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Öğe 89Zr-Labeled DFO@Durvalumab-HSA nanoparticles: In vitro potential for triple-negative breast cancer(Wiley, 2024) Yurt, Fatma; Ozel, Derya; Karagul, Seyma; Tuncel, Ayca; Durkan, Kubra; Medine, Emin IlkerThis study presents the development and evaluation of a DFO@mAb-NP (DFO@Durvalumab-HSA-DTX nanoparticle) nanoplatform for imaging in triple-negative breast cancer (TNBC). The nanoplatform demonstrated significant changes postconjugation with DFO, evidenced by increased particle size from 178.1 +/- 5 nm to 311 +/- 26 nm and zeta potential alteration from -31.9 +/- 3 mV to -40.5 +/- 0.8 mV. Fourier-transform infrared spectroscopy and ultraviolet spectral analyses confirmed successful DFO conjugation, with notable shifts in peak wavelengths. High labeling efficiency was achieved with Zr-89, as indicated by thin layer radio chromatography and high-performance liquid radio chromatography results, with labeling efficiencies of 98 +/- 2% for Zr-89-DFO@mAb and 96 +/- 3% for Zr-89-DFO@mAb-NP. The nanoplatforms maintained stability over 24 h, showing less than 5% degradation. Lipophilicity assays revealed logP values of 0.5 +/- 0.03 for Zr-89-DFO@mAb-NP and 0.98 +/- 0.2 for Zr-89-DFO@mAb, indicating a higher lipophilic tendency in the radiolabeled Durvalumab. Cell uptake experiments showed an initial high uptake in MDA-MB-468 cells (45.1 +/- 3.2%), which decreased over time, highlighting receptor-specific interactions. These comprehensive findings suggest the promising potential of the DFO@mAb-NP nanoplatform for targeted imaging in TNBC, with implications for improved diagnostic accuracy and treatment strategies.Öğe Biodistribution of radiolabeled alpha-amanitin in mice: An Investigation(Pergamon-Elsevier Science Ltd, 2024) Durkan, Kubra; Ichedef, Cigdem; Baris, Elif; Arici, M. AylinMushroom poisonings caused by Amanita phalloides are the leading cause of mushroom -related deaths worldwide. Alpha-Amanitin (alpha-AMA), a toxic substance present in these mushrooms, is responsible for the resulting hepatotoxicity and nephrotoxicity. The objective of our study was to determine the distribution of alpha-AMA in Balb/c mice by labeling with Iodine -131. Mice were injected with a toxic dose (1.4 mg/kg) of alpha-AMA labeled with Iodine -131. The mice were sacrificed at the 1st, 2nd, 4th, 8th, 24th, and 48th hours under anesthesia. The organs of the mice were removed, and their biodistribution was assessed in all experiments. The percent injected dose per gram (ID/g %) value for kidney, liver, lung, and heart tissues at 1st hour were 1.59 +/- 0.07, 1.25 +/- 0.33, 3.67 +/- 0.80 and 1.07 +/- 0.01 respectively. This study provides insights into the potential long-term effects of alpha-AMA accumulation in specific organs. Additionally, this study has generated essential data that can be used to demonstrate the impact of antidotes on the biological distribution of alpha-AMA in future toxicity models.Öğe Biodistribution of Tc-99m-creatinine in rats with ablation nephropathy(Springer, 2008) Lambrecht, Fatma Yurt; Soylu, Alper; Yilmaz, Osman; Durkan, Kubra; Kavukcu, SalihÖğe Design and synthesis of Tc-99m-citro-folate for use as a tumor-targeted radiopharmaceutical(Elsevier Science Bv, 2010) Altiparmak, Burcu; Lambrecht, Fatma Yurt; Bayrak, Elif; Durkan, KubraFolate conjugates exhibit high affinity for folate receptor (FR) positive cells and tissues, such as those in tumors, making them attractive candidates and of interest in diagnostic tumor imaging. The aim of study was to