CeO ₂ @Cu _x OS Photocatalyst for Diabetic Wound Healing via Programmable ROS Regulation

Bacterial infection and the overproduction of reactive oxygen species (ROS) significantly impede diabetic wound healing. Herein, an intelligent ROS-regulating platform is developed by utilizing copper oxysulfide-loaded mesoporous ceria (CeO₂@Cu_<i>x</i>OS) for the treatment of infected diabetic wounds. The CeO₂@Cu_<i>x</i>OS nanocomposite exhibits a narrower bandgap and higher charge separation efficiency compared to pure CeO₂, leading to superior photocatalytic performance. Under light illumination, CeO₂@Cu_<i>x</i>OS efficiently generates ROS, and the Cu_<i>x</i>OS component simultaneously reacts with high concentrations of glutathione (GSH) at the wound site, releasing copper ions that act synergistically with ROS to achieve a potent antibacterial effect. <i>In vitro</i> antibacterial studies revealed that CeO₂@Cu_<i>x</i>OS disrupts bacterial redox homeostasis, interferes with the tricarboxylic acid cycle, and induces bacterial cuproptosis. In the absence of light, the material effectively scavenges excess ROS to mitigate host cell damage and promotes macrophage polarization toward the anti-inflammatory M2 phenotype, thereby alleviating inflammation and accelerating wound healing. By employing light as an external stimulus, CeO₂@Cu_<i>x</i>OS facilitates a precise functional transition from antibacterial to anti-inflammatory activity, thereby offering an alternative strategy for managing diabetic chronic wounds.