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Öğe Determination of mold contamination using ergosterol imprinted particles(Wiley, 2021) Oktay Basegmez, Hatice Imge; Baydemir Pesint, Gozde; Nergiz, Mustafa; Zenger, OkanErgosterol is a key biochemical marker for fungal mycelial growth. In this study, molecularly ergosterol imprinted particles (Erg-MIPs) were newly synthesized for the selective detection of ergosterol in mold samples. Erg-MIPs were characterized via scanning electron microscopy, swelling studies, and surface area measurements. Maximum selective ergosterol adsorption achieved as 28.50 mg/g Erg-MIP. Selectivity studies showed that Erg-MIPs adsorbed Erg 2.01 and 3.27 times higher than that of cholesterol and stigmasterol, respectively. Erg adsorption fromAspergillus nigerwas found as 23.87 mg/g. Reusability of Erg-MIPs was studied and decrease in Erg adsorption capacity of the particles was negligible (3%). Erg-MIPs are good affinity materials for the selective Erg detection from food samples, prior to use in food industry.Öğe Determination of Neopterin as a Prognostic Indicator Using Neopterin-Imprinted Cryogel Membranes(Humana Press Inc., 2021) Zenger, Okan; Eren, Burcu; Arısoy, Pırıl; Özdaş, Sibel; Baydemir Peşint, GözdeNeopterin (Neo) is thought of as a key biomarker for the diagnosis and prognosis of a wide variety of diseases associated with cellular immune response. Therefore, it has become a vital need to be able to specifically determine the Neo concentration in human serum. Molecularly imprinted cryogels have come into prominence among other affinity systems by combining advantages of Molecular Imprinting Technology (MIT) and cryogels. In this chapter, synthesis of novel Neopterin-imprinted cryogel membranes (Neo-mip), characterization studies of synthesized materials, and their use in the determination of Neo in human serum is described in detail. In addition, the evaluation of selective Neo adsorption properties of Neo-mip against competitors (Pterin and Glucose) is discussed. Neo-mip will come into prominence as important affinity materials for the selective Neo recognition in body fluids, prior to use in the health sector. © 2021, The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.Öğe Double-imprinted polymers for selective HSA depletion from human serum(Adana Alparslan Türkeş Bilim ve Teknoloji Üniversitesi, 2021) Zenger, Okan; Peşint, Gözde Baydemirİnsan Serum Albümini (HSA) insan kanında en bol bulunan serum proteinidir, serum proteinlerinin yaklaşık yarısını oluşturur. Kan plazmasının proteomik çalışmalarında, albümin ve hemoglobin gibi kanda bol miktarda bulunan proteinler, düşük miktarda bulunan ve hastalıkların teşhisi ile ilgili olabilecek proteinlerin analizini zorlaştırmaktadır. Bu yüzden, bu proteinlerin uzaklaştırılması veya azaltılması proteomik çalışmalar için hayati öneme sahiptir. Bu tez çalışmasında, çift-tabakalı baskılanmış kriyojeller kullanılarak HSA'nın direkt olarak insan serumundan tek adımda azaltılması amaçlanmıştır. Çalışma kapsamında, ilk olarak HSA-baskılanmış kriyojeller %8 monomer konsantrasyonu ile sentezlenmiştir. Daha sonra, %8'lik kriyojel üzerine HSA içeren %16'lık polimer çözeltisi dökülerek, ilk kriyojel tabakasının birbirleriyle bağlantılı makrogözenekleri arasında ikinci polimer çözeltisinin jelleşmesi sağlanmıştır. Böylelikle, HSA-baskılanmış çift tabakalı polimerler (HSA-DIP) elde edilmiştir. Kontrol grubu olarak, çift-tabakalı baskılama tekniği ile üretilmiş fakat kalıp molekül içermeyen polimerler (DL-NIP) ve farklı monomer konsantrasyonlarında üretilmiş tek tabakalı HSA-spesifik polimerler (%8 ve %16 monomer konsantrasyonu için sırasıyla; HSA-MIP8% ve HSA-MIP16%) sentezlenmiş ve elde edilen sonuçlar birbirleriyle karşılaştırılmıştır. Sentezlenen kriyojel kolonları şişme testleri, Taramalı Elektron Mikroskobu (SEM) ve Mikro Bilgisayarlı Tomografi (Mikro-CT) analizi ile karakterize edilmiştir. Sonrasında, HSA tanıma bölgeleriyle ilişkili olarak HSA'nın sulu çözeltilerden adsorpsiyonu incelenmiştir. Ayrıca, HSA-DIP kolonlarının HSA molekülü için seçiciliği İnsan Hemoglobin (Hb) ve İmmünoglobulin G (IgG) yarışmacı moleküllerine karşı test edilmiştir. Elde edilen sonuçlar, sistemin adsorpsiyon özelliklerini belirlemek için kinetik analizlerle incelenmiştir. Son olarak, doğrudan insan serumundan HSA'nın azaltılması incelenmiştir. Ayrıca, çift-tabakalı baskılanmış polimerler yeniden kullanılabilirlik çalışmaları ile test edilmiş ve 10 adsorpsiyon-desorpsiyon döngüsünden sonra bile HSA-DIP kolonlarının HSA adsorpsiyon kapasitelerini önemli ölçüde koruduğu sonucuna ulaşılmıştır.