synthesize a novel radiopharmaceutical based folate conjugate, Tc-99m-citro-folate, and to evaluate its efficiency as a targeted agent for imaging tumors that over express FR. TLC, HPLC H-1 NMR and LC-MS/MS methods were used to check and confirm the synthesized citro-folate. Citro-folate was labeled with Tc-99m with high labeling efficiency (97 +/- 1.0%). Biodistribution of the radiolabeled conjugate Tc-99m-citro-folate was investigated in vivo using two groups of rats: FR saturated and unsaturated. These experiments showed high uptake of Tc-99m-citro-folate in FR rich tissues and demonstrated its sensitivity and specificity in imaging ovary and uterus. Based on the demonstrated good radiolabeling and biodistribution properties, the compound Tc-99m-citro-folate may potentially be used as a radiopharmaceutical agent for imaging the FR-positive tumors. (C) 2010 Elsevier B.V. All rights reserved.Öğe A heterodimeric [RGD-Glu-[Cu-64-NO2A]-6-Ahx-RM2] alpha(v)beta(3)/GRPr-targeting antagonist radiotracer for PET imaging of prostate tumors(Elsevier Science Inc, 2014) Durkan, Kubra; Jiang, Zongrun; Rold, Tammy L.; Sieckman, Gary L.; Hoffman, Timothy J.; Bandari, Rajendra Prasad; Szczodroski, Ashley F.; Liu, Liqin; Miao, Yubin; Reynolds, Tamila Stott; Smith, Charles J.Introduction: In the present study, we describe a Cu-64-radiolabeled heterodimeric peptide conjugate for dual alpha(v)beta(3)/GRPr (alpha(v)beta(3) integrin/gastrin releasing peptide receptor) targeting of the form [RGD-Glu-[Cu-64-NO2A]-6-Ahx-RM2] (RGD: the amino acid sequence [Arg-Gly-Asp], a nonregulatory peptide used for alpha(v)beta(3) integrin receptor targeting; Glu: glutamic acid; NO2A: 1,4,7-triazacyclononane-1,4-diacetic acid; 6-Ahx: 6-amino hexanoic acid; and RM2: (D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2), an antagonist analogue of bombesin (BBN) peptide used for GRPr targeting). Methods: RGD-Glu-6Ahx-RM21 was conjugated to a NOTA (1,4,7-triazacyclononane-1,4,7-triacetic acid) complexing agent to produce [RGD-Glu-[NO2A]-6-Ahx-RM2], which was purified by reversed-phase high-performance liquid chromatography (RP-HPLC) and characterized by electrospray ionization-mass spectrometry (ESI-MS). Radiolabeling of the conjugate with Cu-64 produced [RGD-Glu-[64Cu-NO2A]-6-Ahx-RM2 in high radiochemical yield (>= 95%). In vivo behavior of the radiolabeled peptide conjugate was investigated in normal CF-1 mice and in the PC-3 human prostate cancer experimental model. Results: A competitive displacement receptor binding assay in human prostate PC-3 cells using I-125-[Tyr(4)]BBN as the radioligand showed high binding affinity of [RGD-Glu-[Cu-nat-NO2A]-6-Ahx-RM21 conjugate for the GRPr (3.09 +/- 0.34 nM). A similar assay in human, glioblastoma U87-MG cells using I-125-Echistatin as the radioligand indicated a moderate receptor-binding affinity for the alpha(v)beta(3) integrin (518 +/- 37.5 nM). In vivo studies of [RGD-Glu-[Cu-64-NO2A]-6-Ahx-RM2] showed high accumulation (4.86 +/- 1.01 %ID/g, 1 h post-intravenous injection (p.i.)) and prolonged retention (4.26 +/- 1.23 %ID/g, 24 h p.i.) of tracer in PC-3 tumor-bearing mice. Micro-positron emission tomography (microPET) molecular imaging studies produced high-quality, high contrast images in PC-3 tumor-bearing mice at 4 h p.i. Conclusions: The favorable pharmacokinetics and enhanced tumor uptake of Cu-64-NOTA-RGD-Glu-6Ahx-RM2 warrant further investigations for dual integrin and GRPr-positive tumor imaging and possible radiotherapy. (C) 2014 Elsevier Inc. All rights reserved.