Ultrasound-driven electrical stimulation based on 3D hierarchical porous piezoelectric nanofiber-aerogel scaffold promotes bone defect repair

Electroactive scaffolds with three-dimension (3D) hierarchical porous structure have demonstrated immense potential in tissue repair and regeneration by providing an electrical microenvironment at bone defect sites. Herein, we designed a biodegradable nanofiber-aerogel scaffold with hierarchical porous structure and rehabilitated electrical microenvironment for accelerated bone regeneration. Incorporating piezoelectrical ZnO/ polyhydroxybutyrate nanofibers and chitosan into three-dimensional porous structure, the nanofiber-aerogel scaffold with extracellular matrix (ECM)-like structure effectively facilitated adhesion, migration and recruitment of stem cells, which also rehabilitated electric microenvironment for accelerating osteogenic differentiation under controllable ultrasonic (US) stimulation. A series of biological experiments in vitro and in vivo had been performed to verify osteogenic performance of nanofiber-aerogel scaffolds. This work highlights the potential application of nanofiber-aerogel scaffold processing ECM-like structure and rehabilitating electrical microenvironment in the therapy of bone defects.