Öğe Enhanced laccase separation from fermentation medium using cryogel columns(Elsevier, 2023) Eren, Burcu; Zenger, Okan; Basegmez, Hatice Imge Oktay; Pesint, Gozde BaydemirThe laccase enzyme family belongs to the oxidoreductase enzyme class and is one of the most commercially valuable enzymes that catalyzes the oxidation of one electron of a wide range of phenolic compounds. Separation and purification of laccases are crucial for industry since they play an important role in dye decolorization, biodegradation and food processing. Therefore, developing effective, high yielding and cost-effective methods for laccase production is vital. In this study, it was aimed to prepare cryogel columns for laccase purification following the bioproduction of laccase via Aspergillus niger. 2-hydroxyethyl methacrylate based cryogels were synthesized in the presence of 1-vinylimidazole as the affinity ligand and characterized by swelling tests, Bru-nauer-Emmett-Teller surface area measurement and scanning electron microscopy analysis. Surface area and water uptake ratio of cryogel columns were 35 m2/g and 93 %, respectively. The effect of pH, equilibrium laccase concentration, flow rate, interaction time and temperature on laccase adsorption were examined. The purifi-cation factor was calculated as 10.53 under optimum conditions and the enzyme recovery was found to be 86.7 % from fermentation medium. Current study revealed that laccase purification using cryogels following filtration of fermentation medium could be a promising candidate for industrial applications with eliminating the need for complex chromatographic steps.Öğe L-proline determination by molecularly imprinted nanoparticles: A potential nanoscale tool for the diagnosis of metabolic disorders(Elsevier, 2024) Nergiz, Mustafa; Zenger, Okan; Pesint, Gozde BaydemirDetecting and quantifying amino acids is vital in biochemical analyses, especially for diagnosing metabolic disorders. L-proline, among these amino acids, holds significant relevance for various metabolic disorders in living organisms, particularly in humans. hyperprolinemia arises when ineffective breakdown of L-proline occurs due to enzyme deficiencies, leading to its accumulation in the body and underscoring the need for precise monitoring. To address this challenge, molecular imprinting offers a reliable single-step technique for detecting target molecules like proteins, peptides, amino acids, or ions with high selectivity. Moreover, nanoparticles, with significant surface area-to-volume ratios, enable high-level mass transfer and binding kinetics, making them ideal for nano-scale sensitive applications. In this study, 2-hydroxyethyl methacrylate-based molecularly imprinted nanoparticles were synthesized via mini-emulsion polymerization, combining the advantages of molecular imprinting technique and nanoparticles for the specific recognition of L-proline, and were well-characterized by Scanning Electron Microscopy, zeta-sizer particle size analysis, and Fourier Transform Infrared Spectroscopy. Based on zeta-sizer analysis, the estimated diameters of L-proline-imprinted and non-imprinted nanoparticles (Pro-MIPs and NIPs) were determined to be approximately 27.51 nm and 20.66 nm, respectively. The adsorption of L-proline onto nanoparticles from aqueous solutions was investigated in a batch system, and the maximum Lproline adsorption capacity was determined to be 26.58 mg/g for Pro-MIPs and 4.65 mg/g for and NIPs. The selectivity of Pro-MIPs was assessed using Liquid Chromatography-Tandem Mass Spectrometry, even in human serum and in the presence of competing molecules (L-histidine and L-phenylalanine). Additionally, Pro-MIPs maintained their adsorption capacity through up to 10 adsorption-desorption cycles without significant decrease.