Öğe In vitro evaluation of Tc-99m- EDDA/tricine-HYNIC-Q-Litorin in gastrin-releasing peptide receptor positive tumor cell lines(Taylor & Francis Ltd, 2013) Lambrecht, Fatma Yurt; Durkan, Kubra; Ozgur, Aykut; Gunduz, Cumhur; Avci, Cigir Biray; Susluer, Sunde YilmazBombesin and its derivatives exhibit a high affinity for gastrin-releasing peptide receptor (GRPr), which is over-expressed in a variety of human cancers (prostate, pancreatic, lung, etc.). The aim of this study was to investigate the in vitro potential of the hydrazinonicotinamide (HYNIC)-Q-Litorin. Tc-99m labeling was performed by using different co-ligands: tricine and ethylenediamine diacetic acid (EDDA). The radiochemical stability of radiolabeled peptide conjugates was checked at room temperature and in cysteine solution up to 24 h. The in vitro cell uptake of Tc-99m-EDDA-HYNIC-Q-Litorin and Tc-99m-tricine-HYNIC-Q-Litorin were evaluated on pancreatic tumor and control cell lines. Optimum specific activity and incubation time were determined for all the cell lines. The results showed that the cell uptake of the radiolabeled peptide conjugates in tumor cell lines were higher than in the control cell line. The findings of this study indicated the need for further development of in vivo study as a radiopharmaceutical for pancreatic tumor imaging.Öğe In vitro evaluation of Tc-99m-sultamicillin for infection imaging(Wiley, 2021) Durkan, Kubra; Tuncel, Ayca; Yurt, FatmaEarly detection of the site of infection non-invasively with radiolabeled molecules is important for the success of treatment. Technetium-99m labeled antibiotics have the potential to discriminate between bacterial infection and sterile inflammation. Sultamicillin is the tosylate salt of the double ester of sulbactam plus ampicillin. In this study, sultamicillin was labeled with Tc-99m according to the stannous chloride method. Quality control studies of radiolabeled sultamicillin were performed by radiochromatographic methods. In vitro binding assays were performed in live and heat-killed gram-positive Staphylococcus aureus and gram-negative Escherichia coli strains. The radiolabeling yield of Tc-99m-sultamicillin was determined as 97.8% +/- 3.1% (n = 5). The maximum bacterial uptake of Tc-99m-sultamicillin was 80.7% +/- 11.00% at 4 h for living S. aureus and 93.2% +/- 4.40% at 2 h for E. coli. Bacterial uptake study results show that sultamicillin has the potential to be a nuclear imaging agent, especially in infections caused by gram-negative E. coli and gram-positive S. aureus.Öğe Preparation of I-131-Pyrimethamine and evaluation for scintigraphy of experimentally Toxoplasma gondii-infected rats(Informa Healthcare, 2013) Inceboz, Tonay; Lambrecht, Fatma Yurt; Surucu, Erdem; Yilmaz, Osman; Yavasoglu, Altug; Durkan, Kubra; Baykara, Basak; Bekis, Recep; Uner, AhmetWe aimed to assess the ability of I-131-Pyrimethamine scintigraphy to detect the lesions of Toxoplasma gondii infection. An experimental model of toxoplasmosis was developed. The presence of toxoplasmosis was confirmed 60 days after implantation. Pyrimethamine was radioiodinated with I-131. The radioligand was validated by the requisite quality control tests to check its radiolabeling efficiency, in vitro stability and radiochemical purity etc. I-131-Pyrimethamine (specific activity: 7.08 MBq/mu mol) was injected intravenously into the tail vein of the control and infected rats. Static whole body images of the rats were acquired under the gamma camera at 5 min, 45 min, 2 h, 6 h, and 24 h following the intravenous administration of the