovascular implants like artificial vascular prostheses, implants, and various blood contacting devices. Saravana Kumar Jaganathan, Hemanth Mohandas, Gunalan Sivakumar, Palaniappan Kasi, Theertha Sudheer, Sruthi Avineri Veetil, Selvakumar Murugesan, and Eko Supriyanto Copyright © 2014 Saravana Kumar Jaganathan et al. All rights reserved. RhoA Controls Wnt Upregulation on Microstructured Titanium Surfaces Wed, 14 May 2014 00:00:00 +0000 Rough topography enhances the activation of Wnt canonical signaling in vitro, and this mediates its effects on cell differentiation. However, the molecular mechanisms underlying topography-dependent control of Wnt signaling are still poorly understood. As the small GTPase RhoA controls cytoskeletal reorganization and actomyosin-induced tensional forces, we hypothesized that RhoA could affect the activation of Wnt signaling in cells on micropatterned titanium surfaces. G-LISA assay revealed that RhoA activation was higher in C2C12 cells on rough (SLA) surfaces under basal conditions than on smooth (Polished) titanium. Transfection with dominant negative RhoA decreased Wnt activation by normalized TCF-Luc activity on SLA, whilst transfection with constitutively active RhoA increased TCF-Luc activation on Polished titanium. One mM Myosin II inhibitor Blebbistatin increased RhoA activation but decreased Wnt activation on SLA surfaces, indicating that tension-generating structures are required for canonical Wnt modulation on titanium surfaces. Actin inhibitor Cytochalasin markedly enhanced RhoA and TCF-Luc activation on both surfaces and increased the expression of differentiation markers in murine osteoblastic MC3T3 cells. Taken together, these data show that RhoA is upregulated in cells on rough surfaces and it affects the activation of Wnt canonical signaling through Myosin II modulation. Simone Lumetti, Silvia Mazzotta, Sara Ferrillo, Maddalena Piergianni, Marilina Piemontese, Giovanni Passeri, Guido Maria Macaluso, and Carlo Galli Copyright © 2014 Simone Lumetti et al. All rights reserved. Bone Marrow Stem Cells Added to a Hydroxyapatite Scaffold Result in Better Outcomes after Surgical Treatment of Intertrochanteric Hip Fractures Wed, 14 May 2014 00:00:00 +0000 Introduction. Intertrochanteric hip fractures occur in the proximal femur. They are very common in the elderly and are responsible for high rates of morbidity and mortality. The authors hypothesized that adding an autologous bone marrow stem cells concentrate (ABMC) to a hydroxyapatite scaffold and placing it in the fracture site would improve the outcome after surgical fixation of intertrochanteric hip fractures. Material and Methods. 30 patients were randomly selected and divided into 2 groups of 15 patients, to receive either the scaffold enriched with the ABMC (Group A) during the surgical procedure, or fracture fixation alone (Group B). Results. There was a statistically significant difference in favor of group A at days 30, 60, and 90 for Harris Hip Scores (HHS), at days 30 and 60 for VAS pain scales, for bedridden period and time taken to start partial and total weight bearing (). Discussion. These results show a significant benefit of adding a bone marrow enriched scaffold to surgical fixation in intertrochanteric hip fractures, which can significantly reduce the associated morbidity and mortality rates. Conclusion. Bone marrow stem cells added to a hydroxyapatite scaffold result in better outcomes after surgical treatment of intertrochanteric hip fractures. Joao Torres, Manuel Gutierres, M. Ascenção Lopes, J. Domingos Santos, A. T. Cabral, R. Pinto, and Carola van Eck Copyright © 2014 Joao Torres et al. All rights reserved. Biodegradable and Elastomeric Poly(glycerol sebacate) as a Coating Material for Nitinol Bare Stent Tue, 13 May 2014 12:08:20 +0000 We synthesized and evaluated biodegradable and elastomeric polyesters (poly(glycerol sebacate) (PGS)) using polycondensation between glycerol and sebacic acid to form a cross-linked network structure without using exogenous catalysts. Synthesized materials possess good mechanical properties, elasticity, and surface erosion biodegradation behavior. The tensile strength of the PGS was as high as 0.28 ± 0.004 MPa, and Young's modulus was 0.122 ± 0.0003 MPa. Elongation was as high as 237.8 ± 0.64%, and repeated elongation behavior was also observed to at least three times the original length without rupture. The water-in-air contact angles of the PGS surfaces were about 60°. We also analyzed the properties of an electrospray coating of biodegradable PGS on a nitinol stent for the purpose of enhancing long-term patency for the therapeutic treatment of varicose veins disease. The surface morphology and thickness of coating layer could be controlled by adjusting the electrospraying conditions and solution parameters. Min Ji Kim, Moon Young Hwang, JiHeung Kim, and Dong June Chung Copyright © 2014 Min Ji Kim et al. All rights reserved. Antimicrobial and Controlled Release Studies of a Novel Nystatin Conjugated Iron Oxide Nanocomposite Mon, 12 May 2014 08:12:41 +0000 Nystatin is a tetraene diene polyene antibiotic showing a broad spectrum of antifungal activity. In the present study, we prepared a nystatin nanocomposite (Nyst-CS-MNP) by loading nystatin (Nyst) on chitosan (CS) coated magnetic nanoparticles (MNPs). The magnetic nanocomposites were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry analysis (TGA), vibrating sample magnetometer (VSM), and scanning electron microscopy (SEM). The XRD results showed that the MNPs and nanocomposite are pure magnetite. The FTIR analysis confirmed the binding of CS on the surface of the MNPs and also the loading of Nyst in the nanocomposite. The Nyst drug loading was estimated using UV-Vis instrumentation and showing a 14.9% loading in the nanocomposite. The TEM size image of the MNPs, CS-MNP, and Nyst-CS-MNP was 13, 11, and 8 nm, respectively. The release profile of the Nyst drug from the nanocomposite followed a pseudo-second-order kinetic model. The antimicrobial activity of the as-synthesized Nyst and Nyst-CS-MNP nanocomposite was evaluated using an agar diffusion method and showed enhanced antifungal activity against Candida albicans. In this manner, this study introduces a novel nanocomposite that can decrease fungus activity on-demand for numerous medical applications. Samer Hasan Hussein-Al-Ali, Mohamed E. El Zowalaty, Aminu Umar Kura, Benjamin Geilich, Sharida Fakurazi, Thomas J. Webster, and Mohd Zobir Hussein Copyright © 2014 Samer Hasan Hussein-Al-Ali et al. All rights reserved. Substituted Hydroxyapatites with Antibacterial Properties Sun, 11 May 2014 08:55:05 +0000 Reconstructive surgery is presently struggling with the problem of infections located within implantation