PRP ORTHOBIOLOGICS 2010

PRP ORTHOBIOLOGICS: WHERE DO WE STAND NOW WITH PLATELET-RICH PLASMA (PRP) APPLICATION IN THERAPEUTIC, REGENERATIVE AND AESTHETIC MEDICINE?

CONTENTS:

1. Abstract: status of PRP 2010
2. Does PRP work? (2010)
3. Classification of PRP-1 (2010)
4. Classification of PRP-2 (2010)
5. Use of gels, lysates, platelet-fibrin-gels, platelet fibrin matrix (2010)
6. Arthrex®: New PRP Technology  (2010)
7. PRP: Clinical Trial Outcomes 2006-2010 ( Table 1)
8. Aesthetic: PRP vs. other salon treatments 2010 ( Table 2)
9. Aesthetics: PRP vs. micro-fat transfer and lipo-filling………merits ( Table 3)
10. Aesthetics: PRP vs. conventional hyaluronic facial fillers ( Table 4)
11. Aesthetics: PRP vs. superficial peels……..salicylic acid ( Table 5)
12. References
13. Disclaimer
14. Website posting 25/4/2010
15. Copyright©2010

PRP ABSTRACT:

Application of PRP in aesthetics and part of therapy has successes and failures so far, and many reports are mixed. The haematological concept and safety of platelet-rich plasma (PRP) is evidenced-based. The idea being to prepare an autologous platelet concentrate (A-PRP) suspended in a relative small quantity of blood, plasma or fibrin-gel. Platelets contain various growth factors (GF) that regulate wound healing. PRP can be generated by automatic devices or prepared from a kit or syringe alone for rapid clinical application. There are 8 commercial-kits available at the moment. PRP may, depending on the technological capability of the kit, provide 3-8 fold increase in platelet count, compared to base-line whole venous-blood. The injectate or product applied is popularly referred to as a “platelet injection”. Most PRP-generation technologies are FDA approved 510 (k) class II clearance and are CE marked, because the plasma-separation and end-biological product is similar to most technologies. Platelet-derived GF’s or proteins include platelet-derived growth factor (PDGF), transforming growth factor (TGF), vascular endothelial growth factor (VEGF), epithelial growth factor (EGF) and insulin-like growth factor (IGF). These proteins are also referred to as cytokines.  Platelet activation status can be confirmed by analysis of platelet-receptor P Selectin. At the time of administration, the platelet injection may contain activated or non-activated platelets, and the volume of PRP used may vary between 3 and 5ml. The clinician has a choice of platelet-enriched plasma or fibrin-platelet-matrix. PRP has been directed at wound-healing, regenerative medicine and aesthetic medicine to ameliorate facial wrinkles. It is technically impossible to inject a thick, fibrinous and gelatinous matrix into the skin-dermis and one has rather to rely on a plasma formulation that can be given through a small-gauge needle. The biological efficacy of PRP has been quantified in the laboratory bydemonstrating the ability to proliferate important wound-healing cell-lines in tissue-culture (TC). More than 20 clinical-trials are in progress and directed at the treatment of tendinopathies (orthopaedics), early arthritis, diabetic-foot ulceration, knee-ligament reconstruction, maxillary-sinus augmentation (dentistry), tennis-elbow, shoulder rotator-cuff disease, dry-eye, muscle-injuries, periodontal disease and cosmetic wrinkle amelioration. Early provisional results (inclusive of anecdotal reports, level I and III evidence-based studies) show possible clinical benefit in two (10%). Because of variable results there are potential limitations to the use of PRP, which often does not render results superior to placebo or saline injections. PRP as anti-aging and wrinkle ameliorator has not stood up to robust science; results vary, and are non-permanent requiring additional beauty treatments or manipulations. Outstanding issues include: when to give injections and how many are needed? In some conditions PRP is still unproven therapy and not a standard of care. PRP may have a role in orthopaedic-related sports medicine and aesthetic practise, and is non-invasive. Poor results may be explained by kit-technological inconsistencies during the generation of the platelet-preparation immediately before administration at the point of care. PRP is very expensive treatment, and reimbursement is not forthcoming for unproven therapy. More time and trials are still needed before writing off platelet injections. Arthrex® has launched new technology and revolutionary type PRP-generation system (double-syringe) without need for blood-collection tubes and good product platelet and GF profile.