radioactivity (3.7 MBq/rat). Then the scintigraphic data were analyzed both visually and semiquantitatively. Regions of interest (ROIs) were drawn over the organs (thyroid, stomach, liver, bladder, and soft tissues) to calculate the ratios of the radiotracer in infected vs. control rats. The mean ratio of radiotracer in infected/control rats in the liver and diaphragm was over 1 at 45 min which persisted till 24 h. In conclusion, I-131-Pyrimethamine may be useful agent for diagnosis toxoplasmosis especially involving liver and diaphragm, needs further preclinical validation before being extended for use in clinical applications.Öğe Preparation of I-131-Pyrimethamine and evaluation for scintigraphy of experimentally Toxoplasma gondii-infected rats(Informa Healthcare, 2013) Inceboz, Tonay; Lambrecht, Fatma Yurt; Surucu, Erdem; Yilmaz, Osman; Yavasoglu, Altug; Durkan, Kubra; Baykara, Basak; Bekis, Recep; Uner, AhmetWe aimed to assess the ability of I-131-Pyrimethamine scintigraphy to detect the lesions of Toxoplasma gondii infection. An experimental model of toxoplasmosis was developed. The presence of toxoplasmosis was confirmed 60 days after implantation. Pyrimethamine was radioiodinated with I-131. The radioligand was validated by the requisite quality control tests to check its radiolabeling efficiency, in vitro stability and radiochemical purity etc. I-131-Pyrimethamine (specific activity: 7.08 MBq/mu mol) was injected intravenously into the tail vein of the control and infected rats. Static whole body images of the rats were acquired under the gamma camera at 5 min, 45 min, 2 h, 6 h, and 24 h following the intravenous administration of the radioactivity (3.7 MBq/rat). Then the scintigraphic data were analyzed both visually and semiquantitatively. Regions of interest (ROIs) were drawn over the organs (thyroid, stomach, liver, bladder, and soft tissues) to calculate the ratios of the radiotracer in infected vs. control rats. The mean ratio of radiotracer in infected/control rats in the liver and diaphragm was over 1 at 45 min which persisted till 24 h. In conclusion, I-131-Pyrimethamine may be useful agent for diagnosis toxoplasmosis especially involving liver and diaphragm, needs further preclinical validation before being extended for use in clinical applications.Öğe Preparation of technetium-99m labeled ibuprofen by direct route and technetium-99m tricarbonyl route: a comparison ofin vivobehaviors(Taylor & Francis Ltd, 2020) Durkan, Kubra; Ichedef, Cigdem; Yurt Kilcar, Ayfer; Arici, Mesut; Ucar, EserIn the current study, ibuprofen (ibu) which is a non-steroidal anti-inflammatory drug (NSAID) was radiolabeled with(99m)Tc using two different methods: stannous chloride method (direct route) and technetium-99m tricarbonyl [Tc-99m(CO)(3)](+)route. Thus, it's aimed to investigate the radiolabeling potential of ibu for inflammation detection and to monitor if there is any difference inin vivodistribution depending on the radiolabeling route. Quality control studies of both radiolabeled ibu were performed by radiochromatographic methods (Thin Layer Liquid Radio Chromatography and High Performance Liquid Radio Chromatography). Radiolabeling yields of(99m)Tc-ibu and(99m)Tc(CO)(3)-ibu were determined as 99.05 +/- 0.83% and 91.79 +/- 3.30% (n = 5), respectively. Experimental lipophilicities of both radiolabeled ibu were determined. the biological behavior of both radiolabeled ibu was investigated in healthy Albino Wistar male rats byin vivobiodistribution studies. It was seen that both radiolabeled ibuprofen showed renal excretion while organ uptakes of(99m)Tc-ibu and(99m)Tc(CO)(3)-ibu differ against time.