Chitosan-based carbon nitride-polydopamine‑silver composite dressing with antibacterial properties for wound healing

Infection represents a major clinical barrier that delays wound healing, while the overuse of antibiotics can lead to bacterial resistance. Hence, it is of particular important to develop a new type of dressing to combat bacterial resistance. Herein, a carbon nitride-polydopamine‑silver complex (C3N4-PDA-Ag) was prepared using the photocatalyst C3N4 and silver nanoparticles (Ag NPs) to achieve a synergistic antimicrobial effect. The solution casting method was then employed to further modify the C3N4-PDA-Ag complex by compounding it with chitosan (CS), thereby forming a C3N4-PDA-Ag@CS film. The results revealed that the C3N4-PDA-Ag@CS film exhibits superior antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa compared to the CS group. The hemolysis, cytotoxicity, and in vivo implantation experiments indicated that the composite film possesses excellent in vitro and in vivo biocompatibility. In addition, the composite dressing promoted wound healing in infected mice by facilitating collagen deposition and accelerating epidermal regeneration. Collectively, the findings of this study clearly demonstrate that the C3N4-PDA-Ag@CS composite dressing has excellent antibacterial properties, biocompatibility, and enhances wound healing, thus providing a strategy for the application of photocatalytic materials for the treatment of infected wounds.