Polyvinyl alcohol/chitosan hydrogel based on deep eutectic solvent for promoting methicillin-resistant Staphylococcus aureus-infected wound healing.

Bacterial-infected wounds usually lead to slow wound healing due to increased inflammation, especially wounds infected by drug-resistant bacteria, which is a serious challenge in the biomedical field. Traditional antimicrobial strategies such as antibiotics lead to a significant increase in drug-resistant strains and have limited efficacy. Therefore, there is an urgent need to develop multifunctional dressings with excellent antibacterial activity and promotion of wound healing. In this study, the hydrogel is cross-linked by natural deep eutectic solvent (DES), polyvinyl alcohol (PVA), chitosan (CS), tannic acid (TA), and Cu through intermolecular interactions (hydrogen bonds and metal coordination bonds). The hydrogel was prepared using a simple one-step mixing method without toxic chemical cross-linkers, which conformed to environmentally friendly chemistry. The prepared hydrogel had excellent injectability and self-healing properties and could fill irregular wound surfaces. In addition, in vitro studies have shown that the hydrogel has excellent hemostatic properties, good biocompatibility, and broad-spectrum antibacterial properties. Most importantly, in the methicillin-resistant Staphylococcus aureus-infected skin wound model, the hydrogel could significantly accelerate the healing of infected wounds by inhibiting the intensification of inflammation, increasing collagen deposition, accelerating re-epithelialization, and promoting the formation of hair follicles and new blood vessels.