An Engineered Multifunctional Asymmetric Bilayer Nanofibrous Membrane of GO@PLGA/PVA-Mg for Guided Bone Tissue Regeneration

Alveolar bone defects from periodontitis are common clinical challenges in dentistry. Guided bone regeneration (GBR) proves effective, yet current membranes like Bio-Gide, suffer from inadequate mechanical strength, rapid degradation, and no antibacterial activity, limiting clinical performance. Asymmetric bilayer nanofibrous membranes with functional zoning offer a promising solution. Herein, we fabricated an asymmetric bilayer nanofibrous membrane via coaxial electrospinning, consisting of a dense PLGA-GO/PVA-MgCl2 outer layer and a highly porous PLGA-GO/PVA-MgCl2 inner layer. The dense layer prevents rapid soft-tissue cells invasion into the defect area while providing antibacterial effects. The porous layer facilitates osteoblast adhesion and proliferation. Graphene oxide (GO) and Mg2+ exert synergistic action: GO facilitates initial bacterial attachment, protein adsorption, and cell adhesion, while released Mg2+ disrupts bacterial membrane integrity and metabolic pathways. This results in durable bacterial killing and enhanced osteogenic effects compared to either component alone. The GO-enhanced membrane exhibited a Young’s modulus of 84.8 MPa and a matched degradation rate (23% over 2 months), providing mechanical support while maintaining structural integrity. This property combination addresses the fragility issue of Bio-Gide membranes. In vitro studies demonstrate that the dense layer effectively blocked soft-tissue invasion while permitting cell proliferation. The porous layer, with high porosity and sustained Mg2+ release, promoted MC3T3-E1 migration and differentiation. Furthermore, the membrane exhibited excellent antibacterial activity, cytocompatibility, and osteogenic capacity, as evidenced by significantly enhanced bone regeneration in a rat cranial defect model. These findings indicate the great potential of this multifunctional asymmetric bilayer membrane for clinical applications in alveolar bone defect repair.