3D-printed Zinc Oxide Nanoparticles Modified Barium Titanate/hydroxyapatite Ultrasound-responsive Piezoelectric Ceramic Composite Scaffold for Treating Infected Bone Defects

Clinically, infectious bone defects represent a significant threat, leading to osteonecrosis, severely compromising patient prognosis, and prolonging hospital stays. Thus, there is an urgent need to develop a bone graft substitute that combines broad-spectrum antibacterial efficacy and bone-inductive properties, providing an effective treatment option for infectious bone defects. In this study, the precision of digital light processing (DLP) 3D printing technology was utilized to construct a scaffold, incorporating zinc oxide nanoparticles (ZnO-NPs) modified barium titanate (BT) with hydroxyapatite (HA), resulting in a piezoelectric ceramic scaffold designed for the repair of infected bone defects. The results indicated that the addition of ZnO-NPs significantly improved the piezoelectric properties of BT, facilitating a higher HA content within the ceramic scaffold system, which is essential for bone regeneration. In vitro antibacterial assessments highlighted the scaffold's potent antibacterial capabilities. Moreover, combining the synergistic effects of low-intensity pulsed ultrasound (LIPUS) and piezoelectricity, results demonstrated that the scaffold promoted notable osteogenic and angiogenic potential, enhancing bone growth and repair. Furthermore, transcriptomics analysis results suggested that the early growth response-1 (EGR1) gene might be crucial in this process. This study introduces a novel method for constructing piezoelectric ceramic scaffolds exhibiting outstanding osteogenic, angiogenic, and antibacterial properties under the combined influence of LIPUS, offering a promising treatment strategy for infectious bone defects.