Surface modification and in vitro Blood compatibilities of polyurethanes containing γ‐Benzyl L ‐glutamate segments in the main chain

Poly(ether urethanes) containing γ‐benzyl L‐glutamate segments in the main chains (PUBLG) were synthesized from 4,4′‐diphenylmethyl diisocyanate, poly(tetramethylene glycol) and γ‐benzyl L‐glutamate oligomer as a chain extender. The surface modification of the PUBLG film was carried out by means of a hydrolysis reaction and heparin immobilization. The surface‐modified PUBLGs were then characterized by attenuated total reflection Fourier‐transform infrared (FT‐IR) spectroscopy and electron spectroscopy for chemical analysis. In vitro blood compatibility of surface‐modified PUBLGs was investigated using plasma proteins, platelets and peripheral blood mononuclear cells. Activated partial thromboplastin time was prolonged on heparin‐immobilized PUBLG (PUBLG‐H), suggesting the binding of immobilized heparin to antithrombin III. The release of serotonin from adhering platelets was significantly suppressed on PUBLG‐H when compared to the other substrates. In the peripheral blood mononuclear cells experiments, the adhesion and activation of the cells were significantly suppressed on PUBLG‐H and the amount of interleukin‐6 released from peripheral blood mononuclear cells stimulated with surface‐modified PUBLGs decreased with a decrease in peripheral blood mononuclear cells adhesion.