biomaterials. Of course, the best antibacterial protection is antibiotic therapy. However, oral antibiotic therapy is sometimes ineffective, while administering an antibiotic at the location of infection is often associated with an unfavourable ratio of dosage efficiency and toxic effect. Thus, the present study aims to find a new factor which may improve antibacterial activity while also presenting low toxicity to the human cells. Such factors are usually implemented along with the implant itself and may be an integral part of it. Many recent studies have focused on inorganic factors, such as metal nanoparticles, salts, and metal oxides. The advantages of inorganic factors include the ease with which they can be combined with ceramic and polymeric biomaterials. The following review focuses on hydroxyapatites substituted with ions with antibacterial properties. It considers materials that have already been applied in regenerative medicine (e.g., hydroxyapatites with silver ions) and those that are only at the preliminary stage of research and which could potentially be used in implantology or dentistry. We present methods for the synthesis of modified apatites and the antibacterial mechanisms of various ions as well as their antibacterial efficiency. Joanna Kolmas, Ewa Groszyk, and Dagmara Kwiatkowska-Różycka Copyright © 2014 Joanna Kolmas et al. All rights reserved. Electrospun Polyhydroxybutyrate and Poly(L-lactide-co-ε-caprolactone) Composites as Nanofibrous Scaffolds Thu, 08 May 2014 07:38:21 +0000 Electrospinning can produce nanofibrous scaffolds that mimic the architecture of the extracellular matrix and support cell attachment for tissue engineering applications. In this study, fibrous membranes of polyhydroxybutyrate (PHB) with various loadings of poly(L-lactide-co--caprolactone) (PLCL) were successfully prepared by electrospinning. In comparison to PLCL scaffolds, PLCL blends with PHB exhibited more irregular fibre diameter distributions and higher average fibre diameters but there were no significant differences in pore size. PLCL/PHB scaffolds were more hydrophilic (<120°) with significantly reduced tensile strength (ca. 1 MPa) compared to PLCL scaffolds ( and  MPa). Increasing PLCL loading in PHB/PLCL scaffolds significantly increased the extension at break, (4–6-fold). PLCL/PHB scaffolds supported greater adhesion and proliferation of olfactory ensheathing cells (OECs) than those exhibiting asynchronous growth on culture plates. Mitochondrial activity of cells cultivated on the electrospun blended membranes was enhanced compared to those grown on PLCL and PHB scaffolds (212, 179, and 153%, resp.). Analysis showed that PLCL/PHB nanofibrous membranes promoted cell cycle progression and reduced the onset of necrosis. Thus, electrospun PLCL/PHB composites promoted adhesion and proliferation of OECs when compared to their individual PLCL and PHB components suggesting potential in the repair and engineering of nerve tissue. Donraporn Daranarong, Rodman T. H. Chan, Nico S. Wanandy, Robert Molloy, Winita Punyodom, and L. John R. Foster Copyright © 2014 Donraporn Daranarong et al. All rights reserved. Biomaterials in Cardiovascular Research: Applications and Clinical Implications Thu, 08 May 2014 00:00:00 +0000 Cardiovascular biomaterials (CB) dominate the category of biomaterials based on the demand and investments in this field. This review article classifies the CB into three major classes, namely, metals, polymers, and biological materials and collates the information about the CB. Blood compatibility is one of the major criteria which limit the use of biomaterials for cardiovascular application. Several key players are associated with blood compatibility and they are discussed in this paper. To enhance the compatibility of the CB, several surface modification strategies were in use currently. Some recent applications of surface modification technology on the materials for cardiovascular devices were also discussed for better understanding. Finally, the current trend of the CB, endothelization of the cardiac implants and utilization of induced human pluripotent stem cells (ihPSCs), is also presented in this review. The field of CB is growing constantly and many new investigators and researchers are developing interest in this domain. This review will serve as a one stop arrangement to quickly grasp the basic research in the field of CB. Saravana Kumar Jaganathan, Eko Supriyanto, Selvakumar Murugesan, Arunpandian Balaji, and Manjeesh Kumar Asokan Copyright © 2014 Saravana Kumar Jaganathan et al. All rights reserved. Bond Strengths of Silorane- and Methacrylate-Based Composites to Various Underlying Materials Wed, 07 May 2014 06:50:36 +0000 Objective. To evaluate shear bond strength (SBS) values of a methacrylate (FZ 250) and a silorane-based (FS) resin composite to various underlying materials. Materials and Methods. A total of 80 samples were prepared with four different underlying materials; a flowable (FLC) and a bulk-fill flowable composite (BFC), and a conventional (CGIC) and resin modified glass-ionomer cement (RMGIC). These underlying materials were laminated plus to methacrylate or silorane-based resin composites . To evaluate the specimens SBS values were evaluated with a universal testing machine (cross-head speed; 1.0 mm/min). Statistical comparisons were carried out using two-way ANOVA and Tukey’s post hoc test with a significance level of . Results. SBS values for FZ250 were significantly higher than for FS for all of the underlying materials tested . SBS values of FZ250 to BFC were significantly higher than to all other materials , whereas SBS values of FS did not vary significantly according to underlying material . Conclusion. The use of FS in conjunction with any of the tested materials showed lower SBS than the FZ 250. Also, new low elastic modulus liner BFC presented slightly good interfacial adhesion so, the usage of BFC as an underlying material may be preferable for FZ 250. Sezin Ozer, Emine Sen Tunc, and Nihan Gonulol Copyright © 2014 Sezin Ozer et al. All rights reserved. Osteoconductive Potential of Barrier NanoSiO2 PLGA Membranes Functionalized by Plasma Enhanced Chemical Vapour Deposition Sun, 04 May 2014 13:41:41 +0000 The possibility of tailoring membrane surfaces with osteoconductive potential, in particular in biodegradable devices, to create modified biomaterials that stimulate osteoblast response should make them more suitable for clinical use, hopefully enhancing bone regeneration. Bioactive inorganic materials, such as silica, have been suggested to improve the bioactivity of synthetic biopolymers. An in vitro study on HOB human osteoblasts was performed to assess biocompatibility and bioactivity of SiO2 functionalized