Table 5: Studies on CS-based scaffolds for regeneration of diverse tissues.

AuthorsTissue typeScaffold typeStudy outlineResultsConclusion

Gupta et al. 2011 [89]Mammary tissueCS+SF (ratio NA) scaffolds impregnated with emodin (antitumor drug)  
MW and DA not reported
In vitro: breast cancer cell culture; evaluation of cell growth and viability  
In vivo: implantation in breast tumor tissue in nude rats; HT analyses  
Control: flap tissue without scaffolds 
Sample: Control
In vitro: cell proliferation with no statistical difference in the control and CS+SF without drugs ()  
In vivo: there was a reduction in cancerous cells only in the CS+SF group with emodin () Tissue regeneration was similar between scaffolds with or without emodin ()
CS+SF scaffolds were effective in absorption, release, and pharmacological activity of the therapeutic agent and in the regeneration of the tissue defect

Seonwoo et al. 2013 [31]Tympanic membraneCS membranes (MW 200 kDa; DA 11%), with or without EGFIn vitro: tympanic membrane cell migration and viability  
In vivo: implantation of CS in tympanic perforations; endoscopic and HT analyses  
Control: untreated perforations 
Sample:
In vitro: CS+EGF demonstrated greater cell migration and viability than pure CS  
In vivo: CS+EGF promoted better closure of perforations and better regeneration than the control
CS+EGF produced favorable results in vitro and in vivo with the regeneration of tympanic perforations (), being a potential alternative to surgery

Zhou et al. 2014 [34]Vascular tissueCS+PCL (ratio NA) in the form of tubules combined with endothelial cells  
MW and DA: NA
In vitro: CC in culture of endothelial cells  
In vivo: implantation in vascular defects in the carotids of dogs; western-blot and RT-PCR analyses  
Sample:
CS+PCL showed cytocompatibility in vitro; CS+PCL+ endothelial cells promoted normal vascular flow and endothelial regeneration in vivoCS+PCL impregnated with endothelial cells were effective in vascular tissue regeneration

Zang et al. 2014 [33]Periodontal ligamentCS (medium MW and DA 15–25%) in the forms of powder or solutionIn vitro: CC (periodontal ligament cells) and physicochemical analyses  
In vivo: insertion of gel in furcation lesions in dogs’ teeth; HT analysis  
Negative control group without CS  
Sample:
The hydrogel obtained with autoclaved CS in the form of powder exhibited the filling of 80% of the defects. Bone and periodontal regeneration was effective after 12 weeks ()The autoclaving of CS in the form of powder did not change its physicochemical properties; CS was effective in the regeneration of furcation lesions

Jiang et al. 2015 [90]Periodontal ligamentCS, whether or not combined with PCE  
MW and DA not reported
In vitro: CC (rat BMMSCs) and expression of periodontal ligament markers;  
In vivo: insertion in periodontal defects with BiOss® in rats; HT, immunofluorescence, and micro-CT analyses; negative control without scaffold; sample:
CS and CS+PCE promoted periodontal regeneration, with greater organization of fibers in the CS+PCE group after 8 weeks ()CS scaffolds with PCE nanofibrils were found to have great potential for application for regeneration of periodontal ligament

Denost et al. 2015 [26]Colorectal tissueCS membranes with two types of hydrogel (DA 98.5% and 97%; MW 420 and 487 kDa, resp.)In vitro: CC and cell differentiation (human adipose-derived stem cells)  
In vivo: implantation in lesions in the intestines of rabbits; macroscopic and HT analyses  
Sample:
In vitro: CS and control (commercial membrane) were cytocompatible  
In vivo: CS exhibited lower () degree of inflammation and complete colorectal regeneration after 8 weeks
Membranes in multiple layers of CS demonstrated potential in colorectal regeneration, suggesting better results than with the commercial material

CC: cytocompatibility; CS: chitosan; CT/micro-CT: computed tomography/micro-computed tomography; DA: degree of acetylation; EGF: epithelial growth factor; HT: histological; kDa: kilodaltons; MW: molecular weight; PCE: polycaprolactone-polyethylene glycol polymer; PCL: polycaprolactone; PCR: polymerase chain reaction; SF: silk fibroin.