Chairside-applicable MS/FGelMA hydrogel with enhanced osteogenesis and mechanical adaptability for alveolar ridge preservation

Current alveolar ridge preservation (ARP) materials face unresolved trade-offs between mechanical stability, bioactivity, and clinical operability. To address this, we developed a fish-derived methacrylated gelatin (FGelMA) hydrogel composited with magnesium silicate (MS) microparticles combining the low immunogenicity of FGelMA with the dual osteo-angiogenic potential of MS. To characterize the physical properties of this material, the composite hydrogels (MS/FGelMA) were tested using a mechanical tester and a rheometer, and then its biocompatibility and <i>in vitro</i> osteogenic properties were analyzed using bone marrow mesenchymal stem cells (BMSCs) in a three-dimensional environment. <i>In vivo</i> model was further established to evaluate the effect of MS/FGelMA on ARP in SD rats. The results indicated that MS/FGelMA hydrogels exhibited rapid crosslinking within 20 s (365 nm UV, 10 mW/cm²), excellent shear-thinning behavior enabled precise defect adaptation, enhanced mechanical robustness, improved osteogenesis and angiogenesis capacity, especially for the optimized 1%MS/15%FGelMA formulation. 1%MS/15%FGelMA had compressive strength of 231 ± 10.149 kPa (378.69% of pure 15%FGelMA), and 2.3-4.1 folds upregulation of osteogenic markers (RUNX2/ALP/OCN) and angiogenic marker (VEGF) in rat BMSCs cultured in 3D hydrogels compared with that in pristine FGelMA hydrogel. Micro-CT analysis revealed 1%MS/15%FGelMA had socket volume preservation of 61% (vs. 46% in controls) at 3 weeks and had bone density of 75% (vs. 62% in controls) at 6 weeks. In general, this species-independent, chairside-applicable platform demonstrates superior clinical translation potential for complex ARP scenarios.