Browsing by Author "Tekin V."

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    Radiosynthesis and biodistribution of 99mTc-trimethoprim: A novel radiolabeled antibiotic for bacterial infection imaging using experimental animals; [ 99mTc-Trimethoprim’in radyosentezi ve biyodağılımı: Deney hayvanları kullanılarak bakteriyel enfeksiyon görüntüleme için yeni bir radyoişaretli antibiyotik]
    (Veteriner Fakultesi Dergisi, 2018) Demiroğlu H.; Topal G.; Parlak Y.; Gümüşer F.G.; Türköz E.U.; Tekin V.; Ateş B.; Ünak P.; Avcibaşi U.
    In the present article, we focused on the radiolabeling and evaluation of 99mTc–TMH complex as a potential candidate for infection imaging in vivo. For this; Trimethoprim (TMH) used to treat bacterial infections was investigated to label with99mTc. Labeling was performed using thin (II) chloride as a reducing agent at room temperature for 1 h and radiochemical analysis involved thin layer radiochromatography (TLRC) and high pressure liquid radiochromatograpy (HPLRC) methods. The stability of labeled antibiotic was checked in the presence of rat blood serum at 37.C up to 180 min. The maximum radiolabeling yield was found to be 96±2% and remained constant at more than 85±1% even in rat serum for 180 min after radiolabeling. Static image of 99mTc-TMH in male rats demonstrated that important radiation signals are present in the infected site at first glance in 30 min. After 30 min the uptake of the 99mTc-TMH as ID/g% in the infected muscle (INM) and normal muscle (NM) of the rats were 7.5±1.5% and 5.00±1.2%, respectively. In the INM/NM ratio a desirable behavior was observed as the values for the INM/ NM increased up to 10.6. 99mTc-TMH prepared with high yield is able to localize well in the bacterially infected muscle of the rats. As a result,99mTc-TMH may be developed as a radiopharmaceutical agent to distinguish infection from inflammation by nuclear imaging. © 2018, Veteriner Fakultesi Dergisi. All rights reserved.
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    The effect of radiolabeled antibiotics on biofilm and microorganism within biofilm
    (Springer Netherlands, 2018) Avcıbaşı U.; Demiroğlu H.; Sakarya S.; Ünak P.; Tekin V.; Ateş B.
    The aim of this study was to investigate the 131I and 127I labeled linezolid and moxifloxacin effects of minimum inhibitory concentration, and minimum bactericidal concentration on mature biofilm and microorganism within the biofilm. Linezolid and moxifloxacin were labeled with 131I and 127I and chromatography studies were carried out with thin layer radiochromatograpy and high-pressure liquid radiochromatography techniques. Specific activities of radiolabeled LZD and MXF was found to be 53.3 ± 3.1 and 127.3 ± 1.1 MBq/µmol for [131I]LZD and 7.6 ± 0.02 and 55.6 ± 0.8 MBq/µmol for [131I]MXF, respectively. The minimum inhibitory concentration and Time-Kill of Linezolid and moxifloxacin alone and their 131I and 127I labeled forms were tested with a standard strain of meticillin-susceptible Staphylocıccus aureus. MIC values of LNZ and MXF were 2.96 nmol/mL (1 µg/ml) and 0.141 nmol/mL (0.062 µg/ml). Time Kills of MXF and LZD were found to be 0.06 and 1 μg, respectively. Antibiotics labeled with beta-emitting radioactive molecule may be a new theranostics strategy for biofilm infections. © 2018, Akadémiai Kiadó, Budapest, Hungary.
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    A novel radiolabeled graft polymer: Investigation of the radiopharmaceutical potential using Albino Wistar rats
    (Elsevier Ltd, 2019) Avcıbaşı U.; Ateş B.; Ünak P.; Gümüşer F.G.; Gülcemal S.; Ol K.K.; Akgöl S.; Tekin V.
    Fe3O4 magnetic graft-Lys-poly(HEMA) was synthesized, labeled with 99mTc for the first time and its radiopharmaceutical potential was investigated using animal models in this study. Quality control procedures were carried out using thin layer radiochromatography. The labeling yield of radiolabeled polymer was found to be about 100%. Then, stability and lipophilicity were determined. The lipophilicity of 99mTc labeled Fe3O4 graft-Lys-poly(HEMA) was found to be 3.77. The serum stability experiments demonstrated that approximately 100% of radiolabeled polymer existed as an intact complex in the rat serum within 240 min. Biodistribution of radiolabeled magnetic graft-Lys-poly(HEMA) was performed on female Albino Wistar rats by scintigraphy and biodistribution studies. High uptake was seen in the stomach, the pancreas, brain, ovarian, intestines and the breast. © 2019 Elsevier Ltd
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    Preparation of a 99mTc-labeled graft polymer and its in vitro and in vivo evaluation
    (Springer Science and Business Media B.V., 2021) Avcıbaşı U.; Türkyarar T.; Karadağ A.; Bakan B.; Yavaşoğlu N.Ü.K.; Kuşat K.; Akgöl S.; Gülcemal D.; Tekin V.; Müftüler F.Z.B.; Topal G.; Parlak Y.; Gümüşer F.G.