poly(lactide-co-glycolide) (PLGA) membranes, prior to clinical use. A 15 nm SiO2 layer was deposited by plasma enhanced chemical vapour deposition (PECVD), onto a resorbable PLGA membrane. Samples were characterized by X-ray photoelectron spectroscopy, atomic force microscopy, scanning electron microscopy, and infrared spectroscopy (FT-IR). HOB cells were seeded on sterilized test surfaces where cell morphology, spreading, actin cytoskeletal organization, and focal adhesion expression were assessed. As proved by the FT-IR analysis of samples, the deposition by PECVD of the SiO2 onto the PLGA membrane did not alter the composition and other characteristics of the organic membrane. A temporal and spatial reorganization of cytoskeleton and focal adhesions and morphological changes in response to SiO2 nanolayer were identified in our model. The novedous SiO2 deposition method is compatible with the standard sterilization protocols and reveals as a valuable tool to increase bioactivity of resorbable PLGA membranes. Antonia Terriza, Jose I. Vilches-Pérez, Emilio de la Orden, Francisco Yubero, Juan L. Gonzalez-Caballero, Agustin R. González-Elipe, José Vilches, and Mercedes Salido Copyright © 2014 Antonia Terriza et al. All rights reserved. Complete Cell Killing by Applying High Hydrostatic Pressure for Acellular Vascular Graft Preparation Wed, 30 Apr 2014 07:32:07 +0000 Pressure treatment has been developed in tissue engineering application. Although the tissue scaffold prepared by a ultrahydrostatic pressure treatment has been reported, an excessive pressure has a potential to disrupt a structure of extracellular matrix through protein denaturation. It is important to understand the suitable low-pressure condition and mechanisms for cell killing. In this study, cellular morphology, mitochondria activity, and membrane permeability of mammalian cells with various pressure treatments were investigated with in vitro models. When the cells were treated with a pressure of 100 MPa for 10 min, cell morphology and adherence were the same as an untreated cells. Dehydrogenase activity in mitochondria was almost the same as untreated cells. On the other hand, when the cells were treated with the pressure of more than 200 MPa, the cells did not adhere, and the dehydrogenase activity was completely suppressed. However, green fluorescence was observed in the live/dead staining images, and the cells were completely stained as red after above 500 MPa. That is, membrane permeability was disturbed with the pressure treatment of above 500 MPa. These results indicated that the pressure of 200 MPa for 10 min was enough to induce cell killing through inactivation of mitochondria activity. Atsushi Mahara, Naoki Morimoto, Takahiro Sakuma, Toshiya Fujisato, and Tetsuji Yamaoka Copyright © 2014 Atsushi Mahara et al. All rights reserved. Vertical Ridge Augmentation of the Atrophic Posterior Mandible with Sandwich Technique: Bone Block from the Chin Area versus Corticocancellous Bone Block Allograft—Clinical and Histological Prospective Randomized Controlled Study Tue, 29 Apr 2014 09:15:49 +0000 The aim of the present study is to compare the histological aspects of bone formation in atrophic posterior mandibles augmented by autologous bone block from chin area with corticocancellous bone block allograft used as inlays with the sandwich technique. Materials and Methods. Sixteen patients with bilateral partial edentulism in the posterior mandible were selected. The residual bone height, preliminarily measured by computed tomography scans, ranged between 5 and 7 mm from the inferior alveolar nerve. All patients required regeneration procedure with autologous bone block from chin area (control group) versus bone block allograft Puros (Zimmer Dental, 1900 Aston Avenue, Carlsbad, CA, USA) (test group). Histological and histomorphometric samples were collected at the time of implant positioning in order to analyze the percentage of newly formed bone, the residual graft material, and marrow spaces/soft tissue. Results. No statistically significant differences between the two groups were found regarding the percentage of newly formed bone. The percentage of residual grafted material was significantly higher in the test group, whilst the percentage of marrow spaces was higher in control group. Conclusions. In conclusion, both procedures supported good results, although the use of bone blocks allograft was less invasive and preferable than harvesting bone from the mental symphysis. Luigi Laino, Giovanna Iezzi, Adriano Piattelli, Lorenzo Lo Muzio, and Marco Cicciù Copyright © 2014 Luigi Laino et al. All rights reserved. Artificial Extracellular Matrices with Oversulfated Glycosaminoglycan Derivatives Promote the Differentiation of Osteoblast-Precursor Cells and Premature Osteoblasts Mon, 28 Apr 2014 06:21:12 +0000 Sulfated glycosaminoglycans (GAG) are components of the bone marrow stem cell niche and to a minor extent of mature bone tissue with important functions in regulating stem cell lineage commitment and differentiation. We anticipated that artificial extracellular matrices (aECM) composed of collagen I and synthetically oversulfated GAG derivatives affect preferentially the differentiation of osteoblast-precursor cells and early osteoblasts. A set of gradually sulfated chondroitin sulfate and hyaluronan derivatives was used for the preparation of aECM. All these matrices were analysed with human bone marrow stromal cells to identify the most potent aECM and to determine the influence of the degree and position of sulfate groups and the kind of disaccharide units on the osteogenic differentiation. Oversulfated GAG derivatives with a sulfate group at the C-6 position of the N-acetylglycosamine revealed the most pronounced proosteogenic effect as determined by tissue nonspecific alkaline phosphatase activity and calcium deposition. A subset of the aECM was further analysed with different primary osteoblasts and cell lines reflecting different maturation stages to test whether the effect of sulfated GAG derivatives depends on the maturation status of the cells. It was shown that the proosteogenic effect of aECM was most prominent in early osteoblasts. Ute Hempel, Carolin Preissler, Sarah Vogel, Stephanie Möller, Vera Hintze, Jana Becher, Matthias Schnabelrauch, Martina Rauner, Lorenz C. Hofbauer, and Peter Dieter Copyright © 2014 Ute Hempel et al. All rights reserved. Synthesis and Evaluation of Tetramethylguanidinium-Polyethylenimine Polymers as Efficient Gene Delivery Vectors Thu, 24 Apr 2014 12:23:40 +0000 Previously, we demonstrated that 6-(N,N,N′,N′-tetramethylguanidinium chloride)-hexanoyl-polyethylenimine (THP) polymers exhibited significantly enhanced transfection efficiency and cell viability. Here, in the present