Conferring BiVO₄ Nanorods with Oxygen Vacancies to Realize Enhanced Sonodynamic Cancer Therapy

Owing to the high depth of tissue penetration, non-invasiveness, and controllability, ultrasound (US)-mediated sonodynamic therapy (SDT) has shown broad application prospects for tumor treatment. However, the electron-hole separation inefficiency of sonosensitizers and the tumor hypoxia remain two major challenges limiting the effect of SDT. Here, ultrafine photoetched bismuth vanadate (BiVO₄) nanorods modified with DSPE-PEG₂₀₀₀ (PEBVO@PEG NRs) were fabricated to achieve in situ self-supply of oxygen (O₂) and reactive oxygen species (ROS) for hypoxic tumor therapy. The photoetching approach could enhance the charge separation by inducing enriched oxygen vacancies on the surface of BiVO₄, thereby improving the generation efficiency of ROS and O₂. The PEBVO@PEG overcome the main obstacles of traditional sonosensitizers in the SDT process and show promising sonodynamic therapeutic effects, thus providing new strategies for improving the performance of sonosensitizer and hypoxic tumor elimination.