Activation of human platelet-rich plasmas: effect on growth factors release, cell division and in vivo bone formation.
OBJECTIVE
Aims of this controlled study were to determine the effects of activated human platelet-rich plasmas (PRPs) on early and mature bone formation in vivo, and to characterize the effect of PRP activation on growth factors release and endothelial cell division in vitro.


METHODS
PRPs were prepared from four volunteers with the platelet concentrate collector system (PCCS) system and activated with three concentrations of calcium and thrombin. Platelet-derived growth factor (PDGF)-BB, vascular endothelial growth factor (VEGF), transforming growth factor beta (TGF-beta) and interleukin-1beta (IL-1beta) levels released in supernatants were measured by ELISA, at time 0, 1h, 24h and 6 days following PRP activation. Mitogenic potential of PRP supernatants were tested on endothelial cells in vitro, and the effects of activated human PRPs on bone formation in vivo were measured in athymic rats by micro-CT analyses.


RESULTS
Activation of PRPs with calcium and thrombin triggered an immediate release of VEGF, PDGF-BB and TGF-beta and a delayed release of IL-1beta in PRP supernatants. Higher endothelial cell division was observed with supernatants from activated PRPs than from non-activated PRPs. Positive correlations were observed between VEGF levels and endothelial cell division and bone formation. A negative correlation was also found between PDGF-BB concentration and bone formation. However, early and mature bone formations with activated PRPs did not significantly differ from the ones obtained in the control group.


CONCLUSIONS
Activation of PRPs with calcium and thrombin regulates growth factors release and endothelial cell division in vitro. However, activated PRPs does not improve the early or mature bone formations in vivo in this athymic rat model.
Roussy
Yanik
Y
Faculté de Médecine dentaire, Quebec, QC, Canada.
Bertrand Duchesne
Marie-Pierre
MP
Gagnon
Guy
G
D043925:Angiogenesis Inducing Agents / Q000378:metabolism; D000818:Animals; D000077214:Becaplermin; D001847:Bone Diseases / Q000601:surgery; D002118:Calcium / Q000494:pharmacology; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D003094:Collagen / Q000627:therapeutic use; D004337:Drug Carriers; D042783:Endothelial Cells / Q000187:drug effects / Q000502:physiology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D053583:Interleukin-1beta / Q000378:metabolism; D008934:Mitogens / Q000494:pharmacology; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology*; D015539:Platelet Activation / Q000187:drug effects / Q000502:physiology*; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D053657:Platelet-Rich Plasma / Q000502:physiology*; D020574:Proto-Oncogene Proteins c-sis; D051381:Rats; D011923:Rats, Nude; D013917:Thrombin / Q000494:pharmacology; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016212:Transforming Growth Factor beta / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D043925:Angiogenesis Inducing Agents; C488453:CollaCote; D004337:Drug Carriers; D036341:Intercellular Signaling Peptides and Proteins; D053583:Interleukin-1beta; D008934:Mitogens; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A; D000077214:Becaplermin; D003094:Collagen; D013917:Thrombin; D002118:Calcium