AUTOLOGOUS PLATELET-RICH PLASMA (A-PRP): ERA OF PLATELET-INJECTIONS AT THE POINT-OF-CARE.

The platelet is the king-pin and Achilles-Heel of PRP and platelet-injections. In a definitive research publication in 1994, Dr Brian Eppley and co-workers, of Indiana University School of Medicine, pointed out the strategic importance of platelet and GF quantification in PRP (1). This group showed that it was possible to generate an 8-fold increase in platelet-count in A-PRP, compared to baseline whole blood. Also, that platelet derived GF such as PDGF-BB, TGF-1, VEGF, EGF, were increased with increasing platelet-count, but important inter-patient variance was evident. The relevance of these findings which are relevant to tissue-healing and regenerative-medicine has been emphasized by Marx and Karg from the Miami School of Medicine in 2005 (2). Numerous studies are underway to assess the efficacy and application of PRP, platelet-activation, fibrin-gels and platelet-derived GF in therapeutic, aesthetic and regenerative-medicine. PRP is not viewed as stem cell therapy but may act as a stimulant for enhanced wound-healing by stimulation of recipient mesenchymal-cells. Researchers and clinicians should remember that PRP is blood-component therapy (i.e. platelet-rich plasma or fibrin-gel for reinjection) and the rules and principles of blood-transfusion practice still exist, in order to prevent contamination, needle-pricks and transmission of infections. Regarding aesthetic medicine, manufacturers and distributors should provide clinicians with further convincing evidence , regarding anti-aging or anti-wrinkle action, if A-PRP is indeed equal to or superior to non-invasive RF, fractional-RF, fractional-laser, peels, and IPL. Manufacturers and distributors of PRP-devices can vouch for FDA and CE technology-certification, but as is the case with other biologicals, cannot predict or guarantee the tissue-response or regenerative outcomes ( or provide markers for the clinician and to guide him/her).The questions  that remain are: “ Does the PRP work and is it going to work in this patient?”.

BIOMEDICAL SCIENCE OF AUTOLOGOUS PLATELET-RICH PLASMA (A-PRP): SHOULD WE USE LYSEATE, PLASMA, GEL OR FIBRIN MATRIX ?

Platelets are anucleate blood-components and are cytoplasmic fragments of megakaryocytes. These cells are the progeny of the hemoblast and myeloid stem cell and their formation is regulated by thrombopoietin. Normal blood contains between 150,000 and 400,000 platelets. PRP generation –technology allows us to generate up to 5 times the number of platelets found in normal whole-blood (1,2). Relevant to platelet-plug formation and haemostasis, platelets, apart from GF release, also release serotonin, adenosine diphosphate (ADP) and thromboxane A-2 (2). Centrifugation of anti-coagulated blood produces separation of the RBC’s and plasma in the blood-collection tube supplied in the kit (1,2). The platelets separate out just above the buffy-layer, on centrifugation of whole blood (1,2). Thus, the plasma consists of a platelet-rich (PRP) and platelet-poor (PPP) zone. About 3-5 ml of A-PRP is generated but depends on the volume of whole blood used for centrifugation. Because most blood-collection tubes contain ACD, the plasma is anti-coagulated and will not clot. Some kit manufacturers avoid platelet activation and fibrin-matrix precipitation by excluding the use of thrombin and calcium. In these cases the PRP is injected and coagulation occurs when the platelets and plasma make contact with the recipient’s collagen. A platelet-rich fibrin-mesh can be precipitated by addition of calcium and or thrombin to the centrifuged blood (2). If bovine thrombin is used, care must be exercised to detect lowering of Factor-V (proaccellerin). Plateltex® precipitates the fastest and makes the most consistent gel by the application of calcium gluconate and batroxibin (3). This avoids platelet-activation and allows for a more controlled release of GF compared to a more non-physiological bolus release (3). All human PRP contains committed CD34+ progenitor cells  in peripheral venous-blood ( especially after exercise). CD34+ cells are of haemopoeitic origin and found in umbilical blood and bone-marrow. These bone-marrow derived cells have unproven physiological effect in the PRP-gel as reported by others. A-PRP would not be considered as optimal stem cell therapy in a 40-60 year old patient. And we know that human blood transfusions or platelet-transfusions in man do not have proven anti-aging effects. PRP can be prepared by automation or manually by the use of kits at the point-of-care ( Regen®, MyCells®, Selphyl®, Arthrex®, Plateltex® and Fibrinet®). The Arthrex® system is unique and practical, because blood-collection tubes are not needed and the double-syringe is centrifuged instead of blood-collection tubes. In the case of Arthrex®, the PRP is generated in a double-syringe system and not in blood-collection tubes. The following A-PRP preparations are recorded in 2010:

