Defect engineering to modulate polarization and electronic structure for efficient piezocatalytic therapy

Abstract

Ultrasound (US)-mediated piezocatalytic therapy (PCT) is a non-invasive therapeutic strategy that relies on the generation of reactive oxygen species (ROS) by activated piezoelectric piezocatalysts to eradicate tumors. Despite satisfactory results, the inadequate piezoelectric response, low electron-hole separation efficiency, and incomplete mechanistic understanding have limited the development of piezoelectric piezocatalysts. Herein, we report structure defect UiO-66 nanoparticles (D-UiO-66 NPs) as piezocatalysts to improve their piezoelectric property for cancer therapy. D-UiO-66 NPs have a more inhomogeneous charge distribution, which exhibited stronger polarization under US irradiation, thus improving the piezoelectric responsive. Importantly, the defect structure of D-UiO-66 NPs narrows the band gap, suppresses the electron-hole complexation and accelerates carrier migration, which in turn enhanced ROS generation. This combined therapeutic strategy demonstrates excellent tumors suppression and good biocompatibility both in vitro and in vivo. Our findings reveal synergistic potential of D-UiO-66 NPs and US can be effectively utilized in tumor therapy, offering a promising new perspective for investigating the underlying mechanisms of piezoelectric catalysis.