Features of PRP preparations

PRP (Platelet-Rich Plasma), according to R. Marx et al. (2001), is blood plasma in which the concentration of platelets exceeds the norm. Normally, the platelet concentration ranges from 150⎼350 thousand cells/μL and averages 200 thousand cells/μL. A therapeutically effective concentration of a PRP drug is considered to be a platelet concentration of more than 1 million cells/μL, that is, approximately 4⎼7 times higher than the level of blood platelets.

Platelets contain a large number of growth factors (GFs), cyto- and chemokines, plasma blood proteins (fibrin, fibronectin, vitronectin), which are deposited in the organelles of these cells - a-granules, electron-dense bodies and lysosomes. This set of growth factors plays a major role in regulating the process of tissue repair and regeneration, while blood plasma proteins serve as a scaffold for the regeneration of connective tissue and the migration of epithelial cells.

Growth factors

The main growth factors are contained in a-granules, from where they are released into the extracellular environment as a result of exocytosis after activation of platelets. In the first 10 minutes, platelets secrete about 70% of the risk factors, and within an hour they are almost completely released. The synthesis of additional amounts of GF by platelets continues for up to 7 days, after which they complete their life cycle.

IGF (insulin-like growth factor) – insulin-like growth factor.

Functions: stimulation of fibroblast proliferation, synthesis of collagen and other components of MCM.

FGF (fibroblast growth factor) – fibroblast growth factor.

Functions: induction of fibroblast proliferation, stimulation of endothelial cell growth, stimulation of angiogenesis, stimulation of vascular growth.

EGF (epidermal growth factor) – epidermal growth factor.

Functions: stimulation of keratinocyte migration, stimulation of proliferation of epithelial, mesenchymal cells and fibroblasts, stimulation of migration and proliferation of endothelial cells and angiogenesis, regulation of collagenase production.

VEGF (vascular endothelial growth factor) – vascular endothelial growth factor.

Functions: stimulation of endothelial cell proliferation and angiogenesis, stimulation of lymphogenesis, increasing the permeability of the vascular wall.

TGF-β1 (transforming growth factor-beta1) is a transforming factor.

Functions: induction of MCM synthesis, regulation of keratinocyte proliferation and stimulation of collagen production.

PDGF (platelet-derived growth factor) – platelet-derived growth factor.

Functions: activation of migration migration of proliferation of MMSCs, fibroblasts, smooth muscle cells, osteoblasts; activation of migration of monocytes, macrophages, neutrophils; activation of macrophages.

Types of PRP drugs

Guidelines issued by the American Association of Blood Bank state that platelet-rich plasma is obtained from whole blood using low-speed centrifugation, and then the platelets are concentrated using high-speed centrifugation, followed by removal of the supernatant consisting of blood plasma. .

According to the latest international classification proposed by a team of specialists from the USA, South Korea, Switzerland, Holland, Poland, Italy, Sweden, all PRP preparations are divided into four categories depending on the content of leukocytes and fibrin in them:

• fibrin enriched with leukocytes and platelets (L-PRF - Leucocyte and Platelet-Rich Fibrin), production method - Choukroun's PRF;
• pure platelet-rich fibrin (P-PRF – Pure Platelet-Rich Fibrin), production method – Fibrinet;
• pure platelet-rich plasma (P-PRP - Pure Platelet-Rich Plasma), obtained using a blood separator (PRP separator) using the Vivostat PRP or Anitua's PRGF method;
• blood plasma enriched with leukocytes and platelets (L-PRP - Leucocyte and Platelet-Rich Plasma), production methods - Curasan, Regen, Plateltex, SmartPReP, PCCS, Magellan, Ycellbiokit and GPS PRP.

It should be noted that P-PRF and L-PRP fibrin gels are activated (by calcium chloride or other agents) forms, while P-PRP and L-PRP suspensions are inactive liquid forms of PRP products.

Thus, the PRP drug must be used within 10 minutes of activation. The concentrated platelet preparation remains viable for 8 hours and remains sterile.

Read the full version of the article in Les Nouvelles Esthétiques Ukraine" No. 2 (102)/2017