Basic studies on the bone formation ability by platelet rich plasma in rabbits

Purpose: Platelets, which contain many growth factors, such as platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta), can be obtained in high concentrations by centrifugal separation and are being used as platelet-rich plasma (PRP) in clinical applications. The authors evaluated the bone formation ability by PRP in rabbits. Materials and Methods: In experiment 1, the authors made platelet precipitations from the whole blood obtained from rabbits. Each precipitated platelet was resuspended in fibrin glue. The glue was applied to a 1-mm wide slit defect of the same rabbit mandible. After I week, the authors observed the histologic appearances. In experiment 2, the fibrin glue containing the precipitated platelet was applied to a bicortical defect of a rabbit cranium with beta-tricalcium phosphate (beta-TCP) granules as artificial bone material. After 1 week, 1 month, and 2 months, the authors observed the radiologic and histologic appearances. Results and Conclusions: In both experiments, a prosperous bone formation was observed from the beginning more in the group treated with PRP than in the group untreated. In experiment 2, gradual appearances of the bone formation were observed in the bubble of beta-TCP. In application with artificial bone materials, bone formations by PRP were suitably observed.