Synergistic Functions of the Janus Fibrous Membrane for Enhanced Bone Repair

The treatment of bone defects presents significant challenges in clinical practice. Guided bone regeneration (GBR) strategies offer a new approach, but existing commercial GBR membranes still lack optimal barrier and osteogenic functions. This study presents the design of a Janus fibrous membrane using classic amphiphilic block copolymers and gelatin methacryloyl containing unsaturated double bonds through a gradient electrospinning process. Specifically, by controlling electrospinning parameters, self-assembly of block copolymers, and secondary photo-cross-linking, differential composition, topological structure, and properties between different layers were achieved, thereby realizing synergistic physiological barrier and repair-promoting functions. By leveraging the Janus effect, it effectively blocks the adverse effects of soft tissue cell ingrowth on bone repair while guiding osteogenic cell proliferation and differentiation. Furthermore, the membrane's functionality is optimized by incorporating the antimicrobial component ε-poly-l-lysine and the osteogenic component niobium. In vivo studies demonstrate the membrane's excellent biocompatibility, antibacterial activity, and remarkable bone regeneration potential in both normal and infectious bone defect animal models. The developed Janus fibrous membrane serves as a versatile platform for biomedical applications, offering the vast potential to effectively address the limitations of current GBR membranes in clinical bone defect treatment.