TREHALOSE CAN IMPROVE PLATELET AGGREGATION VERSUS COLLAGEN AGONIST DURING LYOPHILIZED PLATELET PREPARATION

Due to short shelf life of platelet concentrate 3-5 days, long-term preservation of human platelets will greatly reduce the risk of their shortage. Lyophilization has been proved feasible approach for this purpose. We want to show that platelets can be preserved by freeze-drying them with loading buffer containing trehalose, a sugar found at high concentrations in organisms that naturally survive drying. Washed platelet samples in a concentration of 0.8-1x10 9 plt/mL in loading buffers containing trehalose at various concentrations were incubated at 37°C for 4 h. Platelets were lyophilized with optimized concentration of trehalose 40 mmol/L. The aggregation response of trehalose-loaded platelets was tested against collagen agonist (2.0 µg/ml). Our results showed that  aggregation of PRP, resuspended platelet samples in loading buffers containing 10, 20, 30 and 40 mmol/L trehalose  and rehydrated lyophilized platelet containing 40 mmol/L trehalose were measured versus collagen agonist by aggregometry instrument with the activity of 7.7%, 22.3%, 45.9%, 71.4% and 35.3% respectively. However, when the platelets lyophilized without trehalose, most of the platelets disintegrated during rehydration step, some fused with adjacent cells and formed an insoluble clump. We concluded that trehalose at the concentration of 40 mmol/L can improve platelet aggregation activity versus collagen agonist in the loading buffer or dried state. Keywords: Trehalose; collagen; lyophilized platelet; platelet aggregation