Chitin-Assisted Synthesis\nof CuS Composite Sponge\nfor Bacterial Capture and Near-Infrared-Promoted Healing of Infected\nDiabetic Wounds

Diabetic wounds are prone to recurrent infections, often\nleading\nto delayed healing. To address this challenge, we developed a chitin–copper\nsulfide (CuS@CH) composite sponge, which combines bacterial trapping\nwith near-infrared (NIR) activated phototherapy for treating infected\ndiabetic wounds. CuS nanoparticles were synthesized and incorporated <i>in situ</i> within the sponge using a chitin assisted biomineralization\nstrategy. The positively charged chitin surface effectively adhered\nbacteria, while NIR irradiation of CuS generated reactive oxygen species\n(ROS) heat and Cu<sup>2+</sup> to rapidly damage the trapped bacteria.\nThis synergistic effect resulted in an exceptional antibacterial performance\nagainst <i>E. coli</i> (∼99.9%) and <i>S. aureus</i> (∼99.3%). The bactericidal mechanism involved NIR-induced\nglutathione oxidation, membrane lipid peroxidation, and increased\nmembrane permeability. In diabetic mouse models, the CuS@CH sponge\naccelerated the wound healing of <i>S. aureus</i> infected\nwounds by facilitating collagen deposition and reducing inflammation.\nFurthermore, the sponge demonstrated good biocompatibility. This dual-functional\nplatform integrating bacterial capture and NIR-triggered phototherapy\nshows promise as an antibacterial wound dressing to promote healing\nof infected diabetic wound.