• Activated or non-activated PRP (no application of calcium or thrombin).
• Vortexed-A-PRP free of calcium or thrombin ( MyCells®).
• PRP generation in the syringe with no need for blood-collection tubes ( Arthrex®)
• Autologous conditioned plasma ( Arthrex® ACP System®): same as point 3.
• Batroxibin-induced platelet-gel and fibrin-gel ( Plateltex®)
• Platelet-rich fibrin matrix( PRFM): Selphyl® ( newly launched in the USA for aesthetic work) and solid fibrin-web ( SFW: Fibrinet)®
• PRP for aesthetic work and wrinkle amelioration: Regen®, Selphyl®, Mycells®

BIOLOGICAL ACTIVITY AND BIOSCIENCE OF PLATELET-RICH PLASMA: NEED FOR CLOT, PLASMA, OR FIBRIN MATRIX  AT POINT OF CARE ?

Current ex vivo research indicates that platelet-lysates can increase wound-healing by stimulating keratin migration through calcium and P38 dependent mechanisms. Furthermore, international ex vivo studies confirm that PRP as well as diluted-PRP in concentrations of 5-20%, can promote proliferation of human adipose-derived stem cells, keratinocytes, dermal fibroblasts and tenocytes (3-7). Safety has been reported (1,2).The GF released by platelets in the PRP such as PDGF-AB and TGF-beta 1 are thought to be the cell-proliferation drivers (2). These GF may upregulate proteoglycans and collagen synthesis and build ECM by enhanced cell-cell interactions. PRP and the GF may well facilitate recruitment of reparative cells, at the same time suppressing macrophage function in the early phase of inflammation. The GF effects may be more focused on the cell proliferation phase of healing rather than the inflammatory phase. Quality fibrin-platelet gel that promotes haemostasis and wound-healing can be induced by mixing PRP with calcium-chloride or gluconate and thrombin. Agonist priming of the platelets ex vivo in the PRP leads to release of PDGF and TGF. Batroxibin, in Plateltex®, gives a rapid onset platelet-rich fibrin-matrix and consistent gel-formation. This facilitates application of A-PRP for soft and hard tissue treatments. A recent French-publication showed that Plateltex® (a semi-solid- gel network of polymerized fibrin) renders the highest concentration of platelets in the smallest volume available. Regenlab PRP® also rendered good yields. No comparable data is available for other PRP-generation technologies such as Selphyl®, Fibrinet®, Mycells® and Arthrex®. Not much data is available regarding bioavailability of GF in tissue-healing, nor kinetics of GF release from PRP-gels. But recent work from Alessandria, Italy shows that similar methods of platelet gel preparation are associated with different performances concerning GF recovery and GF kinetics during release from fibrin-platelet gels. Clearly this may well explain the variable results seen in the clinic in aesthetics and in trials. Or also explain and elucidate successes and failures that have occurred so far. Clearly there are different PRP products with differing biology. PRP has in Veterinary Medicine been shown to facilitate wound-healing, especially in horses. The Sahlgrenska Academy at the University of Gothenburg, Sweden and other academic units suggest a new functional classification based on leukocyte and fibrin-content.

