ADSORPTION BEHAVIOR OF FIBRINOGEN TO SULFONATED POLYETHYLENEOXIDE-GRAFTED POLYURETHANE SURFACES

Fibrinogen adsorptions to surface modified polyurethanes (PU, PU-PEO, and PU-PEO-SO3) were studied from plasma in vitro. PU and PU-PEO surfa ces demonstrated that initial adsorption increases with increasing pla sma concentration in kinetic profiles and adsorption time in adsorptio n profiles as a function of plasma concentration, but after the platea u is reached, its adsorption amount decreases as plasma concentration (0.2-2.0%) and adsorption time (1-120 min) increase, respectively. In contrast, PU-PEO-SO3 showed that initial adsorption is almost same reg ardless of plasma concentration and adsorption time, which is due to t he high affinity of surface sulfonate group to fibrinogen. All the sur faces indicated the Vroman effect at about 0.6% plasma concentration; however, the displacement was relatively low. Adsorbed amount of fibri nogen at steady state decreased in the order: PU > PU-PEO-SO3 > PU-PEO , regardless of adsorption time and plasma concentration. The adsorpti on behavior of PU-PEO-SO3 is attributed to both effect of low binding affinity of PEO chain and high affinity of pendant sulfonate group tow ard fibrinogen.