Dehydration of blood platelets by zeodration: in vitro characterization and hemostatic properties in vivo.

BACKGROUND: Platelets (PLTs) are currently stored at room temperature (RT) for 5 to 7 days. So far, there exists no validated method for the preparation and long-term storage of dehydrated PLTs suitable for transfusion after rehydration. In this study, a desiccation process, zeodration, was applied to PLTs. STUDY DESIGN AND METHODS: A complete procedure of dehydration at RT by zeodration was employed. Zeodrated human and mouse PLTs were characterized in vitro. Zeodrated mouse PLTs were transfused into clopidogrel-treated mice to evaluate their hemostatic properties. RESULTS: The optimal conditions for dehydration of PLTs at RT in a laboratory scale zeodrator were defined as 145 mbar and 20.2 +/- 1.5 degrees C. The recovery rate was 85 +/- 2% and the dryness of zeodrated PLTs (Z_PLTs) indicated that they were sufficiently stable for long-term storage. Rehydrated Z_PLTs were round, were not aggregated, and expressed the glycoproteins required for PLT function. Z_PLTs agglutinated in the presence of von Willebrand factor (VWF) and aggregated in response to thrombin or collagen independently of an active metabolism. In a flow system, Z_PLTs could adhere to VWF and form aggregates on a collagen matrix. Thrombin was generated at the surface of Z_PLTs as efficiently as on fresh PLTs. In clopidogrel-treated mice, which exhibited a severely prolonged bleeding time, continuous perfusion of Z_PLTs restored normal hemostasis. CONCLUSION: Zeodration represents a new strategy to prepare PLTs with partly preserved aggregative properties after storage and rehydration. Z_PLTs have potential hemostatic properties provided it is possible to improve their transfusion efficacy.