Synergistic Photodynamic and Piezocatalytic Therapies for Enhanced Infected Wound Healing via Piezo-Phototronic Effect

The rapid healing of infected wounds holds immense significance for patients suffering from persistent inflammation, which could lead to disability or even mortality if left unaddressed. However, current therapeutic modalities face formidable challenges in effectively addressing the complex pathogenesis of chronic wounds. Herein, a robust strategy is reported to combine synergistic photodynamic and piezocatalytic therapies through the piezo-phototronic effect for rapid and efficient infected wound healing. The approach capitalizes on a flexible organic/inorganic piezoelectric film composed of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) and zinc oxide (ZnO) nanorods as the substrate. Additionally, tetraphenylporphyrin (TPP), a photosensitizer, is integrated into the P(VDF-TrFE)/ZnO framework to create a composite film, P(VDF-TrFE)/ZnO/TPP. This composite film generates both a piezoelectric field and reactive oxygen species (ROS) upon mechanical deformation, and the built-in piezoelectric field further enhances ROS production by the photosensitizers upon light exposure. Both in vivo and in vitro experiments demonstrate that wound healing is significantly accelerated with the combined light illumination and mechanical stimulation, showcasing the profound synergistic effect of photodynamic and piezocatalytic therapies on wound healing. This work not only elucidates the mechanisms underlying these coupled therapies but also introduces an efficient and practical method for treating chronic wounds through routine outdoor activities under sunlight.