Composition Of Platelet-rich Plasma Research Articles

Bioactive Factors in Platelet-Rich Plasma Obtained by Apheresis

SummaryIntroduction: The use of platelet-rich plasma (PRP) in regenerative approaches in cartilage repair is becoming more common. Information about PRP composition and its content of putative bioactive chondrogenic growth factors (GF) that may support cartilage regeneration is scarce. Methods: GF composition of a pool of 6 PRP preparations was determined using Protein Antibody Membrane Arrays covering 507 GF, signaling molecules, and receptors. To verify the chondrogenic GF variability in PRP, Growth Factor Antibody Membrane Arrays covering 26 GF were applied to 6 individual PRP preparations. Selected GF involved in chondrogenic differentiation were quantified by Enzyme-Linked Immunosorbent Assay (ELISA). Results: 417 out of 507 possible detectable proteins were present in the PRP pool, including 76 GF. Quantification of selected chondrogenic GF by ELISA showed an average of 0.31 ng/ml bone morphogenetic protein-2, 0.50 ng/ml connective tissue growth factor, 0.76 ng/ml fibroblast growth factor-2, and 0.59 ng/ml transforming growth factor-β3. Conclusion: PRP as a therapeutic option in regenerative cartilage repair strategies is a powerful tool for the local application of chondrogenic GF to the site of injury. Chondrogenic GF are present in PRP and may support cartilage repair by inducing cell differentiation and cartilage matrix formation.

Optimization of Leukocyte Concentration in Platelet-Rich Plasma for the Treatment of Tendinopathy

Numerous methods are available for platelet-rich plasma (PRP) generation, but evidence defining the optimum composition is lacking. We hypothesized that leukocyte-reduced PRP would result in lower inflammatory cytokine expression compared with concentrated-leukocyte PRP and that maintaining the platelet:white blood cell (WBC) ratio would compensate for the effect of increased WBC concentration. Blood and flexor digitorum superficialis tendons were collected from young adult horses. Three PRP groups were generated with the same platelet concentration but different WBC concentrations: intermediate-concentration standard PRP, leukocyte-reduced PRP, and concentrated-leukocyte PRP. An additional high-concentration PRP group was generated with the same WBC concentration as the concentrated-leukocyte PRP group and the same platelet:WBC ratio as the standard PRP group. The PRP groups were used as media for flexor digitorum superficialis tendon explants in culture for seventy-two hours with 10% plasma in Dulbecco modified Eagle medium (DMEM) serving as control. Tendon gene expression for collagen types I (COL1A1) and III (COL3A1), cartilage oligomeric matrix protein (COMP), matrix metalloproteinase (MMP-13), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α) was performed. The desired PRP groups were successfully generated. The expression of COMP, the COL1A1:COL3A1 ratio, and the expression of MMP-13 in flexor digitorum superficialis tendon explants was not different between PRP groups. The expression of COMP (p = 0.0027) and the COL1A1:COL3A1 ratio (p < 0.0001) were increased in the PRP groups as compared with the control group, and the expression of MMP-13 was decreased in the PRP groups as compared with the control group (p < 0.0001). The expression of IL-1β was lowest in leukocyte-reduced PRP and highest in concentrated-leukocyte PRP (p = 0.0001). The leukocyte-reduced PRP group and the control group had the lowest TNF-α expression, whereas the high-concentration PRP and concentrated-leukocyte PRP groups had the highest expression (p = 0.0224). A high absolute WBC concentration in PRP contributes to the expression of inflammatory cytokines in flexor digitorum superficialis tendon explants, and maintenance of the platelet:WBC ratio is not able to counteract this effect. The optimum composition of PRP for the treatment of tendinopathy has not been directly investigated. Persistent inflammation results in inferior repair with scar tissue. The present study indicates that in an animal model, WBC in PRP contributes to inflammatory cytokine production. Therefore, leukocyte-reduced PRP may be the optimum preparation to stimulate superior healing without scar tissue formation.

