Piezoelectric nanocomposites for sonodynamic bacterial elimination and wound healing

Sonodynamic therapy is considered as a minimally invasive method for pathogen elimination and cancer therapy with high spatial and temporal accuracy. However, sonosensitizers with good biocompatibility and high efficiency are still urgently needed. Herein, we have developed a piezoelectric nanocomposite, barium titanate (BaTiO3, BTO) nanocubes with Schottky junction modified by Au nanoparticles (Au@BTO) as a new kind of sonosensitizer for high-efficient sonodynamic therapy. Ultrasound as an exogenous mechanical wave can trigger the piezotronic effect of Au@BTO to facilitate the separation and migration of charge carriers at the piezoelectric/metal interface, which further effectively increases reactive oxygen species (ROS) generation via redox reaction. Due to the high ROS generation efficiency, Au@BTO as the sonosensitizer shows a high antibacterial efficiency against representative Gram-negative and Gram-positive bacteria. Furthermore, the in vitro and in vivo results illustrate that the sonodynamic process also promotes fibroblast migration, which contributes to dermal wound healing in mice. The proposed piezoelectric nanocomposite as a new kind of sonosensitizer has great potential for sonodynamic therapy.