Engineering Injectable\nCoassembled Hydrogel by Photothermal\nDriven Chitosan-Stabilized MoS<sub>2</sub> Nanosheets for Infected\nWound Healing

The application of enzyme-like molybdenum disulfide (MoS<sub>2</sub>) in tissue repair was confronted with stable dispersion,\nsolubilization,\nand biotoxicity. Here, the injectable self-healing hydrogel was successfully\ndesigned using a step-by-step coassembly of chitosan and MoS<sub>2</sub>. Polyphenolic chitosan as a “structural stabilizer”\nof MoS<sub>2</sub> nanosheets reconstructed well-dispersed MoS<sub>2</sub>@CSH nanosheets, which improved the biocompatibility of traditional\nMoS<sub>2</sub>, and strengthened its photothermal conversion and\nenzyme-like activities, guaranteeing highly efficient radical scavenging\nand antimicrobial properties. Furthermore, the polyphenol chitosan\nwas employed again as a “molecular cross-linking agent”\nto form the injectable NIR-responsive MoS<sub>2</sub>@CSH hydrogel\nby accelerating hydrogen-bond interaction among chitosan and the multicross-linking\nreaction among polyphenols. The rapid self-healing ability was conducive\nto wound closure and dynamic adaptability. An experimental study on\ninfected wound healing demonstrated that MoS<sub>2</sub>@CSH hydrogel\ncould substantially eradicate bacteria and accelerate the angiogenesis\nof infected wounds. The photothermal-driven coassembly of MoS<sub>2</sub> and polycation provided an alternative strategy for infected\nwound healing.