WHAT IS A-PRP® / PRP™?
AUTOLOGOUS PLATELET RICH PLASMA BIOLOGY
Platelets are key factors in hard and soft tissue repair mechanisms. They provide the essential growth factors FGF, PDGF, TGF-ß, EGF, VEGF, IGF that are involved in stem cell migration, differentiation and proliferation. The stimulation of fibroblasts and endothelial cells induces new extracellular matrix deposition and neo-vascularization.
Plasma is essential for cell survival as it contains nutrients, vitamins, hormones, electrolytes and proteins. Proteins are key molecules for the coagulation process and the formation of the fibrin polymer that will serve as a scaffold for cell migration, differentiation and proliferation.
THERAPEUTIC PLATELET CONCENTRATION
The Regen™ BCT (Blood Cell Therapy) tube prepares 5 to 6 ml of autologous platelet rich plasma with a platelet recovery greater than 80% and a concentration factor of 1.6-fold. Although the system is technically capable of producing significantly higher platelet concentrations, it is not what research shows to be beneficial for clinical use. More and more studies demonstrate that concentrations of platelets 1 to 3 times over the baseline show more robust healing rates than those with concentrations of 3 to 8 times the baseline1.
Some studies even showed that too high platelet concentrations may actually have negative effects. In a in vivo study2 it was shown that highly concentrated platelet preparations had an inhibitory influence on osteoblast activity, probably due to unwanted inhibitory and cytotoxic effects of growth factors at such high concentrations. Similarly, an in vitro study3 demonstrated that platelet concentration over 2.5-fold, resulted in a reduction in proliferation and a suboptimal effect on osteoblast function.
WHITE BLOOD CELLS IN TISSUE REGENERATION
White blood cells are strongly reduced (> 85% depletion) with the Regen™ PRP® system.
The role of white blood cells (WBC) in healing is controversially discussed among physicians. To address this concern scientifically, WBC subsets, granulocytes and mononuclear cells, need to be looked at individually. Granulocytes, and more specifically neutrophils, are the front-line defenders against invading pathogens and are associated with the inflammatory response. They release a large variety of highly active antimicrobial substances and proteases. Uncontrolled release of these factors can cause severe damage to the tissue, delay healing rates and increase the risk of scarring4. Thanks for the Regen™ PRP® system, more than 96% of the granulocytes are removed from autologous platelet rich plasma. The few white blood cells still present in autologous platelet rich plasma are mostly mononuclear cells(lymphocytes and monocytes). These two cell types are also involved in thr immune response, but have also been shown to support the healing process5,6.
1- Rappl LM et al. Effect of platelet-rich plasma gel in a physiologically relevant platelet concentration on wounds in persons with spinal cord injury. Int Wound J 2011; 8:18.7–195.
2- Weibrich G. et al., Effect of platelet concentration in platelet-rich plasma on peri-implant bone regeneration. Bone 2004; 34:665-671.
3- Graziani F. et al.,The in vitro effect of different PRP concentrations on osteoblasts and fibroblasts. Clin. Oral. Impl. Res. 17, 2006; 212–219.
4- Brubaker A.L. et al. Neutrophils and natural killer T cells as negative regulators of wound healing. Expert Rev. Dermatol. 2011; 6(1). 5-8
5- Barbul, A.et al. Wound healing in nude mice: a study on the regulatory role of lymphocytes in fibroplasia. Surgery 1989;105(6): 764-769.
6- Brancato S.K. and Albina J. E. Wound Macrophages as Key Regulators of Repair. Am J Pathol 2011, Vol. 178, No. 1, 19-25.