Surface properties and blood compatibility of polyurethaneureas.

A series of polyurethaneureas of varying soft segment type and hard/soft segment ratio were synthesized, and their bulk and surface properties evaluated. A canine ex vivo arteriovenous series shunt was used to monitor initial thrombus deposition. Significant levels of surface hard segment components are apparent in these materials. Polymers with poly(tetramethylene oxide) and poly(propylene oxide) soft segments showed blood compatibility variations with changes in hard/soft segment ratios: the more well-phase-separated materials showing lower platelet and fibrinogen deposition levels. Those trends apparent in polymers synthesized with poly(dimethylsiloxane) or poly(ethylene oxide) soft segments, but poly(dimethylsiloxane)-based materials showed higher levels of thrombus deposition than the poly(ethylene oxide)-based polymers.