A bioinspired all-silk membrane with architecture-driven mechanical competence for guided bone regeneration

Guided bone regeneration (GBR) requires resorbable barrier membranes that preserve regenerative space despite soft-tissue pressure, suture traction, hydration, and progressive degradation, yet current membranes often lose mechanical competence during early healing. Here, we developed a bioinspired all-silk membrane in which a continuous degummed silk fiber (DSF) network provides load-bearing pathways and a β-sheet-reinforced regenerated silk fibroin (RSF) matrix establishes cohesive interfibrillar binding. The resulting Janus DRSF membrane was systematically evaluated for hydrated mechanical properties, suture retention, tear resistance, degradation-associated mechanical retention, cytocompatibility, osteogenic compatibility, barrier performance, and GBR efficacy in a rat cranial defect model. The hierarchical architecture markedly improved tensile, tear, and suture pull-out resistance compared with RSF and the commercial collagen membrane Bio-Gide. During enzymatic degradation, persistent DSF fibers maintained structural continuity, enabling greater retention of tensile strength and modulus despite progressive matrix resorption. The membrane also showed favorable cytocompatibility, supported osteogenic cell attachment and differentiation, and restricted fibroblast penetration. In vivo, both DRSF and Bio-Gide promoted bone regeneration relative to uncovered defects, whereas DRSF retained substantially greater membrane thickness and more effectively limited fibrous tissue invasion at 6 weeks. These findings demonstrate that architecture-driven organization within a chemically unified silk fibroin system can improve early mechanical competence and barrier-function retention, providing a promising strategy for stabilizing resorbable GBR membranes during the mechanically vulnerable healing phase.