Yazar "Ozyurt, Canan" seçeneğine göre listele

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    MerR-fluorescent protein chimera biosensor for fast and sensitive detection of Hg2+ in drinking water
    (Wiley, 2019) Ozyurt, Canan; Ustukarci, Handan; Evran, Serap; Telefoncu, Azmi
    Mercury ion (Hg2+) is a universal pollutant and its detection is crucial for public healthcare. In this study, we developed a novel fluorescent biosensor by construction of a protein fusion between the mercury-sensing transcription factor MerR and enhanced yellow fluorescent protein (EYFP). Hg2+-induced conformational change of MerR was transduced into fluorescence signal. Fluorescence intensity of the biosensor protein decreased with increasing concentrations of Hg2+ and a linear response was obtained in the range of 0.5-40 nM. The limit of detection was 0.5 nM, which was much lower than the maximum allowed level in water. The biosensor specificity was highly dependent on type and concentration of metal ion. The biosensor exhibited high specificity in a mixture of metal ions at 0.5 nM concentration. However, the interference effect was more pronounced at 40 nM concentration of metal ions. The measurement was completed in less than 1 Min with no need for sample preparation or preincubation steps. The biosensor achieved accurate and reliable detection in the spiked drinking water sample, as validated by the inductively coupled plasma optical emission spectrometry.
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    Sensitive and specific detection of ctDNA using Copper-Free click chemistry and magnetic bead Technology
    (Academic Press Inc Elsevier Science, 2026) Didarian, Reza; Kanarya, Dilek; Sahin, Sonya; Ozyurt, Canan; Evran, Serap; Odaci, Dilek; Yildirim-Tirgil, Nimet
    Liquid biopsy, particularly the analysis of circulating tumor DNA (ctDNA), offers immense potential for noninvasive cancer diagnosis and monitoring. It provides a less invasive alternative to traditional tissue biopsies, enabling earlier detection and real-time assessment of disease progression. However, a significant hurdle in its widespread adoption is the extremely low concentration of ctDNA in biological samples, especially during the early stages of cancer, making sensitive and specific detection challenging. This work addresses the critical problem of developing a highly sensitive and specific method for low abundance ctDNA detection. We developed a novel, highly sensitive, and specific method for ctDNA analysis, employing copper-free click chemistry (strain-promoted azide-alkyne cycloaddition, SPAAC) for enzyme-free amplification, coupled with magnetic bead-assisted fluorometric detection. This enzyme-free approach significantly enhanced specificity and reduced background noise. We meticulously optimized parameters, including primer length and annealing temperature, finding that 30-base primers and a 50 degrees C annealing temperature yielded optimal amplification efficiency. Our method successfully detected ctDNA at concentrations as low as 10 pM (15 bp primer). Agarose gel electrophoresis confirmed highly specific amplification with minimal non-specific products, and the assay demonstrated excellent allelic discrimination, accurately distinguishing single-nucleotide mutations. Importantly, the method proved robust in complex human serum samples, demonstrating its practical applicability. This innovative, cost-effective, and enzyme-free platform overcomes many limitations of current ctDNA detection technologies. By enabling highly sensitive and specific detection of low abundance ctDNA, this methodology represents a significant leap forward for non-invasive cancer diagnostics, paving the way for earlier disease detection, improved treatment monitoring, and the broader implementation of personalized medicine.
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    Single-stranded DNA (ssDNA) Aptamer targeting SipA protein inhibits Salmonella Enteritidis invasion of intestinal epithelial cells
    (Elsevier, 2020) Shatila, Fatima; Yalcin, H. Tansel; Ozyurt, Canan; Evran, Serap; Cakir, Busra; Yasa, Ihsan; Nalbantsoy, Ayse
    Salmonella Enteritidis is an important pathogen that can invade the intestinal cells of its host causing salmonellosis. SipA protein, an effector protein secreted by T3SS, maintains invasion of host cells more efficient. Thus, inhibitory aptamers against SipA protein were developed using magnetic bead-based Systematic Evolution of Ligands by Exponential Enrichment (SELEX) method. The enriched sequences were obtained after 9 SELEX rounds. Among which, an aptamer namely Apt17 displayed Kd values equivalent to 114.9 and 63.4 nM at 27 degrees C and 37 degrees C, respectively. The effect of Apt17 on adhesion and invasion of Caco-2 cells by the tested strains was determined. While the adhesion and invasion of Salmonella Enteritidis TM 6 were inhibited by 70% and 37.7%, those of Salmonella Enteritidis TM 68 were inhibited by 45.71% and 39.5% respectively. These results represent a corner stone for future studies that could aim to develop putative inhibitors against Salmonellosis. (C) 2020 Elsevier B.V. All rights reserved.
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    The single-step synthesis of thiol-functionalized phosphazene-based polymeric microspheres as drug carrier
    (Taylor & Francis Inc, 2020) Ozay, Hava; Ilgin, Pinar; Ozyurt, Canan; Özay, Özgür
    Herein, new microspheres were successfully fabricated from pentaerythritol tetrakis(3-mercaptopropionate) as model monomer and hexachlorocyclotriphosphazene as crosslinker using a single-step via precipitation polymerization method. Trimethoprim was chosen as the model antibiotic drug for drug release and antimicrobial activity studies. The percent of drug loading and drug entrapment efficiency of the microspheres was calculated to be 0.85% and 42.2%. According to correlation coefficients, the release kinetic was found to be Higuchi kinetic model and the release mechanism was non-Fickian model for microspheres. The drug-loaded microspheres exhibited excellent bacterial inhibition against gram-positive (Staphylococcus aureusandBacillus subtilis) and gram-negative (Escherichia coli) bacteria.