Production and preservation of platelet concentrates. Evaluation of elutruation technigue and advanced preservation technologies.

This thesis includes various studies on improving the collection and preservation of the platelet product, The conventional differential centrifugation method of platelet isolation, witch quantitatively is the common source of platelet supply, has several shortcomings. The technique depends solely on difference in specific gravity between the blood cell components. Therefore, cells with similar specific gravities (e.g red cells and granulocytes, or platelets and lymphocytes) are difficult to separate. Attempts to increase the resolution of platelets and white cells by modification of the technique, occur at the expense of platelet yield. The manual preparative manipulations - including a two-step centrifugation, resuspension and agitation result in a combination of activation and damage processes. Platelets are exposed twice to high shear forces, created by the large diameter of the centrifuge. Platelets remain in the viscinity of red and white cells during processing, and mediators leaking from shear damaged platelets and erythrocytes secondarily activate other unaffected platelets. Packing of platelets during processing add to the initial activation and damage. Therefore, the development of relatively gentle methods of platelet isolation, or pharmacological strategies interfering with the processing damage and with platelet activation following contact with damaged cells appears a necessity. ... Zie: Summary