Platelet-Rich Plasma: A Milieu of Bioactive Factors

Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Arthroscopy The Journal of Arthroscopic and Related Surgery (Impact Factor: 3.21). 03/2012; 28(3):429-39. DOI: 10.1016/j.arthro.2011.10.018
Source: PubMed


Platelet concentrates such as platelet-rich plasma (PRP) have gained popularity in sports medicine and orthopaedics to promote accelerated physiologic healing and return to function. Each PRP product varies depending on patient factors and the system used to generate it. Blood from some patients may fail to make PRP, and most clinicians use PRP without performing cell counts on either the blood or the preparation to confirm that the solution is truly PRP. Components in this milieu have bioactive functions that affect musculoskeletal tissue regeneration and healing. Platelets are activated by collagen or other molecules and release growth factors from alpha granules. Additional substances are released from dense bodies and lysosomes. Soluble proteins also present in PRP function in hemostasis, whereas others serve as biomarkers of musculoskeletal injury. Electrolytes and soluble plasma hormones are required for cellular signaling and regulation. Leukocytes and erythrocytes are present in PRP and function in inflammation, immunity, and additional cellular signaling pathways. This article supports the emerging paradigm that more than just platelets are playing a role in clinical responses to PRP. Depending on the specific constituents of a PRP preparation, the clinical use can theoretically be matched to the pathology being treated in an effort to improve clinical efficacy.

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Available from: Lisa A Fortier, Feb 02, 2015
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    • "To date, local administration of growth factors contained in PRP is an increasing and valuable way to treat tendinitis and in particular Achilles tendinopathies. There are many PRP formulations, which differ in terms of cell type content, platelet concentration, storage methods, activation methods and protocols for therapeutic application [15] [16]. "
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    ABSTRACT: The aim of this retrospective study is evaluating the long-term clinical outcome in patients affected by mid-portion Chronic Recalcitrant Achilles Tendinopathies (CRAT) treated with administration of single platelet-rich plasma (PRP). A total of 83 tendons (73 patients, 59 males and 14 females; age 43±17.5 years) affected by non-insertional CRAT were treated with single PRP injection. These were evaluated with the Victorian Institute of Sport Assessment - Achilles (VISA-A) questionnaire, Blazina score and satisfaction index at baseline at intervals of 3 weeks, 3 months, 6 months. Final follow-up was carried out at a mean of 50.1 months (range, 24-96). Baseline VISA-A was 45±15. Results relative to the final follow-up improved significantly to a mean of 88±8 (p<00.1). Blazina was used for patients practicing sports (54 tendons out of 46 different patients): 37 tendons were grade IIIa, 11 II, and 6 IIIbis. Final follow-up Blazina scores improved for 45 grade 0, 5 I, 4 II (p<00.5). Seventy-six tendons (91.6%) were rated as satisfactory and patients would repeat the treatment. Seven tendons (8.4%) were classified as unsatisfactory at the 6 months follow-up and underwent a second PRP injection. In addition to this, patients reported no Achilles tendon rupture. The study shows beneficial effects and low complication rate following of single PRP injections on a large cohort of patients with mid-long-term follow-up. No cases reported Achilles tendon rupture, in contrast to literature, which described CRAT as one of the most common risk factors. The use of a single PRP injection can therefore be a safe and attractive alternative in the treatment of non-insertional CRATs. Copyright © 2014 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.
    Full-text · Article · Sep 2015 · Foot and Ankle Surgery
    • "Furthermore, it is a versatile product since it can be prepared and used directly in the operating theatre, through intra-articular injections or in the shape of a membrane that can be placed directly onto the target site. The healing potential of PRP has been shown in several preclinical and clinical studies [13] [16] [17], revealing that its action is directed toward all the articular tissues, ranging from meniscus to cartilage and even soft tissues like synovium, tendons, and ligaments: the effects of PRP are several, including an anabolic stimulus toward cells, an increase in extracellular matrix deposition, reduction of proapoptotic signals, and even an anti-inflammatory effect in the joint environment [13]. "
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    ABSTRACT: Current research is investigating new methods to enhance tissue healing to speed up recovery time and decrease the risk of failure in Anterior Cruciate Ligament (ACL) reconstructive surgery. Biological augmentation is one of the most exploited strategies, in particular the application of Platelet Rich Plasma (PRP). Aim of the present paper is to systematically review all the preclinical and clinical papers dealing with the application of PRP as a biological enhancer during ACL reconstructive surgery. Thirty-two studies were included in the present review. The analysis of the preclinical evidence revealed that PRP was able to improve the healing potential of the tendinous graft both in terms of histological and biomechanical performance. Looking at the available clinical evidence, results were not univocal. PRP administration proved to be a safe procedure and there were some evidences that it could favor the donor site healing in case of ACL reconstruction with patellar tendon graft and positively contribute to graft maturation over time, whereas the majority of the papers did not show beneficial effects in terms of bony tunnels/graft area integration. Furthermore, PRP augmentation did not provide superior functional results at short term evaluation.
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    • "These molecules bind to the transmembrane receptors of their target cells regulating cell signaling pathways [1] [7] [8]. Alpha-granules also contain cytokines, chemokines, and many other bioactive proteins that stimulate chemotaxis, cell proliferation, and maturation, modulate inflammatory molecules, and attract leukocytes [8]. Preclinical evidence supports the use of intra-articular PRP injections for joint degenerative pathology, by targeting not only cartilage but also synovial and meniscal tissues and thus promoting a favorable environment for joint tissue healing [1]. "
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    ABSTRACT: PRP cryopreservation remains a controversial point. Our purpose was to investigate the effect of freezing/thawing on PRP molecule release, and its effects on the metabolism of chondrocytes and synoviocytes. PRP was prepared from 10 volunteers, and a half volume underwent one freezing/thawing cycle. IL-1β, HGF, PDGF AB/BB, TGF-β1, and VEGF were assayed 1 hour and 7 days after activation. Culture media of chondrocytes and synoviocytes were supplemented with fresh or frozen PRP, and, at 7 days, proliferation, gene expression, and secreted proteins levels were evaluated. Results showed that in the freeze-thawed PRP the immediate and delayed molecule releases were similar or slightly lower than those in fresh PRP. TGF-β1 and PDGF AB/BB concentrations were significantly reduced after freezing both at 1 hour and at 7 days, whereas HGF concentration was significantly lower in frozen PRP at 7 days. In fresh PRP IL-1β and HGF concentrations underwent a significant further increase after 7 days. Similar gene expression was found in chondrocytes cultured with both PRPs, whereas in synoviocytes HGF gene expression was higher in frozen PRP. PRP cryopreservation is a safe procedure, which sufficiently preserves PRP quality and its ability to induce proliferation and the production of ECM components in chondrocytes and synoviocytes.
    Full-text · Article · Jul 2014 · BioMed Research International
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