International Journal of Biomaterials The latest articles from Hindawi © 2017 , Hindawi Limited . All rights reserved. Comparative Effectiveness of Bone Grafting Using Xenograft Freeze-Dried Cortical Bovine, Allograft Freeze-Dried Cortical New Zealand White Rabbit, Xenograft Hydroxyapatite Bovine, and Xenograft Demineralized Bone Matrix Bovine in Bone Defect of Femoral Diaphysis of White Rabbit: Experimental Study In Vivo Thu, 28 Sep 2017 08:31:10 +0000 Autogenous bone graft is gold standard in treating bone defects, but it might have difficulty in corporation and rejection reaction. This study is to compare the effectiveness among freeze-dried xenograft, freeze-dried allograft, hydroxyapatite xenograft, and demineralized bone matrix xenograft as bone graft to fill bone defect in femoral diaphysis of white rabbit. Thirty male New Zealand white rabbits were distributed into five groups. Bone defect was filled correspondingly with xenograft freeze-dried cortical bovine, allograft freeze-dried cortical New Zealand white rabbit, xenograft hydroxyapatite bovine, and xenograft demineralized bone matrix bovine. No graft was used in control group. VEGF, osteoblast, and woven bone were higher in allograft freeze-dried cortical New Zealand white rabbit (mean 5.6625 ()) and xenograft demineralized bone matrix bovine (mean 5.2475 ()) with calcification of woven bone was already seen in week 2 in the latter group. There was a decrease of woven bone (mean 4.685 ()) fibrous tissue (mean 41.07 ()) in xenograft demineralized bone matrix bovine. The Immunoglobulin-G was elevated in control and all study groups but not significantly (). Bone healing process in xenograft demineralized bone matrix bovine is more effective than in xenograft hydroxyapatite bovine, allograft freeze-dried New Zealand white rabbit, xenograft freeze-dried cortical bovine, and control. Ferdiansyah Mahyudin, Dwikora Novembri Utomo, Heri Suroto, Tri Wahyu Martanto, Mouli Edward, and Imelda Lumban Gaol Copyright © 2017 Ferdiansyah Mahyudin et al. All rights reserved. Effect of Injection Molding Melt Temperatures on PLGA Craniofacial Plate Properties during In Vitro Degradation Wed, 06 Sep 2017 10:17:08 +0000 The purpose of this article is to present mechanical and physicochemical properties during in vitro degradation of PLGA material as craniofacial plates based on different values of injection molded temperatures. Injection molded plates were submitted to in vitro degradation in a thermostat bath at 37 ± 1°C by 16 weeks. The material was removed after 15, 30, 60, and 120 days; then bending stiffness, crystallinity, molecular weights, and viscoelasticity were studied. A significant decrease of molecular weight and mechanical properties over time and a difference in FT-IR after 60 days showed faster degradation of the material in the geometry studied. DSC analysis confirmed that the crystallization occurred, especially in higher melt temperature condition. DMA analysis suggests a greater contribution of the viscous component of higher temperature than lower temperature in thermomechanical behavior. The results suggest that physical-mechanical properties of PLGA plates among degradation differ per injection molding temperatures. Liliane Pimenta de Melo, Gean Vitor Salmoria, Eduardo Alberto Fancello, and Carlos Rodrigo de Mello Roesler Copyright © 2017 Liliane Pimenta de Melo et al. All rights reserved. Influence of Vanadium 4+ and 5+ Ions on the Differentiation and Activation of Human Osteoclasts Tue, 29 Aug 2017 08:59:58 +0000 Background. In the pathophysiology of implant failure, metal ions and inflammation-driven osteoclasts (OC) play a crucial role. The aim of this study was to investigate whether vanadium (V) ions induce differentiation of monocytic OC precursors into osteoresorptive multinucleated cells. In addition, the influence of V ions on the activation and function of in vitro generated OC was observed. Methods. Human monocytes and osteoclasts were isolated from peripheral blood monocytic cells (PBMCs). Exposition with increasing concentrations (0–3 μM) of V4+/V5+ ions for 7 days followed. Assessment of OC differentiation, cell viability, and resorptional ability was performed by standard colorimetric cell viability assay 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenil)-2H-tetrazolium (MTS), tartrate-resistant acid phosphatase (TRAP) expression, and functional resorption assays on bone slides during a period of 21 days. Results. No significant differences were noted between V4+/V5+ ions (). MTS showed significant reduction in cellular viability by V concentrations above 3 μM (). V concentrations above 0.5 μM showed negative effects on OC activation/differentiation. Higher V concentrations showed negative effects on resorptive function (all ) without affecting cell viability. V4+/V5+ concentrations below 3 μM have negative effects on OC differentiation/function without affecting cell survival. Conclusion. Vanadium-containing implants may reduce implant failure rate by influencing osteoclast activity at the bone-implant interface. V-ligand complexes might offer new treatment options by accumulating in the bone. Matthias A. König, Oliver P. Gautschi, Hans-Peter Simmen, Luis Filgueira, and Dieter Cadosch Copyright © 2017 Matthias A. König et al. All rights reserved. Silicone Substrate with Collagen and Carbon Nanotubes Exposed to Pulsed Current for MSC Osteodifferentiation Wed, 23 Aug 2017 00:00:00 +0000 Autologous human adipose tissue-derived mesenchymal stem cells (MSCs) have the potential for clinical translation through their induction into osteoblasts for regeneration. Bone healing can be driven by biophysical stimulation using electricity for activating quiescent adult stem cells. It is hypothesized that application of electric current will enhance their osteogenic differentiation, and addition of conductive carbon nanotubes (CNTs) to the cell substrate will provide increased efficiency in current transmission. Cultured