Photothermal Nanozyme System Based on CeO2 for Accelerated Diabetic Wound Healing

Abstract

In diabetic wounds, diverse reactive oxygen species (ROS) intertwine to form a complex oxidative stress network, directly causing damage to cells and tissues. Most single-therapy materials fail to fully regulate this complex oxidative stress microenvironment, hindering wound healing. In this study, a nanozyme-hydrogel composite system was constructed. Through the complementarity of photothermal and enzyme-catalytic functions, cellular functions were enhanced while the oxidative stress microenvironment of diabetic wounds was alleviated, thereby collectively promoting wound healing. A cerium oxide (CeO2)-based nanozyme with abundant oxygen vacancies and high photothermal efficiency was fabricated via gadolinium (Gd) doping and platinum (Pt) nanocluster modification. Gd doping enhanced the catalase (CAT) -mimetic activity by increasing oxygen vacancies, while Pt nanoclusters enabled photothermal conversion. Through this functional complementarity, efficient wound regulation was achieved. To ensure stable retention, the nanozyme (GCP) was loaded into an in situ photo-cross-linkable hydrogel to form the GCP@PG dressing. In vitro and in vivo, GCP@PG scavenged intracellular ROS and promoted angiogenesis. In diabetic rats with full-thickness skin defects, the wound closure rate reached 97.95% on day 14. By integrating the functional complementarity of enzyme catalysis and photothermal effects, this composite system provides a strategy for diabetic wound repair.