study, we have synthesized a series of N,N,N′,N′-tetramethylguanidinium-polyethylenimine (TP1-TP5) polymers via a single-step reaction involving peripheral primary amines of bPEI and varying amounts of 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU). These polymers were found to interact efficiently with negatively charged pDNA and formed stable complexes in the size range of ~240–450 nm. Acid-base titration profiles revealed improved buffering capacity of TP polymers as compared to bPEI. Transfection and cytotoxicity assays performed with TP/pDNA complexes on HEK293, CHO, and HeLa cells showed significantly higher transfection efficiency and cell viability with one of the complexes, TP2/pDNA complex, exhibited the highest transfection efficiency (~1.4–2.3-fold) outcompeting native bPEI and the commercially available transfection reagent, Lipofectamine 2000. Compared to previously reported THP polymers, the transfection efficiency of TP/pDNA complexes was found to be lower, as examined by flow cytometry. These results highlight the importance of the hydrophobic C-6 linker in THP polymers in forming compact nanostructures with pDNA, which might lead to efficient uptake and internalization of the complexes; however, the projected TP polymers offer an advantage of their rapid and economical one-step synthesis. Manohar Mahato, Santosh Yadav, Pradeep Kumar, and Ashwani Kumar Sharma Copyright © 2014 Manohar Mahato et al. All rights reserved. Surface Characteristics and Bioactivity of a Novel Natural HA/Zircon Nanocomposite Coated on Dental Implants Wed, 16 Apr 2014 16:45:25 +0000 The surface characteristics of implant which influence the speed and strength of osseointegration include surface chemistry, crystal structure and crystallinity, roughness, strain hardening, and presence of impurities. The aim of this study was to evaluate the bioactivity and roughness of a novel natural hydroxyapatite/zircon (NHA/zircon) nanobiocomposite, coated on 316L stainless steel (SS) soaked in simulated body fluid (SBF). NHA/zircon nanobiocomposite was fabricated with 0 wt.%, 5 wt.%, 10 wt.%, and 15 wt.% of zircon in NHA using ball mill for 20 minutes. The composite mixture was coated on 316L SS using plasma spray method. The results are estimated using the scanning electron microscopy (SEM) observation to evaluate surface morphology, X-ray diffraction (XRD) to analyze phase composition, and transmission electron microscopy (TEM) technique to evaluate the shape and size of prepared NHA. Surfaces roughness tester was performed to characterize the coated nanocomposite samples. The maximum average (14.54 μm) was found in the NHA 10 wt.% of zircon coating. In addition, crystallinity () was measured by XRD data, which indicated the minimum value ( = 41.1%) for the sample containing 10 wt.% of zircon. Maximum bioactivity occurred in the sample containing 10 wt.% of zircon, which was due to two reasons: first, the maximum roughness and, second, the minimum crystallinity of nanobiocomposite coating. Ebrahim Karamian, Amirsalar Khandan, Mahmood Reza Kalantar Motamedi, and Hesam Mirmohammadi Copyright © 2014 Ebrahim Karamian et al. All rights reserved. Mechanical Stress Stimulates the Osteo/Odontoblastic Differentiation of Human Stem Cells from Apical Papilla via ERK 1/2 and JNK MAPK Pathways Tue, 15 Apr 2014 00:00:00 +0000 Background Information. Stem cells from apical papilla (SCAPs) are a potent candidate for the apexogenesis/apexification due to their multiple differentiation capacity. During the orthodontic treatment of developing teeth, SCAPs in vivo are usually subjected to the cyclic stress induced by compression forces. However, it remains unclear whether mechanical stress can affect the proliferation and differentiation of human SCAPs. Results. Human SCAPs were isolated and stimulated by 200 g mechanical stimuli for 30 min and their proliferation and differentiation capacity were evaluated in vitro at different time points. MTT and FCM results demonstrated that cell proliferation was enhanced, while TEM findings showed the morphological and ultrastructural changes in stress-treated SCAPs. ALP activity and mineralization capacity of stress-treated SCAPs were upregulated . In the meantime, higher odontogenic and osteogenic differentiation were found in stress-treated SCAPs by real-time RT-PCR and Western blot, as indicated by the expression of related markers at both mRNA and protein levels. Moreover, the protein expressions of pJNK and pERK MAPK pathways were upregulated. Conclusion. Together, these findings suggest that mechanical stress is an important factor affecting the proliferation and differentiation of SCAPs via the activation of ERK and JNK signaling pathway. Chao Mu, Taohong Lv, Zilu Wang, Shu Ma, Jie Ma, Jin Liu, Jinhua Yu, and Jinquan Mu Copyright © 2014 Chao Mu et al. All rights reserved. Methoxy-Poly(ethylene glycol) Modified Poly(L-lactide) Enhanced Cell Affinity of Human Bone Marrow Stromal Cells by the Upregulation of 1-Cadherin and Delta-2-catenin Mon, 14 Apr 2014 13:57:08 +0000 Poly(l-lactide) (PLLA), a versatile biodegradable polymer, is one of the most commonly-used materials for tissue engineering applications. To improve cell affinity for PLLA, poly(ethylene glycol) (PEG) was used to develop diblock copolymers. Human bone marrow stromal cells (hBMSCs) were cultured on MPEG-b-PLLA copolymer films to determine the effects of modification on the attachment and proliferation of hBMSC. The mRNA expression of 84 human extracellular matrix (ECM) and adhesion molecules was analyzed using RT-qPCR to understand the underlying mechanisms. It was found that MPEG-b-PLLA copolymer films significantly improved cell adhesion, extension, and proliferation. This was found to be related to the significant upregulation of two adhesion genes, CDH1 and CTNND2, which encode 1-cadherin and delta-2-catenin, respectively, two key components for the cadherin-catenin complex. In summary, MPEG-b-PLLA copolymer surfaces improved initial cell adhesion by stimulation of adhesion molecule gene expression. Xueli Mao, Zetao Chen, Junqi Ling, Jingjing Quan, Hui Peng, and Yin Xiao Copyright © 2014 Xueli Mao et al. All rights reserved. Application of Ultrasound on Monitoring the Evolution of the Collagen Fiber Reinforced nHAC/CS Composites In Vivo Mon, 14 Apr 2014 09:03:00 +0000 To date, fiber reinforce scaffolds have been largely applied to repair hard and soft tissues. Meanwhile, monitoring the scaffolds for long periods in vivo is recognized as a crucial issue before its wide use. As a consequence, there is a growing need for noninvasive and convenient methods to analyze the implantation remolding process in situ and in real time. In this paper, diagnostic medical ultrasound was used to monitor