MSCs were seeded and grown onto fabricated silicone-based composites containing collagen and CNT fibers. Chemical inducers, namely, glycerol phosphate, dexamethasone, and vitamin C, were then added to the medium, and pulsatile submilliampere electrical currents (about half mA for 5 cycles at 4 mHz, twice a week) were applied for two weeks. Calcium deposition indicative of MSC differentiation and osteoblastic activity was quantified through Alizarin Red S and spectroscopy. It was found that pulsed current significantly increased osteodifferentiation on silicone-collagen films without CNTs. Under no external current, the presence of 10% (m/m) CNTs led to a significant and almost triple upregulation of calcium deposition. Both CNTs and current parameters did not appear to be synergistic. These conditions of enhanced osteoblastic activities may further be explored ultimately towards future therapeutic use of MSCs. Daniyal Jamal and Roche C. de Guzman Copyright © 2017 Daniyal Jamal and Roche C. de Guzman. All rights reserved. Influence of Processing Conditions on the Mechanical Behavior and Morphology of Injection Molded Poly(lactic-co-glycolic acid) 85:15 Mon, 07 Aug 2017 00:00:00 +0000 Two groups of PLGA specimens with different geometries (notched and unnotched) were injection molded under two melting temperatures and flow rates. The mechanical properties, morphology at the fracture surface, and residual stresses were evaluated for both processing conditions. The morphology of the fractured surfaces for both specimens showed brittle and smooth fracture features for the majority of the specimens. Fracture images of the notched specimens suggest that the surface failure mechanisms are different from the core failure. Polarized light techniques indicated birefringence in all specimens, especially those molded with lower temperature, which suggests residual stress due to rapid solidification. DSC analysis confirmed the existence of residual stress in all PLGA specimens. The specimens molded using the lower injection temperature and the low flow rate presented lower loss tangent values according to the DMA and higher residual stress as shown by DSC, and the photoelastic analysis showed extensive birefringence. Liliane Pimenta de Melo, Gean Vitor Salmoria, Eduardo Alberto Fancello, and Carlos Rodrigo de Mello Roesler Copyright © 2017 Liliane Pimenta de Melo et al. All rights reserved. Intrinsic Osteoinductivity of Porous Titanium Scaffold for Bone Tissue Engineering Wed, 26 Jul 2017 07:38:10 +0000 Large bone defects and nonunions are serious complications that are caused by extensive trauma or tumour. As traditional therapies fail to repair these critical-sized defects, tissue engineering scaffolds can be used to regenerate the damaged tissue. Highly porous titanium scaffolds, produced by selective laser sintering with mechanical properties in range of trabecular bone (compressive strength 35 MPa and modulus 73 MPa), can be used in these orthopaedic applications, if a stable mechanical fixation is provided. Hydroxyapatite coatings are generally considered essential and/or beneficial for bone formation; however, debonding of the coatings is one of the main concerns. We hypothesised that the titanium scaffolds have an intrinsic potential to induce bone formation without the need for a hydroxyapatite coating. In this paper, titanium scaffolds coated with hydroxyapatite using electrochemical method were fabricated and osteoinductivity of coated and noncoated scaffolds was compared in vitro. Alizarin Red quantification confirmed osteogenesis independent of coating. Bone formation and ingrowth into the titanium scaffolds were evaluated in sheep stifle joints. The examinations after 3 months revealed 70% bone ingrowth into the scaffold confirming its osteoinductive capacity. It is shown that the developed titanium scaffold has an intrinsic capacity for bone formation and is a suitable scaffold for bone tissue engineering. Maryam Tamaddon, Sorousheh Samizadeh, Ling Wang, Gordon Blunn, and Chaozong Liu Copyright © 2017 Maryam Tamaddon et al. All rights reserved. Magnesium Oxide Nanoparticles Reinforced Electrospun Alginate-Based Nanofibrous Scaffolds with Improved Physical Properties Sun, 11 Jun 2017 00:00:00 +0000 Mechanically robust alginate-based nanofibrous scaffolds were successfully fabricated by electrospinning method to mimic the natural extracellular matrix structure which benefits development and regeneration of tissues. Alginate-based nanofibres were electrospun from an alginate/poly(vinyl alcohol) (PVA) polyelectrolyte complex. SEM images revealed the spinnability of the complex composite nanofibrous scaffolds, showing randomly oriented, ultrafine, and virtually defects-free alginate-based/MgO nanofibrous scaffolds. Here, it is shown that an alginate/PVA complex scaffold, blended with near-spherical MgO nanoparticles (⌀ 45 nm) at a predetermined concentration (10% (w/w)), is electrospinnable to produce a complex composite nanofibrous scaffold with enhanced mechanical stability. For the comparison purpose, chemically cross-linked electrospun alginate-based scaffolds were also fabricated. Tensile test to rupture revealed the significant differences in the tensile strength and elastic modulus among the alginate scaffolds, alginate/MgO scaffolds, and cross-linked alginate scaffolds (). In contrast to cross-linked alginate scaffolds, alginate/MgO scaffolds yielded the highest tensile strength and elastic modulus while preserving the interfibre porosity of the scaffolds. According to the thermogravimetric analysis, MgO reinforced alginate nanofibrous scaffolds exhibited improved thermal stability. These novel alginate-based/MgO scaffolds are economical and versatile and may be further optimised for use as extracellular matrix substitutes for repair and regeneration of tissues. R. T. De Silva, M. M. M. G. P. G. Mantilaka, K. L. Goh, S. P. Ratnayake, G. A. J. Amaratunga, and K. M. Nalin de Silva Copyright © 2017 R. T. De Silva et al. All rights reserved. Novel Nanotechnology of TiO2 Improves Physical-Chemical and Biological Properties of Glass Ionomer Cement Mon, 22 May 2017 10:00:41 +0000 The aim of this study was to assess the performance of glass ionomer cement (GIC) added with TiO2 nanotubes. TiO2 nanotubes [3%, 5%, and 7% (w/w)] were incorporated into GIC’s (Ketac Molar EasyMix™) powder component, whereas unblended powder was used as control. Physical-chemical-biological analysis included energy dispersive spectroscopy (EDS), surface roughness (SR), Knoop hardness (SH), fluoride-releasing analysis, cytotoxicity, cell morphology, and extracellular matrix (ECM) composition. Parametric or nonparametric ANOVA were used for statistical comparisons (). Data analysis revealed that EDS only detected Ti at the 5% and 7% groups and that GIC’s physical-chemical properties were significantly improved by the addition of 5% TiO2 as compared to 3% and GIC alone. Furthermore, regardless of TiO2 concentration, no significant effect was found on SR, whereas GIC-containing 7% TiO2 presented decreased SH values. Fluoride release lasted longer for the 5% and 7% TiO2 groups, and cell morphology/spreading and ECM composition were found to be positively affected by TiO2 at 5%. In conclusion, in the current study, nanotechnology incorporated in GIC affected ECM composition and was important for the superior microhardness and fluoride release, suggesting its potential for higher stress-bearing site restorations. Daniela Dellosso Cibim, Miki Taketomi Saito, Priscila Alves Giovani, Ana Flávia Sanches Borges, Vanessa Gallego Arias Pecorari, Orisson Ponce Gomes, Paulo Noronha Lisboa-Filho, Francisco Humberto Nociti-Junior, Regina Maria Puppin-Rontani, and Kamila Rosamilia Kantovitz Copyright © 2017 Daniela Dellosso Cibim et al. All rights reserved. Fabrication of Polycaprolactone/Polyurethane Loading Conjugated Linoleic Acid and Its Antiplatelet Adhesion Tue, 16 May 2017 07:20:11 +0000 Polycaprolactone/polyurethane (PCL/PU) fibrous scaffold was loaded with conjugated linoleic acid (CLA) by electrospinning method to improve the hemocompatibility of the polymeric surface. Fourier Transform Infrared Spectroscopy (FT-IR) analysis and Scanning Electron Microscopy (SEM) observation were employed to characterize the chemical structure and the changing morphology of electrospun PCL/PU and PCL/PU loaded with CLA (PCL/PU-CLA) scaffolds. Platelet adhesion and whole blood clot formation tests were used to evaluate the effect of CLA on antithrombotic property of PCL/PU-CLA scaffold. Endothelial cells (EC) were also seeded on the scaffold to examine the difference in the morphology of EC layer and platelet attachment with and without the presence of CLA. SEM results showed that CLA supported the spreading and proliferation of EC and PCL/PU-CLA surface induced lower platelet adhesion as well as attachment of other blood cells compared to the PCL/PU one. These results suggest that electrospinning method can successfully combine the antiplatelet effects of CLA to improve hemocompatibility of PCL/PU scaffolds for applications in artificial blood vessels. Ho Hieu Minh, Nguyen Thi Hiep, Nguyen Dai Hai, and Vo Van Toi Copyright © 2017 Ho Hieu Minh et al. All rights reserved. Stabilisation of Collagen Sponges by Glutaraldehyde Vapour Crosslinking Tue, 09 May 2017 00:00:00 +0000 Glutaraldehyde is a well-recognised reagent for crosslinking and stabilising collagens and other protein-based materials, including gelatine. In some cases, however, the use of solutions can disrupt the structure of the material, for example, by causing rapid dispersion or distortions from surface interactions. An alternative approach that has been explored in a number of individual cases is the use of glutaraldehyde vapour. In this study, the effectiveness of a range of different glutaraldehyde concentrations in the reservoir providing vapour, from 5% to 25% (w/v), has been explored at incubation times from 5 h to 48 h at room temperature. These data show the effectiveness of the glutaraldehyde vapour approach for crosslinking collagen and show that materials with defined, intermediate stability could be obtained, for example, to control resorption rates in vivo. Yong Y. Peng, Veronica Glattauer, and John A. M. Ramshaw Copyright © 2017 Yong Y. Peng et al. All rights reserved. Influence of Teeth Preparation Finishing on the Adaptation of Lithium Disilicate Crowns Thu, 23 Mar 2017 08:41:38 +0000 The polishing step of teeth preparations for crowns is a step often performed, so that there is an increased time during the clinical procedure. The aim of this study is to evaluate the marginal and internal adaptation of all-ceramic CAD/CAM lithium disilicate crowns in polished preparations for crown and nonpolished preparations for crowns. For this purpose, 20 first molars were selected, which were divided into two groups () G1, teeth that received surface roughening similar to preparation without polishing, and G2 (control), polished preparations. After the preparations were completed the teeth were scanned (Cerec Bluecam, Sirona, Bensheim, Germany), and the crowns were designed and machined using CAD/CAM technology (Sirona, Bensheim, Germany). The adaptation of the pieces was evaluated using polyvinyl siloxane replicas and stereomicroscope photographs with 70x magnifications. The normality test indicated a nonnormal result, so a Man–Whitney nonparametric test was performed. One out of the 24 measured regions showed a statistically significant difference (). With this study it can be concluded that crowns fabricated by CAD/CAM technology performed on unpolished preparations are not influenced by the internal marginal adaptation and the ceramic part and are different from polished preparations. Bruna Salamoni Sinhori, Mauro Amaral Caldeira de Andrada, Guilherme Carpena Lopes, Sylvio Monteiro Junior, and Luiz Narciso Baratieri Copyright © 2017 Bruna Salamoni Sinhori et