Öğe Molecularly imprinted composite discs for transferrin recognition(Taylor & Francis Inc, 2022) Aylaz, Gulgun; Zenger, Okan; Baydemir Pesint, Gozde; Andac, MugeHuman Transferrin (HTr) imprinted composite cryogel (HTr-MIPCC) discs were synthesized with distinctive structure and increased adsorption capacity and specificity for HTr by combining the advantages of the surface imprinting technique. HEMA-based cryogel was embedded with HTr-surface imprinted particles. Thanks to the imprinted particles embedding, both the higher surface area and specific recognition are provided. The structure of the HTr-MIPCC was characterized by FTIR Spectrometer, SEM, swelling studies, flow dynamics, and surface area measurements. The addition of surface imprinted particles into the cryogel disc has resulted in an increased surface area, enhancing the capacity of composite cryogel for HTr adsorption up to 10.96 mg/g and gel fractionation yields reached up to 83%. Selectivity studies were carried out against HIgG and HSA as competitors. The HTr-MIPCC discs were packaged into an FPLC column for selective depletion of HTr. It was calculated that the HTr-MIPCC is 1.071 and 1.062 times selective for HTr than HSA and HIgG, respectively. According to FPLC studies HTr-MIPCC can be considered as an excellent alternative for affinity matrixes used for the detection and selective recognition of HTr directly from human serum. HTr-MIPCC discs can be used several times without any noteworthy reduction in the adsorption capacity of HTr.Öğe Monolithic hydrophobic cryogel columns for protein separation(Springer, 2022) Erzengin, Mahmut; Baydemir Pesint, Gozde; Zenger, Okan; Odabasi, MehmetThe present study was conducted for the synthesis of a novel supermacroporous monolithic hydrophobic adsorbent for lysozyme (Lyz) selected as a model protein from aqueous solution. After preparation of poly(2-hydroxyethyl methacrylate-co-N-methacryloyl-(l)-tyrosine methyl ester) monolithic cryogel column, 1-naphthylamine was covalently attached, and the prepared column was abbreviated as NA-Mcc. Scanning electron microscopy, Fourier transform infrared spectroscopy and Brunauer, Emmett and Teller device were utilized for the morphology, functional groups and surface area measurements of the column. Effects of several parameters including Lyz content of the adsorption solution, pH of the medium used, ambient temperature, type of salt and flow rate on the adsorption capacity of the polymeric material were examined in continuous operation. The maximum value achieved for Lyz adsorption from aqueous phase was found to be 105.8 mg/g in phosphate buffer. In addition, NA-Mcc was investigated in terms of reusability, and it was demonstrated that there is no significant change in the adsorption properties of prepared monolithic hydrophobic cryogels after 30 adsorption-desorption cycles.Öğe Neopterin-Imprinted Columns for Selective Neopterin Recognition from Serum and Urine Samples(Elsevier Ltd, 2021) Özdaş, Sibel; Baydemir Peşint, Gözde; Arısoy, Pırıl; Zenger, Okan; Eren, BurcuNeopterin (Np), a catabolic product of guanosine triphosphate (GTP), is synthesized by human macrophages and is an important indicator of cellular immune system activation. Np is associated with the activated cellular immune response and therefore this molecule is a potential biomarker for the diagnosis and follow-up of a wide variety of physiological conditions including cardiovascular and neurodegenerative diseases, autoimmune disorders and viral infections. Within the scope of this study, it was aimed to synthesize neopterin-imprinted cryogel columns (Np-MIPs), which can selectively recognize Np in human body fluids. Np-MIPs were synthesized via the cryo-polymerization in presence of Np as the template molecule and characterized by swelling test, polymerization yield calculations, Brunauer-Emmett-Teller (BET) measurements and Scanning Electron Microscopy (SEM). The surface area was measured as 22 m2/g. Adsorption and desorption of Np from aqueous solutions were investigated, and selectivity studies were performed against pterine and glucose molecules. Maximum Np adsorption on Np-MIP was found to be 249.2 ?g/g and Np-MIPs can adsorb Np 1.09 and 3.84 