Modification of XXXX with Polyethylene Glycol- @entity4336 Trypsin Inhibitor for Inhibition of Factor Xlla in Blood Contact.

@entity4336 @entity2636 @entity970 @entity968
UNASSIGNED: In previous work using gold as a model substrate, we showed that modification of surfaces with @entity968 ( @entity970 ) and @entity4336 trypsin inhibitor (CTI) rendered them protein resistant and inhibitory against activated factor XII. Sequential attachment of @entity970 followed by CTI gave superior performance compared to direct attachment of a preformed @entity970 -CTI conjugate. In the present work, a sequential method was used to attach @entity970 and CTI to a @entity2636 (PU) substrate to develop a material with applicability for blood-contacting medical devices. Controls included surfaces modified only with @entity970 and only with CTI. Surfaces were characterized by water contact angle and X-ray photoelectron spectroscopy. The surface density of CTI was in the range of a monolayer and was higher on the PU substrate than on gold reported previously. Biointeractions were investigated by measuring fibrinogen adsorption from buffer and plasma, factor XIIa inhibition and plasma clotting time. Both the PU- @entity970 surfaces and the PU- @entity970 -CTI surfaces showed low fibrinogen adsorption from buffer and plasma, indicating that @entity970 retained its protein resistance when conjugated to CTI. Although the CTI density was lower on PU- @entity970 -CTI than on PU modified only with CTI, PU- @entity970 -CTI exhibited greater factor XIIa inhibition and a longer plasma clotting time, suggesting that @entity970 facilitates the interaction of CTI with factor XIIa. Thus sequential attachment of @entity970 and CTI may be a useful approach to improve the thromboresistance of PU surfaces.
