Influence of preadsorbed PEO-containing copolymers on BSA and fibrinogen adsorption and on blood compatibility

The effects of coating with various poly(ethylene-oxide) - poly(propylene-o xide) - poly(ethylene-oxide) block copolymers on the adsorption of blood pr oteins (bovine serum albumin, fibrinogen) were examined/ X-Ray Photoelectro n Spectroscopy and wettability measurements confirmed the attachment of the copolymers to the hydrophobic surfaces. Adsorption isotherms for hydrophob ic, hydrophilic and PEOcoated surfaces were determined at 25 degreesC, and modified blood coagulation tests (aPTT with and without phospholipid) were also carried out in the presence of the above surfaces. All three copolymer s used caused suppression of the protein adsorption when compared to standa rd hydrophobic and hydrophilic surfaces, with the effect being the most mar ked in the case of the copolymer PE6800, the one with the highest ratio of poly(ethylene-oxide). That coating proved to be the most effective in delay of blood coagulation induced by the contact of foreign surface with plasma . The increase in clotting tune was in good correlation with the protein re sistant property of the PEO containing surfaces.