Visible-Light-Driven TiO/Pt Nanozyme-Embedded Dressings: Integrating PDT, Oxygenation, and Biomechanical Support for Pressure Ulcer Repair.

Pressure ulcer (PU) cause metabolic disorders and ischemia via prolonged pressure, leading to secondary infection, inflammation, and vascular neuropathy. However, existing therapies rely on microenvironment, HO, low repair efficiency, and lack efficient collaborative therapy. Herein, a confined multifunctional TiO/Pt nanozyme is developed via atomic layer deposition for PUs repair. Pt doping narrowed the TiO bandgap (3.30→3.05 eV), enhance visible-light-driven •OH generation, and achieves 100% and 97.38% antibacterial efficacy against E. coli and S. aureus by visible photodynamic therapy (PDT). Demonstrating robust CAT/SOD-like activities, it neutralizes ROS in wound microenvironments. For clinical translation, the nanozyme is embedded into a thermosensitive chitosan/β-glycerophosphate hydrogel (TPCG) and combined with a compressible chitosan/nanofibrillated cellulose aerogel. In vitro and in vivo therapeutic experiments, the TPCG hydrogel have proved that in TPCG hydrogel can sterilize and neutralize ROS by visible light while producing O to promote cell migration, angiogenesis and reduce inflammation, thereby promoting PU healing, while the aerogel mitigated mechanical stress. Biosafety assays confirmed negligible systemic toxicity. This work provides a synergistic strategy combining nanocatalytic therapy, PDT, and biomechanical support for advanced PU management.