Title:Do the Fibrin Architecture and Leukocyte Content Influence the Growth Factor Release of Platelet Concentrates? An Evidence-based Answer Comparing a Pure Platelet-Rich Plasma (P-PRP) Gel and a Leukocyte- and Platelet-Rich Fibrin (L-PRF)
Volume: 13
Issue: 7
Author(s): David M. Dohan Ehrenfest, Tomasz Bielecki, Ryo Jimbo, Giovanni Barbe, Marco Del Corso, Francesco Inchingolo and Gilberto Sammartino
Affiliation:
Keywords:
Blood platelet, fibrin, growth factors, leukocytes, platelet-rich fibrin (PRF), platelet-rich plasma (PRP), regenerative
medicine, wound healing
Abstract: Platelet concentrates for surgical use are tools of regenerative medicine designed for the local release of platelet
growth factors into a surgical or wounded site, in order to stimulate tissue healing or regeneration. Leukocyte content and
fibrin architecture are 2 key characteristics of all platelet concentrates and allow to classify these technologies in 4 families,
but very little is known about the impact of these 2 parameters on the intrinsic biology of these products. In this demonstration,
we highlight some outstanding differences in the growth factor and matrix protein release between 2 families
of platelet concentrate: Pure Platelet-Rich Plasma (P-PRP, here the Anitua’s PRGF - Preparation Rich in Growth Factors -
technique) and Leukocyte- and Platelet-Rich Fibrin (L-PRF, here the Choukroun’s method). These 2 families are the extreme
opposites in terms of fibrin architecture and leukocyte content. The slow release of 3 key growth factors (Transforming
Growth Factor β1 (TGFβ1), Platelet-Derived Growth Factor AB (PDGF-AB) and Vascular Endothelial Growth
Factor (VEGF)) and matrix proteins (fibronectin, vitronectin and thrombospondin-1) from the L-PRF and P-PRP gel
membranes in culture medium is described and discussed. During 7 days, the L-PRF membranes slowly release significantly
larger amounts of all these molecules than the P-PRP gel membranes, and the 2 products display different release
patterns. In both platelet concentrates, vitronectin is the sole molecule to be released almost completely after only 4 hours,
suggesting that this molecule is not trapped in the fibrin matrix and not produced by the leukocytes. Moreover the P-PRP
gel membranes completely dissolve in the culture medium after less than 5 days only, while the L-PRF membranes are
still intact after 7 days. This simple demonstration shows that the polymerization and final architecture of the fibrin matrix
considerably influence the strength and the growth factor trapping/release potential of the membrane. It also suggests that
the leukocyte populations have a strong influence on the release of some growth factors, particularly TGFβ1. Finally, the
various platelet concentrates present very different biological characteristics, and an accurate definition and characterization
of the different families of product is a key issue for a better understanding and comparison of the reported clinical effects
of these surgical adjuvants.