One-dimensional Bi2S3 nanorod empowered synergistic photothermal/photocatalytic dual-modal therapy of breast cancer

Phototherapy has emerged as a promising approach for cancer treatment, yet challenges like glutathione (GSH) over-expression and hypoxia within tumors hinder its efficacy. Here, we developed a bismuth-based semiconductor nanotherapy agent, Bi₂S₃ nanorod, stabilized by polyvinylpyrrolidone (PVP). Compared with commercial Bi₂S₃, the Bi₂S₃ nanorods our synthesized exhibited a narrower bandgap, leading to improved electron-hole separation efficiency under near-infrared (NIR) light excitation. Bi₂S₃ nanorods exhibit a high photothermal conversion efficiency of 36.8 %, allowing it to convert light into heat effectively. This thermal effect enhances blood circulation at tumor sites, thereby alleviating hypoxia. Under NIR laser (730 nm) irradiation, Bi₂S₃ nanorods generates elevated levels of cytotoxic reactive oxygen species (ROS) and depletes GSH, increasing oxidative stress and amplifying ROS toxicity, which leads to tumor cell apoptosis. Both in vitro and in vivo experiments demonstrate Bi₂S₃ nanorods' efficacy in synergistic photothermal-photodynamic therapy, suggesting high potential for malignant tumor treatment. This study provides a strategy for enhanced phototherapy and a promising direction for designing integrated nanoplatforms in cancer therapy.