Growth factor and proteinase profile of Vivostat® platelet-rich fibrin linked to tissue repair

Background and Objectives Autologous platelet-rich fibrin (PRF (R)) is prepared by the automatic Vivostat (R) system. Conflicting results with Vivostat PRF in acute wound healing prompted us to examine its cellular and biomolecular composition. Specifically, platelets, selected growth factors and matrix metalloproteinase (MMP)-9 were quantified using novel analytical methods. Materials and Methods Ten healthy non-thrombocytopenic volunteers donated blood for generation of intermediate fibrin-I and final PRF. Anticoagulated whole blood and serum procured in parallel served as baseline controls. Leucocyte, erythrocyte and platelet counts in whole blood and fibrin-I were determined by automated haematology analyser. Platelet concentration in PRF was quantified manually by stereologic analysis of Giemsa-stained tissue sections, and the total content of five growth factors and MMP-9 by enzyme-linked immunosorbent assays. Results The number of leucocytes and erythrocytes was reduced (P < 0.001), whereas platelets increased (P < 0.001) in fibrin-I versus whole blood. PRF contained 982 +/- 206 x 10(9) platelets/l representing 3.9-fold (P < 0.001) enrichment relative to whole blood. Growth factor abundance in Vivostat PRF and serum was in descending order: transforming growth factor-beta 1 [5.1-fold higher in PRF than serum, P < 0.001] > platelet-derived growth factor (PDGF)-AB [2.5-fold, P < 0.01] > PDGF-BB [1.6-fold, P < 0.05] > vascular endothelial growth factor > basic fibroblast growth factor [75-fold, P < 0.001]. MMP-9 was reduced 139-fold (P < 0.001) compared with serum, reflecting leucocyte depletion in PRF. Conclusion The gained knowledge on platelet enrichment and biomolecular constituents may guide clinicians in their optimal use of Vivostat PRF for tissue regenerative applications.