Dual-gene regulation of NGF overexpression and P75NTR knockdown enhances BMSC osteogenesis by suppressing pyroptosis.

Bone defects present a major clinical challenge in regenerative medicine, where bone marrow mesenchymal stem cells (BMSCs) are widely used but often show limited osteogenic efficacy. In this study, we developed an engineered tissue strategy combining lentivirus-mediated dual-gene regulation and an allogeneic bone scaffold to enhance bone regeneration. BMSCs were modified to overexpress nerve growth factor (NGF) and knock down the p75 neurotrophin receptor (P75NTR), and their effects on osteogenesis and pyroptosis were evaluated in vitro and in a rat femoral condyle defect model. The dual-gene modification suppressed NF-κB nuclear translocation and reduced pyroptosis-related protein expression, while significantly enhancing osteogenic differentiation of BMSCs. In vivo, scaffold-assisted delivery of engineered BMSCs promoted new bone formation and improved structural regeneration in critical-sized defects. These findings demonstrate that coordinated regulation of NGF and P75NTR signaling within a biomaterial-based system can enhance stem cell-mediated bone repair and improve functional bone regeneration outcomes.