Sonodynamic therapy (SDT) triggered by ultrasound (US) is a non-invasive therapeutic strategy that can be applied to treat deeply-seated tumors. However, the limitations of the current sono-sensitizers have substantially hindered the extensive clinical applications of SDT. Traditional organic sono-sensitizers are often derived from photo-sensitizers that show photo-toxicity toward the skin. Meanwhile, the inorganic sono-sensitizers (titanium dioxide, TiO2) have low quantum yield of US-triggered ROS generation. Therefore, the development of novel sono-sensitizers with high sono-sensitizing efficiency and biosafety is urgently demanded. Titanium hydride (TiH1.924) has been explored for applications in hydrogen storage, the production of metallic foams, as well as producing highly purified titanium. Considering the unique valence status of Ti in TiH1.924, we hypothesize that it might be easily activated by external stimuli (e.g., light, ultrasound, and microwave) for applications in photo-catalysis and sono-catalysis. However, the bioapplication of the nano-structured titanium hydride has not yet been reported to our best knowledge.
Recently, the research groups of Prof. Zhuang Liu and Prof. Liang Cheng fabricated titanium hydride (TiH1.924) nanodots from its powder form via the liquid-phase exfoliation, and applied these metal hydride nanodots for effective cancer treatment. Such TiH1.924 nanodots could produce reactive oxygen species (ROS) under ultrasound, presenting a highly efficient sono-sensitizing effect. Meanwhile, TiH1.924 nanodots with strong near-infrared (NIR) absorbance could serve as a robust photothermal agent. By using the mild photothermal effect to enhance intra-tumoral blood flow and improve tumor oxygenation, a remarkable synergistic therapeutic effect was achieved in the combined photothermal-sonodynamic therapy. Importantly, most of these TiH1.924 nanodots would be cleared out from the body. This work presents the promises of functional metal hydride nanomaterials for biomedical applications.
The first author, Dr. Fei Gong, is from FUNSOM, Soochow University, and this work is supported by the National Basic Research Programs of China (973 Program) (2016YFA0201200), the National Natural Science Foundation of China (51525203, 51761145041, 51572180).
Link to paper: https://www.nature.com/articles/s41467-020-17485-x
Link to Prof. Liu’s Group: http://nano.suda.edu.cn/lz/
Link to Prof. Cheng’s Group: http://funsom.suda.edu.cn/80/82/c4746a32898/page.htm
Editor: Danting Xiang