Influence of platelet-rich plasma on ectopic bone formation of bone marrow stromal cells in porous coral

This study evaluated the effect of platelet-rich plasma (PRP) on the bone formation of marrow stromal cells (MSCs) in porous coral. MSCs in 50 μl of PRP were seeded into natural coral disks (diameter 8.0 mm; thickness 2.0 mm). The composites were clotted and cultured in vitro or implanted subcutaneously into nude mice. Coral scaffolds loading MSCs or PRP alone acted as control. Alkaline phosphatase (ALP) activity of the specimens cultured in vitro for 7 and 14 days was measured, and the level of ectopic bone formation was investigated 4 and 8 weeks after operation. The samples from the coral/PRP/MSC group exhibited significantly higher ALP activity, compared with that from the coral/MSC group or the coral/PRP group (p < 0.05). New bone and/or cartilage formation could be observed in specimens from both coral/PRP/MSC and coral/MSC groups in ectopic sites, and osteogenesis followed the pattern of endochondral bone formation. Histomorphometric analyses showed enhanced cartilage and/or bone formation in the coral/PRP/MSC group, 4 and 8 weeks after implantation. No bone or cartilage formation could be observed in the coral/PRP group. The authors concluded that PRP could improve the ALP activity of MSCs on coral and increase ectopic bone formation.