Au@MnO_x Nanocomplexes For Enhanced Sonodynamic Cancer Therapy

Ultrasound（US） has received widespread attention and research as a promising non-invasive disease treatment modality with high tissue penetration and high biosafety.Sonodynamic therapy（SDT）is mostly dependent on the production of reactive oxygen species（ROS）,and the lack of ROS production during treatment by a single functional sonosensitiser greatly affects the efficacy.In this paper,a metal-semiconductor heterostructured Au@Mn Ox nanoparticle was constructed with a narrower band gap and lower excitation energy requirement than Mn Ox,and the electrons separated from Mn Ox under US irradiation were trapped by Au as electron traps,effectively reducing electron-hole complexation while efficiently generating ROS.In addition,the oxidase（OXD）-like and catalase（CAT）-like enzymatic activities of Mn Ox can respond to the low p H microenvironment of tumors.The CAT-like enzymes catalyze the production of O₂from H₂O₂in the tumor microenvironment,enhancing the oxygen-dependent SDT effect while acting as a reactive substrate for the OXD-like enzymatic activity,further increasing ROS production.The unique properties of Au nanoparticles can be used as a contrast agent for tumor CT imaging and have been validated in in vivo experiments.Finally,Au@Mn Ox combined with US irradiation showed highly effective inhibition of tumor growth in vivo with an inhibition rate of95.02%.The sonosensitizer based on metal-semiconductor in this paper can realize the integration of tumor diagnosis and treatment,and has a good development and application prospect in SDT tumor treatment.