Effect of Cryo-Processing on Platelet-Rich Autoplasma Preparations

Platelet-derived growth factor (PDGF) plays an important role in angiogenesis, affects activation of migration and proliferation of mesenchymal stem cells, fibroblasts, smooth muscle cells, osteoblasts; activation of migration of monocytes, macrophages, and neutrophils. The aim of the investigation was to study the effect of cryo-processing on the qualitative properties of platelet-rich autoplasma (PRP) at different time intervals.

Autologous plasma preparations were obtained from the blood of 31 donors. The biological material was prepared by double centrifugation according to the protocol for obtaining P-PRP and L-PRP. Platelet count and the concentration of growth factors (PDGF-AA and PDGF-BB) were studied in fresh PRP preparations. In frozen PRP samples, the concentration of PDGF-AA and PDGF-BB was determined 2 weeks after cryo-processing and 2 months after cryo-processing at -35 °С. P-PRP and L-PRP samples activated with 10% CaCl² solution and those non-activated were studied.

L-PRP preparations are significantly superior to P-PRP preparations: the concentration of platelets is 1.7 times higher in them. The level of PDGF-AA in non-activated L-PRP is 1.8 times higher than in non-activated P-PRP (p<0.05). The level of PDGF-AA is 1.5 times higher in activated L-PRP than in activated P-PRP (p<0.05). The level of PDGF-BB is 2.9 times higher in non-activated L-PRP than in non-activated P-PRP and 1.8 times higher in activated L-PRP than in activated P-PRP (p<0.05). The concentration of PDGF-BB in non-activated P-PRP sharply increases in the 2^nd week after freezing and remains at the same level after 2 months (p<0.05). The concentration of PDGF-BB in activated plasma does not change (p>0.05).

Cryo-processing of non-activated autologous L-PRP allows preserving and subsequently enhancing the properties of plasma concentrate, which makes it possible to apply it in clinical practice.