Carboxymethyl Chitosan Hydrogel Loaded with the Antimicrobial Peptide FK-13 Promotes Healing of Diabetic Skin Wounds by Inhibiting Infection and Biofilm Formation

Diabetic foot ulcer (DFU) wounds are highly susceptible to infection by pathogens, which can lead to biofilm infections. These infections are persistent and stubborn, making wounds difficult to heal. The use of hydrogels loaded with antimicrobial peptides (AMPs) for treating DFU infections shows promise in resolving chronic biofilm infections and promoting wound healing. In this study, a carboxymethyl chitosan/genipin hydrogel loaded with the AMP FK-13 (FK-13@CMCS/GP) was prepared by physical blending to achieve the continuous release of FK-13 in DFU wounds and to reduce biofilms. In vitro experiments verified that the hydrogel initially released FK-13 at a high concentration quickly to exert antibacterial and antibiofilm functions. It was then released slowly over a long period to promote angiogenesis, facilitate fibroblast migration, and balance inflammation. A diabetic mouse skin wound biofilm infection model further confirmed its role in reducing biofilms at the wound site, reducing inflammation caused by infection, and exerting the angiogenic function of FK-13. The results showed that FK-13@CMCS/GP effectively resolved biofilm infections in wounds and promoted the healing of chronic DFUs, demonstrating a promising application prospect.