A hybrid system of hydrogel/frog egg-like microspheres accelerates wound healing via sustained delivery of RCSPs

In this article, a hybrid system of hydrogel/frog egg-like microspheres (H-FMS) formed by the combination of coaxial electrostatic spraying and freeze-drying was introduced for enhancing wound healing efficiency through the sustained release of Rana chensinensis skin peptides (RCSPs). The porous PVA/gelatin hydrogel were obtained and frog egg-like microspheres (FMS) of sodium alginate (SA), shaping uniform and smooth, were embedded into hydrogel. Based on PVA/gelatin hydrogel, the FMS addition increased the water absorption of hydrogel to 1,105%. RCSPs were more effectively encapsulated into FMS than solid microspheres (MS). Not only does the H-FMS act as good “depots” for sustained release of RCSPs over 9 days, without exhibiting obvious burst release, but also show good biocompatibility in vitro. In vivo studies on wound healing as well as the histology of fibroblasts, re-epithelialization, inflammation, and hair follicles indicated that the structure of H-FMS released RCSPs continuously and promoted wound healing in rats significantly.