[Protection of cryopreserved platelets by dimethyl sulfoxide combined with trehalose]

This study was aimed to investigate the protective effects of dimethylsulfoxide (DMSO) combined with trehalose on the cryopreserved platelets. The platelets were preserved at -80 degrees C. The experiments were divided into 5 groups: blank control group composed of apheresis platelet suspension; trehalose group composed of apheresis platelet suspension and 0.25 mol/L trehalose; DMSO group composed of apheresis platelet suspension and 5% DMSO; 5% combined group composed of apheresis platelet suspension, 5% DMSO and 0.25 mol/L trehalose; 2.5% combined group composed of apheresis platelet suspension, 2.5% DMSO and 0.25 mol/L trehalose. All the groups were thawed at 37 degrees C in a waterbath. The recovery rate of platelets and mean platelet volume (MPV) were assayed by using hemocytometer; the ultrastructural changes were examined by electron microscopy; the expressions of CD41, CD42b, CD61 and CD62p on platelets were detected by flow cytometry. The results indicated that single use of trehalose had no strong effect in increasing the recovery rate of platelets, but the morphology of platelets was close to normal. The DMSO showed significant effect in increasing the recovery rate of platelets and maintaining the intact property of platelets, however, the shape of platelets tended to sealing, and partial platelets still displayed heteromorphic changes. The combination of DMSO and trehalose revealed the protective effect on the external morphology and internal structure of platelets to be close to the normal homeostasis, and ensured an ideal recovery rate of the cryopreserved platelets and higher expression levels of CD41, CD42b, CD61 and CD62p in the same time. It is concluded that the combined use of DMSO and trehalose possesses the synergistic protective effect on the cryopreserved platelets, therefore, the combined use of both as the protective agent is hopeful to further raise the effectiveness of clinical infusion of the cryopreserved platelets.