Microsphere of apatite-gelatin nanocomposite as bone regenerative filler.

In this study, we developed novel microspheres comprised of an apatite-gelatin nanocomposite. This microsphere formulation is considered to be useful as a bone regenerative filler, either directly or combined with polymeric matrices. Using the water-in-oil emulsion technique, the apatite-gelatin viscous nanocomposite solution was successfully formulated into microspheres with an average diameter of approximately 110 microm. The microspheres were composed of apatite nanocrystallines precipitated within the gelatin matrix, revealing a typical nanocomposite internal structure. This nanocomposite structure contrasted markedly with that of the conventional composite microspheres which were obtained by directly mixing gelatin with apatite powder. Initial cellular assays showed that the microspheres maintained the adhesion and proliferation of the osteoblastic cells, suggesting the usefulness of the apatite-gelatin nanocomposite microspheres in the bone regeneration field.