A novel method for the preparation and frozen storage of growth factors and cytokines obtained from platelet-rich plasma

Abstract

Platelet-rich plasma (PRP) therapy is employed to treat damaged connective tissues and osteoarthritis. PRP is collected in the presence of an anticoagulant to avoid premature activation. The PRP is then activated by various activation methods that all have regulatory or cost drawbacks. Additionally, activated PRP can only be stored for a limited time. The purpose of this study was to assess the biological stability of a PRP composition obtained from platelets of healthy volunteers using a mechanical activation by passing PRP through a 0.22 µm filter and stored for up to 9 months. The PRP fraction was isolated and then activated using either mechanical or thrombin techniques: 9 samples were evaluated in each experiment. The concentrations of interleukin (IL)-4, IL-10, IL-13, platelet-derived growth factor, transforming growth factor beta 1, insulin-like growth factor 1, and vascular endothelial growth factor were compared in samples that were freshly collected and samples that were previously stored at −80 °C for 9 months. Protein concentration analysis showed no statistically significant differences in the composition of the PRP when the platelets were activated by thrombin or mechanical activation. There was also no statistically significant difference in the concentration of cytokines and growth factors in the PRP autologous composition after storage for 9 months at −80 °C. Mechanical activation is an efficient method to activate PRP, and the PRP-derived autologous composition is capable of being stored for up to 9 months without affecting the concentration of the analyzed proteins.