Enhancing Bone Regeneration and Osteogenic Quality by n-HA Internalized Osteoblasts Synergized with ON Protein: Mechanistic Insights

Bone scaffolds offer hope for oral jawbone repair, yet improving their osteogenic performance remains a clinical challenge. This study investigates a novel approach to enhance early bone formation and osteogenic quality by coloading hydroxyapatite (HA)─internalized osteoblasts (OHA) and osteonectin (ON) onto various scaffolds. Our findings demonstrated that the OHA could effectively facilitate the early bone regeneration by providing rapid calcium and phosphorus ion release via lysosome-mediated HA degradation, while the ON protein helps in ion deposition, cell proliferation, and matrix mineralization. When the PHA (PCL+HA) scaffold was incorporated with both the OHA and ON, the scaffold exhibited superior pro-osteogenic performance, driven by synergistic effects of rapid ion release from the OHA, slow ion release from the PHA, and upregulation of osteogenesis-related genes. The analyses of mechanisms revealed that the OHA activated MAPK and PI3K–Akt pathways, while ON stimulated calcium and Wnt signaling, collectively promoting the osteogenic potential. The strategy presented in this study paves a promising way for the development of advanced bone scaffolds to improve the bone regeneration quality.