Platelet-Rich Plasma: Quantification of Growth Factor Levels and the Effect on Growth and Differentiation of Rat Bone Marrow Cells

Abstract

Platelet-rich plasma (PRP) is a new application of tissue engineering and a developing area for clinicians and researchers. It is a storage vehicle of growth factors (GFs) such as platelet-derived growth factor (PDGF)-AA, -BB, -AB; transforming growth factor (TGF)-b1 and -2; platelet-derived epidermal growth factor (PDEGF); platelet-derived angiogenesis factor (PDAF); insulin growth factor-1 (IGF-1); and platelet factor-4 (PF-4), which are known to influence bone regeneration. However, animal and clinical studies reveal different results with the use of PRP and its effect on bone healing. This could be due to the differences between species, that is, differences between species in GF concentrations or variation in presence of GFs between the various PRPs. In this study, rat bone marrow cells were cultured in PRP-coated wells or in uncoated wells for 16 days in osteogenic medium, and analyzed on cell growth (DNA content) and cell differentiation (alkaline phosphatase [ALP] activity, calcium content, scanning electron microscopy, and QPCR). The concentrations of TGF-b1, PDGF-AA, PDGF-AB, and PDGF-BB in rat, goat, and human PRP were subsequently determined. The results showed that PRP stimulated initial cell growth and had no effect on ALP activity. The calcium measurements showed a significant increase in calcium at days 8, 12, and 16. The real-time PCR results showed that PRP upregulated osteocalcin at day 1 and collagen type I at day 8. Overall, the immunoassays revealed that human PRP contained higher concentrations of growth factors per platelet compared to rat and goat PRP. Goat PRP showed higher concentrations of growth factors per platelet as compared to rat PRP except for PDGF-BB, which had a higher concentration in rat PRP. TGF-b1 was the most abundant growth factor in all 3 PRPs. On the basis of our results, we conclude that platelet-rich plasma contains osteo-inductive growth factors, which are probably species related. However, we cannot generalize the results because of large intraspecies variations. Further, we conclude that rat PRP gel stimulates initial growth and differentiation of rat bone marrow cells in vitro.

Platelet-Rich Plasma Favors Proliferation of Canine Adipose-Derived Mesenchymal Stem Cells in Methacrylate-Endcapped Caprolactone Porous Scaffold Niches

“…PRGF might constitute an autologous source of growth factors (GFs) that can contribute to tissue regeneration [11,12]. In fact, PRGF contains GFs that induce growth of mesenchymal stem cells (MSCs) and osteogenic lineage cells which can accelerate bone repair [13]. Therefore, a combination of ASCs and PRGF can produce a synergistic effect to increase the yield on bone formation and consolidation [14].…”

Synthesis, development, characterization and effectiveness of bovine pure platelet gel‐collagen‐polydioxanone bioactive graft on tendon healing

“…Van den Dolder et al . 38 showed that PRP has considerable amounts of all the three isoforms of PDGF-AA, -BB and -AB. Lepistö et al .…”

Regeneration of Autotransplanted Avascular Lymph Nodes in the Rat Is Improved by Platelet-Rich Plasma

“…Their α-granules contain platelet-derived growth factor, transforming growth factor-β, platelet-derived epidermal growth factor, insulin growth factor, platelet-derived angiogenesis factor, and growth factors of the vascular endothelial growth factor family, some of the most potent angiogenic and lymphangiogenic growth factors known [21,22,23]. However, their quantity can only be individually ascertained for each probe, a fact that renders this procedure difficult to reproduce.…”

“…Not only can the composition of α-granules vary in the same individual, but platelet counts in peripheral blood are also variable for each person. Additionally, differences between species should also be taken into account when interpreting experiments in animal models, as rat platelets contain less growth factors per platelet than human platelets [23]. However, PRP still possesses many advantages to outweigh its measurement difficulties, the first being that it is an autologous material.…”