al. All rights reserved. Development and In Vitro Evaluation of Liposomes Using Soy Lecithin to Encapsulate Paclitaxel Sun, 26 Feb 2017 11:44:34 +0000 The formulation of a potential delivery system based on liposomes (Lips) formulated from soy lecithin (SL) for paclitaxel (PTX) was achieved (PTX-Lips). At first, PTX-Lips were prepared by thin film method using SL and cholesterol and then were characterized for their physiochemical properties (particle size, polydispersity index, zeta potential, and morphology). The results indicated that PTX-Lips were spherical in shape with a dynamic light scattering (DLS) particle size of  nm. Besides, PTX was efficiently encapsulated in Lips, % for drug loading efficiency, and slowly released up to 96 h, compared with free PTX. More importantly, cell proliferation kit I (MTT) assay data showed that Lips were biocompatible nanocarriers, and in addition the incorporation of PTX into Lips has been proven successful in reducing the toxicity of PTX. As a result, development of Lips using SL may offer a stable delivery system and promising properties for loading and sustained release of PTX in cancer therapy. Thi Lan Nguyen, Thi Hiep Nguyen, and Dai Hai Nguyen Copyright © 2017 Thi Lan Nguyen et al. All rights reserved. New Biofunctional Loading of Natural Antimicrobial Agent in Biodegradable Polymeric Films for Biomedical Applications Mon, 14 Nov 2016 07:52:20 +0000 The study focuses on the development of novel Aloe vera based polymeric composite films and antimicrobial suture coatings. Polyvinyl alcohol (PVA), a synthetic biocompatible and biodegradable polymer, was combined with Aloe vera, a natural herb used for soothing burning effects and cosmetic purposes. The properties of these two materials were combined together to get additional benefits such as wound healing and prevention of surgical site infections. PVA and Aloe vera were mixed in a fixed quantity to produce polymer based films. The films were screened for antibacterial and antifungal activity against bacterial (E. coli, P. aeruginosa) and fungal strains (Aspergillus flavus and Aspergillus tubingensis) screened. Aloe vera based PVA films showed antimicrobial activity against all the strains; the lowest Aloe vera concentration (5%) showed the highest activity against all the strains. In vitro degradation and release profile of these films was also evaluated. The coating for sutures was prepared, in vitro antibacterial tests of these coated sutures were carried out, and later on in vivo studies of these coated sutures were also performed. The results showed that sutures coated with Aloe vera/PVA coating solution have antibacterial effects and thus have the potential to be used in the prevention of surgical site infections and Aloe vera/PVA based films have the potential to be used for wound healing purposes. Bakhtawar Ghafoor, Murtaza Najabat Ali, Umar Ansari, Muhammad Faraz Bhatti, Mariam Mir, Hafsah Akhtar, and Fatima Darakhshan Copyright © 2016 Bakhtawar Ghafoor et al. All rights reserved. Fracture Resistance of Endodontically Treated Maxillary Premolars Restored by Various Direct Filling Materials: An In Vitro Study Tue, 30 Aug 2016 13:44:51 +0000 The aim of this study is to compare the effect of various restorative materials on fracture resistance in maxillary premolars. Premolars () with no restorations or cracks were selected. MOD cavities were prepared considering the buccolingual width to be equal to half of the intercuspal distance. The specimens were randomly divided into 8 groups, 8 specimens each: group A intact teeth, group B unfilled cavity, group C composite made by oblique layering technique, group D composite with 2 mm cusp coverage, group E bulk-filled posterior composite, group F glass-ionomer, group G amalgam, and group H composite with proximal boxes. The specimens were subjected to an axial compression load with the mean values of fracture resistance in group A: 1289 N, group B: 181.75 N, group C: 445.38 N, group D: 645.88 N, group E: 355.13 N, group F: 352.00 N, group G: 191.38 N, and group H: 572.00 N. There was no significant difference between groups B and G, between C and D, E, and F, and between group D and H. All other measurements were statistically significant. We conclude that composite restoration with cusp coverage is the most ideal nonprosthetic solution for endodontically treated teeth. Cusp coverage increases the fracture resistance compared to the conventional cavity design. Jozef Mincik, Daniel Urban, Silvia Timkova, and Renata Urban Copyright © 2016 Jozef Mincik et al. All rights reserved. Silver Nanoparticles: Biosynthesis Using an ATCC Reference Strain of Pseudomonas aeruginosa and Activity as Broad Spectrum Clinical Antibacterial Agents Tue, 31 May 2016 08:14:51 +0000 Currently, the biosynthesis of silver-based nanomaterials attracts enormous attention owing to the documented antimicrobial properties of these ones. This study reports the extracellular biosynthesis of silver nanoparticles (Ag-NPs) using a Pseudomonas aeruginosa strain from a reference culture collection. A greenish culture supernatant of P. aeruginosa incubated at 37°C with a silver nitrate solution for 24 h changed to a yellowish brown color, indicating the formation of Ag-NPs, which was confirmed by UV-vis spectroscopy, transmission electron microscopy, and X-ray diffraction. TEM analysis showed spherical and pseudospherical nanoparticles with a distributed size mainly between 25 and 45 nm, and the XRD pattern revealed the crystalline nature of Ag-NPs. Also it provides an evaluation of the antimicrobial activity of the biosynthesized Ag-NPs against human pathogenic and opportunistic microorganisms, namely, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Proteus mirabilis, Acinetobacter baumannii, Escherichia coli, P. aeruginosa, and Klebsiella pneumonia. Ag-NPs were found to be bioactive at picomolar concentration levels showing bactericidal effects against both Gram-positive and Gram-negative