Recent progress of ultrasound-responsive titanium dioxide sonosensitizers in cancer treatment

Sonodynamic therapy (SDT) exhibits promising clinical applications in cancer treatment owing to its advantages, including ultrasonic cavitation effect, mechanical effect, and deep tissue penetration. Titanium dioxide (TiO2) nanomaterials, recognized as excellent sonosensitizers, have been extensively studied in cancer SDT. This review first outlines the mechanism of TiO2-based SDT, then systematically discusses the regulation of TiO2 sonosensitivity, covering aspects such as morphology, particle size, element doping, defect engineering, heterojunction structure, and interactions with the tumor microenvironment. Furthermore, the review generalizes ultrasound-responsive TiO2-based therapeutic modalities for tumor treatment, including SDT, SDT combined with chemotherapy, chemodynamic therapy, photothermal therapy, immunotherapy, and treatment visualization. Finally, the review navigates the ongoing challenges and prospects in TiO2-based cancer SDT.