    The aim of this study is the synthesis of a novel 99mTc-labeld graft polymer and the biological evaluation of its in vitro and in vivo properties. To this end, a L-proline-graft-poly(HEMA) was prepared and labeled with 99mTc. The radiochemical yield of approximately the 99mTc-labeled compound amounted to 97 ± 2.3%. The cytotoxicity test revealed no cytotoxic effect after a 24- and 48-h incubation. The results of the hemolysis test showed that hemolysis was non-toxic with an effect level of less than 2%. Subsequently, the biodistribution in healthy rats was determined. High accumulation of the polymer was observed in the pancreas, thyroid and prostate. © 2021, Akadémiai Kiadó, Budapest, Hungary.
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    Synthesis of Novel Plant-Derived Encapsulated Radiolabeled Compounds for the Diagnosis of Parkinson’s Disease and the Evaluation of Biological Effects with In Vitro/In Vivo Methods
    (Springer, 2024) Uygur E.; Karatay K.B.; Derviş E.; Evren V.; Kılçar A.Y.; Güldü Ö.K.; Sezgin C.; Çinleti B.A.; Tekin V.; Muftuler F.Z.B.
    Parkinson’s disease (PD) is a neurodegenerative disorder that affects millions of individuals globally. It is characterized by the loss of dopaminergic neurons in Substantia Nigra pars compacta (SNc) and striatum. Neuroimaging techniques such as single-photon emission computed tomography (SPECT), positron emission tomography (PET), and magnetic resonance imaging (MRI) help diagnosing PD. In this study, the focus was on developing technetium-99 m ([99mTc]Tc) radiolabeled drug delivery systems using plant-derived compounds for the diagnosis of PD. Madecassoside (MA), a plant-derived compound, was conjugated with Levodopa (L-DOPA) to form MA-L-DOPA, which was then encapsulated using Poly Lactic-co-Glycolic Acid (PLGA) to create MA-PLGA and MA-L-DOPA-PLGA nanocapsules. Extensive structural analysis was performed using various methods such as Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), liquid chromatography–mass spectrometry (LC–MS), thin layer chromatography (TLC), high performance liquid chromatography (HPLC), dynamic light scattering (DLS), and scanning electron microscopy (SEM) to characterize the synthesized products. Radiochemical yields of radiolabeled compounds were determined using thin layer radio chromatography (TLRC) and high performance liquid radio chromatography (HPLRC) methods. In vitro cell culture studies were conducted on human neuroblastoma (SH-SY5Y) and rat pheochromocytoma (PC-12) cell lines to assess the incorporation of [99mTc]Tc radiolabeled compounds ([99mTc]Tc-MA, [99mTc]Tc-MA-L-DOPA, [99mTc]Tc-MA-PLGA and [99mTc]Tc-MA-L-DOPA-PLGA) and the cytotoxicity of inactive compounds (MA and MA-L-DOPA compounds and encapsulated compounds (MA-PLGA and MA-L-DOPA-PLGA). Additionally, the biodistribution studies were carried out on healthy male Sprague–Dawley rats and a Parkinson’s disease experimental model to evaluate the compounds’ bioactivity using the radiolabeled compounds. The radiochemical yields of all radiolabeled compounds except [99mTc]Tc-L-DOPA-PLGA were above 95% and had stability over 6 h. The cytotoxic effects of all substances on SH-SY5Y and PC-12 cells increase with increasing concentration values. The uptake values of PLGA-encapsulated compounds are statistically significant in SH-SY5Y and PC-12 cells. The biodistribution studies showed that [99mTc]Tc-MA is predominantly retained in specific organs and brain regions, with notable uptake in the prostate, muscle, and midbrain. PLGA-encapsulation led to higher uptake in certain organs, suggesting its biodegradable nature may enhance tissue retention, and surface modifications might further optimize brain penetration. Overall, the results indicate that radiolabeled plant-derived encapsulated drug delivery systems with [99mTc]Tc hold potential as diagnostic agents for PD symptoms. This study contributes to the advancement of drug delivery agents in the field of brain research. © The Author(s) 2024.