Yazar "Armutcu, Canan" seçeneğine göre listele

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    Histidine-epoxy-activated sepharose beads embedded poly (2-hydroxyethyl methacrylate) cryogels for pseudobiospecific adsorption of human immunoglobulin G
    (Taylor & Francis Inc, 2017) Corman, Mehmet Emin; Armutcu, Canan; Bereli, Nilay; Elkak, Assem
    The use of highly purified immunoglobulin became among the most powerful adopted strategies in therapeutic trials nowadays. Their role as immunomodulatory and anti-inflammatory agents has widened their scope of use. A novel continuous supermacroporous monolithic cryogels embedded with histidine-epoxy-activated-sepharose beads were synthetized as a new monolithic adsorbents for the separation of immunoglobulin G from human serum. The histidine-epoxy-activated-sepharose beads were embedded into the 2-hydroxyethyl methacrylate (HEMA) cryogels present in frozen aqueous solution inside a plastic syringe. The microstructure morphology of the cryogels was characterized by swelling measurement and scanning electron microscopy. The adsorption of human IgG on the histidine-epoxy-activated-sepharose beads pHEMA cryogels appeared to follow the Langmuir-Freundlich adsorption isotherm model. The maximum IgG adsorption was observed at 4 degrees C and pH 7.4 and was found to be 26.95mg/g of cryogel which is close to that obtained experimentally (24.49mg/g). The cryogels were used for several adsorption-desorption cycles without any negligible decrease in their adsorption capacity.
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    Interface imprinted polymers with well-oriented recognition sites for selective purification of hemoglobin
    (Elsevier, 2021) Armutcu, Canan; Ozgur, Erdogan; Corman, M. Emin; Uzun, Lokman
    In this study, we introduced a new strategy to design interface imprinted polymers for a novel aspect of molecular imprinting technique, utilization of sacrificial metal oxide particles. In the first step, bovine hemoglobin (BHb) was adsorbed on zinc oxide (ZnO) particles, which were then used to synthesize polyacrylic acid-based molecular imprinting membrane by bulk polymerization in the presence of ethylene glycol dimethacrylate as a cross-linking agent. After polymerization terminated, BHb-ZnO particles were removed to leave effective imprint sites onto the bulk polymeric network which is responsible for the formation of template orientation. The characterization of membranes was investigated by using Fourier transform infrared (FTIR), Raman spectroscopy (RS), scanning electron microscopy (SEM), surface area measurements (BET analyses) and thermogravimetric analysis (TGA). The interface molecularly imprinted membranes (iMIMs) have a relatively high specific rebinding capacity of 65.98 mg/g and excellent selectivity towards BHb with a separation factor of 6.78. The equilibrium adsorption isotherms fitted well to Langmuir isotherms (R-2 = 0.9944) and the value of adsorption capability (Q(max)) and equilibrium constant (b) were estimated to be 73.53 mg/g and 1.36 mg/mL for the iMIM, respectively. The kinetics of adsorption fitted best to pseudo-second order (R-2 = 0.9912). The ZnO particles were used not only to ensure the preservation of the imprint cavities in the polymer network but also to lead to high template removal and better rebinding kinetics. This novel design with multiple recognition sites is quite simple and suitable for the separation of biomacromolecules.
