Yazar "Cianga, Ioan" seçeneğine göre listele

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    Fluorescent micellar nanoparticles by self-assembly of amphiphilic, nonionic and water self-dispersible polythiophenes with "hairy rod" architecture
    (Royal Soc Chemistry, 2014) Cianga, Luminita; Bendrea, Anca-Dana; Fifere, Nicusor; Nita, Loredana Elena; Doroftei, Florica; Ag, Didem; Seleci, Muharrem; Timur, Suna; Cianga, Ioan
    Polymers with "hairy-rod" architecture having oligo/polythiophene (PTh) as main chain and poly (ethylene glycol) (PEG) (M-n = 2000) as flexible side chains were obtained by combining the "macromonomer technique" with specific methods for the synthesis of conjugated polymers. Fluorescent nanoparticles of core-shell type with high colloidal stability were obtained from these water self-dispersible materials by a direct dissolution method in aqueous media. It has been shown that the size and photophysical properties of the micellar nanoparticles in aqueous dispersions as well as the bulk properties of the investigated materials can be tuned by varying the PEG side chain density and by the modality of PEG connection to the PTh main chains. The presence of the PEG shells in the structure of these fluorescent nanoparticles cans suppress the non-specific interactions with biomolecules on the one side and on the other side they work as a biomimetic interface that could facilitate their potential use as cell-imaging agents. The present attempt offers an ease of access alternative to conducting polymer nanoparticle encapsulation in a biocompatible matrix by nanoprecipitation.
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    From Invisible Structures of SWCNTs toward Fluorescent and Targeting Architectures for Cell Imaging
    (Amer Chemical Soc, 2013) Ag, Didem; Seleci, Muharrem; Bongartz, Rebecca; Can, Mustafa; Yurteri, Seda; Cianga, Ioan; Stahl, Frank; Timur, Suna; Scheper, Thomas; Yagci, Yusuf
    Single-walled carbon nanotubes (SWNTs) are unique nanostructures used as cargo systems for variety of diagnostic and therapeutic agents. For taking advantage of these structures in biological processes, they should be visible. Therefore, fluorescence labeling of SWCNTs with various probes is a significant issue. Herein, we demonstrate a simple approach for cell specific imaging and diagnosis by combining SWCNTs with a copolymer poly(para-epsilon-caprolactone) (PCL) side chains (PPP-g-PSt-PCL). In this approach PPP-g-PSt-PCL is noncovalently attached on carboxyl functional SWCNTs. The obtained fluorescent probe is bound to folic acid (FA) for targeted imaging of folate receptor (FR) positive HeLa cells. In vitro studies demonstrate that this conjugate can specifically bind to HeLa cells and indicate great potential for targeting and imaging studies.
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    An immunoelectrochemical platform for the biosensing of 'Cocaine use'
    (Elsevier Science Sa, 2017) Sengel, Tulay Yilmaz; Guler, Emine; Gumus, Z. Pinar; Aldemir, Ebru; Coskunol, Hakan; Akbulut, Huseyin; Colak, Demet Goen; Cianga, Ioan; Yamada, Shuhei; Timur, Suna; Endo, Takeshi; Yagci, Yusuf
    In the present work, we demonstrate a novel surface design by combination of benzoylecgonine (BE) antibody and poly-L-phenylalanine bearing electroactive macromonomer (EDOT-BTDA-PPhe). This system served as an electro-immunosensor platform for the analysis of cocaine use by detecting both BE and cocaine. To construct the immunosensor, a glassy carbon electrode was covered with EDOT-BTDA-PPhe. Subsequently, BE antibody was immobilized on the polypeptide chains. The surface modifications were confirmed by electrochemical techniques. The immunosensor was used for the electrochemical detection of BE and cocaine as evidence of drug addiction. For both analytes, linearity was obtained between 0.5-25 mu M. Finally, the proposed system was successfully employed for the analysis of synthetic biological fluids. (C) 2017 Elsevier B.V. All rights reserved.
