Polydopamine reduced graphene oxide/ chitosan-based hydrogel for the therapy of diabetic wound

Diabetic foot ulcer (DFU) is a serious complication of diabetes, often leading to high risks of amputation and imposing considerable economic burdens on patients. Hyperglycemia induced impaired angiogenesis and increased susceptibility to bacterial infection are common obstacles in DFU wound healing, which impede the recovery process. In this work, a novel multifunctional polydopamine reduced graphene oxide chelating copper ions chitosan (PDA-rGO@Cu/CS) hydrogel was developed. Specifically, PDA-rGO@Cu/CS hydrogel dressing was facilitated efficient sterilization and angiogenesis, which attributed to the remarkable photothermal performance and the catalyzing NO release function of hydrogel. Experimental results indicated that the hydrogel accelerated the wound healing process in diabetic rats after topical application and the wound closure rate reached up to 91.57% (vs. 60% of the control) on day 14. Furthermore, in vitro/vivo antibacterial assays demonstrated that the hydrogel possessed antibacterial activity against E.coli and S.aureus , and improved infected wound healing as well as wound closure, which reached up to 90.42% on day 10. Mechanistically, H&E staining, Masson staining, immunofluorescent staining for CD31&α-SMA and IL-6 exhibited that the hydrogel accelerated full-thickness skin wound reconstruction by inhibiting inflammation, promoting collagen deposition and accelerating angiogenesis. Collectively, PDA-rGO@Cu/CS hydrogel provided a promising and efficient treatment strategy for DFU.