SA/HA double-network hydrogel combined with PVDF electret membrane enhances osteogenic differentiation of DPSCs and promotes mandibular bone defect repair

Introduction: Bone tissue defects frequently occur following trauma, bone tumor resection, and orthopedic surgery. The complex local microenvironment serves as a critical factor impeding bone tissue repair. Cell-based scaffolds typically exhibit stable physicochemical properties, provide a favorable growth microenvironment. Hydrogels and electret membranes have been widely applied in bone tissue engineering. Methods: In this study, we fabricated polyvinylidene fluoride (PVDF) electret membranes and sodium alginate/sodium hyaluronate (SA/HA) double-network hydrogels separately, and systematically characterized their physicochemical and biological properties. Results: Following verification of their favorable biocompatibility, we found that the combined application of SA/HA@PVDF composites significantly enhances calcium nodule formation in human dental pulp stem cells (DPSCs) in vitro. In addition, the expression levels of osteogenic marker proteins were elevated in the SA/HA@PVDF group and were significantly higher than those in the single-agent application groups, indicating that SA/HA@PVDF exhibits a stronger capacity to promote the osteogenic differentiation of DPSCs in vitro. Subsequently, rat mandibular defect models were established, and PVDF electret membranes, SA/HA hydrogels, and SA/HA@PVDF composites were transplanted into the defect sites. The results of micro-computed tomography, hematoxylin-eosin staining, Masson staining, and immunohistochemical staining demonstrated that the composite scaffold significantly accelerated the repair of mandibular bone defects. Conclusions: Our findings may provide novel insights into the combined application of electret membranes and hydrogels in bone regeneration.