title: Oxidation of proteins adsorbed on hemodialysis membranes and model materials.
abstract: The cleaning of cellulosic hemodialysis membrane Cuprophan and model materials (glass; polystyrene and polypropylene, as such and surface-oxidized), conditioned by adsorption of blood plasma proteins (HSA, fibrinogen, IgG) was investigated in vitro. Sodium hypochlorite (NaClO) and Renalin, a product containing hydrogen peroxide and peroxyacetic acid, were used as cleaning reagents. X-ray photoelectron spectroscopy and the use of radiolabeled fibrinogen demonstrated the presence of varying amounts of a polypeptidic residue, with sulfur brought to a high oxidation stage (sulfonate-like). The trends were the same for the three proteins regarding the effectiveness of the oxidizer and the influence of the surface properties. NaClO was much more effective than Renalin to remove the adsorbed proteins. The proteins adsorbed on Cuprophan were more sensitive to the oxidizers, when compared with proteins adsorbed on other materials. This may be due to both the lower protein-surface affinity, as indicated by radiochemical measurements, and the sensitivity of the material itself to the oxidizer, as revealed by weight loss measurements. These results support the attribution of hemocompatibility improvement after regeneration of Cuprophan with Renalin to the masking of the activating surface by a residue from previously adsorbed proteins.
authors.affiliation: Unité de chimie des interfaces, Université catholique de Louvain, Croix du Sud 2/18, B-1348 Louvain-la-Neuve, Belgium.
authors.forename: Samuel
authors.initials: S
authors.lastname: Caillou
authors.forename: Christophe J P
authors.initials: CJ
authors.lastname: Boonaert
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Dewez
authors.forename: Paul G
authors.initials: PG
authors.lastname: Rouxhet
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D000327:Adsorption; D001672:Biocompatible Materials; D001798:Blood Proteins / Q000737:chemistry*; D002482:Cellulose / Q000031:analogs & derivatives / Q000737:chemistry; D004338:Drug Combinations; D005340:Fibrinogen / Q000737:chemistry; D005898:Glass; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D007074:Immunoglobulin G / Q000737:chemistry; D007553:Isotope Labeling; D008567:Membranes, Artificial; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D010463:Peracetic Acid / Q000737:chemistry; D011126:Polypropylenes / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D006435:Renal Dialysis / Q000295:instrumentation*; D012588:Scintillation Counting; D012709:Serum Albumin / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission
chemical_list: D001672:Biocompatible Materials; D001798:Blood Proteins; D004338:Drug Combinations; D007074:Immunoglobulin G; D008567:Membranes, Artificial; D016877:Oxidants; D011126:Polypropylenes; D011137:Polystyrenes; C117603:Renalin; D012709:Serum Albumin; D005340:Fibrinogen; D002482:Cellulose; C009865:cuprammonium cellulose; D006861:Hydrogen Peroxide; D010463:Peracetic Acid; D019342:Acetic Acid