Development of Gelatin-Silk Sericin Incorporated with Poly(vinyl alcohol) Hydrogel-Based Nanocomposite for Articular...

Sericin, a silk protein, has a high potential for use as an extracellular matrix in tissue engineering applications. In this study, novel gelatin (GEL) and silk sericin (SS) were incorporated with a polyvinyl alcohol) PVA hydrogel nanocomposite (GEL-SS-PVA) scaffold that can be applied to repair cartilage. Glutaraldehyde was used as a cross-linking agent, with hydrochloric acid acting as an initiator. The microstructure characteristics of the obtained GEL-SS and GEL-SS-PVA scaffolds were also examined using FTIR and XRD spectra and their enhanced thermal stability was assessed by TGA. The blended GEL-SS and GEL-SS-PVA scaffolds were confirmed by SEM analysis to be highly porous with optimum pore sizes of 172 and 58 µm, respectively. Smaller pore sizes and improved uniformity were observed as the concentration of PVA in the GEL-SS-PVA scaffold increased. PVA decreased the tensile strength and elongation of the membranes but increased the modulus. Swelling studies showed high swellability and complete degradation in the presence of phosphate-buffered saline. Cytocompatibility of the GEL-SS-PVA scaffolds showed that these had the highest potential to promote cell proliferation as evaluated with standard microscopy using L929 fibroblasts. The prepared GEL-SS composite scaffold incorporated with the PVA hydrogel was implanted in full-thickness articular cartilage defects in rats. The repair effect of cartilage defects was observed and evaluated among the GEL-SS-PVA, GEL-SS, and control operation groups. The defects were almost completely repaired after 14 weeks in the GEL-SS-PVA group, thereby indicating that the GEL-SS-PVA composite had a favorable effect on articular cartilage defects in rat knee joint repair.