Contents and Formulations of Platelet-Rich Plasma

Multiple studies have demonstrated a role for platelet-rich plasma (PRP) in accelerating and facilitating improved response to injury. The cellular response to injury progresses through 4 general stages: hemostasis, inflammation, proliferation, and finally remodeling. Each phase is characterized by enhanced cellular or molecular activity, all of which involve platelets. Blood plasma and platelets are responsible for hemostasis, whereas leukocytes and activated platelets mediate inflammation, and growth factors derived from platelet α-granules influence tissue regeneration. Specifically, the leukocyte content of PRP is thought to influence the inflammatory phase, whereas angiogenic and mitogenic growth factor concentrations are believed to aid tissue regeneration. Both the precise composition of PRP and its formulation affect the cellular environment in which it is placed and determine its overall effect on tissue repair.

Effects of Platelet-Rich Plasma Composition on Anabolic and Catabolic Activities in Equine Cartilage and Meniscal Explants.

Objective:To evaluate the effects of single- and double-spin preparations of platelet-rich plasma (PRP) on anabolic and catabolic activities of cartilage and meniscal explants in vitro.Methods:Single- and double-spin PRP was prepared using laboratory processing or commercial kits. The cellular contents were quantified, and each PRP was mixed in equal quantities with cell culture medium and added to cartilage or meniscus explant cultures, with or without interleukin 1 β (IL-1β). Extracellular matrix synthesis was quantified over 24 hours via 35S-sulfate and 3H-proline incorporation, while gene expression of catabolic enzymes was evaluated using real-time PCR.Results:The platelet concentration in single-spin laboratory PRP was 59% higher than blood. Platelet and white blood cell concentrations in single-spin laboratory and kit PRP were not significantly different, while the double-spin kit resulted in approximately 2.5-fold higher platelet and approximately 400-fold higher white blood cell concentrations. In cartilage cultures without IL-1β, radiolabel incorporation in single-spin PRP cultures was significantly higher than in double-spin cultures. Similar results were obtained for 35S-sulfate incorporation in meniscus cultures without IL-1β. In IL-1β, radiolabel incorporation was largely similar among all PRPs. After 24 hours of culture, ADAMTS-4 gene expression in cartilage was lowest for single-spin PRP, while expression in the double-spin kit was not significantly different from double-spin laboratory PRP in which platelets were concentrated 6-fold.ConclusionsThis study suggests that single-spin PRP preparations may be the most advantageous for intra-articular applications and that double-spin systems should be considered with caution.

