SURFACE MODIFICATION OF POLYETHERURETHANEUREAS AND THEIR ANTITHROMBOGENICITY

Polyetherurethaneurea (PU) films were treated by oxygen plasma dischar ge followed by acrylic acid (AA) grafting. The carboxyl groups of the AA-grafted PU (PU-AA) surface were coupled with bovine serum albumin a nd heparin via water soluble carbodiimide. Surface characterization of the modified PUs was carried out by attenuated total reflection Fouri er transform infrared (ATR-FTIR) spectroscopy and electron spectroscop y for chemical analysis (ESCA). The amount of immobilized albumin and heparin on the PU surface was 1.8 and 1.5 mu g/cm(2), respectively, as determined by the dye interaction method. Interactions between the su rface-modified PUs and blood components such as plasma proteins and pl atelets were investigated to evaluate the blood compatibility of the s amples. Plasma recalcification time (PRT) and activated partial thromb oplastin time (APTT) of the albumin-immobilized PU (PU-Al) were almost the same as those of PU, while platelets were less adhered on the PU- Al than on PU. On the other hand, PRT and APTT of the PU-He were signi ficantly longer than those of the PU, PU-AA, and PU-Al. Moreover, adhe sion of platelets was effectively suppressed on the PU-He, leading to good in vitro blood compatibility.