Effect of bone morphogenetic protein on Zn-HAp and Zn-HAp/collagen composite: A systematic in vivo study.

Due to good biocompatibility and osteoconductivity, hydroxyapatite (HAp) and its composite with different polymers have been widely investigated for the application in the field of bone tissue engineering. The present study reports the, in vivo performance of zinc doped HAp and HAp/collagen composite (HAC) using bone morphogenetic protein-2. It was done for a span of two months on New Zealand rabbit model. After two months postoperatively, there was no marked inflammatory reaction in experimental groups and control groups. The histological images showed well-formed bony matrix with well differentiated haversian system. From the fluorochrome labeling study, it was observed that higher amount of new bone formed in case of bone morphogenetic protein-2 (BMP-2) loaded Zn-HAp (50%) and HAC (27%) specimens than control. The percentage of new bone formation was significantly higher in case of BMP loaded Zn-HAp group than BMP loaded HAC group. From the SEM images similar trend was observed. As the HAC specimen consists of amorphous phase, it had a negative impact on new bone formation.