the in vivo bone formation and degradation process of the novel mineralized collagen fiber reinforced composite which is synthesized by chitosan (CS), nanohydroxyapatite (nHA), and collagen fiber (Col). To observe the impact of cells on bone remodeling process, the scaffolds were planted into the back of the SD rats with and without rat bone mesenchymal stem cells (rBMSCs). Systematic data of scaffolds in vivo was extracted from ultrasound images. Significant consistency between the data from the ultrasound and DXA could be observed . This indicated that ultrasound may serve as a feasible alternative for noninvasive monitoring the evolution of scaffolds in situ during cell growth. Yan Chen, Yuting Yan, Xiaoming Li, He Li, Huiting Tan, Huajun Li, Yanwen Zhu, Philipp Niemeyer, Matin Yaega, and Bo Yu Copyright © 2014 Yan Chen et al. All rights reserved. Reduction-Triggered Breakable Micelles of Amphiphilic Polyamide Amine-g-Polyethylene Glycol for Methotrexate Delivery Sun, 13 Apr 2014 16:13:19 +0000 Reduction-triggered breakable polymeric micelles incorporated with MTX were prepared using amphiphilic PAA-g-PEG copolymers having S–S bonds in the backbone. The micelles were spherical with diameters less than 70 nm. The micelles could encapsulate the hydrophobic MTX in the hydrophobic core. The drug loading content and drug loading efficiency of the micelles were highly dependent on the copolymer chemical structure, ranging from 2.9 to 7.5% and 31.9 to 82.5%, respectively. Both the drug loading content and drug loading efficiency increased along with more hydrophobic segments in the copolymers. In normal circumstance, these micelles were capable of keeping stable and hold most of the MTX in the core, stabilizing the incorporated MTX through the stacking with the phenyl groups in the backbone of the copolymers. In reductive environments that mimicked the intracellular compartments, the entire MTX payload could be quickly released due to the reduction-triggered breakage of the micelles. These micelles showed good antiproliferative activity against several cancer cell lines, including KB, 4T-1 and HepG2, especially within the low drug concentration scope. Yihang Huang, Jun Liu, Yani Cui, Huanan Li, Yong Sun, Yujiang Fan, and Xingdong Zhang Copyright © 2014 Yihang Huang et al. All rights reserved. Suppressive Effects of D-Glucosamine on the 5-HT Sensitive Nociceptive Units in the Rat Tooth Pulpal Nerve Sun, 13 Apr 2014 00:00:00 +0000 It is well known that D-glucosamine hydrochloride (DGL) has a variety of biological activities and is regarded as a nutritional supplement effective in improving various disorders, including osteoarthritis and atherosclerosis. Although it has been reported that DGL has a significant pain relief effect in treating osteoarthritis, little is known about the characteristics of the effects of this compound on dental pain. The present study was undertaken to evaluate the applicability of DGL as a medicament to control pulpalgia. Using an in vitro rat mandible-inferior alveolar nerve preparation (jaw-nerve preparation), we evaluated the effects of DGL on 5-hydroxytryptamine (5-HT) sensitive nociceptive responses in the tooth pulpal nerve. 5-HT-induced nociceptive responses were fairly suppressed by direct application of DGL, suggesting that DGL have a pain relief effect on patients with dental pain. Kei Kaida, Hiromi Yamashita, Kazuo Toda, and Yoshihiko Hayashi Copyright © 2014 Kei Kaida et al. All rights reserved. Distinct Characteristics of Mandibular Bone Collagen Relative to Long Bone Collagen: Relevance to Clinical Dentistry Thu, 10 Apr 2014 09:31:29 +0000 Bone undergoes constant remodeling throughout life. The cellular and biochemical mechanisms of bone remodeling vary in a region-specific manner. There are a number of notable differences between the mandible and long bones, including developmental origin, osteogenic potential of mesenchymal stem cells, and the rate of bone turnover. Collagen, the most abundant matrix protein in bone, is responsible for determining the relative strength of particular bones. Posttranslational modifications of collagen, such as intermolecular crosslinking and lysine hydroxylation, are the most essential determinants of bone strength, although the amount of collagen is also important. In comparison to long bones, the mandible has greater collagen content, a lower amount of mature crosslinks, and a lower extent of lysine hydroxylation. The great abundance of immature crosslinks in mandibular collagen suggests that there is a lower rate of cross-link maturation. This means that mandibular collagen is relatively immature and thus more readily undergoes degradation and turnover. The greater rate of remodeling in mandibular collagen likely renders more flexibility to the bone and leaves it more suited to constant exercise. As reviewed here, it is important in clinical dentistry to understand the distinctive features of the bones of the jaw. Takashi Matsuura, Kentaro Tokutomi, Michiko Sasaki, Michitsuna Katafuchi, Emiri Mizumachi, and Hironobu Sato Copyright © 2014 Takashi Matsuura et al. All rights reserved. Outer Electrospun Polycaprolactone Shell Induces Massive Foreign Body Reaction and Impairs Axonal Regeneration through 3D Multichannel Chitosan Nerve Guides Wed, 09 Apr 2014 14:10:24 +0000 We report on the performance of composite nerve grafts with an inner 3D multichannel porous chitosan core and an outer electrospun polycaprolactone shell. The inner chitosan core provided multiple guidance channels for regrowing axons. To analyze the in vivo properties of the bare chitosan cores, we separately implanted them into an epineural sheath. The effects of both graft types on structural and functional regeneration across a 10 mm rat sciatic nerve gap were compared to autologous nerve transplantation (ANT). The mechanical biomaterial properties and the immunological impact of the grafts were assessed with histological techniques before and after transplantation in vivo. Furthermore during a 13-week examination period functional tests and electrophysiological recordings were performed and supplemented by nerve morphometry. The sheathing of the chitosan core with a polycaprolactone shell induced massive foreign body reaction and impairment of nerve regeneration. Although the isolated novel chitosan core did allow regeneration of axons in a similar size distribution as the ANT, the ANT was superior in terms of functional regeneration. We conclude that an outer polycaprolactone shell should not be used for the purpose of bioartificial nerve grafting, while 3D multichannel porous chitosan cores could be candidate scaffolds for structured nerve grafts. Sven Duda, Lutz Dreyer, Peter Behrens, Soenke Wienecke, Tanmay Chakradeo, Birgit