Carbon dot-functionalized hydrogel with photothermal performance and SOD-like activity for accelerating wound healing

The reactive oxygen species (ROS)-induced inflammatory microenvironment and impaired angiogenesis severely hinder wound healing. Traditional wound dressings fail to address these complex pathological conditions simultaneously. Therefore, the development of novel wound treatment strategies is highly desirable. Herein, carbon dot (CD) nanozymes with a photothermal conversion efficiency of 38.51% and superoxide dismutase-like activity of 13,577 U mg -1 are embedded in polyvinyl alcohol (PVA) to fabricate a multifunctional PVA/CDs hydrogel dressing. The PVA/CDs hydrogel effectively relieves oxidative stress in vitro through scavenging excessive ROS. Under 808 nm near-infrared irradiation, the tunable photothermal response of CDs enabled the PVA/CDs hydrogel to exert potent antibacterial activity in vitro through high-temperature photothermal bacterial killing (∼77°C), while mild photothermal heating (∼40°C) promoted the proliferation of human umbilical vein endothelial cells. In a female Kunming mouse model of skin wounds, the PVA/CDs hydrogel demonstrates a significantly accelerated healing process by maintaining a moist microenvironment, alleviating inflammation, and promoting angiogenesis. Furthermore, the PVA/CDs hydrogel exhibits good biocompatibility, supporting its potential as a multifunctional platform for wound healing.