Multifunctional hydrogel based on polyvinyl alcohol/chitosan/metal polyphenols for facilitating acute and infected wound healing

Bacterial-infected wounds could cause delayed wound healing due to increased inflammation, especially wounds infected by drug-resistant bacteria remain a major clinical problem. However, traditional treatment strategies were gradually losing efficacy, such as the abuse of antibiotics leading to enhanced bacterial resistance. Therefore, there was an urgent need to develop an antibiotic-free multifunctional dressing for bacterially infected wound healing. This study demonstrated the preparation of a multifunctional injectable hydrogel and evaluated its efficacy in treating acute and infected wounds. The hydrogel was prepared by a one-step mixing method, and cross-linked by natural deep eutectic solvent (DES), polyvinyl alcohol (PVA), chitosan (CS), tannic acid (TA), and Cu²⁺ through non-covalent interactions (hydrogen bonds and metal coordination bonds). PVA/CS/DES/CuTA₅₀₀ hydrogel has multiple functional properties, including injectability, tissue adhesion, biocompatibility, hemostasis, broad-spectrum antibacterial, anti-inflammatory, and angiogenesis. Most importantly, in the MRSA-infected skin wound model, PVA/CS/DES/CuTA₅₀₀ hydrogel could ultimately accelerate infected wound healing by killing bacteria, activating M2 polarization, inhibiting inflammation, and promoting angiogenesis. In summary, the PVA/CS/DES/CuTA₅₀₀ hydrogel showed great potential as a wound dressing for bacterial infected wounds treatment in the clinic.