Ex vivo and in vitro Blood Response to Surface-Modified Poly(styrene-b-butadiene-b-4-vinylpyridine) Triblock Polymers

Abstract

An acute ex vivo canine series shunt technique, together with in vitro blood contact experiments, were used to study the blood compatibility of poly(styrene-b-butadiene-b-4vinylpyridine) triblock polymers. The ABC type triblock polymers were solvent cast from different solvents, and were chemically modified by quaternization of the pyridine block, crosslinking of the butadiene block, and sulfonation of the styrene block. The surface properties of the polymers were studied using contact angle measurements, ESCA, ATR-IR, and SEM. The polymers cast from chloroform were more thromboresistant than those cast from a mixture of butyraldehyde and chloroform. The chloroform-cast materials were more hydrophilic and contained a greater proportion of surface nitrogen than those materials cast from the mixed solvent. Quaternization dramatically increased thrombogenicity. Subsequent crosslinking and sulfonation to produce a charge mosaic structure did not improve blood compatibility. KEY WORDS ABC Type Triblock Copolymer I Charge Mosaic Poiymer 1 Blood Compatibility I Ex Vivo Series Shunt I Surface Characterization I Number average mol wt (x 10-3) Volume composition 842