Polydopamine-Engineered TiO 2 Nanocomposites for Photothermally Enhanced Sonodynamic Tumor Therapy

Sonodynamic therapy (SDT) offers deep-tissue cancer treatment potential but is limited by inefficient sonosensitizers like TiO 2 (due to wide bandgap and electron–hole recombination) and aggregation issues in doping various properties. To overcome this, we engineered polydopamine-dotted TiO 2 nanocomposites (PDA@TiO 2 ), utilizing the superior photothermal properties and anchoring ability of PDA to ensure TiO 2 dispersion and stability. The resulting PDA@TiO 2 demonstrated robust photothermal conversion and significantly enhanced sonodynamic ROS generation in vitro and in vivo; localized heat from photothermal therapy not only improved tumor penetration but also thermally augmented SDT efficacy by promoting electron–hole separation in TiO 2, creating a spatiotemporally synchronized synergistic effect. This dual-functional platform effectively eradicates tumors, overcoming limitations of individual therapies and doped TiO 2 dispersibility, demonstrating significant potential for treating deep-seated malignancies.