Hemolysis with red cell covered surfaces

Polypropylene (PP) disks activated by exposure to ammonia glow discharge were used as substrates for red cells deposited from saline suspensions. In some cases these cell-coated disks were further treated by glutaraldehyde to bind the cells more strongly. Each disk was used in a rotational blood-shearing device to induce hemolysis, which was compared with that induced by virgin PP. When the cell coating was uniform and dense from a single settling of cells, the glutaraldehyde-fixed surfaces were about 10% less hemolytic than PP. Non-fixed cells detached from outer regions of the disk and apparently contributed additional hemolysis in the process. Secondary layers of settled cells, both fixed and non-fixed, also proved to be more hemolytic than PP. Coatings of gamma-globulin reduced hemolysis relative to uncoated cell surfaces. The best performance was that of activated surfaces without cells, with hemolysis about 20% less than PP. Tests of cells hemolyzing during detachment in a saline medium suggested that hemolysis of whole blood involves a series of brief attachment/detachment events at the solid surface.