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    Polypeptide with electroactive endgroups as sensing platform for the abused drug 'methamphetamine' by bioelectrochemical method
    (Elsevier Science Bv, 2016) Demir, Bilal; Yilmaz, Tulay; Guler, Emine; Gumus, Z. Pinar; Akbulut, Huseyin; Aldemir, Ebru; Coskunol, Hakan; Colak, Demet Goen; Cianga, Ioan; Yamada, Shuhei; Timur, Suna; Endo, Takeshi; Yagci, Yusuf
    Affinity-type sensors have emerged as outstanding platforms in the detection of diagnostic protein markers, nucleic acids and drugs. Thus, these novel platforms containing antibodies could be integrated into the monitoring systems for abused drugs. Herein, we established a novel detection platform for the analysis of a common illicit drug; methamphetamine (METH). Initially, a fluorescent-labeled polypeptide (EDOT-BTDA-Pala), derived from L-alanine N-carboxyanhydride (L-Ala-NCA) via ring-opening polymerization using 4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)benzo[c][1,2,5]thiadiazole-5,6-diamine (EDOT-NH2-BTDA) as initiator, was employed as a glassy carbon electrode (GCE) covering host, in order to immobilize the METH selective antibody. Prior to the examination of analytical features, GCE/EDOT-BTDA-Pala/Antibody surface was successfully characterized in the way of electrochemical (cyclic voltammetry and electrochemical impedance spectroscopy) and microscopic techniques (scanning electron microscopy and fluorescence microscopy). As for the analytical characterization, linearity and limit of detection (LOD) were found as 10-100 mu g/mL with an equation of y=0.0429x-0.2347, (R-2=0.996) and 13.07 mu g/mL, respectively. Moreover, sample application using artificial urine, saliva and serum samples spiked with METH (10, 25, 50 mu g/mL) were performed and LC-MS/MS system was used for further confirmation. The described platform can be adapted to monitor the other types of abused drugs by using suitably selected biorecognition elements.
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    Synthesis and application of a novel poly-L-phenylalanine electroactive macromonomer as matrix for the biosensing of 'Abused Drug' model
    (Royal Soc Chemistry, 2016) Yilmaz, Tulay; Guler, Emine; Gumus, Z. Pinar; Akbulut, Huseyin; Aldemir, Ebru; Coskunol, Hakan; Colak, Demet Goen; Cianga, Ioan; Yamada, Shuhei; Timur, Suna; Endo, Takeshi; Yagci, Yusuf
    Polypeptide-functionalized macromonomers are very fascinating candidates for the modification of various surfaces of different sizes as well as geometry, and have attracted considerable attention for biomolecule stabilization, biomedical device fabrication and bioanalytical applications. In the present work, synthesis and characterization of a novel poly-L-phenylalanine-bearing electroactive macromonomer (EDOT-BTDA-PPhe) were carried out. In the following steps, a glassy carbon electrode was covered with this material, and then cocaine aptamer was immobilized to obtain a biofunctional surface for the biosensing of ` Abused Drug' model. Aptamers attached to polypeptide side chains on the macromonomer with good orientation are induced for conformational change into three-way junction form as a result of selective binding of cocaine or its metabolite. This aptamer folding-based conformational response provides detectable signals due to formation of a compact interface which restricts electron transfer of redox probe. The stepwise modification of the surface was confirmed by electrochemical techniques. At the final step, the aptasensor was applied for the electrochemical detection of cocaine and its major metabolite, benzoylecgonine (BE), which exhibited a linear correlation between 1.0 and 10 nM and between 0.5 and 10 mu M respectively. The proposed methods were successfully employed for the analysis of synthetic biological fluids.
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    The synthesis and targeting of PPP-type copolymers to breast cancer cells: Multifunctional platforms for imaging and diagnosis
    (Royal Soc Chemistry, 2012) Colak, Demet Goen; Cianga, Ioan; Demirkol, Dilek Odaci; Kozgus, Ozge; Medine, E. Ilker; Sakarya, Serhan; Unak, Perihan; Timur, Suna; Yagci, Yusuf
    Herein, we demonstrate the synthesis and application of water-soluble, biomolecule conjugated PPP copolymers bearing poly(ethylene glycol) (PEG) side chains as fluorescent probes for the in vitro imaging of cancer cells. The targeting of fluorescent polymers to breast cancer cells allows effective visualization and discrimination of MCF7 cells from human mammary epithelial cells. Furthermore, these materials are also suitable for efficient radiolabeling via I-125 which enables dual-modality holding the possibility of both radioactive and fluorescence imaging in cancer diagnosis applications.