Glasmacher, and Kirsten Haastert-Talini Copyright © 2014 Sven Duda et al. All rights reserved. Dried Fruit of the Luffa Sponge as a Source of Chitin for Applications as Skin Substitutes Wed, 09 Apr 2014 09:00:03 +0000 LUFFACHITIN obtained from the residue of the sponge-like dried fruit of Luffa aegyptiaca was developed as a weavable skin substitute in this study. A chemical analysis revealed that LUFFACHITIN was composed of a copolymer containing N-acetyl-glucosamine (~40%) as a major monomer with a filamentary structure as demonstrated by both optical and scanning electron microscopy. The pulp-like white residue of the sponge-like dried fruit of Luffa aegyptiaca after treatment was then woven into a thin, porous membrane by filtration and lyophilization as a skin substitute for conducting wound-healing study on rats. The results indicated that the LUFFACHITIN membrane showed significant wound-healing enhancement (25 days to complete healing) compared to cotton gauze (>30 days), but not inferior to that of SACCHACHITIN. Furthermore, the LUFFACHITIN membrane had advantages of having a high yield, better physical properties for fabrication, and a more attractive appearance. Ping-Lun Jiang, Mei-Yin Chien, Ming-Thau Sheu, Yi-You Huang, Meng-Hsun Chen, Ching-Hua Su, and Der-Zen Liu Copyright © 2014 Ping-Lun Jiang et al. All rights reserved. Solubility of Two Resin Composites in Different Mouthrinses Mon, 07 Apr 2014 16:29:59 +0000 Aim. This study aimed to compare the solubility of a universal restorative resin composite (Filtek Z250; FZ250) and a silorane-based resin composite (Filtek Silorane; FS) after immersion in alcohol-containing mouthrinse, alcohol-free mouthrinse, and artificial saliva. Methods. 30 discs (10 mm × 1 mm) were prepared from each material and desiccated until a constant mass was obtained. Specimens were immersed in the test solutions for two days and desiccated again. Solubility was calculated based on the change in weight of each specimen before and after immersion. Data was analyzed using two-way ANOVA and Tukey’s Post Hoc test . Results. Solubility values for both resin composites were the highest in the alcohol-containing mouthrinse. FZ250 showed greater solubility than FS; the difference was only significant in artificial saliva. Conclusion. Both resin-composite materials tested exhibited some degree of solubility in each of the test solutions. The use of an alcohol-free mouthrinse may be preferable for patients with extensive composite restorations. Sezin Ozer, Emine Sen Tunc, Nuray Tuloglu, and Sule Bayrak Copyright © 2014 Sezin Ozer et al. All rights reserved. Biological Safety of Fish (Tilapia) Collagen Mon, 07 Apr 2014 06:53:08 +0000 Marine collagen derived from fish scales, skin, and bone has been widely investigated for application as a scaffold and carrier due to its bioactive properties, including excellent biocompatibility, low antigenicity, and high biodegradability and cell growth potential. Fish type I collagen is an effective material as a biodegradable scaffold or spacer replicating the natural extracellular matrix, which serves to spatially organize cells, providing them with environmental signals and directing site-specific cellular regulation. This study was conducted to confirm the safety of fish (tilapia) atelocollagen for use in clinical application. We performed in vitro and in vivo biological studies of medical materials to investigate the safety of fish collagen. The extract of fish collagen gel was examined to clarify its sterility. All present sterility tests concerning bacteria and viruses (including endotoxin) yielded negative results, and all evaluations of cell toxicity, sensitization, chromosomal aberrations, intracutaneous reactions, acute systemic toxicity, pyrogenic reactions, and hemolysis were negative according to the criteria of the ISO and the Ministry of Health, Labour and Welfare. The present study demonstrated that atelocollagen prepared from tilapia is a promising biomaterial for use as a scaffold in regenerative medicine. Kohei Yamamoto, Kazunari Igawa, Kouji Sugimoto, Yuu Yoshizawa, Kajiro Yanagiguchi, Takeshi Ikeda, Shizuka Yamada, and Yoshihiko Hayashi Copyright © 2014 Kohei Yamamoto et al. All rights reserved. Glycosaminoglycan Monosaccharide Blocks Analysis by Quantum Mechanics, Molecular Dynamics, and Nuclear Magnetic Resonance Mon, 07 Apr 2014 06:49:57 +0000 Glycosaminoglycans (GAGs) play an important role in many biological processes in the extracellular matrix. In a theoretical approach, structures of monosaccharide building blocks of natural GAGs and their sulfated derivatives were optimized by a B3LYP6311ppdd//B3LYP/6-31+G(d) method. The dependence of the observed conformational properties on the applied methodology is described. NMR chemical shifts and proton-proton spin-spin coupling constants were calculated using the GIAO approach and analyzed in terms of the method's accuracy and sensitivity towards the influence of sulfation, O1-methylation, conformations of sugar ring, and ω dihedral angle. The net sulfation of the monosaccharides was found to be correlated with the 1H chemical shifts in the methyl group of the N-acetylated saccharides both theoretically and experimentally. The ω dihedral angle conformation populations of free monosaccharides and monosaccharide blocks within polymeric GAG molecules were calculated by a molecular dynamics approach using the GLYCAM06 force field and compared with the available NMR and quantum mechanical data. Qualitative trends for the impact of sulfation and ring conformation on the chemical shifts and proton-proton spin-spin coupling constants were obtained and discussed in terms of the potential and limitations of the computational methodology used to be complementary to NMR experiments and to assist in experimental data assignment. Sergey A. Samsonov, Stephan Theisgen, Thomas Riemer, Daniel Huster, and M. Teresa Pisabarro Copyright © 2014 Sergey A. Samsonov et al. All rights reserved. The Morphology and Functions of Articular Chondrocytes on a Honeycomb-Patterned Surface Sun, 06 Apr 2014 12:20:46 +0000 The present study investigated the potential of a novel micropatterned substrate for neocartilage formation. Articular chondrocytes were cultured on poly(ɛ-caprolactone) materials whose surfaces were either flat or honeycomb-patterned. The latter was prepared using a novel self-organization technique, while the former, was prepared by spin-coating. The chondrocytes attached and proliferated on both surfaces. On the honeycomb films, chondrocytes were found at the top surface and encased within the 10 μm pores. Meanwhile, chondrocytes on the spin-coated surface flattened out. Accumulation of DNA and keratin sulphate was comparatively higher on the honeycomb