Abstract: The skin wound is susceptible to bacterial invasion, which hinders the healing of the wound, especially when infected with multi-drug resistant strains. This demands novel bioactive materials to combat bacterial infections. In this study, gallium oxide nanoparticles (Ga₂O₃ NPs) were successfully synthesized through high-temperature thermal decomposition, exhibiting excellent biocompatibility and photocatalytic antimicrobial activity. The Ga₂O₃ NPs were crosslinked into chitosan hydrogel to create a light-responsive multilayered 3D porous hydrogel (Ga₂O₃ NPs hydrogel) for use in photocatalytic antimicrobial therapy (PCAT). The prepared Ga₂O₃ NPs hydrogel exhibits broad-spectrum photocatalytic activity and remarkable antibacterial efficacy against E. coli and S. aureus. It effectively eradicates biofilms, promotes reactive oxygen species production, disrupts bacterial cell membranes, and induces nucleic acid leakage, ultimately resulting in bacterial death. Additionally, it exhibits excellent biosafety. Both in vitro pigskin and in vivo mouse wound infection models have confirmed the remarkable efficacy of Ga₂O₃ NPs hydrogel in PCAT. Notably, Ga₂O₃ NPs hydrogel created a moist environment for the wound in an MDR S. aureus-infected mouse wound model, demonstrating significant potential to facilitate wound healing and minimize scar formation. This study introduces a novel hydrogel dressing without antibiotic components for resistant bacterial-infected wounds.

Key words: Light-responsive, 3D porous structure, Moist environment, Photocatalysis, Wound healing