NIR-II photothermal CSGGT hydrogel for antibacterial therapy and accelerated healing of infected wounds

Abstract

Infected skin wounds demand integrated strategies for rapid bacterial clearance and tissue repair. We developed a β-glucan–gelatin–tannic acid–Cu9S8 (CSGGT) composite hydrogel combining NIR-II photothermal therapy (1064 nm) with a bioactive physical network. The hydrogel exhibited self-healing, injectability, rapid swelling, and excellent biocompatibility. Cu9S8 nanoparticles (photothermal conversion efficiency: 43.87%) enabled efficient bacterial killing (≥2.5-log reduction for S. aureus and E. coli) under laser irradiation. In an S. aureus-infected murine full-thickness wound model, CSGGT + NIR achieved near-complete closure by day 12, with robust re-epithelialization, regenerated skin appendages, dense collagen deposition, and reduced inflammatory infiltration, significantly outperforming all controls. No systemic toxicity was observed. This work presents a combined therapeutic platform that merges immediate photothermal antibacterial action with sustained pro-healing microenvironment support, offering a promising non-antibiotic solution for infected wound management.