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Cryopreservation of platelets is of great interest, since it could extend the shelf life of therapeutic platelet concentrates and facilitate stockpiling and inventory control in blood banking. Despite the use of many cryopreservation procedures the optimal cryopreservation procedure is not defined yet. We have compared the cryopreservation of human platelets by various protocols employing controlled-rate and non-controlled-rate freezing procedures in combination with different concentrations of DMSO (6% and 10%) or 5% DMSO + 6% HES combination. After storage for 1 to 3 months, samples were thawed and analyzed. Measurements included cell recovery, platelet viability according to hypotonic shock response (HSR), platelet aggregation with ADP, morphological and ultrastructural properties of defrozen platelets. Our findings show that the application of our original procedure for controlled-rate freezing consisting of six cooling steps (cooling rate 1 degree C/min) with compensation of released heat of fusion (cooling rate 2 degrees C/min) has significantly influenced the quality of thawed platelets. At the same time, a concentration of 6% DMSO proved to be the most effective. In summary, cryopreservation of human platelets using controlled-rate freezing procedure in combination with lower (6%) DMSO concentration resulted in less damage from freezing and higher recovered function of platelets.

The purpose of the study was to evaluate the hemostatic effectiveness of fibrin glue (FG) prepared by a modification of cryoprecipitation technique in experimental rat liver surgery. FG component I was prepared by triple or 'recycled' cryoprecipitation method from single-donor plasma. Rats subjected to liver incision, partial and total lobectomy were treated with FG on the surgical cut surface or underwent standard surgical technique. The efficacy of FG-treatment was evaluated on the basis of the 24-hour survival ratio and peripheral blood hematological parameters. The mean values of fibrinogen, FXIII, fibronectin and horizontal tensile strength of FG were 54.2 +/- 19.9 g/l, 13.5 +/- 3.6 IU/ml, 3103.1 +/- 148.9 mg/l, and 1.076 +/- 0.18 N/cm(2), respectively. The survival of FG-treated rats subjected to partial and total lobectomy was significantly higher in comparison to the FG-nontreated animals, accompanied with higher values of red blood cell counts, hemoglobin concentration and hematocrit. When liver incision was performed, although there were no differences in survival rate, FG-treated animals had significantly higher values of the tested hematological parameters. The presented results demonstrated that by using 'recycled' cryoprecipitation it is possible to obtain high quality single-donor FG with successful hemostatic therapeutical effects, as confirmed in the experimental rat model of liver surgery.