Distribution of platelets, transforming growth factor-β1, platelet-derived growth factor-BB, vascular endothelial growth factor and matrix metalloprotease-9 in advanced platelet-rich fibrin and concentrated growth factor matrices

Aim Platelet-rich fibrin (PRF) matrices are compared with regard to their ability to retain and release growth factors. Although this ability is thought to influence regenerative outcomes, it remains unclear how it is regulated. To address this question, we compared advanced PRF (A-PRF) and concentrated growth factor (CGF) matrices in terms of distribution of platelets, transforming growth factor-beta 1, platelet-derived growth factor-BB, vascular endothelial growth factor and matrix metalloprotease-9 (MMP9). Methods Blood samples were obtained in glass tubes and immediately centrifuged to prepare A-PRF or CGF matrix according to their specific protocols. Both matrices were compressed, embedded in paraffin and subjected to immunohistochemical examination. Results Leukocytes and plasma proteins were localized on the proximal surface including the interface corresponding to buffy coat. In A-PRF, platelets were distributed homogenously, while growth factors and fibronectin were localized on the distal surface and MMP9 was mainly colocalized with leukocytes. In CGF, in contrast, platelets were localized on and below the proximal surface like leukocytes, growth factors were diffused homogenously and MMP9 was found in the plasma protein layers. Conclusion Although these preparations do not allow accurate quantification, platelet counts and growth factor levels seemed higher and leukocytes were less activated in A-PRF. This may explain A-PRF's higher ability to release growth factors.