A method for evaluating the influence of porosity on the early reactions of blood with materials

A method is presented for evaluating the influence of porosity on the early reactions of blood with polymer membranes of cellulose acetate and polyeth ersulfone with two different pore sizes, 0.1-0.2 mum and 0.8 mum. A system of two phases consisting of capillary blood and Dulbecco's phosphate buffer ed saline was constructed. Platelet adhesion and exposure of thrombospondin was examined by immunofluorescence. Platelet adhesion was higher on the me mbrane with 0.8 mum pore size. Leukocyte adhesion and viability was measure d by fluorescein diacetate/propidium iodide staining, and the respiratory b urst response to PMA and opsonized zymosan was measured by chemiluminescenc e. Leukocyte viability was higher on the membranes with 0.8 mum pore size a nd higher on the cellulose membrane for exposures upto 2 h. After 3 h the l eukocyte viability was highest on the polyethersulfone membrane with a pore size of 0.8 mum. The respiratory burst response of membrane-adhering leuko cytes could not be triggered by opsonized zymosan on any of the tested memb ranes. A response was seen after stimulation with PMA of cells adhering to the cellulose membrane with a pore size of 0.8 mum. (C) 2001 Elsevier Scien ce Ltd. All rights reserved.