β3GALT2 Gene Promotes Osteogenic Differentiation of BMSCs on n-HA/PA66 Via Exosomes.

While β3GalT2 has been implicated in osteogenic regulation, its synergistic application with bioactive scaffolds remains unexplored. This study pioneers a dual-functional bone regeneration strategy by integrating β3GalT2-engineered bone marrow mesenchymal stem cells (BMSCs-β3GalT2) with nano-hydroxyapatite/polyamide 66 (n-HA/PA66) composites. First, we studied the effect of β3GalT2 on rat BMSCs (rBMSCs) by overexpression the β3GalT2 gene. Following this, we extracted exosomes and verified that β3GalT2 influences osteogenesis of rBMSCs through exosomes. Subsequently, we inoculated these rBMSCs on n-HA/PA66 and demonstrated the effects of β3GalT2 and n-HA/PA66 on osteogenic differentiation of rBMSCs. On this basis, we also explored the molecular mechanism of β3GalT2 regulating M1 polarization through exosomes. Finally, we verified our study by using animal models of skull defect and femur defect. Our results suggest that β3GalT2 promotes osteogenic differentiation of rBMSCs through exosomes. At the same time, rBMSCs-β3GalT2 combined with n-HA/PA66 showed good osteogenic effect in vivo and in vitro. In addition, we also found that β3GalT2 can regulate M1 polarization through exosomes. Our findings establish β3GalT2 as a master regulator of osteogenesis through cellular-exosomal-circuitry mechanisms. The biohybrid system synergistically combines gene-enhanced stem cells with tunable biomaterials, representing a paradigm shift in bone tissue engineering.