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    Affinity microspheres and their application to lysozyme adsorption: Cibacron Blue F3GA and Cu(II) with poly(HEMA-EGDMA)
    (Wiley, 1999) Denizli, F; Denizli, A; Arica, MY
    Lysozyme adsorption onto Cibacron Blue F3GA attached and Cu(II) incorporated poly(2-hydroxyethyl methacrylate-ethylene glycol dimethacrylate) [poly(HEMA-EGDMA)] microspheres was investigated. The microspheres were prepared by suspension polymerization. Various amounts of Cibacron Blue F3GA were attached covalently onto the microspheres by changing the initial concentration of dye in the reaction medium. The microspheres with a swelling ratio of 65%, and carrying different amounts of dye (between 1.4 and 22.5 mu mol/g(-1)) were used in the lysozyme adsorption studies. Lysozyme adsorption on these microspheres from aqueous solutions containing different amounts of lysozyme at different pH values was investigated in batch reactors. The lysozyme adsorption capacity of the dye-metal chelated microspheres (238.2 mg g(-1)) was greater than that of the dye-attached microspheres (175.1 mg g(-1)). The maximum lyzozyme adsorption capacities (q(m)) and the dissociation constant (k(d)) values were found to be 204.9 mg g(-1) and 0.0715 mg ml(-1) with dye-attached and 270.7 mg g(-1) and 0.0583 mg ml(-1) with dye-metal chelated microspheres, respectively. More than 90% of the adsorbed lysozyme were desorbed in 60 min in the desorption medium containing 0.5 M KSCN at pH 8.0 or 25 mM. EDTA at pH 4.9. (C) 1999 Society of Chemical Industry.
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    In vitro cadmium removal from human serum by Cibacron Blue F3GA-thionein-complex conjugated affinity membranes
    (John Wiley & Sons Ltd, 2000) Denizli, F; Denizli, A; Arica, MY
    A new membrane affinity biosorbent carrying thionein has been developed for selective removal of cadmium ions from human serum. Microporous poly(2-hydroxyethyl methacrylate) (pHEMA) membranes were prepared by photopolymerization of HEMA. The pseudo dye ligand Cibacron Blue F3GA (CB) was covalently immobilized on the pHEMA membranes. Then, the cysteine-rich metallopeptide thionein was conjugated onto the CB-immobilized membrane. The maximum amounts of CB immobilized and thionein conjugated on the membranes were 1.07 mu mol cm(-2) and 0.92 mu mol cm(-2), respectively. The hydrophilic pHEMA membrane had a swelling ratio of 58% (w/w) with a contact angle of 45.8 degrees. CB-immobilized and CB-immobilized-thionein-conjugated membranes were used in the Cd(II) removal studies. Cd(II) ion adsorption appeared to reach equilibrium within 30 min and to follow a typical Langmuir adsorption isotherm. The maximum capacity (q(m)) of the CB-immobilized membranes was 0.203 (mu mol Cd(II))cm(-2) membrane and increased to 1.48 (mu mol Cd(II))cm(-2) upon CB-thionein-complex conjugation. The pHEMA membranes retained their cadmium adsorption capacity even after 10 cycles of repeated use. (C) 2000 Society of Chemical Industry.
  • Küçük Resim
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    Removal of cadmium(II) ions from human plasma by thionein modified pHEMA based membranes
    (Elsevier Science Bv, 2000) Denizli, F; Arica, Y; Denizli, A
    Microporous poly(2-hydroxyethylmethacrylate) [pHEMA] membranes carrying Cibacron Blue F3GA and/or thionein were prepared and used for cadmium(II) removal from human plasma. pHEMA membranes were produced by a photopolymerization of HEMA in the presence of azobisisobutyronitrile. The reactive dye-ligand Cibacron Blue F3GA was then covalently attached onto the pHEMA membranes. The maximum dye-loading was 1.07 mu mol/cm(2). Then, thionein was adsorbed onto the Cibacron Blue F3GA-carrying membranes. The maximum amount of thionein adsorbed was 0.92 mu mol/cm(2). The aqueous swelling properties and contact angle lair underwater) of the pHEMA membrane were not observed to change following derivatisation with Cibacron Blue F3GA. These hydrophilic membranes (contact angle value: 45.3 degrees) with a swelling ratio of 58% (w/w), and carrying Cibacron Blue F3GA and/or thionein were used in the Cd(II) removal studies. The maximum amounts of Cd(II) removed from human plasma by Cibacron Blue F3GA-attached and Cibacron Blue F3GA-attached/thionein adsorbed pHEMA membranes were of 1.72 mu mol used as pectively. Cd(II) ions could be repeatedly adsorbed and desorbed with both types of these novel metallo-peptide affinity pHEMA membranes without noticeable loss in their Cd(II) adsorption capacity. (C) 2000 Elsevier Science B.V. All rights reserved.