Poly (vinyl alcohol)/sodium alginate/carboxymethyl chitosan multifunctional hydrogel loading HKUST-1 nanoenzymes for diabetic wound healing

Bacterial infection, hyperinflammation and hypoxia, which can lead to amputation in severe cases, are frequently observed in diabetic wounds, and this has been a critical issue facing the repair of chronic skin injuries. In this study, a copper-based MOF (TAX@HKUST-1) highly loaded with taxifolin (TAX) with a drug loading of 41.94 ± 2.60 % was prepared. In addition, it has excellent catalase activity, and by constructing an oxygen-releasing hydrogel (PTH) system with calcium peroxide (CaO 2 ), it can be used as a nano-enzyme to promote the generation of oxygen from hydrogen peroxide (H 2 O 2 ) to provide sufficient oxygen to the wound, and at the same time, solve the problem of the oxidative stress damage caused by excess H 2 O 2 to the cells during the oxygen-releasing process. On the other hand, TAX and HKUST-1 in PTH synergistically promoted antimicrobial and anti-oxidative stress properties, and the bacterial inhibition rate against Staphylococcus aureus and Escherichia coli reached 90 %. In vivo experiments have shown that PTH hydrogel is able to treat diabetic skin repair by inhibiting the expression of inflammation-related proteins and promoting epidermal neogenesis, angiogenesis and collagen deposition.