Photosensitizer-synergized g-carbon nitride nanosheets with enhanced photocatalytic activity for eradicating drug-resistant bacteria and promoting wound healing

The rapid emergence of drug-resistant bacterial strains undermines the efficacy of conventional antibiotics, necessitating the development of alternative therapies. Antimicrobial photodynamic therapy (PDT) is a promising approach, but its effectiveness is often limited by the suboptimal photocatalytic activity of photosensitizers. In this study, we introduce a novel photoresponsive carbon-based antibacterial agent, Ce6/g-C3N4, which combines the photocatalytic properties of graphite-phase carbon nitride (g-C3N4) with the photodynamic attributes of chlorin e6 (Ce6). This agent, with an average particle size of 250.7 nm, demonstrates significantly enhanced photocatalytic activity. Additionally, the strong affinity of Ce6/g-C3N4 for bacteria and efficient delivery of Ce6 result in an inhibition rate exceeding 99% against Gram-positive bacteria and excellent biofilm eradication under light irradiation. In vivo experiments reveal that Ce6/g-C3N4 effectively inhibits bacterial growth on wounds, and promotes wound healing post-light treatment, while maintaining good biocompatibility. Overall, the Ce6/g-C3N4 antibacterial agent synergizes photodynamic and photocatalytic mechanisms, offering a new avenue for the photo-mediated, multi-strategic treatment of bacterial infections and wound healing.