Removal of endotoxin in blood by polymyxin B immobilized polystyrene-derivative fiber.

Polymyxin B, a cationic cyclic decapeptide antibiotic, is well known to bind endotoxin and to neutralize its toxicity. Based on this principle, polymyxin B was immobilized on the chloroacetamidomethylated polystyrene fiber that is reinforced by polypropylene. The adsorbing capacity of the obtained fibers (polymyxin B immobilized fiber [PMX-F]) was evaluated on endotoxin and other serum components in serum and on heparin in phosphate-buffered saline. Fluorescein isothiocyanate-labeled or tetramethylrhodamine isothiocyanate-labeled lipopolysaccharide (LPS) was used as endotoxin. The measurement of the fluorescence intensity showed that PMX-F adsorbed these LPSs depending on their concentration and on amount. The adsorption of endotoxin was confirmed by desorption of LPS from PMX-F as well. PMX-F adsorbed serum amyloid protein A besides LPS, but neither C-reactive protein nor low-density lipoprotein. The adsorbing property of heparin was low.