Platelet-rich plasma (PRP), separated by centrifugation of autologous blood, is a plasma containing numerous platelets. Consequently, efficient separation of PRP can provide highly concentrated autologous growth factors, including platelet-derived growth factor (PDGF), transforming growth factor-β (TGF-β), and insulin-like growth factor-I (IGF-I), derived from α granules. However, it requires a substance to trigger platelet aggregation, in order to activate platelets to release the growth factors.
In the present study, we investigated a procedure of activating platelets (aggregation) with calcium chloride alone, in the absence of thrombin, the safety of which is suspected. Prior to the investigation, we sought the optimal centrifugal conditions, i.e., centrifugal gravity and time, for separation of PRP. As a result, we discovered that a centrifugal gravity of 130 (×g) and a centrifugal time of 10 min, are the optimal conditions for separating PRP. The time required for platelet aggregation was prolonged in platelet activation by calcium chloride alone, as compared with platelet activation by thrombin. However, activation of platelets with calcium chloride alone demonstrated gelatinization of PRP indicative of sufficient fibrin formation.
