Lysine-oligoether-modified electrospun poly(carbonate urethane) matrices for improving hemocompatibility response

Abstract

Although biomedical devices have greatly evolved, none of the materials that have been used to date are able to meet all the hemocompatibility criteria. The rapid accumulation of proteins at the implant surface and the subsequent physiological response are the main causes of failure. Thus, the appropriate design of antithrombotic materials is of the utmost importance. In this work, we employed Carbothane® electrospun matrices (PCU) for lysine surface modification, using oligomers obtained from allyl glycidyl ether (AGE) reaction as spacers. This technique enables the binding of several lysine molecules per urethane linkage, which, along with the large surface-to-volume ratio of the electrospun membranes, leads to high ε-amino free lysine grafting (29 ± 2 nmol cm−2). The incorporation of AGE oligomers significantly reduced the nonspecific protein adsorption, while further modification with lysine led to a more pronounced decrease (25% for BSA, 35% for fibrinogen, and 30% for PNP proteins, with respect to PCU membranes). The lysine-modified matrices presented increased plasminogen adsorption capacity and in vitro clot lysis ability after incubation in pooled normal human plasma and tissue plasminogen activator, confirming the plasminogen adsorption selectivity and thus improving the hemocompatibility behavior of these matrices. Therefore, the obtained electrospun membranes are promising coatings for biomedical devices with fibrinolytic activity.