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    Molecularly imprinted cryogel cartridges for the specific filtration and rapid separation of interferon alpha
    (Royal Soc Chemistry, 2015) Corman, Mehmet Emin; Armutcu, Canan; Ozkara, Serpil; Uzun, Lokman; Denizli, Adil
    In this study, we synthesised specific filtration cartridges with selective recognition sites for target molecules and used them to separate interferon alpha-2b from aqueous solutions. We combined molecular imprinting technology with cryogel to achieve specific and rapid filtration of interferon alpha-2b through the macroporous structure of a cryogel network. Recombinant interferon alpha-2b-imprinted poly(2-hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan) P(HEMATrp)/alpha-2bIFN cryogels were synthesised via free-radical bulk polymerisation under partially frozen conditions. The interferon alpha-2b filtration conditions were subsequently optimised with respect to factors such as pH, initial concentration, temperature, centrifugation speed, salt concentration and type and the amount of precomplex incorporated. Selectivity experiments were conducted in respect to isoelectric point as well as size of the competitor proteins under both uncompetitive and competitive conditions. The relative selectivity coefficients of the specific filtration cartridge in respect to isoelectronic points for interferon/ IgG, interferon/HSA and interferon/insulin pairs were 3.72, 7.10 and 10.68 times greater than the coefficient of a non-imprinted [P(HEMATrp)] filtration cartridge, respectively. Similarly, the relative selectivity coefficients of the specific filtration cartridge in respect to competitor size for interferon/ lysozyme, interferon/myoglobin and interferon/carbonic anhydrase pairs were calculated as 7.58, 10.40 and 11.68 under uncompetitive conditions whereas those values under competitive conditions were calculated as 1.08, 1.05 and 1.34, respectively. The results indicated that specific filtration cartridges developed could repeatedly adsorb interferon alpha-2b with a short separation time without any significant decrease in the adsorption capacity even if competitive conditions were conducted.
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    Purification of Fab and Fc using papain immobilized cryogel bioreactor separator system
    (Elsevier, 2020) Armutcu, Canan; Corman, Mehmet Emin; Bayram, Engin; Uzun, Lokman
    The continuous bed bioreactor systems have been used for the production of protein therapeutics, such as IgG, using immobilized enzyme in biopharmaceutical applications. We developed macroporous poly(hydroxyethyl methacrylate-co-glycidyl methacrylate) cryogel-based bioreactor matrix using sodium dodecyl sulfate as surfactans in the presence of ethylene glycol dimethacrylate as cross linking agent by bulk polymerization. The developed polyGMA immobilized bioreactor with papain enzyme was used for specific fragmentation of immunoglobulin G. The catalysis efficiency for immobilized enzyme were investigated in comparison with free enzyme. The immobilized papain displayed broad catalytic activity over a variety of conditions, with maximal activity around pH 7.0 and 70 degrees C. The Michaelis-Menten kinetic constant (K-m), the maximum reaction velocity (V-max), and the catalytic efficiency (k(cat)) for free enzyme were 0.1097 mg/mL, 29.9 mg/mL/min, and 92.01 1/min, respectively, whereas for immobilized enzyme, K-m, V-max, and k(cat) values were 0.1078 mg/mL, 30.53 mg/mL/min, and 94.3 1/min, respectively. In a further step, after digestion, remarkable digestion products of bioreactor, Fab and Fc fragments, produced with immobilized papain bioreactors were analyzed in two ways by SDS-PAGE and reversed-phase HPLC; it was demonstrated that papain immobilized bioreactor successfully used for the digestion of human IgG with high activity. Therefore, the polyGMA cryogel immobilized with papain exhibited a very effective matrix for the bioreactor which can be considered as an alternative bioreactor matrix with great promise in biopharmaceutical applications.
