EXVIVO INTERACTIONS AND SURFACE-PROPERTY RELATIONSHIPS OF POLYETHERURETHANES

In order to investigate blood-polyurethane interactions, a number of different polyurethanes were examined in an acute canine ex vivo series shunt experiment. Multiprobe surface characterization techniques were used to obtain surface property information on the materials studied. The polyurethanes examined included several with different soft segment types, a series of materials with different hard segment diisocyanates and chain extenders, a series consisting of the same polymer cast from different solvents, a zwitterionomer, and a hard segment analog. Two commercial urethanes were also examined, and the effect of methanol extraction on these materials was studied. Methanol extraction was found to improve the thromboresistance of the commercial polyurethanes. Both the surface properties and thrombogenicity of a particular polyurethane were changed by casting from different solvents, indicating the need to optimize and control fabrication conditions.