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    Evaluation of human interferon adsorption performance of Cibacron Blue F3GA attached cryogels and interferon purification by using FPLC system
    (Elsevier, 2012) Dogan, Ali; Ozkara, Serpil; Sari, Mufrettin Murat; Uzun, Lokman; Denizli, Adil
    In this study, we have focused our attention on preparing supermacroporous cryogels as a potential dye-affinity adsorbent for interferon purification. For this purpose, 2-hydroxyethyl methacrylate (HEMA) and Cibacron Blue F3GA (CB) were selected as main monomer and dye-ligand. Cibacron Blue F3GA attached supermacroporous poly(2-hydroxyethyl methacrylate) [poly( HEMA)/CB] cryogels were prepared and characterized by swelling test, scanning electron microscopy, elemental analysis, and FTIR. After that, the effecting factors such as pH, concentration, interaction time, and ionic strength on the interferon separation were evaluated. The maximum adsorption capacity of poly(HEMA)/CB cryogels was obtained as 38.2 mg/g at pH 6.0. Fast protein liquid chromatography (FPLC) system was used for interferon purification from human gingival fibroblast extract. The chromatography parameters, capacity and selectivity factors, resolution and theoretical plate number were found as 7.79, 9.62, 4.23 and 554, respectively. Although some decreases in total protein content, from 320 mu g to 18 mu g, and interferon activity, from 2.6 x 10(3) IU to 2.2 x 10(3) IU, were determined, specific antiviral activity increased from 7.19 IU/mu g to 122.2 IU/mu g. The purified interferon samples have 97.6% purity determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After repeated ten adsorption-desorption cycles, no significant decrease was determined in adsorption capacity of cryogel. In result, poly(HEMA)/CB cryogels have an application potential for rapid, cheap and specific purification of interferon. (C) 2012 Elsevier B.V. All rights reserved.
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    Hydrophobic microbeads as an alternative pseudo-affinity adsorbent for recombinant human interferon-? via hydrophobic interactions
    (Elsevier, 2012) Saylan, Yeseren; Sari, Mufrettin Murat; Ozkara, Serpil; Uzun, Lokman; Denizli, Adil
    Hydrophobic interaction chromatography (HIC) is increasingly used for protein purification, separation and other biochemical applications. The aim of this study was to prepare hydrophobic microbeads and to investigate their recombinant human interferon-alpha (rHuIFN-alpha) adsorption capability. For this purpose, we had synthesized functional monomer, N-methacryloyl-L-phenylalanine (MAPA), to provide a hydrophobic functionality to the adsorbent. The poly(2-hydroxyethyl methacrylate-N-methacryloyl-L-phenylalanine) [poly(HEMA-MAPA)] microbeads were prepared by suspension copolymerization. microbeads were characterized using FTIR, swelling behavior, and SEM micrographs. Equilibrium swelling ratio of poly(HEMA-MAPA) and poly(HEMA) microbeads were 53.3% and 69.3%, respectively. The specific surface area and average pore diameters determined by BET apparatus were 17.4 m(2)/g and 47.3 angstrom for poly(HEMA) microbeads and 18.7 m(2)/g and 49.8 angstrom for poly(HEMA-MAPA) microbeads. Adsorption experiments were performed under different conditions. Maximum rHuIFN-alpha adsorption capacity was found to be 137.6 +/- 6.7 mg/g by using poly(HEMA-MAPA) microbeads with a size range of 150-250 mu m and containing 327 mu mol MAPA/g microbeads. Compared with poly(HEMA-MAPA) microbeads, nonspecific rHuIFN-alpha adsorption onto plain poly(HEMA) microbeads was very low, about 4.2 +/- 2.3 mg/g. To determine the effects of adsorption conditions on possible conformational changes of rHuIFN-alpha structure, fluorescence spectrophotometry was employed. Repeated adsorption-elution processes showed that these microbeads are suitable for repeatable rHuIFN-alpha adsorption. (c) 2012 Elsevier B.V. All rights reserved.
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    Mastoid Cavity Obliteration with Cartilage Graft; Evaluation of 35 Patients
    (2019) Kalcıoğlu, Mehmet Tayyar; Eğilmez, Oğuz Kadir; Kökten, Numan; Uzun, Lokman; Tekin, Muhammet; Özerk, Ali; Toplu, Yüksel
    Abstract: Objective: Cartilage is a rigid material that is highly resistant to infection and retraction and is tolerated well by the middle ear. The purpose of this study was to review retrospectively the results of cases of mastoid cavity obliteration with cartilage performed after canal wall down (CWD) mastoidectomy and to discuss the literature.Method: Of 983 patients who underwent surgery for chronic otitis media between January 2000 and June 2012, 54 patients who underwent CWD mastoidectomy plus mastoid cavity oblitera-tion with cartilage and who were followed up regularly were selected from the database and in-vited for re-evaluation. All patients who came for a follow up after the invitation were examined and their data were evaluated retrospectively.Results: Thirty-five of the patients who accepted the invitation were included in the study. All of the patients in the study underwent mastoid cavity obliteration with conchal and/or tragal cartilage grafts. The duration of follow up ranged from 21 to 41 months (average, 27.3 months). Epithelization occurred in all patients with dry cavity, except one who had residual cholestea-toma and underwent revision surgery.Conclusion: The results of this study indicate that cartilage can be preferred for obliteration of mastoid cavity after CWD mastoidectomy.