Biocomposite containing polyetherketoneketone and heterojunction of NaNbOX@CeO2 with improved piezoelectricity and nanozyme activity for killing bacteria and enhancing osteoblastic differentiation

Combination of piezoelectricity with nanozyme activity is promising strategy to develop a novel biofunctional composite for repair of infectious bone defect. Herein, a heterojunction containing oxygen vacancy sodium niobate (NaNbO_X, NO_X) with improved piezoelectricity and cerium oxide (CeO₂) with nanozyme activity (NCH) is fabricated, and a biocomposite containing polyetherketoneketone (PEKK) and NCH (PNC) is prepared, which exhibits both piezoelectricity and nanozyme activity. Under acidic condition (simulating microenvironment of bacterial infection), triggered by US, the piezoelectric effect of PNC not only remarkably improves sonodynamic efficiency for producing more reactive oxygen species (ROS), but also enhances peroxidase (POD)-like activity for generating more ROS. The US-driven piezoelectric effect of PNC significantly enhances both sonodynamic performance and enzyme-like activity that produce a large amount of ROS, synergistic killing bacteria and removing biofilms. Moreover, driven by US, the piezoelectric effect of PNC generates electrical signals, which remarkably promotes osteoblasts proliferation and osteogenic differentiation. This study opens up a new path for design a novel composite biomaterial with capability of production of ROS and pro-osteogenesis by electrical stimulation, and PNC with piezoelectricity and POD-like activity displays great potential for application in the treatment of bacterial infectious bone defects.