title: Adsorption and carbonylation of plasma proteins by dialyser membrane material: in vitro and in vivo proteomics investigations.
abstract: BACKGROUND
  Protein carbonylation is an irreversible and not reparable reaction which is caused by the introduction into proteins of carbonyl derivatives such as ketones and aldehydes, generated from direct oxidation processes or from secondary protein reaction with reactive carbonyl compounds. Several studies have demonstrated significantly increased levels of reactive carbonyl compounds, a general increase in plasma protein carbonyls and carbonyl formation on major plasma proteins in blood from uremic patients, particularly those undergoing chronic haemodialysis.
  
  
  METHODS
  In the present preliminary study, we first assessed by an in vitro filtration apparatus the possible effects of different materials used for haemodialysis membranes on protein retention and carbonylation. We employed hollow fiber minidialyzers of identical structural characteristics composed of either polymethylmethacrylate, ethylenevinyl alcohol, or cellulose diacetate materials. Protein Western Blot and SDS-PAGE coupled to mass spectrometry analysis were applied to highlight the carbonylated protein-binding characteristics of the different materials. We also investigated in vivo protein carbonylation and carboxy methyl lisine-modification in plasma obtained before and after a haemodialysis session.
  
  
  RESULTS
  Our data underline a different capability on protein adsorption associated with the different properties of the filter materials, highlighting the central buffering and protective role of serum albumin. In particular, polymethylmethacrylate and cellulose diacetate showed, in vitro, the highest capacity of binding plasma proteins on the surface of the hollow fiber minidialyzers.
  
  
  CONCLUSIONS
  The present study suggests that biomaterials used for fabrication of haemodialysis membrane may affect the carbonyl balance in chronic uremic patients.
authors.affiliation: Centre of Investigation on Aging (Ce.S.I.), G. d'Annunzio University Foundation, Chieti-Pescara, Rome.
authors.forename: Barbara
authors.initials: B
authors.lastname: Pavone
authors.forename: Vittorio
authors.initials: V
authors.lastname: Sirolli
authors.forename: Sonia
authors.initials: S
authors.lastname: Bucci
authors.forename: Fulvio
authors.initials: F
authors.lastname: Libardi
authors.forename: Paolo
authors.initials: P
authors.lastname: Felaco
authors.forename: Luigi
authors.initials: L
authors.lastname: Amoroso
authors.forename: Paolo
authors.initials: P
authors.lastname: Sacchetta
authors.forename: Andrea
authors.initials: A
authors.lastname: Urbani
authors.forename: Mario
authors.initials: M
authors.lastname: Bonomini
mesh_terms: D000327:Adsorption; D001798:Blood Proteins / Q000032:analysis*; D002482:Cellulose / Q000009:adverse effects / Q000031:analogs & derivatives; D006801:Humans; D008567:Membranes, Artificial; D019904:Polymethyl Methacrylate / Q000009:adverse effects; D050050:Protein Carbonylation; D040901:Proteomics / Q000379:methods*; D006435:Renal Dialysis / Q000009:adverse effects*
chemical_list: D001798:Blood Proteins; D008567:Membranes, Artificial; D002482:Cellulose; D019904:Polymethyl Methacrylate; C026170:cellulose diacetate