Tough, hybrid chondroitin sulfate nanofibers as a promising scaffold for skin tissue engineering.

Fabrication of gelatin/polyvinyl alcohol/chondroitin sulfate (GEL/PVA/CS) hybrid nanofibrous scaffolds using acetic acid and water as an environmentally friendly solvent system via electrospinning for skin tissue engineering was investigated. Modeling and optimization of the nanofibers were performed using response surface methodology (RSM). The influence of CS ratio on mechanical, physical and biological properties of the nanofibers was studied. PVA was used as a carrier and enhancer of mechanical properties. The mechanical properties of hybrid nanofibers were investigated in dry and wet states. The results showed that in the cross-linked dry state the tensile strength was up to 4 MPa. In the wet state, nanofibers exhibited 200% elongation at break, indicating a toughness behavior which enhances the flexibility for clinical applications. Scanning electron microscope (SEM) confirmed the stability of nanofibrous morphology during degradation up to 21 days. Human dermal fibroblast-green fluorescent protein-positive (HDF-GFP+) cells were cultured on the scaffolds and results showed the appropriate biocompatibility. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay was employed to study cell proliferation, and the results confirmed the positive effect of CS ratio on HDF cells attachment as well as proliferation on the nanofibers. Considering the results of in vitro assay, nanofibers containing 15% CS ratio suggested as an optimum CS ratio.