A Thermosensitive Hydrogel with Efficient NIR Photothermal Conversion as Injectable Wound Dressing for Accelerating Skin Wound Healing

Abstract Bacterial infection at wound sites can easily induce robust inflammation. M1 macrophages at wound sites can cause cascade inflammatory reactions to mediate a vicious inflammation cycle. Meanwhile, the hypoxia situation further aggravates the destruction and contraction of blood vessels in the wound microenvironment, therefore, hindering the infected wound healing process. Here, a thermosensitive hydrogel is reported to solve the above challenges by eliminating bacteria based on the photothermal effect, regulating the inflammatory immune microenvironment, and providing oxygen (O 2 ). In vitro and in vivo experiments confirmed that the hydrogel has great O 2 ‐producing properties. Based on the excellent photothermal properties of AIEgens, the hydrogel has a good bactericidal effect against S. aureus (100%) and E. coli (98.85%). The RNA‐sequencing revealed that Cur@AIE@MnO 2 /gel can interfere with the metabolic process and genetic material repair process to impact bacteria proliferation and biofilm dispersal, thus achieving excellent anti‐bacterial efficacy. Moreover, Cur@AIE@MnO 2 /gel can also up‐regulate anti‐inflammatory genes, down‐regulate pro‐inflammatory genes in macrophages, and facilitate the promotion of macrophage polarization from M1 to M2 to relieve inflammation. The therapeutic experiments show that this hydrogel accelerated the wound‐healing process. Therefore, this work may open new avenues for the development of novel dressings for bacterial‐infected wounds.