Öğe Radiochemical and radiobiological evaluation of a new Tc-99m-labelled litorin derivative(Elsevier Science Inc, 2010) Durkan, Kubra; Gourni, Eleni; Bouziotis, Penelope; Xanthopoulos, Stavros; Zikos, Christos; Karachaliou, Chrissoula; Paravatou, Maria; Livaniou, Evangelia; Varvarigou, Alexandra D.Öğe Radiolabeling of bombesin-like peptide with Tc-99m : Tc-99m-Litorin and biodistribution in rats(Amer Chemical Soc, 2007) Durkan, Kubra; Lambrecht, Fatma Yurt; Unak, PerihanBombesin-like peptides are related to several human cancer receptors, including small cell lung, prostate, breast, colon, and pancreatic cancers. Litorin, an amphibian bombesin peptide derivative, is found to stimulate the contraction of smooth muscle, to stimulate gastrin, gastric acid, and pancreatic secretion, and to suppress the nutriment in in vivo experiments. In the present study, litorin was labeled with 99mTc by the stannous chloride procedure. Labeling yield is 95 +/- 1.4%, as determined by radio thin layer chromatography (RTLC) and radio high performance chromatography (RHPLC). Results of in vitro studies demonstrated a high stability in serum and cysteine solutions. In vivo biodistribution was investigated with normal male Albino Wistar rats. Biodistribution data showed fast clearance, low intestinal accumulation, and significant uptake in bombesin/gastrin releasing peptide (BN/GRP) receptor rich tissues such as the pancreas (23.56 +/- 0.01 %ID/g 30 min pi). It can be blocked partially by previous administration of 'cold' litorin. The results showed specificity of the uptake. As Tc-99m-litorin displays good radiolabeling and biodistribution, it is a potentially useful radiopharmaceutical for detection of bombesin receptor-expressing cancers.Öğe Radiolabeling of Zonisamide for a Diagnostic Perspective(Bentham Science Publ Ltd, 2024) Dervis, Emine; Karatay, Kadriye Busra; Durkan, Kubra; Kilcar, Ayfer YurtObjective: Epilepsy is one of the oldest and the most common chronic neurological diseases. Antiepileptic drugs (AEDs) are the backbone of epilepsy treatment. However, epileptogenesis has not been fully elucidated. One of the critical reasons for this is the lack of reliable biomarkers. Neuroimaging suggests a non-invasive examination and investigation tool that can detect critical pathophysiological changes involved in epileptogenesis and monitor disease progression. In the current study, the radiolabeling potential of Zonisamide (ZNS) (the secondgeneration AED) with Technetium-(99m) (Tc-99m) is examined to neuroimage the epileptogenic processes by contributing to the development of potential radiotracers. Methods: ZNS was labeled with Tc-99m and the radiochemical yield of [Tc-99m]Tc-ZNS was determined with TLRC (Thin Layer Liquid Radio Chromatography and HPLRC (High Performance Liquid Radio Chromatography) radiochromatographic methods. In vitro behavior of [Tc-99m]Tc-ZNS was determined with time-dependent uptake of [Tc-99m]Tc-ZNS on the SHSY5Y human neuroblastoma cells. Results: The radiochemical yield of [Tc-99m]Tc-ZNS was determined as 98.03 +/- 1.24% (n = 6) according to radiochromatographic studies results. [Tc-99m]Tc-ZNS demonstrated 5.38 and 6.18 times higher uptake values than the control group on the human neuroblastoma SH-SY5Y cell line at 120 and 240 minutes, respectively. Conclusion: This study showed that the current radiolabeled antiepileptic drug has a diagnostic potential to be used in imaging neurological processes.
