ZnO-incorporated chitin hydrogels for infected wound therapy

Chronic wounds caused by pathogenic bacterial infections have been a worldwide medical threat and challenge, ZnO is a promising antibacterial agent to promote infected wound healing. However, ZnO particles need to be with a wound dressing material to improve low-dose antibacterial efficacy while reducing cytotoxicity. The natural polysaccharide, chitin-based hydrogels can be applied as a preferential supporting matrix for the deposition of ZnO. In this study, we developed chitin/ZnO composite hydrogels (CZG hydrogels), which were applied for the biofilm-infected full-thickness wound treatment. The three-dimensional hydrophilic network structure of chitin hydrogels provided a large number of absorption sites for Zn²⁺ ions, and CZG hydrogels were prepared by in situ synthesis of ZnO. CZG hydrogels had potent broad-spectrum and long-lasting antibacterial activity, good bacteriostatic ability against high concentration of bacterial fluids. The in vivo studies showed that CZG hydrogels have a significant effect of accelerating biofilm-infected wound healing. Collectively, this work confirmed that chitin hydrogels could be applied as a preferential natural supporting matrix for the deposition of inorganic metal and metal oxide nanoparticles, and provided alternative antibacterial dressing for treating microbial infections and promoting wound healing.