ANTITHROMBOGENICITY OF HYDROPHILIC POLYURETHANE-HYDROPHOBIC POLYSTYRENE IPNS .2. IN-VITRO AND EX-VIVO STUDIES

To investigate the effect of hydrophilic and hydrophobic surfaces with phase separated structure on their blood responses, interpenetrating polymer networks (IPNs) composed of hydrophilic polyurethane (PU) and hydrophobic polystyrene (PS) were prepared by simultaneous polymerizat ion. In vitro protein adsorption, in vitro platelet adhesion, and ex v ivo A-A shunt test were carried out to evaluate the blood compatibilit y of the PU/PS IPNs. The results of protein adsorption on the PU/PS IP N surfaces indicated that albumin preferentially adsorbed on the hydro philic surface (PU), while fibrinogen preferentially adsorbed on the h ydrophobic surface (PS). The PU/PS IPNs exhibited suppressive properti es for both platelet adhesion and activation. The occlusion time of U5 0S50 IPN containing 50 wt% of PS was twice as long as that of the PU c ontrol (50 min), indicating enhanced blood compatibility, presumably d ue to the selective adsorption of plasma proteins and the suppression of the adhesion and activation of platelets.