Oxygen‐Vacancy‐Engineered W18O49−x Nanobrush with a Suitable Band Structure for Highly Efficient Sonodynamic Therapy

Abstract With the rapid development of external minimally invasive or noninvasive therapeutic modalities, ultrasound‐based sonodynamic therapy (SDT) is a new alternative for treating deep tumors. However, inadequate sonosensitizer efficiency and poor biosecurity limit clinical applications. In this study, we prepared an oxygen‐vacancy‐engineered W 18 O 49−x nanobrush with a band gap of 2.79 eV for highly efficient SDT using a simple solvothermal method. The suitable band structures of the W 18 O 49−x nanobrush endows it with the potential to simultaneously produce singlet oxygen ( 1 O 2 ), superoxide anions (⋅O 2 − ), and hydroxyl radicals (⋅OH) under ultrasound irradiation. Additionally, abundant oxygen vacancies that serve as further charge traps that inhibit electron‐hole recombination are incidentally introduced through one‐step thermal reduction. Collectively, the in vitro and in vivo results demonstrate that the oxygen‐vacancy‐engineered W 18 O 49−x nanobrush delivers highly efficient reactive oxygen species (ROS) for SDT in a very biosafe manner. Overall, this study provides a new avenue for discovering and designing inorganic nanosonosensitizers with enhanced therapeutic efficiencies for use in SDT.