A Dual-Catalysis Mode for ROS Regulation to Accelerate Biointegration of Implants in Infected Diabetic Wound

Pathological microenvironment of diabetes including hyperglycemia, excessive reactive oxygen species (ROS), and accumulation of advanced glycation end products leads to high risk of infection and persistent inflammatory reaction, retarding biointegration of implants. To address this issue, a dual-catalysis system consisting of Na₂TiO₃ nanotubes with CeO₂ nanodots and polydopamine (PDA) cover is constructed on Ti implant to manipulate ROS generation and scavenging for antibiosis and tissue regeneration. Na₂TiO₃ and CeO₂ form heterojunction, in which oxygen vacancies (VOs) contribute to the separation of electron-hole pairs under near-infrared light (NIR) irradiation. In NIR mode, the photocatalysis-induced ROS and photothermal-induced hyperthermia by Na₂TiO₃-CeO₂ heterojunction and PDA cover synergistically kill bacteria efficiently. In non-NIR mode, CeO₂ nanodots and PDA cover show excellent superoxide dismutase (SOD) and catalases (CAT) like enzyme activities, and they catalyze ROS (e.g., ·O₂⁻ and H₂O₂) thoroughly into benign O₂ and H₂O, relieving the oxidative stress of microenvironment and accelerating M2 macrophage phenotype. It helps biofunctional recovery of endothelial cells and fibroblasts, promoting tissue regeneration around implants in diabetic models. This work proposes a promising approach of manipulating ROS generation and scavenging to treat infection and regulate inflammatory reaction, thereby improving biointegration and performance of implants in diabetic microenvironment.