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Öğe Affinity separation of plasma proteins using a newly synthesized methacrylamidoalanine incorporated porous pHEMA membranes(Marcel Dekker Inc, 2002) Yavuz, H.; Patir, S.; Say, R.; Arica, Y.; Denizli, A.In this study, we synthesized a novel adsorbent to obtain high protein-adsorption capacity utilizing 2-methacrylamidoalanine (MAAL) containing membrane. Amino acid-ligand MAAL was synthesized by using methacrylochloride and alanine. Then, poly(2-hydroxyethylmethacrylate-co-2-methacrylamidoalanine) [p(HEMA-co-MAAL)] membranes were prepared by UV-initiated photopolymerization of HEMA and MAAL in the presence of an initiator (azobisisobutyronitrile, AIBN). Synthesized MAAL was characterized by nuclear magnetic resonance spectroscopy. p(HEMA-co-MAAL) membranes were characterized by swelling studies, porosimeter, scanning electron microscopy, Fourier transform-infra red spectroscopy, and elemental analysis. These membranes have macropores in the size range 5-10 mum. Different metal ions including Zn(II), Ni(II), Co(II), and Cu(II) were chelated on these membranes. p(HEMA-co-MAAL) were used in the adsorption of human serum albumin (HSA) from aqueous media containing different amounts of albumin (0.1-5.0 mg L-1) and at different pH values (4.0-8.0). The maximum HSA adsorption was observed at pH 5.0. The nonspecific adsorption of HSA on the pHEMA membranes was negligible 0.9 mug cm(-2). MAAL incorporation significantly increased the HSA adsorption (1.76 mg cm(-2)). The HSA adsorption capacities of the metal-incorporated membranes were Greater than that of the p(HEMA-co-MAAL) membranes under the same conditions. Higher HSA adsorption capacity was observed from the human plasma (2.88 mg HSA cm(-2)).Öğe Heavy metal separation capacity of a porous methacrylamidophenylalanine containing membrane based on a polyhydroxyethyl methacrylate matrix(Marcel Dekker Inc, 2001) Denizli, A.; Say, R.; Patir, S.; Arica, Y.The abilities of various sorbent materials for heavy metal removal have been reported in the literature. We have developed a novel approach to obtain high metal-sorption capacity utilizing a membrane containing 2-methacrylamidophenylalanine. Metal-complexing ligand 2-methacrylamidophenylalanine (MAPA) was synthesized through the use methacrylo chloride and phenylalanine. Then, poly(2-hydroxyethyhmethacrylate-co-2-methacrylamidophenylalanine) (p(HEMA-co-MAPA)) membranes were prepared by UV-initiated photopolymerization of HEMA and MAPA in the presence of the initiator azobisisobutyronitrile. MAPA monomer was characterized by nuclear magnetic resonance spectroscopy. p(HEMA-co-MAPA) membranes were characterized by swelling studies, scanning electron microscopy, Fourier transform infrared spectroscopy, and elemental analysis. These membranes have large pores; the micropore dimensions are approximately 5-10 mum. p(HEMA-co-MA-PA) affinity membranes with a swelling ratio of 133.2% and containing 18.9 mmol MAPA/m(2) were used in the removal of the heavy-metal ions of copper, nickel, and mercury from aqueous media containing different amounts of these ions (5-600 mg/L) and at different pH values (2.0-7.0). The maximum adsorption capacities of heavy metal ions onto the MAPA-containing membranes under noncompetitive conditions were 23.8 = mmol/m(2) for Cu(II), 29.1 mmol/m(2) for Ni(II), and 50.3 mmol/m(2) for Hg(II). The affinity order was Hg(II) > Ni(II) > Cu(II). The adsorption of heavy metal ions increased with increasing pH and reached a plateau value at approximately pH 5.0. Adsorption of heavy metal ions from artificial wastewater was also studied. The adsorption capacities were 11.9 mmol/m(2) for Cu(II), 7.33 mmol/m(2) for Ni(II), and 9.79 mmol/m(2) for Hg(II). Desorption of heavy metal ions was performed using 0.1 M HNO3. The p(HEMA-co-MAPA) membranes are suitable for more than five cycles without noticeable loss of capacity.