bacterial strains. This work demonstrates the first helpful use of biosynthesized Ag-NPs as broad spectrum bactericidal agents for clinical strains of pathogenic multidrug-resistant bacteria such as methicillin-resistant S. aureus, A. baumannii, and E. coli. In addition, these Ag-NPs showed negligible cytotoxic effect in human neutrophils suggesting low toxicity to the host. Melisa A. Quinteros, Ivana M. Aiassa Martínez, Pablo R. Dalmasso, and Paulina L. Páez Copyright © 2016 Melisa A. Quinteros et al. All rights reserved. Shear Bond Strengths between Three Different Yttria-Stabilized Zirconia Dental Materials and Veneering Ceramic and Their Susceptibility to Autoclave Induced Low-Temperature Degradation Thu, 12 May 2016 15:03:34 +0000 A study was undertaken to evaluate the effect of artificial aging through steam and thermal treatment as influencing the shear bond strength between three different commercially available zirconia core materials, namely, Upcera, Ziecon, and Cercon, layered with VITA VM9 veneering ceramic using Universal Testing Machine. The mode of failure between zirconia and ceramic was further analyzed as adhesive, cohesive, or mixed using stereomicroscope. X-ray diffraction and SEM (scanning electron microscope) analysis were done to estimate the phase transformation (m-phase fraction) and surface grain size of zirconia particles, respectively. The purpose of this study was to simulate the clinical environment by artificial aging through steam and thermal treatment so as the clinical function and nature of the bond between zirconia and veneering material as in a clinical trial of 15 years could be evaluated. Manoti Sehgal, Akshay Bhargava, Sharad Gupta, and Prateek Gupta Copyright © 2016 Manoti Sehgal et al. All rights reserved. Novel Vanadium-Loaded Ordered Collagen Scaffold Promotes Osteochondral Differentiation of Bone Marrow Progenitor Cells Wed, 11 May 2016 09:22:09 +0000 Bone and cartilage regeneration can be improved by designing a functionalized biomaterial that includes bioactive drugs in a biocompatible and biodegradable scaffold. Based on our previous studies, we designed a vanadium-loaded collagen scaffold for osteochondral tissue engineering. Collagen-vanadium loaded scaffolds were characterized by SEM, FTIR, and permeability studies. Rat bone marrow progenitor cells were plated on collagen or vanadium-loaded membranes to evaluate differences in cell attachment, growth and osteogenic or chondrocytic differentiation. The potential cytotoxicity of the scaffolds was assessed by the MTT assay and by evaluation of morphological changes in cultured RAW 264.7 macrophages. Our results show that loading of VOAsc did not alter the grooved ordered structure of the collagen membrane although it increased membrane permeability, suggesting a more open structure. The VOAsc was released to the media, suggesting diffusion-controlled drug release. Vanadium-loaded membranes proved to be a better substratum than for all evaluated aspects of BMPC biocompatibility (adhesion, growth, and osteoblastic and chondrocytic differentiation). In addition, there was no detectable effect of collagen or vanadium-loaded scaffolds on macrophage viability or cytotoxicity. Based on these findings, we have developed a new ordered collagen scaffold loaded with VOAsc that shows potential for osteochondral tissue engineering. Ana M. Cortizo, Graciela Ruderman, Flavia N. Mazzini, M. Silvina Molinuevo, and Ines G. Mogilner Copyright © 2016 Ana M. Cortizo et al. All rights reserved. Liposomal Systems as Nanocarriers for the Antiviral Agent Ivermectin Sun, 08 May 2016 10:40:57 +0000 RNA virus infections can lead to the onset of severe diseases such as fever with haemorrhage, multiorgan failure, and mortality. The emergence and reemergence of RNA viruses continue to pose a significant public health threat worldwide with particular attention to the increasing incidence of flaviviruses, among others Dengue, West Nile Virus, and Yellow Fever viruses. Development of new and potent antivirals is thus urgently needed. Ivermectin, an already known antihelminthic drug, has shown potent effects in vitro on Flavivirus helicase, with EC50 values in the subnanomolar range for Yellow Fever and submicromolar EC50 for Dengue Fever, Japanese encephalitis, and tick-borne encephalitis viruses. However ivermectin is hampered in its application by pharmacokinetic problems (little solubility and high cytotoxicity). To overcome such problems we engineered different compositions of liposomes as ivermectin carriers characterizing and testing them on several cell lines for cytotoxicity. The engineered liposomes were less cytotoxic than ivermectin alone and they showed a significant increase of the antiviral activity in all the Dengue stains tested (1, 2, and S221). In the current study ivermectin is confirmed to be an effective potential antiviral and liposomes, as drug carriers, are shown to modulate the drug activity. All together the results represent a promising starting point for future improvement of ivermectin as antiviral and its delivery. Romina Croci, Elisabetta Bottaro, Kitti Wing Ki Chan, Satoru Watanabe, Margherita Pezzullo, Eloise Mastrangelo, and Claudio Nastruzzi Copyright © 2016 Romina Croci et al. All rights reserved. Bioceramic-Based Root Canal Sealers: A Review Tue, 03 May 2016 12:28:06 +0000 Bioceramic-based root canal sealers are considered to be an advantageous technology in endodontics. The aim of this review was to consider laboratory experiments and clinical studies of these sealers. An extensive search of the endodontic literature was made to identify publications related to bioceramic-based root canal sealers. The outcome of laboratory and clinical studies on the biological and physical properties of bioceramic-based sealers along with comparative studies with other sealers was assessed. Several studies were evaluated covering different properties of bioceramic-based sealers including physical