Platelet Cryopreservation Using A Reduced Dimthyl Sulfoxide Concentration And Second-messenger Effectors As Cryopreserving Solution

[Objective] To observe the protective function at -196癈 on platelet concentrates of 2 - percent dimethyl sulfoxide(DMSO) plus ThromboSol, a mixture of second - messenger effectors, and to realize the long - term (6 months) protective function of this platelet storage solution. [Methods] Platelet concentrates were treated with 2% DMSO,6%DMSO and 2% DMSO plus ThromboSol, then placed in liquid nitrogen. After frozen for 1 month, 3 months or 6 months, samples were thawed and analyzed. Measurements included platelet count, ADP and arachidonic acid(AA) induced aggregation, expression levels of CD42b and CD62p on membrane and ultrastructure of platelets. [Results] According to the results of platelet count, aggregatory reaction to ADP and AA, expression levels of CD42b, platelets treated with 2%DMSO plus ThromboSol were similar to those stored by the method using 6% DMSO (P>0.05). They were all superior to those frozen with 2% DMSO (P<0.05). In comparison to fresh platelets, the frozen platelets showed declined number and functional activity (P<0.05). In addition, the platelets treated with 2%DMSO plus ThromboSol displayed statistically lower expression of CD62p than those frozen with 6%DMSO and 2%DMSO (PO.05).Platelets treated with 6%DMSO and 2%DMSO showed same expression level (P>0.05). The frozen platelets showed increased surface expression of CD62p in comparison to fresh platelets (PO.05). Platelets treated with 2%DMSO plus ThromboSol retained intact ultrastructure which were superior to other frozen platelets. But the electronic micrographs demonstrated that the frozen platelets had been activated slightly. There were no differences among the platelets stored with 2% DMSO plus ThromboSol for 1 month, 3 months and 6 months (P>0.05). [Cone I us i on] The use of second - messenger effectors allows for a reduction of the DMSO concentration from 6 to 2 percent, with the same maintenance of in vitro viability and function. Platelets frozen with this method can retain intact ultrastructure and inhibit to be activated. This protective function to platelets is fine within 6 months.