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Öğe Preparation and characterization of metal-chelated poly(HEMA-MAH) monolithic cryogels and their use for DNA adsorption(Wiley-Blackwell, 2010) Odabaşı, Mehmet; Baydemir, Gözde; Karataş, Melike; Derazshamshir, AliDNA adsorption properties of Zn(2+)-chelated supermacroporous poly(2-hydroxyethyl methacrylate-N-methacryloyl-(L)-histidine methyl ester) [poly(HEMA-MAH)] monolithic cryogel column were investigated for the application of DNA-affinity adsorbents. The monolithic cryogel was loaded with Zn(2+) ions to form the metal-chelated affinity sorbent. Poly(HEMA-MAH) cryogel was characterized by swelling tests, FTIR, scanning electron microscopy (SEM), and elemental analysis. SEM analysis indicates that the cryogel have a heteroporous structure with interconnected pores of 10-50 mu m size, which ascribed to the porogens effect of frozen water crystals. Poly(HEMA-MAH) cryogel containing 45.8 mu mol MAH was used in the adsorption/desorption of DNA from aqueous solutions. The maximum amount of DNA adsorption was 32.93 mg/g in Tris buffer at pH 7.0. It was observed that DNA could be repeatedly adsorbed and desorbed with the poly(HEMA-MAH) cryogel without significant loss of adsorption capacity. As a result, these higher amounts of DNA adsorbed poly (HEMA-MAH) cryogels are expected to be good candidate for achieving higher removal of anti-DNA antibodies from systemic lupus erythematosus (SLE) patients plasma. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 116: 1306-1312, 2010Öğe Preparation of cryogel columns for depletion of hemoglobin from human blood(Taylor & Francis, 2016) Derazshamshir, Ali; Baydemir, Gözde; Yılmaz, Fatma; Bereli, Nilay; Denizli, AdilIn this study, we aimed to prepare the metal chelate affinity cryogels for the hemoglobin (Hb) depletion. Poly(2-hydroxyethyl methacrylate) (PHEMA) cryogels were selected as base matrix because of their blood compatibility, osmotic, chemical, and mechanical stability. Cryogels are also useful when working with the viscous samples such as blood, because of their interconnected macroporous structure. Iminodiacetic acid (IDA), the chelating agent, was covalently coupled with PHEMA cryogels after activation with the epichlorohydrin and then the Ni(II) ions were chelated to the IDA-bound cryogels. The depletion of the Hb from hemolysate was shown by SDS-PAGE.Öğe Preparation of Zn2+-chelated poly(HEMA-MAH) cryogel for affinity purification of chicken egg lysozyme(John Wiley and Sons Limited, 2008) Derazshamshir, Ali; Ergün, Bahar; Peşint, Gözde; Odabaşı, MehmetSupermacroporous poly(2-hydroxyethyl methacrylate) [poly(HEMA)]-based monolithic cryogel column was prepared by radical cryocopolymerization of HEMA with N-methacryloyl-L-histidine methyl ester (MAH) as functional comonomer and N,N'-methylene-bisacrylamide (MBAAm) as crosslinker directly in a plastic syringe for affinity purification of lysozyme from chicken egg white. The monolithic cryogel containing a continuous polymeric matrix having interconnected pores of 10-50 mu m size was loaded with Zn2+ ions to form the metal chelate with poly(HEMA-MAH) cryogel. Poly(HEMA-MAH) cryogel was characterized by swelling studies, FTIR, scanning electron microscopy, and elemental analysis. The equilibrium swelling degree of the poly(HEMA-MAH) monolithic cryogel was 5.62 g H2O/g cryogel. Poly(HEMA-MAH) cryogel containing 45.8 mu mol MAH/g was used in the adsorption/desorption of lysozyme from aqueous solutions. The nonspecific adsorption of lysozyme was very low (7.5 mg/g). The maximum amount of lysozyme adsorption from aqueous solution in phosphate buffer was 209 mg/g at pH 7.0. It was observed that lysozyme could be repeatedly adsorbed and desorbed with the poly (HEMA-MAH) cyogel without significant loss of adsorption capacity. (C) 2008 Wiley Periodicals, Inc.Öğe Surface plasmon resonance sensors for medical diagnosis(Springer Berlin Heidelberg, 2018) Yeşeren, Saylan; Yılmaz, Fatma; Özgür, Erdoğan; Derazshamshir, Ali; Bereli, Nilay; Yavuz, Handan; Denizli, Adil[No abstract available]Öğe Synthesis of hydrophobic nanoparticles for real-time lysozyme detection using surface plasmon resonance sensor(Wiley, 2017) Saylan, Yeşeren; Yılmaz, Fatma; Derazshamshir, Ali; Yılmaz, Erkut; Denizli, AdilDiagnostic biomarkers such as proteins and enzymes are generally hard to detect because of the low abundance in biological fluids. To solve this problem, the advantages of surface plasmon resonance (SPR) and nanomaterial technologies have been combined. The SPR sensors are easy to prepare, no requirement of labelling and can be detected in real time. In addition, they have high specificity and sensitivity with low cost. The nanomaterials have also crucial functions such as efficiency improvement, selectivity, and sensitivity of the detection systems. In this report, an SPR-based sensor is developed to detect lysozyme with hydrophobic poly (N-methacryloyl-(L)-phenylalanine) (PMAPA) nanoparticles. The SPR sensor was first characterized by attenuated total reflection-Fourier transform infrared, atomic force microscope, and water contact angle measurements and performed with aqueous lysozyme solutions. Various concentrations of lysozyme solution were used to calculate kinetic and affinity coefficients. The equilibrium and adsorption isotherm models of interactions between lysozyme solutions and SPR sensor were determined and the maximum reflection, association, and dissociation constants were calculated by Langmuir model as 4.87, 0.019nM(-1), and 54nM, respectively. The selectivity studies of SPR sensor were investigated with competitive agents, hemoglobin, and myoglobin. Also, the SPR sensor was used four times in adsorption/desorption/recovery cycles and results showed that, the combination of optical SPR sensor with hydrophobic ionizable PMAPA nanoparticles in one mode enabled the detection of lysozyme molecule with high accuracy, good sensivity, real-time, label-free, and a low-detection limit of 0.66nM from lysozyme solutions. Lysozyme detection in a real sample was performed by using chicken egg white to evaluate interfering molecules present in the medium.
