Thermosensitive hydrogel with antioxidant and photothermal antibacterial effects accelerates healing of bacterial-inflamed maxillofacial wounds.

Bacterial-infected wound treatment remains a substantial clinical challenge due to the deterioration of the tissue microenvironment, including excessive M1 macrophages, impaired angiogenesis, reactive oxygen species (ROS), and bacterial infections. To accelerate the healing of maxillofacial trauma, an immunomodulatory thermosensitive hydrogel was developed that combines scavenging of ROS, alleviation of oxidative stress damage, facilitation of macrophage polarization to the M2 phenotype, and elimination of bacterial infections through thermotherapy, thereby regulating the inflammatory immune microenvironment. In vitro experiments confirmed that the immunomodulatory hydrogel dressing with good antioxidant ability could remove various radicals (1O2, ·O2-, ·OH, and H2O2). Based on the excellent photothermal properties of the near-infrared II (NIR-II) absorption conjugated polymer, the hydrogel had a superior bactericidal effect against E. coli (100 %) and S. aureus (100 %). The results of treating total skin wounds and subcutaneous abscesses in the maxillofacial region showed that this hydrogel accelerated the wound-healing process efficiently with 1064 nm laser irradiation. The current work might open a new avenue for developing novel dressings for bacterial-inflamed wounds.