Öğe Poly(hydroxyethyl methacrylate-co-methacrylamidoalanine) membranes and their utilization as metal-chelate affinity adsorbents for lysozyme adsorption(Vsp Bv, 2002) Garipcan, B.; Say, R.; Patir, S.; Arica, Y.; Denizli, A.Different adsorbents have been reported in the literature for protein purification. The authors have developed a novel and new approach to obtain high protein adsorption capacity utilizing a 2-methacrylamidoalanine-containing membrane. Amino acid ligand 2-methacrylamidoalanine (MAAL) monomer was synthesized using methacryloyl chloride and alanine. Poly(2-hydroxyethylmethacrylate-co-2-methacrylamidoalanine) [p(HEMA-co-MAAL)] membranes were then prepared by UV-initiated photopolymerization of HEMA and MAAL in the presence of an initiator (azobisisobutyronitrile, AIBN). The synthesized MAAL monomer was characterized by NMR. p(HEMA-co-MAAL) membranes were characterized by swelling studies, porosimeter, SEM, FTIR, and elemental analysis. These membranes have macropores in the size range of 5-10 mum. Cu(II) ions (25.9 mmol/m(2)) were chelated on these membranes. p(HEMA-co-MAAL) membranes were used to study the adsorption of lysozyme from aqueous media containing different amounts of lysozyme (0.1-3.0 mg/l) and at different pH values (4.0-8.0). The non-specific adsorption of lysozyme on the pHEMA membranes was negligible (0.9 mug/cm(2)). Incorporation of MAAL increased the lysozyme adsorption significantly up to 2.96 mg/cm(2). The lysozyme adsorption capacity of the Cu(II) incorporated membranes (9.98 mg/cm(2)) was greater than that of the p(HEMA-co-MAAL) membranes. More than 90% of the adsorbed lysozyme was desorbed in I h in the desorption medium containing 1.0 M NaCl and 0.025 M EDTA. The metal-chelate affinity membranes are suitable for repeated use for more than ten cycles without a noticeable loss of capacity.Öğe Separation of human-immunoglobulin-G from human plasma with L-histidine immobilized pseudo-specific bioaffinity adsorbents(Marcel Dekker Inc, 2002) Özkara, S.; Yavuz, H.; Patir, S.; Arica, M.Y.; Denizli, A.The pseudo-biospecific affinity ligand L-histidine immobilized poly(2-hydroxyethylmethacrylate) (PHEMA) in spherical form (100-150 mum in diameter) was used for the affinity chromatographic separation of human-immunoglobulin-G (HIgG) from aqueous solutions and human plasma. The PHEMA adsorbents were prepared by a radical suspension polymerization technique. Reactive aminoacid-ligand L-histidine was then immobilized by covalent binding onto these adsorbents. Elemental analysis of immobilized L-histidine for nitrogen was estimated as 62.3 mg L-histidine/g of PHEMA. The maximum HIgG adsorption on the L-histidine immobilized PHEMA adsorbents was observed at pH 7.4. The non-specific HIaG adsorption onto the plain PHEMA adsorbents was very low- (about 0.167 mg/g). Higher adsorption values (up to 3.5 mg/g) were obtained when the L-histidine immobilized PHEMA adsorbents were used from aqueous solutions. Much higher amounts of HIgG were adsorbed from human plasma (up to 44.8 mg/g). Adsorption capacities of other blood proteins were obtained as 2.2 mg/g for fibrinogen and 2.8 mg/g for albumin. The total protein adsorption was determined as 52.1 mg/g. The affinity microbeads allowed the one-step separation of HIgG from human plasma. The HIgG molecules could be repeatedly adsorbed and desorbed with these L-histidine-immobilized PHEMA adsorbents without noticeable loss in their HIgG adsorption capacity.
