Oxygen self-supplied BTOv-Ru heterojunction boosts the sonodynamic antibacterial efficiency of scaffold

Transplantation-related bacterial infections often slow new tissue regeneration and even cause transplant failure. Sonodynamic therapy is a promising antibacterial method, which kills bacteria by triggering sonosensitizers to generate reactive oxygen species (ROS). Nevertheless, the generation efficiency of ROS is hindered by the fast electron-hole pair recombination in sonosensitizers and the hypoxic of bacteria microenvironment. Herein, ruthenium nanoparticles (Ru NPs) are grown in-situ on the oxygen vacancies-rich barium titanate nanoparticles (BTOv NPs) to form a Schottky heterojunction. The resulting BTOv-Ru NPs as sonosensitizers is uniformly distributed with poly-L-lactic acid (PLLA) powders to fabricate ultrasound-responsive scaffolds via selective laser sintering. On the one hand, the Schottky heterojunction facilitates electron injection from BTOv to Ru, while the resultant charge separation significantly suppresses electron-hole recombination. On the other hand, the catalase-like activity of Ru catalyzes the overexpressed hydrogen peroxide to generate O₂ to achieve O₂ self-supply. This not only alleviates hypoxia but also facilitates the oxygen vacancies of BTOv adsorb more O₂ to generate ROS. The results confirmed PLLA/BTOv-Ru scaffold generated numerous ROS and exhibited excellent antibacterial effects under ultrasonic irradiation, with inhibiting E. coli (89.3 %) and S. aureus (88.1 %). This O₂ self-supplying sonodynamic therapy shows great promise in antibacterial treatment.