Engineering Injectable Coassembled Hydrogel by Photothermal Driven Chitosan-Stabilized MoS2 Nanosheets for Infected Wound Healing

Abstract

The application of enzyme-like molybdenum disulfide (MoS₂) in tissue repair was confronted with stable dispersion, solubilization, and biotoxicity. Here, the injectable self-healing hydrogel was successfully designed using a step-by-step coassembly of chitosan and MoS₂. Polyphenolic chitosan as a "structural stabilizer" of MoS₂ nanosheets reconstructed well-dispersed MoS₂@CSH nanosheets, which improved the biocompatibility of traditional MoS₂, and strengthened its photothermal conversion and enzyme-like activities, guaranteeing highly efficient radical scavenging and antimicrobial properties. Furthermore, the polyphenol chitosan was employed again as a "molecular cross-linking agent" to form the injectable NIR-responsive MoS₂@CSH hydrogel by accelerating hydrogen-bond interaction among chitosan and the multicross-linking reaction among polyphenols. The rapid self-healing ability was conducive to wound closure and dynamic adaptability. An experimental study on infected wound healing demonstrated that MoS₂@CSH hydrogel could substantially eradicate bacteria and accelerate the angiogenesis of infected wounds. The photothermal-driven coassembly of MoS₂ and polycation provided an alternative strategy for infected wound healing.

Keywords: coassembly; infected wounds; molybdenum disulfide nanosheets; photothermal gelatinization; polyphenolic chitosan.