Platelet-Rich Plasma

Several injectable substances have been studied for the treatment of tendinitis of the hand, wrist, and elbow, including corticosteroids, botulinum toxin, autologous blood, and platelet-rich plasma (PRP). 1 Faro F. Wolf J.M. Lateral epicondylitis: review and current concepts. J Hand Surg. 2007; 32A: 1271-1279 Google Scholar , 2 Mishra A. Pavelko T. Treatment of chronic elbow tendinosis with buffered platelet-rich plasma. Am J Sports Med. 2006; 34: 1774-1778 Crossref PubMed Scopus (628) Google Scholar , 3 Peerbooms J.C. Sluimer J. Bruijn D.J. Gosens T. Positive effect of an autologous platelet concentrate in lateral epicondylitis in a double-blind randomized controlled trial: platelet-rich plasma versus corticosteroid injection with a 1-year follow-up. Am J Sports Med. 2010; 38: 255-262 Crossref PubMed Scopus (523) Google Scholar , 4 Szabo R.M. Steroid injection for lateral epicondylitis. J Hand Surg. 2009; 34A: 326-330 Google Scholar , 5 Creaney L. Wallace A. Curtis M. Connell D. Growth factor-based therapies provide additional benefit beyond physical therapy in resistant elbow tendinopathy: a prospective, single-blind, randomised trial of autologous blood injections versus platelet-rich plasma injections. Br J Sports Med. 2011; 45: 966-971 Crossref PubMed Scopus (212) Google Scholar , 6 Thanasas C. Papadimitriou G. Charalambidis C. Paraskevopoulos I. Papanikolaou A. Platelet-rich plasma versus autologous whole blood for the treatment of chronic lateral elbow epicondylitis: a randomized controlled clinical trial. Am J Sports Med. 2011; 39: 2130-2134 Crossref PubMed Scopus (262) Google Scholar , 7 Wolf J.M. Ozer K. Scott F. Gordon M.J. Williams A.E. Comparison of autologous blood, corticosteroid, and saline injection in the treatment of lateral epicondylitis: a prospective, randomized, controlled multicenter study. J Hand Surg. 2011; 36A: 1269-1272 Google Scholar , 8 Gosens T. Peerbooms J.C. van Laar W. den Oudsten B.L. Ongoing positive effect of platelet-rich plasma versus corticosteroid injection in lateral epicondylitis: a double-blind randomized controlled trial with 2-year follow-up. Am J Sports Med. 2011; 39: 1200-1208 Crossref PubMed Scopus (387) Google Scholar Whereas empiric data suggest a beneficial effect of many treatments for tendinitis, defined roles for these various injections remain unclear. For several years, orthopedic surgeons have used PRP to treat conditions such as tendinitis about the knee, hip, and shoulder 9 Hall M.P. Band P.A. Meislin R.J. Jazrawi L.M. Cardone D.A. Platelet-rich plasma: current concepts and application in sports medicine. J Am Acad Orthop Surg. 2009; 17: 602-608 Crossref PubMed Scopus (273) Google Scholar , 10 Sampson S. Gerhardt M. Mandelbaum B. Platelet rich plasma injection grafts for musculoskeletal injuries: a review. Curr Rev Musculoskelet Med. 2008; 1: 165-174 Crossref PubMed Scopus (4) Google Scholar , 11 Mishra A. Harmon K. Woodall J. Vieira A. Sports medicine applications of platelet rich plasma. Curr Pharm Biotechnol. 2011 July 8; (Epub ahead of print) Google Scholar ; however, data are inconclusive as to its precise mechanism of action as well as whether it demonstrates lasting benefit. We review the composition and preparation of PRP and list several of the available kits for its preparation. Journal CME QuestionsJournal of Hand SurgeryVol. 37Issue 3Preview Full-Text PDF

Anwendungsoptionen und Evidenz für PRP (platelet-rich plasma) in der Orthopädie

Summary The use of orthobiologics and the progress in tissue engineering have an important and increasing impact in orthopedic surgery. Especially the use of PRP (platelet-rich plasma) is one of the most intense investigated therapeutical options in this field. The application of an autologue, platelet enriched suspension is supposed to cause multiple effects: The induction of a local inflammation process and the release and activation of multiple growth factors within complex signaling cascades. This is included in the wound healing process supporting tissue regeneration. The use and especially a detailed review of the evidence for PRP remains difficult. A clear definition of the cellular composition of PRP in the literature is still missing. Additionally the options to apply PRP are heterogeneous and complicate a final assessment. In the literature a supporting beneficial effect of PRP is described for rotator cuff repair and treatment of tennis-elbow, as well as wound- and bone healing. In Summary PRP is a promising and interesting tool for orthopedic surgeons to support established treatment algorithms. Large prospective, randomized-controlled trials are essential to assess and decide about the use of PRP in the future.

Growth Factor and Catabolic Cytokine Concentrations Are Influenced by the Cellular Composition of Platelet-Rich Plasma

