Photothermal Hydrogel with Gel–Sol Transition for Programmed Antibacterial and Wound Healing

ABSTRACT Conventional wound dressings have challenges in achieving precise spatiotemporal coordination between antibacterial activity and tissue regeneration, leading to poor infection control and delayed healing. Herein, we report a photothermal‐responsive hydrogel for programmed antibacterial and regenerative remodeling with a controllable cascade response. The hydrogel incorporates matrix metalloproteinase (MMP) degradable polyethylene glycol (PEG) cross‐linked networks, thermosensitive gelatin, photothermal indocyanine green (ICG), and the antibiotic levofloxacin, allowing for controlled gel–sol transition and sequential therapeutic release upon near‐infrared (NIR) irradiation. Once implanted onto infected wounds in normal and diabetic rat models, NIR activation induces local heating of the hydrogel, facilitating dissolution of the gelatin and release of the antibiotic from the hydrogel matrix. Early stage antibacterial activities are achieved by both photothermal sterilization and antibiotic release into the wound site, markedly reducing bacterial viability and further inhibiting biofilm formation. In the subsequent regenerative stage, the released gelatin provides favorable adhesion sites for cells and promotes angiogenesis and tissue remodeling, thereby accelerating wound healing. This platform controllably orchestrates antibacterial and regenerative processes, offering a novel strategy for complex tissue repair.