The Study Of A New Process For Platelets Storage--lyophilization

The study of a new process for platelets storage-lyophilizationThe control of hemorrhage due to thrombocytopenia and hematopoiesis reconstruction due to tumor therapy often require transfusion of multiple units of fresh platelets. Currently, platelet concentrates can only be stored at 22?癈 for up to 5 days because of partial loss of viability and microbial contamination. Thus the study of platelet storage is becoming increasingly important as a result of the limited shelf life of platelet concentrates. Lyophilized platelet storage is one of the promising methods. Based on the latest research of freeze-drying of platelet, two reported methods, in which the platelets were processed with paraformaldehyde and trehalose, were investigated. Furthermore, we purposed a new lyophilized platelet method, in which platelets were processed with aldehyde. It is the first time that using aldehyde as a pre-lyophilization reagent in the lyophilizing of platelet is reported. The result of this new method was compared with the results of those reported method as well. The recovery (44.86+14.47%) and aggregation (2.18 + 0.57%) of the rehydrated lyophilized platelets treated with paraformaldehyde are much lower than those of fresh platelets. Experiment results show that when platelets are processed with trehalose, the trehalose can be loaded into the platelets. When the platelets are incubated in 35mM trehalose buffer at 37癈, the loading efficiency of trhalose into cells can go to the top level in 2 hours. After lyophilize these trhalose-loaded platelets, we can get an acceptable recovery rate (67.60 ?14.37%)after rehydration. The aggregation ratio (10.48 ?1.36%) is much lower than the one of the fresh (P<0.05). At last, we studied the effects of aldehyde in platelet lyophilizing. Although the quantity of glycoproteins in the membrane declines slightly, and the positive rate of activation marker raises a little, the recovery rate (68.26?5.34%) of these rehydrated lyophilized platelets is acceptable. The aggregation ratio (31.13?7.40%) is much better than the former results (P<0.05), which is as same as the one of fresh platelets. These results suggest that process of lyophilized platelets with aldehyde is much better than that with paraformaldehyde or trehalose, especially in the aspect of aggregation. It also shows that, as a process for storage, platelet lyophilization with aldehyde is a promising method to be further explored.