title: Blood protein interactions with chromium surfaces.
abstract: Protein adsorption, contact activation, and complement activation were studied on thin evaporated films of chromium (Cr) in vitro. The surfaces were, prior to the experiments, cleaned in either ethanol and water, or in a basic peroxide solution (RCA standard clean 1, SC-1). Surface spectroscopic studies of the outermost oxides showed a significant reduction of carbon contaminants after washing in SC-1 but also suggested an increase in the oxidation state as compared with the ethanol-washed surfaces. In situ ellipsometry combined with antibody techniques was used to determine protein deposition and antibody binding onto surfaces after incubations in heparin plasma or in normal serum. Incubation times from 1 to 10 min in serum showed increased depositions of serum and antibodies to complement factor 3c (C3c) and was larger on ethanol-washed surfaces than on surfaces washed in SC-1. ELISA methods indicated increased amounts of iC3b in serum for both surfaces, but no presence of C3 convertases (C4d or Bb fractions). A low or transient complement activation via the classical pathway was indicated on ethanol washed Cr, since deposition of secondary antibodies to complement factor Iq (CIq) was observed only after short incubation times in serum. No procoagulant activity of Cr was indicated, since only low amounts of antibodies to factor XII (F XII), prekallikrein (PKK), and high molecular weight kiniogen (HMWK) bound to the surfaces after incubations in heparin plasma. These results were confirmed using a colorimetric assay where the relative amounts of free plasma kallikrein was assessed using a chromogenic substrate, H-D-Pro-Phe-Arg-pNA (S-2302).
authors.affiliation: Linköping University, Department of Physics and Measurement Technology, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Wälivaara
authors.forename: A
authors.initials: A
authors.lastname: Askendal
authors.forename: A
authors.initials: A
authors.lastname: Krozer
authors.forename: I
authors.initials: I
authors.lastname: Lundström
authors.forename: P
authors.initials: P
authors.lastname: Tengvall
mesh_terms: D000327:Adsorption; D001798:Blood Proteins / Q000378:metabolism*; D002857:Chromium / Q000378:metabolism*; D002863:Chromogenic Compounds / Q000737:chemistry / Q000378:metabolism; D003167:Complement Activation / Q000502:physiology*; D003176:Complement C3 / Q000378:metabolism*; D003181:Complement C4 / Q000378:metabolism; D015935:Complement C4b; D004797:Enzyme-Linked Immunosorbent Assay; D000431:Ethanol / Q000737:chemistry; D005174:Factor XII / Q000378:metabolism; D006801:Humans; D007704:Kininogens / Q000378:metabolism; D008970:Molecular Weight; D009842:Oligopeptides / Q000737:chemistry; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000378:metabolism; D011288:Prekallikrein / Q000378:metabolism; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D001798:Blood Proteins; D002863:Chromogenic Compounds; D003176:Complement C3; D003181:Complement C4; D007704:Kininogens; D009842:Oligopeptides; D010446:Peptide Fragments; D014867:Water; D002857:Chromium; D000431:Ethanol; C026148:prolyl-phenylalanyl-arginine-4-nitroanilide; D015935:Complement C4b; C032261:complement C4d; D005174:Factor XII; D011288:Prekallikrein