• Pure platelet-rich plasma ( P-PRP): Cell Separator PRP®, Vivostat PRF® and Anitua’s PRGF®
• Leukocyte-and platelet-rich plasma ( L-PRP): Curasin®, Regen®, Plateltex®, SmartPrep®, Magellan or GPS PRP®
• Pure platelet-rich fibrin ( P-PRF): Fibrinet®
• Leukocyte-and platelet-rich fibrin ( L-PRF): Choukroun’s PRF®
• Platelet-rich fibrin matrix (P-PRFM): Selphyl® ( PRFM, an injectable PRFM for the treatment of wrinkles and skin depressions in the United States. Sclafani et al have described the cosmetic facial applications of platelet-rich fibrin –matrix in facial plastic surgery. This entails rejuvenation of the face without tissue manipulation as seen during surgical face-lift or modifications thereof (8).
• Autologous regenerative factor-rich plasma (A-RFRP): for ocular burns by subconjunctival infiltration of A-RFRP.
• Autologous Conditioned Plasma: Double Syringe System of Arthrex®. A new revolutionary system that does away with blood-collection tubes.

ARTHREX® DEVICE SET TO REPLACE CONVENTIONAL BLOOD PREPARATION-TUBES AND COLLECTION-KITS FOR PLATELET-RICH PLASMA

Conventional preparation of PRP includes vena-section, placement of blood in special collection tubes containing an anti-coagulant, centrifugation at low revolutions, and separation of the blood into plasma and RBC, and aspiration of the PRP.
Arthrex® has a new revolutionary way of PRP generation and introduced a new technology that may well phase out all current methods of PRP generation. Their new technology eliminates completely the need for blood collection tubes that potentially brings huge savings to the clinician and the client. The introduction of the double-disposable syringe system and no need for blood collection tubes, ushers in a new era for the quick generation of PRP in a syringe. Both for the use in the clinic and sterile environments such as an operating theatre. The chief advantages of the Arthrex® device compared to conventional PRP-kits is as follows:

• Minimal need for anticoagulant, if any (such as ACD). No need for ACD if intervention takes place in 1 hour.
• No need for blood collection tubes. Therefore massive cost savings (up to R3000).This now makes PRP an affordable treatment and will be looked at more favourably for reimbursement.
• No need for agonists such as calcium chloride or gluconate. The device dispenses with the need to activate the platelets.
• Easy-use centrifugation of the blood filled syringe (not tubes) in special bucket-type carriers.
• Low-revolution centrifugation that is less damaging to platelets and reduces activation (1500 rpm for 5 minutes instead of 3700 rpm for 5-7 minutes as used in other kits).
• Almost 3 times concentration of autologous-platelets in a short-time.
• Product is suitable for orthopaedic-surgery and dentistry as PRP can be mixed with autograft and allograft-bone chips for bony-contouring.
• Quantification of the release of platelet-derived GF’s is excellent compared to conventional devices. This includes verification of PDGF,TGF, IGF, EGF, and VEGF. So, platelet concentrations and GF release is equivalent, if not better than conventional kits.
• The double syringe system facilitates the administration of PRP at the point of care without need for blood collection tubes. Just the syringe and blood therein is centrifuged. The bucket type centrifuge carrier is a known system.
• No further need to worry about gel-formation, matrices, fibrin-scaffolds, activation etc

NEED FOR PRP-BIOEQUIVALENCE GUIDANCE

PRP is a highly variable biological-product with a wide therapeutic-index. Currently, the bioequivalence acceptance range is unknown. Clearly, more research is needed to demonstrate if PRP is bioequivalent with other reference PRP-biologicals. Possibly, for highly variable biologicals such as PRP, scaled average bioequivalence may provide an alternative and practical approach for the comparisons of PRP-biologicals. This may facilitate researchers understanding of PRP-efficacy, when using activated and non-activated fractions, that may induce variable or no clinical results. Currently, there is no data regarding potential therapeutic-inequivalence of available PRP-generation products. We can measure the platelet concentration and GF content in the test-tube of the various PRP-kits, but cannot measure the tissue-response after PRP-injection, because the outcomes are so different."

