Bi2WO6@PDA Nanosheet with Near-Infrared Induced Emission for Combinational Photothermal/Photodynamic Therapy

Abstract

Traditional tumor treatments have the disadvantages of high side effects, single modality, and high damage to healthy tissues. The combination of photothermal and photodynamic therapy (PTT and PDT) shows great potential in tumor treatment. However, it is a challenge to perform both effective PTT and PDT with a single NIR laser irradiation. In this study, photo-responsive bismuth tungstate (Bi₂WO₆) nanosheets are synthesized by a hydrothermal method, and polydopamine (PDA) with photothermal effect are coated on the surface of Bi₂WO₆ by in situ polymerization. This nanocomposite has excellent photothermal, photodynamic response under single laser irradiation. Through 808 nm laser irradiation, using the photothermal properties of PDA and the good photocatalytic properties of Bi₂WO₆, Bi₂WO₆@PDA (0.5 mg mL⁻¹) can rapidly heat up (>50 °C) and produce reactive oxygen species, and the killing rate of 4T1 cells reaches ≈90%. The Bi₂WO₆@PDA shows good biocompatibility during in vitro cytotoxicity. Thus, Bi₂WO₆@PDA can be used for combined PTT and PDT therapy under single NIR laser, providing a reference for multimodal combinational anti-tumor approaches.