Osteoconductive Potential of a Hydroxyapatite Fiber Material with Magnesium: In Vitro and in Vivo Studies

Despite the benefits of hydroxyapatite fiber (HAf) as a synthetic bone substitute, materials capable of faster bone regeneration would be more preferable. In this study, effects of HAf with magnesium (Mg-HAf) on bone regeneration were evaluated. In vitro, levels of osteogenic genes were significantly higher in bone marrow cells cultured with Mg-HAf than in those cultured with HAf alone. Moreover, effects of HAf only (control) and 5.7 mol% Mg-HAf on the cranial bones of Japanese white rabbits were evaluated. MicroCT imaging and histology indicated significant differences between the control and Mg-HAf groups. Significantly higher new bone volumes and percentages were observed in the Mg-HAf group than in controls at 4 and 8 weeks (p<0.05); the newly formed bone was more mature in the Mg-HAf group than in controls. These results indicated that Mg-HAf can enhance osteogenic differentiationrelated gene expression and promote rapid bone formation and maturation.