Albumin and heparin multilayer coatings for blood-contacting medical devices

Three types of covalently crosslinked assemblies consisting of multiple (1) molecular layers of human serum albumin (HSA); (2) alternating layers of H SA and unfractionated heparin; and (3) alternating layers of HSA and partly depolymerized heparin fixed with one end to HSA were prepared on various s urfaces. Adsorption of fibrinogen, IgG, and antithrombin (ATIII) from human citrated plasma on coated surfaces was evaluated by ELISA. Fibrinogen adso rption on coated ELISA plates was lower than that on bare polystyrene. Ther e was no IgG adsorption on the HSA coating alone, but considerably high IgG adsorption was detected on the heparin-containing surface. The adsorption of ATIII. increased with increasing heparin on the surface. The effect of m ultilayer coatings on platelets was tested by incubation of modified vascul ar prostheses with citrated blood. The most favorable interaction with plat elets was observed on the HSA assembly. The interaction of platelets with t he surface bearing unfractionated heparin was higher than that of the surfa ce covered with partly depolymerized heparin. The long-term durability of t he HSA-heparin coating was proven by a 21-day implantation of coated polyur ethane plates in goat heart. (C) 2000 John Wiley & Sons, Inc. J Biomed Mate r Res, 51, 249-257, 2000.