properties, biocompatibility, sealing ability, adhesion, solubility, and antibacterial efficacy. Bioceramic-based sealers were found to be biocompatible and comparable to other commercial sealers. The clinical outcomes associated with the use of bioceramic-based root canal sealers are not established in the literature. Afaf AL-Haddad and Zeti A. Che Ab Aziz Copyright © 2016 Afaf AL-Haddad and Zeti A. Che Ab Aziz. All rights reserved. In Vitro Evaluation of Bacterial Leakage at Implant-Abutment Connection: An 11-Degree Morse Taper Compared to a Butt Joint Connection Tue, 03 May 2016 08:09:23 +0000 Background and Aim. The geometry of implant-abutment interface (IAI) affects the risk of bacterial leakage and invasion into the internal parts of the implant. The aim of this study was to compare the bacterial leakage of an 11-degree Morse taper IAI with that of a butt joint connection. Materials and Methods. Two implants systems were tested ( per group): CSM (submerged) and TBR (connect). The deepest inner parts of the implants were inoculated with 2 μL of Streptococcus mutans suspension with a concentration of 108 CFU/mL. The abutments were tightened on the implants. The specimens were stored in the incubator at a temperature of 37°C for 14 days and the penetration of the bacterium in the surrounding area was determined by the observation of the solution turbidity and comparison with control specimens. Kaplan-Meier survival curve was traced for the estimation of bacterial leakage and the results between two groups of implants were statistically analyzed by chi-square test. Results. No case of the implant system with the internal conical connection design revealed bacterial leakage in 14 days and no turbidity of the solution was reported for it. In the system with butt joint implant-abutment connection, 1 case showed leakage on the third day, 1 case on the eighth day, and 5 cases on the 13th day. In total, 7 (70%) cases showed bacterial leakage in this system. Significant differences were found between the two groups of implants based on the incidence of bacterial leakage (). Conclusion. The 11-degree Morse taper demonstrated better resistance to microbial leakage than butt joint connection. Hooman Khorshidi, Saeed Raoofi, Afagh Moattari, Atoosa Bagheri, and Mohammad Hassan Kalantari Copyright © 2016 Hooman Khorshidi et al. All rights reserved. Oxidative Nanopatterning of Titanium Surface Influences mRNA and MicroRNA Expression in Human Alveolar Bone Osteoblastic Cells Thu, 21 Apr 2016 12:28:13 +0000 Titanium implants have been extensively used in orthopedic and dental applications. It is well known that micro- and nanoscale surface features of biomaterials affect cellular events that control implant-host tissue interactions. To improve our understanding of how multiscale surface features affect cell behavior, we used microarrays to evaluate the transcriptional profile of osteoblastic cells from human alveolar bone cultured on engineered titanium surfaces, exhibiting the following topographies: nanotexture (N), nano+submicrotexture (NS), and rough microtexture (MR), obtained by modulating experimental parameters (temperature and solution composition) of a simple yet efficient chemical treatment with a H2SO4/H2O2 solution. Biochemical assays showed that cell culture proliferation augmented after 10 days, and cell viability increased gradually over 14 days. Among the treated surfaces, we observed an increase of alkaline phosphatase activity as a function of the surface texture, with higher activity shown by cells adhering onto nanotextured surfaces. Nevertheless, the rough microtexture group showed higher amounts of calcium than nanotextured group. Microarray data showed differential expression of 716 mRNAs and 32 microRNAs with functions associated with osteogenesis. Results suggest that oxidative nanopatterning of titanium surfaces induces changes in the metabolism of osteoblastic cells and contribute to the explanation of the mechanisms that control cell responses to micro- and nanoengineered surfaces. Maidy Rehder Wimmers Ferreira, Roger Rodrigo Fernandes, Amanda Freire Assis, Janaína A. Dernowsek, Geraldo A. Passos, Fabio Variola, and Karina Fittipaldi Bombonato-Prado Copyright © 2016 Maidy Rehder Wimmers Ferreira et al. All rights reserved. Developing a Suitable Model for Water Uptake for Biodegradable Polymers Using Small Training Sets Thu, 21 Apr 2016 07:48:23 +0000 Prediction of the dynamic properties of water uptake across polymer libraries can accelerate polymer selection for a specific application. We first built semiempirical models using Artificial Neural Networks and all water uptake data, as individual input. These models give very good correlations ( for test set) but very low accuracy on cross-validation sets (less than 19% of experimental points within experimental error). Instead, using consolidated parameters like equilibrium water uptake a good model is obtained ( for test set), with accurate predictions for 50% of tested polymers. The semiempirical model was applied to the 56-polymer library of L-tyrosine-derived polyarylates, identifying groups of polymers that are likely to satisfy design criteria for water uptake. This research demonstrates that a surrogate modeling effort can reduce the number of polymers that must be synthesized and characterized to identify an appropriate polymer that meets certain performance criteria. Loreto M. Valenzuela, Doyle D. Knight, and Joachim Kohn Copyright © 2016 Loreto M. Valenzuela et al. All rights reserved. Cuspal Displacement Induced by Bulk Fill Resin Composite Polymerization: Biomechanical Evaluation Using Fiber Bragg Grating Sensors Tue, 12 Apr 2016 14:27:27 +0000 Polymerization shrinkage is a major concern to the clinical success of direct composite resin restorations. The aim of this study was to compare the effect of polymerization shrinkage strain of two resin composites on cuspal movement based on the use of fiber Bragg grating (FBG) sensors. Twenty standardized Class II cavities prepared in upper third molars were allocated into two groups (). Restorations involved the bulk fill placement of conventional microhybrid resin composite (Esthet•X® HD, Dentsply DeTrey) (Group 1) or flowable “low-shrinkage” resin composite (SDR™, Dentsply DeTrey) (Group 2). Two FBG sensors were used per restoration for real-time measurement of cuspal linear deformation and temperature variation. Group comparisons were determined using ANCOVA considering temperature as the covariate. A statistically significant correlation between cuspal deflection, time, and material was observed (). Cuspal deflection reached 8.8 μm (0.23) and 7.8 μm (0.20) in Groups 1 and 2, respectively. When used with bulk fill technique, flowable resin composite SDR™ induced significantly less cuspal deflection than the conventional resin composite Esthet•X® HD () and presented a smoother curve slope during the polymerization. FBG sensors appear to be a valid tool for accurate real-time monitoring of cuspal deformation. Alexandra Vinagre, João Ramos, Sofia Alves, Ana Messias, Nélia Alberto, and Rogério Nogueira Copyright © 2016 Alexandra Vinagre et al. All rights reserved. Preparation Methods for Improving PEEK’s Bioactivity for Orthopedic and Dental Application: A Review Mon, 04 Apr 2016 07:53:23 +0000 There is an increased interest in the use of polyether ether ketone (PEEK) for orthopedic and dental implant applications due to its elastic modulus close to that of bone, biocompatibility, and its radiolucent properties. However, PEEK is still categorized as bioinert due to its low integration with surrounding tissues. Many studies have reported on methods to increase the bioactivity of PEEK, but there is still one-preparation method for preparing bioactive PEEK implant where the produced implant with desirable mechanical and bioactivity properties is required. The aim of this review is to present the progress of the preparation methods for improvement of the bioactivity of PEEK and to discuss the strengths and weaknesses of the existing methods. Davood Almasi, Nida Iqbal, Maliheh Sadeghi, Izman Sudin, Mohammed Rafiq Abdul Kadir, and Tunku Kamarul Copyright © 2016 Davood Almasi et al. All rights reserved. The Difference of Structural State and Deformation Behavior between Teenage and Mature Human Dentin Tue, 16 Feb 2016 09:01:33 +0000 Objective. The cause of considerable elasticity and plasticity of human dentin is discussed in the relationship with its microstructure. Methods. Structural state of teenage and mature human dentin is examined by using XRD and TEM techniques, and their deformation behavior under compression is studied as well. Result. XRD study has shown that crystallographic type of calcium hydroxyapatite in human dentin (calcium hydrogen phosphate hydroxide Ca9HPO4(PO4)5OH; Space Group P63/m (176); = 9,441 A; = 6,881 A; = 0,729; Crystallite (Scherrer) 200 A) is the same for these age groups. In both cases, dentin matrix is X-ray amorphous. According to TEM examination, there are amorphous and ultrafine grain phases in teenage and mature dentin. Mature dentin is stronger on about 20% than teenage dentin, while teenage dentin is more elastic on about 20% but is less plastic on about 15% than mature dentin. Conclusion. The amorphous phase is dominant in teenage dentin, whereas the ultrafine grain phase becomes dominant in mature dentin. Mechanical properties of human dentin under compression depend on its structural state, too. Peter Panfilov, Dmitry Zaytsev, Olga V. Antonova, Victoria Alpatova, and Larissa P. Kiselnikova Copyright © 2016 Peter Panfilov et al. All rights reserved. Sol-Gel Derived Mg-Based Ceramic Scaffolds Doped with Zinc or Copper Ions: Preliminary Results on Their Synthesis, Characterization, and Biocompatibility Sun, 14 Feb 2016 09:13:46 +0000 Glass-ceramic scaffolds containing Mg have shown recently the potential to enhance the proliferation, differentiation, and biomineralization of stem cells in vitro, property that makes them promising candidates for dental tissue regeneration. An additional property of a scaffold aimed at dental tissue regeneration is to protect the regeneration process against oral bacteria penetration. In this respect, novel bioactive scaffolds containing Mg2+ and Cu2+ or Zn2+, ions known for their antimicrobial properties, were synthesized by the foam replica technique and tested regarding their bioactive response in SBF, mechanical properties, degradation, and porosity. Finally their ability to support the attachment and long-term proliferation of Dental Pulp Stem Cells (DPSCs) was also evaluated. The results showed that conversely to their bioactive response in SBF solution, Zn-doped scaffolds proved to respond adequately regarding their mechanical strength and to be efficient regarding their biological response, in comparison to Cu-doped scaffolds, which makes them promising candidates for targeted dental stem cell odontogenic differentiation and calcified dental tissue engineering. Georgios S. Theodorou, Eleana Kontonasaki, Anna Theocharidou, Athina Bakopoulou, Maria Bousnaki, Christina Hadjichristou, Eleni Papachristou, Lambrini Papadopoulou, Nikolaos A. Kantiranis, Konstantinos Chrissafis, Konstantinos M. Paraskevopoulos, and Petros T. Koidis Copyright © 2016 Georgios S. Theodorou et al. All rights reserved. Synthesis and Characterization of Chitosan Nanoaggregates from Gladius of Uroteuthis duvauceli Wed, 10 Feb 2016 06:41:24 +0000 We report the synthesis, characterization, and biological properties of chitosan nanoaggregates from gladius of squid, Uroteuthis duvauceli. β-Chitin extracted from gladius was deacetylated to chitosan and further reduced to nanosize using ionic gelation process. The morphology and occurrence of chitosan nanoaggregates (CSNA) were observed using transmission electron microscopy (TEM). The degree of deacetylation (DD%) calculated from Fourier transform infrared (FTIR) spectrum showed