Sustained release of human platelet lysate growth factors by thermosensitive hydroxybutyl chitosan hydrogel promotes skin wound healing in rats

Abstract This study evaluated the effect of thermosensitive hydroxybutyl chitosan (HBC) hydrogel loaded with human platelet lysate (hPL) on skin wound healing in rats. hPLs were generated by freeze–thaw method of platelet‐rich plasma from healthy donors. Successful grafting of hydroxybutyl group to chitosan molecular chain to obtain HBC hydrogel was confirmed by Fourier‐transform infrared spectroscopy. HBC/hPL was prepared by combining 10% (vol/vol) hPL with HBC solution. Surface morphologies were determined by Scanning Electron Microscopy, rheological properties were measured by rheometer, and sustained release of factors from HBC/hPL was measured by enzyme‐linked immunoassay. We evaluated the in vitro effect of HBC/hPL on human umbilical cord vein endothelial cell (HUVEC) proliferation, migration, and tube formation. The effect of growth factors released from HBC/hPL in promoting skin wound healing was evaluated by gross observation, histology, immunohistochemistry, and immunofluorescence in vivo. Rheological analyses indicated the gelation temperatures of HBC and HBC/hPL were 17 and 14°C, respectively. ELISA showed sustained release of human platelet‐derived growth factor, basic fibroblast growth factor, and transforming growth factor‐β1 from HBC/hPL hydrogel. In vitro studies revealed HBC/hPL promoted greater levels of HUVECs proliferation, migration, and tube formation than the HBC and control groups. In vivo studies showed better wound healing, greater amounts of newly formed collagen, as well as neovascular and neo‐epidermis markers in the wound site of HBC/hPL‐treated group compared to the HBC and control groups. HBC/hPL is a promising potential therapeutic agent for promoting skin wound healing via the sustained release of growth factors.