Conferring Ti-Based MOFs with Defects for Enhanced Sonodynamic Cancer Therapy

The development of highly efficient, multifunctional, and biocompatible sonosensitizer is still a priority for current sonodynamic therapy (SDT). Herein, a defect-rich Ti-based metal-organic framework (MOF) (D-MOF(Ti)) with greatly improved sonosensitizing effect is simply constructed and used for enhanced SDT. Compared with the commonly used sonosensitizer TiO2, D-MOF(Ti) results in a superior reactive oxygen species (ROS) yield under ultrasound (US) irradiation due to its narrow bandgap, which principally improves the US-triggered electron-hole separation. Meanwhile, due to the existence of Ti3+ ions, D-MOF(Ti) also exhibits a high level of Fenton-like activity to enable chemodynamic therapy. Particularly, US as the excitation source of SDT can simultaneously enhance the Fenton-like reaction to achieve remarkably synergistic outcomes for oncotherapy. More importantly, D-MOF(Ti) can be degraded and metabolized out of the body after completion of its therapeutic functions without off-target toxicity. Overall, this work identifies a novel Ti-familial sonosensitizer harboring great potential for synergistic sonodynamic and chemodynamic cancer therapy.