Enhancing clinical applications of PVA hydrogel by blending with collagen hydrolysate and silk sericin

Polyvinyl alcohol (PVA) hydrogel is considered suitable for wound dressing but the difficulties in preparation, poor mechanical properties, limited bioactivity and potential cytotoxicity restrict its applications. In the present study, we aim to improve the properties of PVA based hydrogels by combining it with collagen hydrolysate (CH) and silk sericin which are biocompatible proteins and are expected to assist in improving biomedical applications of PVA. Various blends of the polymers were used to prepare hydrogels through the precipitation process and the physical and biological properties were evaluated particularly for controlled release and wound healing applications. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) studies were used to characterize the structure of the hydrogels. Results indicate good interactions and potential crosslinking between PVA and proteins leading to changes in the physicochemical and mechanical properties of the hydrogels. Hydrogels containing both CH and sericin (10P3S5C1G) had comparable properties to neat PVA but with increased water content. Although addition of the proteins leads to marginal decrease in the mechanical strength of the hydrogels, the properties were still in the acceptable range, i.e., tensile strength (3.98 MPa), percentage elongation (365%), and elasticity (2.25 N/mm(2)). Biological tests showed the superiority of 10P3S5C1G blended hydrogel compared to other blends. Patch test evaluation conducted on healthy volunteers to investigate the safety of 10P3S5C1G showed that about 90% were negative and doubtful reactions, while the remaining 10% were weak reactions. Accordingly, the effects of 10P3S5C1G on human wound healing might be examined in future studies.