Abstract
Rationale: Bone defects pose a persistent challenge in orthopedic medicine due to their limited self-repair capacity. Although guided bone regeneration scaffolds have shown therapeutic potential, their clinical efficacy remains constrained by their suboptimal osteoinductive capability. Methods: Herein, we developed biodegradable piezoelectric polyhydroxybutyrate-barium titanate (PHB-BT) nanofiber scaffolds capable of generating synergistic piezoelectric stimulation for bone repair when integrated with low-intensity pulsed ultrasound (LIPUS). Results: Compared with conventional PHB scaffolds, PHB-BT nanofiber scaffolds showed enhanced piezoelectric properties and excellent biocompatibility, thereby facilitating sustained osteogenic activity. In vitro studies revealed that these scaffolds significantly promoted the osteogenic differentiation of bone marrow mesenchymal stem cells under LIPUS stimulation. Notably, in vivo evaluations demonstrated that these scaffolds substantially accelerated bone defect repair, with complete scaffold degradation observed after eight weeks. Mechanistically, PHB-BT nanofibers improved osteogenesis via activating the Ca2+/calcineurin/nuclear factor of activated T-cells signaling pathway in response to ultrasound stimulation. Conclusions: These findings have significant implications for the design of next-generation, implantable electrical stimulators capable of providing sustained electromechanical cues for personalized bone tissue engineering applications.