In vivo animal histomorphometric study for evaluating biocompatibility and osteointegration of nano-hydroxyapatite as biomaterials in tissue engineering.

UNLABELLED: The coming decade will bring new and even more complex advances that will transform oral and maxillofacial surgery practice if the specialty is capable of transferring the advances of basic science into clinical practice. Such advances include those in tissue engineering and nanotechnology. Three groups of eight animals (rats), each was evaluated by grouting bone graft substitutes into 3 mm holes that were made into the anteromedialtibialmetaphyses of rats. Two different formulations varying as to the type of hydroxyapatite (HA) were used; Group 1: Nano-hydroxyapatite, Group 2: Control with HA only. Group 3: Control without any bone graft substitutes (empty defects). Animals of each of the three groups were sacrificed in groups of eight at postoperative week four. Histologic analysis revealed superior biocompatibility and osteointegration of bone graft substitutes when nanohydroxyapatite was employed. At four weeks, there was more reactive new bone formation in this group when compared to the hydroxyapatite group. The control group showed incomplete closure of the defect. This study demonstrated that nano-hydroxyapatite improves the bioactivity of bone implant and repair materials. Nanohydroxyapatite has good biocompatibility, finer mechanical properties, adjustable degradation properties, good osteointegration and offers a wide range of potential applications in the tissue engineering. KEY WORDS: Osteointegration- Nano-Hydroxyapatite- Biomaterials- Tissue engineering.