Novel wound dressing with chitosan gold nanoparticles capped with a small molecule for effective treatment of multiantibiotic-resistant bacterial infections

Wound infection caused by multiantibiotic-resistant bacteria has become a serious problem, and more effective antibacterial agents are required. Herein, we report the preparation of wound dressings using the biocompatible chitosan (CS) as a reducing and stabilizing agent in the synthesis of 2-mercapto-1-methylimidazole (MMT)-capped gold nanocomposites (CS-Au@MMT), with efficient antibacterial effects. The synergistic effects of AuNPs, MMT, and CS led to the disruption of bacterial membranes. After blending with gelatin, crosslinking with tannin acid, and freeze-drying, CS-gelatin (CS-Au@MMT/gelatin) dressing was prepared. It had good mechanical properties as well as efficient water absorption and retention capacities. It exhibited outstanding biocompatibility both in vitro and in a cell-based wound infection model. Moreover, the in vivo rabbit wound healing model revealed that the CS-Au@MMT/gelatin dressing possesses significant antibacterial potential against methicillin-resistant Staphylococcus aureus-associated wound infection. Therefore, the CS-Au@MMT/gelatin dressing described in this study may have huge potential in biomedical applications.