Formulation and storage of platelet-rich plasma homemade product.

The platelet-rich plasma (PRP) is an autologous biotherapy based on platelet-healing properties. Here, we developed a simple and reproducible PRP purification protocol based on two successive centrifugations. We evaluated different centrifugation speeds and time-storage durations on the platelet quantity and quality. Sterility and stability of our PRP homemade product were also performed. We prepared PRP from 54 healthy volunteers. We tested activation state, reactivity, and stability of platelets by flow cytometry using basal and adenosine diphosphate (ADP)-induced P-selectin expression markers; growth factor release after platelet activation by an enzyme-linked immunosorbent assay (ELISA); platelet aggregation capacity by aggregrometry assays; clot formation and retraction by thromboelastography; and platelet morphology by ultrastructural analysis. About 130 and 250 g successive speed centrifugations further concentrated platelets while preserving their bioactivity during 6 h (after that, platelet functions were significantly altered). In these conditions, we obtained a highly concentrated pure PRP product (with a low leukocyte count) suitable to study platelet properties. To avoid the loss of efficacy, we recommend injecting PRP under 3 h after preparation.