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    Rapid Analysis of Polycyclic Aromatic Hydrocarbons in Water Samples Using an Automated On-line Two-Dimensional Liquid Chromatography
    (Springer International Publishing Ag, 2019) Armutcu, Canan; Ozgur, Erdogan; Karasu, Tunca; Bayram, Engin; Uzun, Lokman; Corman, Mehmet Emin
    Two-dimensional HPLC (2D-HPLC) recently has received great attention due to providing high resolving power and higher peak capacities than that of 1D-HPLC, especially dealing with a wide spectrum of sample matrices containing several components. In this work, an on-line heart-cutting two-dimensional liquid chromatography (2D-LC) method was developed using monolithic columns coupled with reversed-phase liquid chromatography (RPLC). 2D-HPLC was successfully carried out using affinity-based monolithic columns at first dimension (20 cm x 4.6 mm I.D.) followed by a Pinnacle II PAH column (50 mm x 4.6 mm I.D.) at the second dimension. Furthermore, good linearity was observed for the correlation of the benzo[a]pyrene (BaP) molecule against the peak areas (R-2 = 0.994) in the concentration range of 0.01-1.0 ng/mL in 30 min. The limit of detection and the limit of quantification were found to be 4.0 pg/mL and 12.0 pg/mL, respectively. Both the intra-day and inter-day precision at 0.01 and 0.1 ng/mL spiked concentrations were below than 2.35% RSD whereas the means of the recovery data of the BaP from the water samples were found to be in the range of 93.71-98.65%. These results demonstrate that the 2D-HPLC system, developed by the combination of the P(HEMA-MAPA) column and Pinnacle II PAH column, is reliable, stable, and well qualified in the extraction of polycyclic aromatic hydrocarbons from the water samples.
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    Rapid, efficient and selective preconcentration of benzo[a]pyrene (BaP) by molecularly imprinted composite cartridge and HPLC
    (Elsevier, 2017) Corman, Mehmet Emin; Armutcu, Canan; Uzun, Lokman; Denizli, Adil
    In this study, cryogel-based molecularly imprinted composite cartridges were designed for the rapid, efficient, and selective preconcentration of benzo[a]pyrene (BaP) from water samples. First, a BaP-imprinted poly(2-hydroxyethyl methacrylate-N-methacryloyl-(L)-phenylalanine) composite cartridge was synthesized under semi-frozen conditions and characterized by scanning electron microscopy, elemental analysis, Fourier transform infrared spectroscopy, and swelling tests. After the optimization of preconcentration parameters, i.e., pH and initial BaP concentration, the selectivity and preconcentration efficiency, and reusability of these cartridges were also evaluated. In selectivity experiments, BaP imprinted composite cartridge exhibited binding capacities 3.09, 9.52, 8.87, and 8.77-fold higher than that of the non-imprinted composite cartridge in the presence of competitors, such as benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), indeno[1,2,3-cd]pyrene (lcdP), and 1-naphthol, respectively. The method detection limit (MDL), relative standard deviation (RSD) and preconcentration efficiency (PE) of the synthesized composite cartridge were calculated as 24.86 mu g/L, 1.60%, and 349,6%, respectively. (C) 2016 Elsevier B.V. All rights reserved.
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    Reversible and easy post-crosslinking method for developing a surface ion-imprinted hypercrosslinked monolith for specific Cd(II) ion removal from aqueous solutions
    (Royal Soc Chemistry, 2016) Corman, Mehmet Emin; Armutcu, Canan; Uzun, Lokman; Say, Ridvan; Denizli, Adil
    In this study, a new surface imprinting technique for preparing a hypercrosslinked monolith to remove Cd(II) ions out from aqueous solutions was proposed. The monoliths were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermal gravimetrical analysis, surface area measurements and elemental analysis. The reversible nature of the hypercrosslinking process was proved by repeated crosslinking and denaturation cycles by using ferric ions as an oxidant and urea as a reductant, respectively meanwhile performing surface area measurements for both situations to demonstrate the variation in the surface porosity. The multipoint BET surface areas of poly(HEMA), surface ion imprinted (Cd-SII-HM) and non-imprinted (NI-HM) monoliths were determined as 269.1 m(2) g(-1), 79.1 m(2) g(-1), and 67.4 m(2) g(-1), respectively. By breaking hypercrosslinks, the micropore volume decreased from 39.7 mm3 g-1 to 11.8 mm(3) g(-1) while the cumulative pore volume decreased from 30.7 mm(3) g(-1) to 9.1 mm(3) g(-1) during urea treatment. At the first step, the affecting factors such as initial Cd(II) ion concentrations, pH and adsorption time were optimized. Then, the selectivity of the Cd-SII-HM for Cd(II) against other metal ions was evaluated not only from singular solutions but also from triple and quadruple solutions, which included Pb(II), Zn(II) and Hg(II) ions as competitors. The relative selectivity coefficients were calculated as 3.28, 15.61 and 58.55 for Cd(II)/Zn(II), Cd(II)/Pb(II) and Cd(II)/Hg(II) pairs. The results obtained indicated that the developed reversible and easy post-crosslinking method is quite applicable for producing the surface ion-imprinted polymers with high selectivity for the template ions [Cd(II)] regarding the potential competitor ions [Zn(II), Pb(II) and Hg(II)].
