Platelet Rich Plasma: Myth or Reality?

Editorial Platelet rich plasma (PRP), also termed autologous platelet gel, plasma rich in growth factors (PRGF), platelet concentrate (PC), is essentially an increased concentration of autologous platelets suspended in a small amount of plasma after centrifugation. Basically, patient's blood is collected and centrifuged at varying speeds until it separates into 3 layers: platelet poor plasma (PPP), PRP, and red blood cells. Usually 2 spins are used. The first spin (" Hard spin ") separates the platelet poor plasma (PPP) from the red fraction and platelet rich plasma (PRP). The second spin (" Soft spin ") separates the red fraction from the PRP. The material with the highest specific gravity (PRP) will be deposited at the bottom of the tube. Immediately prior to application, a platelet activator/agonist (topical bovine thrombin and 10% calcium chloride) is added to activate the clotting cascade, producing a platelet gel. The whole process takes approximately 12 minutes and produces a platelet concentration of 3-5x that of native plasma. Platelets play a fundamental role in hemostasis and are a natural source of growth factors. Growth factors, stored within platelet α-granules, include platelet derived growth factor (PDGF), insulin like growth factor (IGF), vascular endothelial growth factor (VEGF), platelet derived angiogenic factor (PDAF), and transforming growth factor beta (TGF-β). The release of these growth factors is triggered by the activation of platelets that can be initiated by a variety of substances or stimuli such as thrombin, calcium chloride, or collagen. Growth factors are involved in key stages of wound healing and regenerative processes including chemotaxis, proliferation, differentiation, and angiogenesis. 3 According to the definition of PRP, it may be assumed that these growth factors are present at increased concentrations in PRP. In addition to growth factors (GFs), platelets release numerous other substances (e.g., fibronectin, vitronectin, sphingosine 1-phosphate, etc…) that are important in wound healing. An advantage of PRP over the use of single recombinant human growth factor delivery is the release of multiple growth factors and differentiation factors upon platelet activation. 4 Recently, the morphologic and molecular configuration of PRP was reported, it showed PRP is a fibrin framework over platelets that has the potential to support regenerative matrix. 5,6 The rationale for using PRP in soft and hard augmentation are to accelerate vascularization of the graft, improve soft tissue healing, reduce post operative morbidity, and enhance bone regeneration. 7 Advantages of using an autologous PRP include no risk …