CLINICAL EFFICACY OF A-PRP APPLICATION REFLECTED IN HUMAN TRIALS: Pubmed-Indexed.
Details are reflected in the following table that gives provisional and tentative outcomes. Some studies report favourable and encouraging results, but others show unexpected poor, mixed  or variable results (9). Safety has been documented (10).

TABLE 1: EARLY RESULTS OF CLINICAL TRIALS AND PLATELET-RICH PLASMA (PRP)

TABLE 2: AESTHETICS: EXPECTED CLINICAL-OUTCOMES IN SALON . A-PRP VS. OTHER SALON TREATMENTS.

TABLE 3: FACIAL CONTOUR RESPONSE AFTER AUTOLOGOUS MICRO-FAT TRANSFER IS SUPERIOR TO AUTOLOGOUS PLATELET-RICH PLASMA (A-PRP) MESOTHERAPY ALONE FOR FACIAL REJUVENATION AND WRINKLE REDUCTION.

TABLE 4: CLINICAL FACIAL CONTOUR RESPONSE AFTER HYALURONIC-ACID FILLER (IE. JUVEDERM® OR RESTYLANE®) IS SUPERIOR TO BIOLOGICAL AUTOLOGOUS PLATELET-RICH PLASMA (A-PRP) MESOTHERAPY ALONE FOR FACIAL REJUVENATION AND WRINKLE REDUCTION.

TABLE 5: CLINICAL COMPARISON OF REJUVENATION CAPACITY. SUPERFICIAL PEEL VS, PLATELET-RICH PLASMA.

Ingredients: Salicylic acid 14%, lactic acid 14%, PEG-8, Citric acid 8%, hydroxypropylcellulose.

REFERENCES:

1. Eppley BL, Woodell JE, Higgins J. Platelet quantification and growth factor analysis from platelet-rich plasma: implications for wound healing. Plast Reconstr Surg. 2004: 114, 1502-8.
2. Marx RE and Karg A. Dental and cranio-facial applications of platelet-rich plasma. Quintessence, New York, 2005.
3. Mazzucco L et al. Not every PRP-gel is born equal. Evaluation of growth factor availability for tissues through four PRP-gel preparations: Fibrinet®, RegenPRP-kit®, Plateltex®, and one manual procedure. Vox Sang 2009: 97; 110-8.
4. Kakudo N et al. Proliferating-promoting effect of platelet-rich plasma on human adipose-derived stem cells and human dermal fibroblasts. Plast Reconstr Surg 2008: 122; 1352-60.
5. Krasna M et al. Platelet- gel stimulates proliferation of human dermal fibroblasts in vitro. Acta Dermatoven APA. 2007: 16; 105-110.
6. De Mos M et al. Can platelet-rich plasma enhance tendon repair? A cell culture study. Am J S Med 2008: 36; 1171-8.
7. Valeri CR et al. Release of PDGF and proliferation of fibroblasts in releasates from platelets in the liquid state at 22 degrees Celsius after stimulation with agonists. Transfusion 2006: 46; 225-9.
8. Sclafani AP. Applications of platelet-rich fibrin matrix in facial plastic surgery. Facial Plastic Surgery 2009: 25; 270-6.
9. De Vos R et al. Randomized, double-blind, controlled trial of platelet-rich plasma injections for the treatment of chronic Achilles tendinopathy. JAMA 2010: 303; 144-9.
10. Du Toit DF et al. An in vitro tissue culture evaluation of the cellular toxicity of autologous platelet-rich plasma and silver dressings. Jnl of US-China Medical Science. 2010. In Press.

CONFLICT OF INTEREST: Formulation is by an Independent biomedical-expert not associated with industry or manufacturers.

DISCLAIMER: This website provides no medical advice and for medical conditions readers should contact their physicians for a sit-down, face-to-face, eye-balling conversation and assessment. In the case of cosmetic interventions readers should contact a dermatologist, aesthetic specialist or cosmetic surgeon to discuss all the aesthetic options, efficacy in that situation and drawbacks. And what works and what does not work or renders no result.

WEBSITE POSTING 25/4/2010.
COPYRIGHT©: BOLAND CELL® 2010
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