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    Self-oriented nanoparticles for site-selective immunoglobulin G recognition via epitope imprinting approach
    (Elsevier, 2014) Corman, Mehmet Emin; Armutcu, Canan; Uzun, Lokman; Say, Ridvan; Denizli, Adil
    Molecular imprinting is a polymerization technique that provides synthetic analogs for template molecules. Molecularly imprinted polymers (MIPs) have gained much attention due to their unique properties such as selectivity and specificity for target molecules. In this study, we focused on the development of polymeric materials with molecular recognition ability, so molecular imprinting was combined with miniemulsion polymerization to synthesize self-orienting nanoparticles through the use of an epitope imprinting approach. Thus, L-lysine imprinted nanoparticles (LMIP) were synthesized via miniemulsion polymerization technique. Immunoglobulin G (IgG) was then bound to the cavities that specifically formed for L-lysine molecules that are typically found at the C-terminus of the Fc region of antibody molecules. The resulting nanoparticles makes it possible to minimize the nonspecific interaction between monomer and template molecules. In addition, the orientation of the entire IgG molecule was controlled, and random imprinting of the IgG was prevented. The optimum conditions were determined for IgG recognition using the imprinted nanoparticles. The selectivity of the nanoparticles against IgG molecules was also evaluated using albumin and hemoglobin as competitor molecules. In order to show the self-orientation capability of imprinted nanoparticles, human serum albumin (HSA) adsorption onto both the plain nanoparticles and immobilized nanoparticles by anti-human serum albumin antibody (anti-HSA antibody) was also carried out. Due to anti-HSA antibody immobilization on the imprinted nanoparticles, the adsorption capability of nanoparticles against HSA molecules vigorously enhanced. It is proved that the oriented immobilization of antibodies was appropriately succeeded. (C) 2014 Elsevier B.V. All rights reserved.
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    Synthesis and characterization of stimuli-responsive hydrogels: evaluation of external stimuli influence on L929 fibroblast viability
    (Iop Publishing Ltd, 2022) Karasu, Tunca; Erkoc-Biradli, Fatma Zehra; Ozturk-Oncel, M. Ozgen; Armutcu, Canan; Uzun, Lokman; Garipcan, Bora; Corman, Mehmet Emin
    In this study, poly(2-hydroxyethylmethacrylate) [p(HEMA)] based hydrogels responsive to the pH, temperature and magnetic field were synthesized. The surface properties of p(HEMA) were improved by designing the stimuli-responsive hydrogels made of MAGA, NIPAAm and methacrylate-decorated magnetite nanoparticles as a function of pH-, thermo- and magnetic responsive cell culture surfaces. These materials were then modified an abundant extracellular matrix component, type I collagen, which has been considered as a biorecognition element to increase the applicability of hydrogels to cell viability. Based on results from scanning electronmicroscopy (SEM) and thermal gravimetric analysis (TGA), stimuli-responsive hydrogel demonstrated improved non-porous structures and thermal stability with a high degree of cross-linking. Mechanical analyses of the hydrogels also showed that stimuli-responsive hydrogels are more elastomeric due to the polymeric chains and heterogeneous amorphous segments compared to plain hydrogels. Furthermore, surface modification of hydrogels with collagen provided better biocompatibility, which was confirmed with L929 fibroblast cell adhesion. Produced stimuli-responsive hydrogels modulated cellular viability by changing pH and magnetic field.