Evaluation of a Porous Hydroxyapatite Granule and Gelatin Hydrogel Microsphere Composite in Bone Regeneration

The purpose of this study was to investigate the property of hydroxyapatite (HA)/gelatin hydrogel (GH) composite granules as a scaffold and controlled-release carrier of basic fibroblast growth factor (bFGF) for bone regeneration. HA granules and GH microsphere at various weight ratios to the HA granules were mixed. The composite provided the controlled release of bFGF in vitro. The critical-sized bone defects of 6 mm diameter were created in the skull of New Zealand white rabbits and the composite granules with or without incorporated bFGF, were implanted into the defects. Bone regeneration and were evaluated by computed tomography and H-E staining. The composite granules incorporating bFGF promoted significantly higher bone regeneration at the defect site as compared to the bFGF-free composites. Further, the amount of new bone increased in proportion to the amount of GH microspheres incorporated into the composite. We conclude that the bFGF-impregnated HA/GH composite granules is useful for bone regeneration.