Fe₃O₄/ZnTCPP heterojunction for rapid treatment of bacteria-infected wounds

Bacterial infections significantly delay the healing of skin wounds, while the overuse of antibiotics has led to increasing pathogen resistance, further complicating the treatment of skin lesions. Photodynamic therapy has garnered significant attention due to its convenient, controllable antimicrobial properties and low risk of inducing drug resistance. However, traditional metal porphyrin photosensitizers suffer from issues such as rapid recombination of photogenerated charge carriers and insufficient reactive oxygen species (ROS) generation, severely limiting their clinical application in light-controlled antimicrobial therapy. This study synthesized ferrosoferric oxide/Zn-doped porphyrin heterojunction composites (Fe₃O₄/ZnTCPP) via a two-step hydrothermal method. ZnTCPP, acting as a photosensitizer, generates electrons upon excitation by 808 nm near-infrared (NIR) light, while Fe₃O₄ serves as both an electron acceptor and a photothermal component. Electrochemical testing indicates that the heterointerface formed between Fe₃O₄ and ZnTCPP significantly enhances the separation efficiency of photogenerated charges. Under NIR irradiation, the Fe₃O₄/ZnTCPP composite exhibits enhanced ROS generation capacity and superior photothermal effects compared to individual components. In vitro antibacterial testing indicates that Fe₃O₄/ZnTCPP composite achieves a 99.99 % kill rate against Staphylococcus aureus after just 10 min of 808 nm NIR irradiation. Additionally, this composite material accelerates skin tissue regeneration while effectively reducing inflammation levels in infected wounds, maintaining outstanding biocompatibility throughout. This study confirms that the constructed Fe₃O₄/ZnTCPP heterojunction successfully integrates near-infrared responsiveness, photodynamic therapy, and photothermal therapy into a single platform, providing an innovative material design solution for treating bacterial wound infections.