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 (O2). In vitro and in vivo experiments confirmed that the hydrogel has great O2‐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@MnO2/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@MnO2/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.

Advanced Dressings for Chronic Wound Management

“…In diabetic wounds, it may result in foot amputation, while in pressure ulcers it can lead to damage to various organs. These wounds are characterized by mitochondrial damage, coagulation disorders, and immunological dysfunction. – Vancomycin-resistant Enterococcus , methicillin-resistant Staphylococcus aureus (MRSA), and carbapenem-resistant Enterobacteriaceae are the main organisms that cause epidermal wound infection and inflammation . These MDR bacteria develop mechanisms to resist antibiotic toxicity, including acquiring extrachromosomal genetic components through horizontal gene transfer to develop barriers to antibiotic penetration, efflux pumps, alteration of antibiotic targets, and inactivation of enzyme expression .…”