Background: Previous studies of bioactive molecules in platelet-rich plasma (PRP) have documented growth factor concentrations that promote tissue healing. However, the effects of leukocytes and inflammatory molecules in PRP have not been defined. Hypothesis: The hypothesis for this study was that the concentration of growth factors and catabolic cytokines would be dependent on the cellular composition of PRP. Study Design: Controlled laboratory study. Methods: Platelet-rich plasma was made from 11 human volunteers using 2 commercial systems: Arthrex ACP (Autologous Conditioned Plasma) Double Syringe System (PRP-1), which concentrates platelets and minimizes leukocytes, and Biomet GPS III Mini Platelet Concentrate System (PRP-2), which concentrates both platelets and leukocytes. Transforming growth factor-β1 (TGF-β1), platelet-derived growth factor–AB (PDGF-AB), matrix metalloproteinase-9 (MMP-9), and interleukin-1β (IL-1β) were measured with enzyme-linked immunosorbent assay (ELISA). Results: The PRP-1 system consisted of concentrated platelets (1.99×) and diminished leukocytes (0.13×) compared with blood, while PRP-2 contained concentrated platelets (4.69×) and leukocytes (4.26×) compared with blood. Growth factors were significantly increased in PRP-2 compared with PRP-1 (TGF-β1: PRP-2 = 89 ng/mL, PRP-1 = 20 ng/mL, P < .05; PDGF-AB: PRP-2 = 22 ng/mL, PRP-1 = 6.4 ng/mL, P < .05). The PRP-1 system did not have a higher concentration of PDGF-AB compared with whole blood. Catabolic cytokines were significantly increased in PRP-2 compared with PRP-1 (MMP-9: PRP-2 = 222 ng/mL, PRP-1 = 40 ng/mL, P < .05; IL-1β: PRP-2 = 3.67 pg/mL, PRP-1 = 0.31 pg/mL, P < .05). Significant, positive correlations were found between TGF-β1 and platelets (r2 = .75, P < .001), PDGF-AB and platelets (r2 = .60, P < .001), MMP-9 and neutrophils (r2 = .37, P < .001), IL-1β and neutrophils (r2 = .73, P < .001), and IL-1β and monocytes (r2 = .75, P < .001). Conclusion: Growth factor and catabolic cytokine concentrations were influenced by the cellular composition of PRP. Platelets increased anabolic signaling and, in contrast, leukocytes increased catabolic signaling molecules. Platelet-rich plasma products should be analyzed for content of platelets and leukocytes as both can influence the biologic effects of PRP. Clinical Relevance: Depending on the clinical application, preparations of PRP should be considered based on their ability to concentrate platelets and leukocytes with sensitivity to pathologic conditions that will benefit most from increased platelet or reduced leukocyte concentration.

Comparison of Growth Factor and Platelet Concentration From Commercial Platelet-Rich Plasma Separation Systems

Background: Clinical studies claim that platelet-rich plasma (PRP) shortens recovery times because of its high concentration of growth factors that may enhance the tissue repair process. Most of these studies obtained PRP using different separation systems, and few analyzed the content of the PRP used as treatment. Purpose: This study characterized the composition of single-donor PRP produced by 3 commercially available PRP separation systems. Study Design: Controlled laboratory study. Methods: Five healthy humans donated 100 mL of blood, which was processed to produce PRP using 3 PRP concentration systems (MTF Cascade, Arteriocyte Magellan, Biomet GPS III). Platelet, white blood cell (WBC), red blood cell, and fibrinogen concentrations were analyzed by automated systems in a clinical laboratory, whereas ELISA determined the concentrations of platelet-derived growth factor αβ and ββ (PDGF-αβ, PDGF-ββ), transforming growth factor β1 (TGF-β1), and vascular endothelial growth factor (VEGF). Results: There was no significant difference in mean PRP platelet, red blood cell, active TGF-β1, or fibrinogen concentrations among PRP separation systems. There was a significant difference in platelet capture efficiency. The highest platelet capture efficiency was obtained with Cascade, which was comparable with Magellan but significantly higher than GPS III. There was a significant difference among all systems in the concentrations of WBC, PDGF-αβ, PDGF-ββ, and VEGF. The Cascade system concentrated leukocyte-poor PRP, compared with leukocyte-rich PRP from the GPS III and Magellan systems. Conclusion: The GPS III and Magellan concentrate leukocyte-rich PRP, which results in increased concentrations of WBCs, PDGF-αβ, PDGF-ββ, and VEGF as compared with the leukocyte-poor PRP from Cascade. Overall, there was no significant difference among systems in the platelet concentration, red blood cell, active TGF-β1, or fibrinogen levels. Clinical Relevance: Products from commercially available PRP separation systems produce differing concentrations of growth factors and WBCs. Further research is necessary to determine the clinical relevance of these findings.