Synergistic Effect of Bone Marrow-Derived Mesenchymal Stem Cells and Platelet-Rich Plasma on Bone Regeneration of Calvarial Defects in Rabbits

Bone tissue regeneration techniques include tissue engineering approaches which employ mesenchymal stem cells as an osteogenic agent for bone repair. Recent studies have demonstrated that tissue engineering scaffolds and growth factors can support cell proliferation, bone formation, and bone tissue repair in lost bone tissue. Furthermore, many studies have suggested that platelet-rich plasma (PRP) can improve bone regeneration due to the numerous growth factors that it contains. This study was performed to investigate the influence of bone marrow-derived mesenchymal stem cells (BMMSCs) and PRP on bone regeneration of calvarial defects in rabbits. Hydroxyapatite (HA) was used as a scaffold for bone regeneration. There were three groups in this experiment: 1) HA loaded with BMMSCs (HS group), 2) HA loaded with PRP (HP group), and 3) HA loaded with BMMSCs and PRP (HSP group). Two circular bony defects (6 mm in diameter) were made in rabbit calvaria using a trephine bur. BMMSCs and PRP with a HA scaffold (diameter 5.5 mm, height 3 mm) were applied to each defect. The animals were sacrificed after 2 weeks, 4 weeks and 8 weeks. The level of their ability of osteogenesis was evaluated through histological and histomorphometric analyses. High-quality bone regeneration was observed in the HSP group. The percentage of new bone area around the scaffolds was higher in the HSP group than it was in the other groups (HS and HP group), especially at 8 weeks (HS, 72.5 +/- 15%; HP, 85.8 +/- 14%; HSP, 98.8 +/- 2.5%). In addition, the level of bone maturation was higher in the HSP group than in the other groups. The results of this study show that PRP has a positive effect on bone generation. HA with a combination of BMMSCs and PRP can enhance bone regeneration. In addition, the growth factor capacity of PRP may affect the differentiation of BMMSCs and promote bone formation.