Physicians looking to incorporate platelet rich plasma therapy into their practice are met with a wide variety of commercial options. Choosing the right kit requires a thorough understanding of the differences between single spin kits, dual spin methods, gel separators, and the principles of effective centrifugation. Practitioners striving to improve patient outcomes with PRP therapy seek kits with high platelet recovery rates and low hematocrit levels. Our scientific team looked at the options available and found third party research comparing the platelet recovery rate, hematocrit levels, and growth factor release rate amongst five of the most popular options. This article examines the differences between EmCyte Pure PRP kits and Arteriocyte Magellan kits. According to third party research, EmCyte kits achieve a higher platelet recovery rate while Magellan kits yield PRP with higher hematocrit levels.¹
Third Party Analysis Finds Higher Platelet Recovery with EmCyte
A study performed by BioSciences Research Associates (BSR) found EmCyte Pure PRP kits produced a more highly concentrated serum. EmCyte kits produced PRP with an average platelet recovery of 81% compared to 62% with the Arteriocyte Magellan kit. These platelet recovery rates translate to a serum concentration of 7x baseline and 5.7x baseline respectively.
Analysis was conducted by Robert Mandle, PhD, who lead a team to compare growth factor release and platelet concentration amongst commercially available PRP kits. BSR is a research laboratory located in Cambridge and once academically affiliated with Harvard Medical School. BSR is currently affiliated with the Immune Disease Institute at Harvard and draws from a community of nearly 400 bioscience researchers. The BSR laboratory complies with the Food and Drug Administration’s (FDA) Current Good Manufacturing Practice (cGMP) to assist pharmaceutical and biotech companies with product development and clinical trial support.
This study compares platelet concentration and growth factor release between 5 different prp kits:
- Emcyte GS30-PurePRP II
- Emcyte GS60-PurePRP II
- Arteriocyte MAGELLAN
- REGENKIT THT Tube
- ECLIPSE PRP
Platelet Recovery and Therapeutic Response in PRP Therapy
This study assessed platelet recovery rates with a hematology analyzer and found EmCyte kits consistently recovered platelets at a high rate compared to Arteriocyte Magellan kits. Platelet recovery impacts therapeutic results in the most direct way, because platelets play an essential role in tissue repair throughout the body. Platelets contain a wide variety of growth factors which are released and become active during aggregation. Platelets begin to aggregate and degraunate when exposed to the calcium present in collagen or often added as an activator. Platelet aggregation forms necessary clots if blood vessels are ruptured while degranulation refers to the release of bioactive proteins known as growth factors. Growth factors initiate wound healing by binding to the receptors of osteoblasts, mesenchymal stem cells fibroblasts, endothelial cells and epidermal cells to increase mitogenesis and chemotaxis.²
EmCyte vs. Magellan: Growth Factor Release Rates
Researchers drew approximately 200 ml of blood from 4 “healthy” donors and prepared PRP in accordance to manufacturers guidelines. The study utilized a paired assay design meaning that samples from each donor were tested with all 5 kits. Samples were referenced with code numbers; researchers did not track the age, sex or ethnicity of the 4 donors. In addition to platelet recovery rate, researchers measured growth factor release after activation by thrombin and calcium chloride. Evaluated growth factors included; platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF) and transforming growth factor beta (TGF-β). The study found that PRP prepared from EmCyte Pure PRP kits contained higher levels of measured growth factors compared to Arteriocyte Magellan kits.¹ These results are not surprising given that EmCyte kits yield PRP with higher platelet concentration.
Growth Factors and PRP Therapy
In general, growth factors increase chemotaxis and cell mitosis, though each growth factor acts in a distinct way. For example, platelet derived growth factor (PDGF) stimulates collagen synthesis, increases chemotaxis in fibroblasts, macrophages, and neutrophils while increasing mitosis in mesenchymal stem cells. Transforming growth factor beta (TGF-β) stimulates angiogenesis, collagenase secretion, mesenchymal stem cell proliferation, and mitogenesis in osteoblasts, fibroblasts and endothelial cells. Vascular endothelial growth factor (VEGF) increases vessel permeability and angiogenesis, by stimulating mitogenesis in endothelial cells.³ Growth factor release initiates a healing cascade which has downstream effects up to 7 days after administration. Delivering a higher concentration of platelets increases tissue repair leading to better patient outcomes.
Protein structure of vascular endothelial growth factor A (VEGF A)
Hematocrit Levels and Patient Outcomes
BioSciences Research Associates evaluated hematocrit levels in final PRP serums and found the following results:
|PRP Kit||Hematocrit level|
|EmCyte Pure PRP 30 ml (LR-PRP)||3%|
|EmCyte Pure PRP 60 ml (LR-PRP)||9%|
|EmCyte Pure PRP 60 ml (LP-PRP)||1.1%|
Hematocrit refers to the ratio of red blood cells to the total volume of blood. While the activated platelets of PRP provide great therapeutic potential, serums with excessively high hematocrit levels may have a damaging effect on tissues. The variations in hematocrit results found with the EmCyte system (jumping from 3% to 9% between the 30ml and 60ml kits) can be elucidated by understanding variation in preparation protocols.
