Perovskite-structured ultrasensitive CaMnO3 nanoenzyme enables highly efficient ultrasound-amplified and catalysis-involved synergistic tumor therapy

Catalytic nanoenzyme-mediated therapy with reactive oxygen species generation feature and tumor microenvironment regulation characteristic has demonstrated high therapeutic efficacy in oncological field, whereas its low enzyme-mimicking reaction efficacy typically results in dissatisfied therapeutic effect and outcome. Herein, an ultrasensitive CaMnO 3 (CMO) nanoenzyme has been rationally designed and engineered for enzyodynamic-calcium overload synergistic tumor therapy. CMO nanoenzyme with oxidase (OXD)-, peroxidase (POD)- and glutathione peroxidase (GPx)-mimic activities is responsible for the generation of reactive oxygen species, the consumption of intra-tumor glutathione and mitochondrial damage. For the evaluation of OXD and POD-mimicking activities, CMO with ultra low concentration (1 μg ml −1 ) can rapidly catalyze the color reaction of 3,3′,5,5′-tetramethylbenzidine (TMB) hydrochloride and reach the reaction termination in a very short time (1 s). Moreover, the release and overload of Ca 2+ strengthen the tumor cell death. Exogenous ultrasound stimulation further amplifies the enzyodynamic-Ca 2+ overload synergistic tumor-therapeutic efficacy. In vitro and in vivo results affirm the transcendent antineoplastic outcomes of CMO. Meanwhile, the existence of Mn 2+ endows nanoenzyme with T 1 -weighted MR imaging capacity. This work provides new strategies for efficient enzyme-mimicking activity and tumor synergistic treatment based on new perspectives on the engineering of multifunctional therapeutic nanomedicine.