Platelet‐rich plasma (PRP) and platelet derivatives for topical therapy. What is true from the biologic view point?

Abstract

Background PubMed accessed on January 23 revealed 160 items about ‘platelet gel or releasate’ associated to topical therapy. Yahoo! provided 8580 items; Altavista 8650; Google 25 300. Companies providing blood separators are going to offer devices to prepare platelet‐rich plasma (PRP) for topical therapy. Several devices are filling the marketplace aiming to produce platelet gels for human therapy. Never‐ending lists of clinical conditions supposed to benefit from platelet gel application are published. Clinical benefits include bactericidal activity, pain reduction, tissue repair and regeneration. Are platelet derivatives the magic bullet for topical therapy? Methods Many in vitro studies account for clinical benefit from platelet gel. Several in vivo studies provide clinical evidence about healing of tissue repair induced by platelet derivatives. Nevertheless, systematic reviews reveal inadequate studies providing enough methodological strength to confirm evidence‐based efficacy. At present we must deal the subject with care using mostly inductive criteria. Only reproducible scientific data are to be considered. Every effort should be made for commercial, private and personal popularity‐related scenarios to be rejected from our consideration. Sometimes, this is not so simple to be done. Results There is a list of more than 60 biologically active platelet‐derived factors directly involved in tissue repair mechanisms: chemotaxis, cell proliferation, angiogenesis, extracellular matrix deposition and remodelling. Biological functions are also indirectly mediated by platelet‐derived growth factors; such functions are triggered by chemokines and cytokines produced by bystander cells such as fibroblasts, macrophages, endothelial cells, lymphocytes, under platelet‐derived factor stimulation. All of this is well demonstrated. Clinical studies endorsed with stringent randomized controlled trials are lacking. However, several serious studies have been published reporting clinical efficacy of platelet derivatives in many clinical areas. Considering these papers seriously, we maintain that in most cases, clinical efficacy is by far more than just a suggestion. Discussion Although we consider evidence‐based medicine (EBM) highly meaningful, we emphasize that medicine moved forwards also before EBM was conceived. We do not consider platelet gel and releasate such as a ‘magic bullet’, but we are strongly impressed by the results our group, and other groups have obtained treating a variety of tissue lesions in a variety of clinical conditions. Clinical benefits are a composite result of the lesion state, severity and duration, coexisting pathologies, patient's age and product characteristics. From our point of view, the last is a pivotal variable that has strong influence over the clinical outcome. Platelet‐rich plasma, platelet gel and platelet releasate need stringent definitions. Too many methods are used to prepare these products. Both methods and product need definition, validation, specific quality parameters and clin...

Regenerative medicine for the treatment of musculoskeletal overuse injuries in competition horses

“…Platelet products, such as platelet-rich plasma (PRP), are a great reservoir of GFs and cytokines. In fact, activated platelets secrete GFs, such as platelet-derived growth factor (PDGF), transforming growth factors (TGFs), insulinlike growth factor (IGF), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and many other bioactive molecules that enhance angiogenesis and increase the proliferation of undifferentiated mesenchymal stem cells (MSCs) [6,7].…”

The Role of Platelet Gel in Regenerative Medicine

“…The most important GFs released by the platelets are PDGF (the platelet derived growth factor), TGF-& (transforming growth factor alpha & ), EGF (epidermal growth factor), FGF (fibroblast growth factor), IGF (insulin growth factor), PDEGF (platelet derived epidermal growth factor), PDAF (platelet derived angiogenesis factor), IL-8 (interleukin-8), TNF-(tumour necrosis factor alpha), CTGR (connective tissue growth factor), GM-CSF (granulocyte macrophage colony stimulating factor), KGF (keratinocyte growth factor), and Ang-2 (angiopoetin) (Frechette et al, 2005;Borzini & Mazzucco, 2005;Westerhuis et al, 2005;) (see Table 4.). Beside these GFs, there are at least 60 different biologically active substances in the platelets that are involved in tissue repair mechanisms such as chemotaxis, cell proliferation and differentiation, angiogenesis, extracellular matrix deposition, immune modulation, antimicrobial activity, and remodelling (Borzini & Mazzucco, 2007). All these functions have been demonstrated in numerous in vitro (Phillips et al, 1994;Dankert, 1995;Brill et al, 2004;Cenni et al, 2005;Kark et al, 2006) and in vivo experiments (Debus et al, 2001;Kevy et al, 2004).…”

“…The supernatant or releasate of the platelet gel was able to promote dose-dependent proliferation and changes in gene expression as well as in metabolic activities related to protein synthesis (Junger et al, 2000;Valencia et al, 2001;Fang & Galiano, 2008;Bernuzzi et al, 2010;Ficarelli et al, 2008;Chen et al, 2010). The platelet concentrate was used for healing skin, soft tissue wounds, fractures, surgical injuries, diabetic ulcers, dental, oral and maxillofacial settings (Altman et al, 2001;Margolis et al, 2001;Anderson &Baker, 2003;Castro, 2004;Belli et al, 2005;Burkus, 2005;Carreon et al, 2005;Sclafani et al, 2005;Trowbridge et al, 2005;Brown et al, 2006;Driver et al, 2006;Savarino et al, 2006;Rozman & Bolta, 2007;Borzini & Mazzucco 2007;Smrke et al, 2007;Cieslik-Bielecka et al, 2008;).…”

Cardiovascular Tissue Engineering Based on Fibrin-Gel-Scaffolds

“…PDGF is released in conjunction with the platelet release reaction (Witte et al, 1978). Platelet activation induces the release of a variety of low-molecular weight growth factors and more than 60 of these growth factors are directly involved in tissue repair mechanisms such as chemotaxis, cell proliferation, angiogenesis, ECM deposition and remodelling (Borzini & Mazzucco, 2007). Platelets are easily isolated from blood, and can be concentrated in a low volume of plasma known as platelet-rich plasma (PRP).…”