Self-healing hydrogel based on polyvinyl alcohol/dextran with hyperglycemia-triggered cascade enzyme catalytic activity promotes diabetic wound healing.

Bacterial infection, hypoxia and oxidative stress caused by high blood glucose are the main problems in diabetic wound healing. The glucose-activated cascade reaction could fundamentally solve these problems in diabetic wounds by consuming glucose and eliminating bacteria. In this paper, glucose oxidase (GOx) was immobilized on polyethylenimine (PEI) adsorbed molybdenum disulfide (MoS2) to prepare MoS2-PEI-GOx (MPG) composite particles, which were doped into the self-healing hydrogel of polyvinyl alcohol (PVA) and dextran (Dex) for preparing PD@MPG hydrogel. GOx can decompose excessive glucose into H2O2 and gluconic acid, thereby reducing the pH value and improving the microenvironment of the wound. Low pH value enables MoS2 exert a similar role as peroxidase, catalyzing H2O2 to produce hydroxyl radicals (OH) to kill bacteria. After reducing the blood glucose of the wound, MoS2 can play a similar role as catalase, catalyzing the excess H2O2 at the wound converted to O2, thereby alleviating hypoxia and oxidative stress. In addition, the wound healing ability of PD@MPG has been evaluated by in vivo study. The self-healing hydrogels developed in this study hold promise as an innovative dressing for diabetic wound healing.