Regulation of calcium delivery and pore structure via osteoinductive microspheres of HA/CS/PGCL for orbital bone regeneration

, the composite microspheres achieved a new bone volume ratio (BV/TV) of 78.72% at 10 weeks, resulting in complete closure of the bone defect. Their trabecular structural parameters (trabecular thickness, Tb.Th; trabecular number, Tb.N) outperformed those of the single-component groups. Histological staining confirmed their ability to induce ordered collagen arrangement and the formation of dense new bone. In conclusion, the HA/CS synergistic modification strategy achieved the sequential release of calcium ions during bone repair and spatial regulation of the microsphere surface pore structure. The superior performance of HA/CS/PGCL microspheres in repairing complex bone defects lays an experimental foundation for clinical translation. Further research into the interactions between ion release and cell signaling is warranted.