Photo-crosslinked gelatin methacryloyl/methacrylated chitosan Janus membrane with covalently integrated bilayers for enhanced guided bone regeneration.

Alveolar bone regeneration remains a significant clinical challenge, largely because conventional guided bone regeneration (GBR) membranes lack the ability to provide robust, integrated mechanical support and potent osteogenic bioactivity. To address these limitations, we designed a bilayer Janus membrane (G5CS1-G10). It comprises a dense, photo-crosslinked gelatin methacryloyl (GelMA) layer for mechanical support and a porous composite layer of GelMA with methacrylated chitosan (CSMA) for osteogenesis. In a rat calvarial defect model, the G5CS1-G10 membrane significantly outperformed the commercial membrane Bio-Gide®, achieving a 1.5-fold increase in bone volume (BV/TV) and improved osseointegration. Our study demonstrates that this dual functional membrane successfully integrates barrier capacity with osteogenic promotion, offering a promising strategy for advanced maxillofacial bone regeneration.