RESUMO
The modification of hydrophobic polyethylene/polystyrene surfaces of medical devices with bilayer/multilayer coatings (BCs/MCs) based on polyelectrolyte complexes (PEC) of modified poly(N-vinylpyrrolidone-co-maleic acid) copolymer (VPMA) with chitosan, amphiphilic chitosan, or albumin was studied. The VPMA contained l-Lysine as affinity ligand for plasminogen attached through alpha-amino group. The surface properties and chemical composition of the surfaces investigated were analyzed, using sessile-drop water contact angle measurements, attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The specific adsorption of plasminogen (precursor of fibrinolytic enzyme plasmin) from its solutions and from human blood plasma on the modified surfaces was investigated. It was established that polyelectrolyte MCs are more efficient than single-layer BCs and the affine polymer coatings without interlayer. A thrombogenicity decrease for the materials modified with BCs and MCs was shown in in vitro and ex vivo trials.
