Unsubstituted hydrolyzed waxy maize as a potential agent for centrifugal leukacytapheresis

In order to determine whether newer, possibly safer erythrocyte sedimenting agents could be used during centrifugal leukacytapheresis, we tested seven varieties of plant starch. Only waxy maize prepared by partial acid hydrolysis appeared suitable, and it was tested extensively on an analytical device developed especially for testing erythrocyte sedimentation under the conditions of residence time, force, and sedimenting agent concentration used in a cell separator. This species of waxy maize, however, was not quite as effective a sedimenting agent when compared to hydroxyethyl starch (HES 450/0.70) under the test conditions used. Although chromatographic analysis showed the average molecular weights of the unsubstituted waxy maize were considerably higher than those of HES 450/0.70, degradation of waxy maize to smaller molecular weight fragments occurred more rapidly. The rapid degradation of this material may offer significant advantages during centrifugal leukacytapheresis procedures, but additional studies of its storage stability are needed.