Constructing Cu‐MOF/TiO ₂ Heterojunction Exhibits Higher Sonodynamic Activity to Inhibit the Growth of Glioma Cells In Vitro: Characterization and Sonodynamic Mechanism

ABSTRACT In this paper, a Cu‐MOF/TiO 2 composite (CT‐1) sonosensitizer with excellent production of reactive oxygen species (ROS) such as 1 O 2 and •OH and higher performance in inhibiting tumor cell growth through SDT was successfully prepared and characterized. Meanwhile, using ROS probes and U251 cells as a tumor cell model, the sonodynamic mechanism and sonodynamic antitumor activity in vitro of CT‐1 were studied. The results suggested that Cu‐MOF/TiO 2 heterojunction was successfully constructed. The combination of Cu‐MOF and TiO 2 significantly enhanced the absorption of visible light by the composite sonosensitizer, making better use of the energy of sonoluminesence, and the Z‐scheme heterojunction formed enhanced carrier separation, thereby generating more ROS such as 1 O 2 and •OH, which greatly improved the sonodynamic activity of the sonosensitizer. The in vitro results of sonodynamic inhibition of U251 tumor cell growth showed that the Cu‐MOF/TiO 2 composite CT‐1 had higher sonodynamic antitumor activity than both Cu‐MOF and TiO 2 , and the sonodynamic inhibition of U251 tumor cell growth by CT‐1 was dose‐dependent. When the concentration of CT‐1 was 50 μg/mL, the viability of U251 cells was only 27.20%, demonstrating an excellent sonodynamic antitumor effect. The above research results confirmed that the formation of heterojunction was an effective means to enhance the sonodynamic activity of the sonosensitizer and would provide a research basis for the development of new efficient sonosensitizers and the in‐depth study and application of SDT.