times selective than glucose and pterin, respectively. It was demonstrated that Np-MIP columns can selectively adsorb Np from serum and urine, with the adsorption capacities of 36 ?g/g and 38.2 ?g/g Np-MIP, respectively. © 2021Öğe Preparation of molecularly imprinted bilayer cryogel columns for selective protein depletion(Elsevier Sci Ltd, 2022) Zenger, Okan; Pesint, Gozde BaydemirIn this study, bilayer-imprinted cryogels were synthesized for depletion of human serum albumin (HSA) from human serum. For this purpose, a monolayer HSA-imprinted cryogel with 8% monomer concentration was synthesized and second imprinting process was performed using a polymeric solution with 16% monomer concentration in presence of HSA, in the supermacroporous structure of first layer. Thereby, bilayer HSAimprinted cryogel column (HSA-BLIP) with enhanced surface area was obtained. Bilayer non-imprinted polymer (BL-NIP) and monolayer HSA-imprinted polymers with monomer concentrations of 8% and 16% (HSAMIP(8%) and HSA-MIP16%, respectively) were synthesized as the control group. Synthesized columns were characterized by swelling tests, scanning electron microscopy (SEM), multipoint Brunauer-Emmett-Teller (BET) surface area measurement and micro computed tomography (Micro-CT) analysis. Surface areas of HSA-BLIP, BL NIP, HSA-MIP8% and HSA-MIP(16% )were found to be 39 m(2)/g, 37 m(2)/g, 21 m(2)/g and 12 m(2)/g, respectively. Maximum HSA adsorption was calculated as 106.8 mg/g for HSA-BLIP and 5.14 mg/g for BL-NIP. Selectivity studies were conducted in presence of competitor molecules, human hemoglobin (Hb) and immunoglobulin G (IgG). Finally, selective depletion of HSA directly from human serum was studied. In addition, it was demonstrated that HSA-BLIPs can be used up to 10 times without significant decrease in selective adsorption capacity.Öğe Pterostilbene loaded poly(vinyl alcohol)-gelatin cryogels as potential bioactive wound dressing material(John Wiley and Sons Inc, 2023) Canatar, İpek; Zenger, Okan; Özdaş, Sibel; Baydemir Peşint, GözdeCryogels are support materials which are good at mimicking extracellular matrix due to their excellent hydrophilicity, biocompatibility, and macroporous structure, thus they are useful in facilitating cell activities during healing process. In this study, polyvinyl alcohol-gelatin (PVA-Gel) based cryogel membranes loaded with pterostilbene (trans-3,5-dimethoxy-4-hydroxystilbene; PTS) (PVA-Gel/PTS) was synthesized as wound dressing materials. PVA-Gel and PVA-Gel/PTS were synthesized with the polymerization yields of 96% ± 0.23% and 98% ± 0.18%, respectively, and characterized by swelling tests, Brunauer–Emmett–Teller (BET) and scanning electron microscopy (SEM) analysis. The swelling ratios were calculated as 98.6% ± 4.93% and 102% ± 5.1%, macroporosities were determined as 85% ± 2.13% and 88% ± 2.2%, for PVA-Gel and PVA-Gel/PTS, respectively. It was determined that PVA-Gel and PVA-Gel/PTS have 17 m2/g ± 0.76 m2/g and 20 m2/g ± 0.92 m2/g surface areas, respectively. SEM studies were demonstrated that they have ~100 ?m pore sizes. According to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), trypan blue exclusion and live-dead assay results, it was observed that cell proliferation, cell number and cell viability were higher in PVA-Gel/PTS cryogel at 24, 48, and 72 h compared to PVA-Gel. A strong and transparent fluorescent light intensity was observed indicating higher cell population in PVA-Gel/PTS in comparison with PVA-Gel, according to 4?,6-diamidino-2-phenylindole (DAPI) staining. SEM, F-Actin, Giemsa staining and inverted-phase microscope image of fibroblasts in PVA-Gel/PTS cryogels revealed that dense fibroblast proliferation and spindle-shaped morphology of cells were preserved. Moreover, DNA agarose gel data demonstrated that PVA-Gel/PTS cryogels had no effect on DNA integrity. Consequently, produced PVA-Gel/PTS cryogel can be used as wound dressing material to promote wound therapies, inducing cell viability and proliferation. © 2023 Wiley Periodicals LLC.Öğe Spongy membranes for peroxidase purification from Brassica oleracea roots(Elsevier Sci Ltd, 2021) Pesint, Gozde Baydemir; Zenger, Okan; Percin, Isik; Denizli, AdilIn this work, it was aimed to purify peroxidase from Brassica oleracea roots using newly synthesized cryogel membranes. 