Enhancement of the in vivo osteogenic potential of marrow/hydroxyapatite composites by recombinant human bone morphogenetic protein-2

摘要

A composite of marrow mesenchymal stem cells and porous hydroxyapatite (HA) has in vivo osteogenic potential. To investigate factors enhancing the osteogenic potential of marrow/HA composites, we used recombinant human bone morphogenetic protein-2 (rhBMP-2). Marrow/HA composites or composites containing marrow mesenchymal stem cells, rhBMP-2, and HA (marrow/BMP/HA composites) were implanted subcutaneously in 7-week-old male Fischer rats. BMP/HA composites and HA alone were also implanted. The implants were harvested after 2 and 4 weeks. Histologically, obvious de novo bone formation together with active osteoblasts was seen at both 2 and 4 weeks in many pores of the marrow/BMP/HA composites. The marrow/HA composites did not induce bone formation at 2 weeks, but showed moderate bone formation at 4 weeks. In contrast, neither the BMP/HA composites nor HA alone induced bone formation at any time after implantation. These results indicate that the combination of marrow mesenchymal stem cells, porous HA, and BMP synergistically enhances osteogenic potential and that the composites can be utilized effectively in osseous reconstructive surgery.