Bio-inspired temporospatial catalytic cascades systems based on ultrasound-triggered multicomponent piezoelectric microparticles

Reactive oxygen species (ROS) have certain effect in cancer treatment, thus many studies have been focused on developing functional systems to generate ROS in tumor. Here, inspired by the multi-enzyme biocatalysis in organisms, novel ultrasound-triggered temporospatial catalytic cascades systems are presented based on barium titanate (BTO) and platinum (Pt) co-loaded multi-component microparticles (Pt/BTO@MCMPs) to successively achieve oxygen and ROS production for tumor sonodynamic therapy. By using a customized capillary microfluidic device, the Pt/BTO@MCMPs are fabricated with Pt nanoparticles located in their core part and BTO nanocubes located in their peripheral part, alternating with blank porous hydrogel components for increasing interaction areas between the encapsulated nanomaterials and the ambient substrates. In the microparticles, the Pt can catalyze hydrogen peroxide from the tumor microenvironment to generate O2 and H2O serving as substrates for piezoelectric catalytic reactions, contributing to additional generation of ROS under US activation. Based on the system, it is demonstrated that the Pt/BTO@MCMPs are featured with excellent biocompatibility under normal biological conditions and show desired tumor eradication properties under ultrasound irradiation in mice carrying pancreatic tumors. These results indicate that the proposed ultrasound-triggered temporospatial catalytic cascades systems are promising for clinic anti-tumor applications. Inspired by the multi-enzyme biocatalysis in organisms, multicomponent piezoelectric microparticles are designed to realize ultrasound-triggered temporospatial catalysis aiming to produce oxygen and reactive oxygen species at tumor site to relieve hypoxia microenvironment and fight cancer through sonodynamic therapy. image