2-4-vinylphenylboronic acid (VPBA) containing 2-hydroxyethyl methacrylate (HEMA) [PHE-MABA] cryogel membranes were prepared successfully and swelling tests, scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, contact angle measurements, and Brauner-Emmet-Teller (BET) surface area analysis were done for characterization. Effect of experimental conditions on peroxidase binding capacity of PHEMABA cryogel membranes was determined by examining parameters such as pH, temperature and time with binding studies. Maximum peroxidase binding capacity of PHEMABA cryogel membranes was determined as 22.01 mg/g for 2 mg/mL equilibrium peroxidase concentration at pH 8.0. Finally, peroxidase was purified from Brassica oleracea roots with 85.38% yield and 18.38 purification fold. According to obtained re-sults, spongy PHEMABA cryogel membranes show high peroxidase binding capacity and could be suggested as a boronate affinity model system for enzyme purification.Öğe Synthesis of Double-Layer Imprinted Polymers: BSA Depletion(Humana Press Inc., 2021) Zenger, Okan; Baydemir Peşint, GözdeA sensitive, rapid, and cost-effective method for quantitative analysis of proteins (e.g., detection, purification, depletion) for a wide variety of purposes is required in a number of areas, such as immunodiagnostics and biotechnology. Double-layer imprinting technique, which is carried out via polymerization of polymer solution with higher monomer concentration, covering and filling the supermacroporous structure of a pre-synthesized cryogel column with a lower monomer concentration, thus improving the surface area and adsorption capacity of final product, is a brand new approach for the application of cryogels in molecular imprinting technology. Within the scope of this chapter, BSA is selected as a model protein for the application of double-layer imprinting protocol. In this chapter, synthesis of double-layer BSA-imprinted and non-imprinted cryogel columns (BSA-DLIP and DLNIP, respectively) are described. In addition, characterization of synthesized columns and BSA depletion studies from aqueous solutions are described in detail, as well as selectivity of BSA-DLIPs for BSA, against competitors. © 2021, The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.Öğe Tannic acid purification from pomegranate peel via tannic acid imprinted particle-embedded cryogel column(Elsevier, 2023) Pesint, Gozde Baydemir; Cemek, Kardelen; Zenger, Okan; Anar, Baris Can; Basegmez, Hatice Imge OktayTannic acid (TA) is hydrolysable tannin found in the leaves and bark of many herbaceous and woody plants. Purification of TA is important due to its antibacterial, antihistaminic, antioxidant, antimutagenic and antitussive properties. In this study, 2-hydroxyethyl methacrylate-based TA-imprinted particle embedded cryogel (TA-MIP) was synthesized to purify TA from pomegranate peel. Furthermore, non-imprinted particle embedded cryogel (NIP) was synthesized to determine specific adsorption properties of TA-MIP, and control cryogel was synthesized without embedding procedure. The synthesized cryogel columns were characterized via scanning electron microscopy, Brunauer-Emmett-Teller surface area analysis, fourier-transform infrared spectroscopy, and swelling studies. Particle-embedding procedure resulted in a significantly higher specific surface area of particle-embedded columns (TA-MIP and NIP, 29 m(2)/g and 25 m(2)/g, respectively) than the specific surface area of control cryogel (9 m(2)/g). Adsorption studies were performed from aqueous solutions and maximum TA adsorption was found to be 34.4 mg/g for TA-MIP, 3.9 mg/g for NIP, and 2.8 mg/g for control cryogel. Within the scope of selectivity study, it was demonstrated that the synthesized columns have a high selectivity for TA against gallic acid (GA) and quercetin (QCT). Finally, purification of TA directly from pomegranate peel extract was studied and results were confirmed by HPLC. Furthermore, it has been proven that TA-MIP cryogel columns can be repeatedly used up to ten-times without any remarkable reduction in the TA adsorption amount.