films within the first 7 days. At their respective peaks, DNA concentration increased on the honeycomb and flat surfaces by approximately 210% and 400% of their day 1 values, respectively. However, cultures on the flat surface took longer to peak. Extracellular Matrix (ECM) concentrations peaked at 900% and 320% increases for the honeycomb and flat cultures. Type II collagen was upregulated on the honeycomb and flat surfaces by as much as 28% and 25% of their day 1 values, while aggrecan was downregulated with time, by 3.4% and 7.4%. These initial results demonstrate the potential usefulness of honeycomb-based scaffolds during early cultures neocartilage and soft tissue engineering. Joshua O. Eniwumide, Masaru Tanaka, Nobuhiro Nagai, Yuka Morita, Joost de Bruijn, Sadaaki Yamamoto, Shin Onodera, Eiji Kondo, Kazunori Yasuda, and Masatsugu Shimomura Copyright © 2014 Joshua O. Eniwumide et al. All rights reserved. Fabrication and Characteristics of Chitosan Sponge as a Tissue Engineering Scaffold Sun, 06 Apr 2014 11:42:29 +0000 Cells, growth factors, and scaffolds are the three main factors required to create a tissue-engineered construct. After the appearance of bovine spongiform encephalopathy (BSE), considerable attention has therefore been focused on nonbovine materials. In this study, we examined the properties of a chitosan porous scaffold. A porous chitosan sponge was prepared by the controlled freezing and lyophilization of different concentrations of chitosan solutions. The materials were examined by scanning electron microscopy, and the porosity, tensile strength, and basic fibroblast growth factor (bFGF) release profiles from chitosan sponge were examined in vitro. The morphology of the chitosan scaffolds presented a typical microporous structure, with the pore size ranging from 50 to 200 μm. The porosity of chitosan scaffolds with different concentrations was approximately 75–85%. A decreasing tendency for porosity was observed as the concentration of the chitosan increased. The relationship between the tensile properties and chitosan concentration indicated that the ultimate tensile strength for the sponge increased with a higher concentration. The in vitro bFGF release study showed that the higher the concentration of chitosan solution became, the longer the releasing time of the bFGF from the chitosan sponge was. Takeshi Ikeda, Kahori Ikeda, Kouhei Yamamoto, Hidetaka Ishizaki, Yuu Yoshizawa, Kajiro Yanagiguchi, Shizuka Yamada, and Yoshihiko Hayashi Copyright © 2014 Takeshi Ikeda et al. All rights reserved. Induction of Reparative Dentin Formation on Exposed Dental Pulp by Dentin Phosphophoryn/Collagen Composite Sun, 06 Apr 2014 09:28:04 +0000 The ultimate goal of vital pulp therapy is to regenerate rapidly dentin possessing an excellent quality using a biocompatible, bioactive agent. Dentin phosphophoryn (DPP), the most abundant noncollagenous polyanionic protein in dentin, cross-linked to atelocollagen fibrils was applied to direct pulp capping in rats. After 1, 2, and 3 weeks, the teeth applied were examined on the induction of reparative dentin formation and the response of pulp tissue, compared to calcium hydroxide-based agent conventionally used. The reparative dentin formation induced by DPP/collagen composite was more rapid than by calcium hydroxide. In the morphometrical analysis, the formation rate of reparative dentin by DPP/collagen composite was approximately the same as that by calcium hydroxide at 3 weeks. Nevertheless, the compactness of reparative dentin formed by DPP/collagen composite was much superior to what resulted from calcium hydroxide. Also, DPP/collagen composite showed high covering ability of exposed pulp. Moreover, DPP/collagen composite led only to slight pulp inflammation at the beginning whereas calcium hydroxide formed necrotic layer adjacent to the material and induced severe inflammation in pulp tissue at 1 week. The present study demonstrates a potential for DPP/collagen composite as a rapid biocompatible inducer for the formation of reparative dentin of excellent quality in rats. Toshiyuki Koike, Mohammad Ali Akbor Polan, Masanobu Izumikawa, and Takashi Saito Copyright © 2014 Toshiyuki Koike et al. All rights reserved. Effect of Ultrasonication on Physical Properties of Mineral Trioxide Aggregate Tue, 01 Apr 2014 16:09:32 +0000 Aim. To evaluate the effect on physical properties of Mineral Trioxide Aggregate (MTA) of using direct hand compaction during placement and when using hand compaction with indirect ultrasonic activation with different application times. Methods. One hundred acrylic canals were obturated in 3 increments with MTA in sample sizes of 10. One group was obturated by hand with an endodontic plugger and the remainder obturated with indirect ultrasonic application, with times ranging from 2 seconds to 18 seconds per increment. Microhardness values, dye penetration depths, and radiographs of the samples were evaluated. Results. As ultrasonic application time per increment increased, microhardness values fell significantly while dye penetration values increased . Microhardness of MTA ultrasonicated for 2 seconds was significantly higher than hand compaction . Most radiographic voids were visible in the hand-compacted group , which also had higher dye penetration depths than the 2-second ultrasonicated samples. Ultrasonication of MTA for 10–18 seconds resulted in significantly more voids than 2–8 seconds of ultrasonication . Conclusion. The use of ultrasonics with MTA improved the compaction and flow of MTA, but excessive ultrasonication adversely affected MTA properties. A time of 2 seconds of ultrasonication per increment presented the best compromise between microhardness values, dye penetration depths, and lack of radiographic voids. Peter Parashos, Amanda Phoon, and Chankhrit Sathorn Copyright © 2014 Peter Parashos et al. All rights reserved. Characterization of Genipin-Modified Dentin Collagen Tue, 25 Mar 2014 11:23:04 +0000 Application of biomodification techniques to dentin can improve its biochemical and biomechanical properties. Several collagen cross-linking agents have been reported to strengthen the mechanical properties of dentin. However, the characteristics of collagen that has undergone agent-induced biomodification are not well understood. The objective of this study was to analyze the effects of a natural cross-linking agent, genipin (GE), on dentin discoloration, collagen stability, and changes in amino acid composition and lysyl oxidase mediated natural collagen cross-links. Dentin collagen obtained from extracted bovine teeth was treated with three different concentrations of GE (0.01%, 0.1%, and 0.5%) for several treatment times (0–24 h). Changes in biochemical properties of NaB3H4-reduced