The EmCyte system includes protocol instructions for a leukocyte rich PRP (LR-PRP) and PRP without leukocytes (LP-PRP). The 2016 comparative study utilized LR-PRP protocols which includes the top 1 ml of red blood cells in the final serum in order to retain leukocytes. EmCyte LP-PRP protocol instructions yields PRP with an average of 1.1% hematocrit according to comparative research.⁴
Leukocyte Rich vs. Leukocyte Poor PRP
Leukocyte rich PRP includes anti-microbial, immune activating white blood cells and is commonly utilized postoperatively to increase surgical wound healing. Leukocyte-poor PRP is applied in situations where additional inflammatory response could slow the healing process. For example, researchers at Stanford University looked at the use of PRP for osteoarthritis and found superior synoviocyte response with leukocyte-poor PRP.⁵
Hematocrit Levels and PRP
Though red blood cells are essential for delivering oxygen throughout the body, introducing red blood cells outside of vascular pathways damages tissues by dramatically raising levels of harmful reactive oxygen species (ROS). Red blood cells do not thrive outside of endothelial tissue where oxygen becomes disassociated from iron and red blood cell apoptosis occurs. These free oxygen molecules are associated with a wide variety of pathological processes including aging, DNA mutation, and inflammation.⁶ This understanding of harmful role of RBC outside of endothelial tissue coincides with the aforementioned Stanford synoviocyte research.
Anticoagulants and Platelet Recovery Rates
To prepare PRP, blood is drawn in the presence of an anticoagulant according the manufacturer’s protocols. The Emcyte Pure PRP 60 ml kit utilizes 10 ml of sodium citrate (SC) per 50 ml of whole blood while the Magellan system relies on 8 ml of anticoagulant citrate dextrose solution-A (ACD-A) per 52 ml of whole blood. The addition of an anticoagulant is necessary to effectively prepare PRP. Without an anticoagulant, blood will clot and platelets will degranulate during the mechanical stimulation of centrifugation, releasing beneficial growth factors. The resulting product would contain no more platelets than whole blood while all of the growth factors would remain suspended at the top of the supernatant.
Brazilian researchers investigated the influence of a variety of anticoagulants on PRP platelet recovery rates. The researchers collected whole blood samples from 9 volunteers and compared platelet recovery rates amongst common anticoagulants including sodium citrate, ethylenediaminetetraacetic acid (EDTA), and ACD-A. The anticoagulant recommended for use with Emcyte kits produced PRP with the highest platelet recovery rate at 81.21% followed by EDTA and then ACD-A. Platelet recovery from ACD-A, as utilized with the Arteriocyte Magellan kits, were 45.71% almost half that of SC.⁷ Results from this study suggest that differences in platelet recovery rate between the EmCyte Pure PRP kit and the Magellan system are influenced by utilization of distinct anticoagulants.
PRP Preparation: Closed vs. Open System
Though the EmCyte produces PRP with a higher platelet concentration and lower hematocrit levels, the Magellan kit has the advantage of operating as a closed system. The Magellan system is more streamlined which helps to eliminate the potential for human error during the PRP preparation process. Though the closed system lends itself to consistency, this means consistently lower platelet recover rates and higher hematocrit levels with Arteriocyte Magellan PRP.
Administering an adequate dose of platelets is the cornerstone of PRP therapy, so effective PRP systems yield highly concentrated platelet serums. Additionally, PRP with lower hematocrit levels increase patient comfort and minimize ROS damage caused when red blood cells are injected outside of vascular pathways. Excessively high hematocrit levels could counteract the benefit of activated growth factors. With this understanding of how PRP effects damaged tissues, EmCyte kits have the potential to offer patients superior benefit given the results of third party research which found higher platelet recovery rates and lower hematocrit levels with the EmCyte system.
- Mandel R. Research Study: Comparisons of Emcyte GS30-PurePRP II, EmCyte GS60-PurePRP II, Arteriocyte Magellan, Stryker REGENKIT THT, and ECLIPSE PRP. Biosciences Research Associates. 2016; May. [pdf]
- Yun S-H, Sim E-H, Goh R-Y, Park J-I, Han J-Y. Platelet Activation: The Mechanisms and Potential Biomarkers. BioMed Research International. 2016;2016:9060143. doi:10.1155/2016/9060143.[ncbi]
- Dhurat R, Sukesh M. Principles and Methods of Preparation of Platelet-Rich Plasma: A Review and Author’s Perspective. Journal of Cutaneous and Aesthetic Surgery. 2014;7(4):189-197. doi:10.4103/0974-2077.150734.[ncbi]
- Mandel R. Report 515 Research Study: Comparisons of Emcyte Pure PRP II 2015, Harvest/Terumo APC60/Clear PRP, and Arthrex Angel PRP Products. Biosciences Research Associates. 2016; June 2015.[pdf]
- Braun HJ, Kim HJ, Chu CR, Dragoo JL. The effect of platelet-rich plasma formulations and blood products on human synoviocytes: implications for intra-articular injury and therapy. Am J Sports Med. 2014;42(5):1204-10.[ncbi]
- Opher S. Kornfeld, Sunhee Hwang, Marie-Hélène Disatnik, Che-Hong Chen, Nir Qvit, and Daria Mochly-Rose. Mitochondrial reactive oxygen species at the heart of the matter new therapeutic approaches for cardiovascular diseases. Circulation Research. 2015;116(11):1783-1799.[aha]
- DCorrêa do Amaral R, Pereira da Silva N, Haddad N, Lopes L, Ferreira F, Filho R, Cappelletti P, Mello W, Cordeiro-Spinetti E, and Balduino A. Platelet-rich plasma obtained with different anticoagulants and their effect on platelet numbers and mesenchymal stromal cells behavior in vitro. Stem Cells International. 2016; Article ID 7414036, 11 pages.[ncbi]