The effect of platelet-rich plasma in vitro on primary cells: rat osteoblast-like cells and human endothelial cells.

The aim of this study was to evaluate the effects of standardized platelet-rich plasma (PRP) concentrates from 10 human donors on cellular behavior. The standardized PRPs used were fivefold average and fivefold maximum baseline values in whole blood. Both these standardized PRPs were characterized by determining platelet numbers and subsequently growth factor concentrations in activated PRPs, called PRP derivatives. Platelet numbers in both types of standardized PRPs were significantly increased compared with whole blood. Further, both PRP derivatives contained significantly higher concentrations of platelet-derived growth factor-AA, platelet-derived growth factor-AB, and transforming growth factor-beta 1. Vascular endothelial growth factor concentrations were significantly elevated in only the most concentrated PRP derivative. Cell culture experiments with osteoblast-like cells showed that both PRP derivatives stimulated cell proliferation without inducing cell differentiation, whereas tube formation in endothelial cell cultures was significantly increased by adding low volume percentages of PRP derivative (2%–8%). Consequently, it can be concluded that there is no direct relationship between the number of platelets and the level of growth factors released from these platelets. PRP derivatives have the potency to stimulate angiogenesis dose dependently, while lacking the capacity to induce osteogenic differentiation. Yet, the proliferation of osteoblast-like cells can significantly be enhanced by supplementation of PRP derivatives.

Reconstruction of the mandible with a poly(D,L-lactide) scaffold, autogenous corticocancellous bone graft, and autogenous platelet-rich plasma: an animal experiment.

An animal study is presented, evaluating a method of mandibular reconstruction using a poly(D,Llactide) (PDLLA) scaffold. Six goats underwent a continuity resection of the mandibular angle. The defect was bridged with a preshaped PDLLA scaffold, filled with an autogenous particulate bone graft from the anterior iliac crest, and fixed with two preshaped titanium plates. To accelerate bone healing, autogenous platelet-rich plasma was mixed with the particulate bone graft. All goats had an uneventful healing. The osteosynthesis system withstood immediate loading for a period of 6 weeks until sacrifice. The particulate bone grafts within the PDLLA scaffold, which appeared to be narrowed, showed considerable resorption and replacement by fibrous tissue. In all goats, however, callus formation along the reconstructed segment was seen, providing bony continuity and maintaining the original contour of the reconstructed segment. Thus, the technique used may provide an alternative for reconstruction with revascularized composite flaps with less associated donor site morbidity.