collagen were characterized by amino acid and cross-link analyses. The treatment of dentin collagen with GE resulted in a concentration- and time-dependent pigmentation and stability against bacterial collagenase. The lysyl oxidase-mediated trivalent mature cross-link, pyridinoline, showed no difference among all groups while the major divalent immature cross-link, dehydro-dihydroxylysinonorleucine/its ketoamine in collagen treated with 0.5% GE for 24 h, significantly decreased compared to control (). The newly formed GE-induced cross-links most likely involve lysine and hydroxylysine residues of collagen in a concentration-dependent manner. Some of these cross-links appear to be reducible and stabilized with NaB3H4. Hiroko Nagaoka, Hideaki Nagaoka, Ricardo Walter, Lee W. Boushell, Patricia A. Miguez, Andrew Burton, André V. Ritter, and Mitsuo Yamauchi Copyright © 2014 Hiroko Nagaoka et al. All rights reserved. D-Glucosamine Conjugation Accelerates the Labeling Efficiency of Quantum Dots in Osteoblastic Cells Mon, 24 Mar 2014 08:47:48 +0000 Quantum dots (QDs) are useful imaging tools in the medical and biological fields due to their optical properties, such as a high fluorescence intensity, remarkable resistance to photobleaching, broad absorption spectra, and narrow emission spectra. This is the first study to investigate the uptake of carboxylated QDs conjugated with D-glucosamine (core size: approximately 3 nm, final modified size: 20–30 nm) into cultured osteoblastic cells. The QDs attached to the cell surface and were transported into the cytoplasm within approximately three hours of culture, whose process was clearly demonstrated using specific fluorescent staining of the cell membrane. Although the intranuclear distribution was not observed, a dramatic decrease in the transfer of quantum dots into the cytoplasm was recognized after approximately seven days of culture. Other interesting phenomena include the escape of the quantum dots from lysosomes in the cytoplasm, as confirmed by the merging of both QD fluorescence and specific fluorescent staining of lysosomes in the cytoplasm. These findings suggest that D-glucosamine conjugation enhances proton absorption in acid organelles and promotes the lysosomal escape of QDs. Kazunari Igawa, Ming-Fang Xie, Hideki Ohba, Shizuka Yamada, and Yoshihiko Hayashi Copyright © 2014 Kazunari Igawa et al. All rights reserved. Acute and Subacute Toxicity In Vivo of Thermal-Sprayed Silver Containing Hydroxyapatite Coating in Rat Tibia Thu, 20 Mar 2014 09:45:21 +0000 To reduce the incidence of implant-associated infection, we previously developed a novel coating technology using hydroxyapatite (HA) containing silver (Ag). This study examined in vivo acute and subacute toxicity associated with the Ag-HA coating in rat tibiae. Ten-week-old rats received implantation of HA-, 2% Ag-HA-, or 50% Ag-HA-coated titanium rods. Concentrations of silver in serum, brain, liver, kidneys, and spleen were measured in the acute phase (2–4 days after treatment) and subacute phase (4–12 weeks after treatment). Biochemical and histological examinations of those organs were also performed. Mean serum silver concentration peaked in the acute phase and then gradually decreased. Mean silver concentrations in all examined organs from the 2% Ag-HA coating groups showed no significant differences compared with the HA coating group. No significant differences in mean levels of glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, lactate dehydrogenase, creatinine, or blood urea nitrogen were seen between the three groups and controls. Histological examinations of all organs revealed no abnormal pathologic findings. No acute or subacute toxicity was seen in vivo for 2% Ag-HA coating or HA coating. Ag-HA coatings on implants may represent biologically safe antibacterial biomaterials and may be of value for reducing surgical-site infections related to implantation. Masatsugu Tsukamoto, Hiroshi Miyamoto, Yoshiki Ando, Iwao Noda, Shuichi Eto, Takayuki Akiyama, Yutaka Yonekura, Motoki Sonohata, and Masaaki Mawatari Copyright © 2014 Masatsugu Tsukamoto et al. All rights reserved. Effects of Prepolymerized Particle Size and Polymerization Kinetics on Volumetric Shrinkage of Dental Modeling Resins Mon, 17 Mar 2014 09:25:35 +0000 Dental modeling resins have been developed for use in areas where highly precise resin structures are needed. The manufacturers claim that these polymethyl methacrylate/methyl methacrylate (PMMA/MMA) resins show little or no shrinkage after polymerization. This study examined the polymerization shrinkage of five dental modeling resins as well as one temporary PMMA/MMA resin (control). The morphology and the particle size of the prepolymerized PMMA powders were investigated by scanning electron microscopy and laser diffraction particle size analysis, respectively. Linear polymerization shrinkage strains of the resins were monitored for 20 minutes using a custom-made linometer, and the final values (at 20 minutes) were converted into volumetric shrinkages. The final volumetric shrinkage values for the modeling resins were statistically similar () or significantly larger () than that of the control resin and were related to the polymerization kinetics () rather than the PMMA bead size (). Therefore, the optimal control of the polymerization kinetics seems to be more important for producing high-precision resin structures rather than the use of dental modeling resins. Tae-Yub Kwon, Jung-Yun Ha, Ju-Na Chun, Jun Sik Son, and Kyo-Han Kim Copyright © 2014 Tae-Yub Kwon et al. All rights reserved. A Proteomic View to Characterize the Effect of Chitosan Nanoparticle to Hepatic Cells: Is Chitosan Nanoparticle an Enhancer of PI3K/AKT1/mTOR Pathway? Sun, 16 Mar 2014 12:37:43 +0000 Chitosan nanoparticle, a biocompatible material, was used as a potential drug delivery system widely. Our current investigation studies were the bioeffects of the chitosan nanoparticle uptake by liver cells. In this experiment, the characterizations of chitosan nanoparticles were measured by transmission electron microscopy and particle size analyzer. The average size of the chitosan nanoparticle was  nm, and the average zeta potential was  mV. Moreover, using proteomic approaches to analyze the differential protein expression patterns resulted from the chitosan nanoparticle uptaken by HepG2 and CCL-13 cells identified several proteins involved in the PI3K/AKT1/mTOR pathway. Our experimental results have demonstrated that the chitosan nanoparticle may involve in the liver cancer cell metastasis and proliferation. Ming-Hui Yang, Shyng-Shiou Yuan, Ying-Fong Huang, Po-Chiao Lin, Chi-Yu Lu, Tze-Wen Chung, and Yu-Chang Tyan Copyright © 2014 Ming-Hui Yang et al. All rights reserved.