high value (~94 ± 1.25%) for chitosan. The CSNA depicts low molecular weight, stable positive zeta potential, and less ash and moisture content with high water and fat binding capacity. The antimicrobial activity was tested against pathogenic microorganisms, which depicted significant rate of inhibition against Staphylococcus aureus and Escherichia coli due to high cellular uptake. The antioxidant analysis for CSNA demonstrated high reducing power and scavenging activity towards superoxide radicals compared with the commercially available chitosan. Furthermore, nanoaggregates exhibited low cytotoxic behavior in biological in vitro tests performed using cervical cancer cell line. These results indicate that chitosan nanoaggregates synthesized from waste gladius will be highly efficient and safe candidate for biological applications as food packing film, drug carrier, and tissue engineering. J. R. Anusha and Albin T. Fleming Copyright © 2016 J. R. Anusha and Albin T. Fleming. All rights reserved. Biomechanical Performances of Networked Polyethylene Glycol Diacrylate: Effect of Photoinitiator Concentration, Temperature, and Incubation Time Wed, 27 Jan 2016 10:02:12 +0000 Nutrient conduit networks can be introduced within the Polyethylene Glycol Diacrylate (PEGDA) tissue construct to enable cells to survive in the scaffold. Nutrient conduit networks can be created on PEGDA by macrochannel to nanochannel fabrication techniques. Such networks can influence the mechanical and cell activities of PEGDA scaffold. There is no study conducted to evaluate the effect of nutrient conduit networks on the maximum tensile stress and cell activities of the tissue scaffold. The study aimed to explore the influence of the network architecture on the maximum tensile stress of PEGDA scaffold and compared with the nonnetworked PEGDA scaffold. Our study found that there are 1.78 and 2.23 times decrease of maximum tensile stress due to the introduction of nutrient conduit networks to the PEGDA scaffold at 23°C and 37°C temperature conditions, respectively. This study also found statistically significant effect of network architecture, PI concentration, temperature, and wait time on the maximum failure stress of PEGDA samples ( value < 0.05). Cell viability results demonstrated that networked PEGDA hydrogels possessed increased viability compared to nonnetworked and decreased viability with increased photoinitiator concentrations. The results of this study can be used for the design of PEGDA scaffold with macrosize nutrient conduit network channels. Morshed Khandaker, Albert Orock, Stefano Tarantini, Jeremiah White, and Ozlem Yasar Copyright © 2016 Morshed Khandaker et al. All rights reserved. Preparation and Evaluation of Gelatin-Chitosan-Nanobioglass 3D Porous Scaffold for Bone Tissue Engineering Thu, 14 Jan 2016 14:19:02 +0000 The aim of the present study was to prepare and characterize bioglass-natural biopolymer based composite scaffold and evaluate its bone regeneration ability. Bioactive glass nanoparticles (58S) in the size range of 20–30 nm were synthesized using sol-gel method. Porous scaffolds with varying bioglass composition from 10 to 30 wt% in chitosan, gelatin matrix were fabricated using the method of freeze drying of its slurry at 40 wt% solids loading. Samples were cross-linked with glutaraldehyde to obtain interconnected porous 3D microstructure with improved mechanical strength. The prepared scaffolds exhibited >80% porosity with a mean pore size range between 100 and 300 microns. Scaffold containing 30 wt% bioglass (GCB 30) showed a maximum compressive strength of  MPa. Swelling and degradation studies showed that the scaffold had excellent properties of hydrophilicity and biodegradability. GCB 30 scaffold was shown to be noncytotoxic and supported mesenchymal stem cell attachment, proliferation, and differentiation as indicated by MTT assay and RUNX-2 expression. Higher cellular activity was observed in GCB 30 scaffold as compared to GCB 0 scaffold suggesting the fact that 58S bioglass nanoparticles addition into the scaffold promoted better cell adhesion, proliferation, and differentiation. Thus, the study showed that the developed composite scaffolds are potential candidates for regenerating damaged bone tissue. Kanchan Maji, Sudip Dasgupta, Krishna Pramanik, and Akalabya Bissoyi Copyright © 2016 Kanchan Maji et al. All rights reserved. Antibacterial Effect of Hydroalcoholic Extract of Punica granatum Linn. Petal on Common Oral Microorganisms Thu, 14 Jan 2016 14:18:57 +0000 Objectives. This study aimed to assess the effect of hydroalcoholic extract of Punica granatum Linn. (P. granatum) petal on Streptococcus sanguinis, Streptococcus mutans, Streptococcus salivarius, Streptococcus sobrinus, and Enterococcus faecalis. Materials and Methods. In this in vitro study, P. granatum extract was prepared using powdered petals and water-ethanol solvent. Antibacterial effect of the extract, chlorhexidine (CHX), and ampicillin was evaluated on brain heart infusion agar (BHIA) using the cup-plate method. By assessing the diameter of the growth inhibition zone, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract were determined for the above-mentioned bacteria. Results. Hydroalcoholic extract of P. granatum petal had inhibitory effects on the proliferation of all five bacterial strains with maximum effect on S. mutans with MIC and MBC of 3.9 mg/mL. The largest growth inhibition zone diameter belonged to S. sanguinis and the smallest to E. faecalis. Ampicillin and CHX had the greatest inhibitory effect on S. sanguinis. Conclusions. Hydroalcoholic extract of P. granatum had a significant antibacterial effect on common oral bacterial pathogens with maximum effect on S. mutans, which is the main microorganism responsible for dental plaque and caries. Farnaz Hajifattahi, Elham Moravej-Salehi, Maryam Taheri, Arash Mahboubi, and Mohammad Kamalinejad Copyright © 2016 Farnaz Hajifattahi et al. All rights reserved.