Browsing by Author "Ünak P."
Now showing 1 - 13 of 13
Results Per Page
Sort Options
Item Comparison of the radiopharmaceutical potentials of dithizone radiolabeled with 131I and with 99mTc(2007) Ünak T.; Yildirim Y.; Avcibasi U.; Biber Z.; Duman Y.; Ünak P.In this study, dithizone (diphenylthiocarbazone) has been separately radiolabeled with 131I and with 99mTc for preliminarily testing their radiopharmaceutical potentials on male albino rabbits. 131I-dithizone and 99mTc-dithizone were intravenously injected to rabbits via their ear veins after anesthetizing with a mixture of Alfazyne and Alfamine (Serva) to determine their dynamic and static statuses in the metabolism. Also, 99mTc as pertechnetate and 131I as iodate were administered to rabbits as controls. Dynamic and static scintigrams were obtained using a gamma camera (Diacan Instruments). Dynamic scintigrams were obtained over the first half hour with frames of 1 minute following the administrations of the labeled compounds. Static images were obtained from posterior projection at different time intervals up to about 3 hours following the administration of the radiolabeled compounds. 99mTc-dithizone was significantly uptaken by the pancreas in contrast to free 99mTc. In the case of 131I-dithizone, the distribution of 131I activity in the metabolism was clearly different than the case of free 131I and the uptake of 131I-dithizone at the pancreas zone was also significant. These preliminary tests have clearly indicated that especially 99mTc-dithizone has a significant potential to be used as a pancreatic radiopharmaceutical. © 2007 Springer Science+Business Media, Inc.Item Metabolic comparison of radiolabeled aniline- and phenol-phthaleins with 131I(2008) Avcibaşi U.; Avcibaşi N.; Ünak T.; Ünak P.; Müftüler F.Z.; Yildirim Y.; Dinçalp H.; Gümüşer F.G.; Dursun E.R.The metabolic comparison of aniline- and phenol-phthaleins radiolabeled with 131I (131I-APH and 131I-PPH, respectively) has been investigated in this study. To compare the metabolic behavior of these phthaleins and their glucuronide conjugates radiolabeled with 131I, scintigraphic and biodistributional techniques were applied using male Albino rabbits. The results obtained have shown that these compounds were successfully radioiodinated with a radioiodination yield of about 100%. Maximum uptakes of 131I-APH and 131I-PPH, which were metabolized as N- and O-glucuronides, were observed within 2 h in the bladder and in the small intestine, respectively. In the case of verification of considerably up taking of these compounds also by tumors developed in the small intestine and in the bladder tissues, these results can be expected to be encouraging to test these compounds, which will be radiolabeled with other radioiodines such as 125I, 123I and 124I as imaging and therapeutic agents in nuclear medical applications. © 2008 Elsevier Inc. All rights reserved.Item In vivo biodistribution of 131I labeled bleomycin (BLM) and isomers (A2 and B2) on experimental animal models(2010) AvcIbaşI U.; Demiroǧlu H.; Ünak P.; Müftüler F.Z.B.; Içhedef Ç.A.; Gümüşer F.G.Bleomycins (BLMs; BLM, A2, and B2) were labeled with 131I and radiopharmaceutical potentials were investigated using animal models in this study. Quality control procedures were carried out using thin layer radiochromatography (TLRC), high performance liquid chromatography (HPLC), and liquid chromatography (LC/MS/MS). Labeling yields of radiolabeled BLMs were found to be 90, 68, and 71%, respectively. HPLC chromatograms were taken for BLM and cold iodinated BLM (127I-BLM). Five peaks were detected for BLM and three peaks for 127I-BLM in the HPLC studies. Two peaks belong to isomers of BLM. The isomers of BLM were purified with using HPLC. Biological activity of BLM was determined on male Albino Wistar rats by biodistribution and scintigraphic studies were performed for BLMs by using New Zelland rabbits. The biodistribution results of 131I-BLM showed high uptake in the stomach, the bladder, the prostate, the testicle, and the spinal cord in rats. Scintigraphic results on rabbits agrees with that of biodistributional studies on rats. The scintigraphy of radiolabeled isomers (131I-A2 and 131I-B2) are similiarly found with that of 131I-BLM. © 2010 Akadémiai Kiadó, Budapest, Hungary.Item Metabolic comparison of radiolabeled bleomycin and bleomycin-glucuronide labeled with 99mTc(2011) Koçan F.; Avcíbaşí U.; Ünak P.; Müftüler F.Z.B.; Içhedef Ç.A.; Demiroǧlu H.; Gümüşer F.G.The metabolic comparison of bleomycin (BLM) and bleomycin-glucuronide (BLMG) radiolabeled with 99mTc ( 99mTc-BLM and 99mTc-BLMG, respectively) has been investigated in this study. Quality control procedures were carried out using thin-layer radiochromatography and high-performance liquid chromatography. To compare the metabolic behavior of BLM and its glucuronide conjugate radiolabeled with 99mTc, scintigraphic, and biodistributional techniques were applied using male New Zealand rabbits and Albino Wistar rats. The results obtained have shown that these compounds were successfully radiolabeled with a labeling yield of about 100%. Maximum uptakes of 99mTc-BLM and 99mTc-BLMG metabolized as N-glucuronide were observed within 2 hours in the liver, the bladder, and the spinal cord for 99mTc-BLM and the lung, the liver, the kidney, the large intestine, and the spinal cord for 99mTc-BLMG, respectively. Scintigraphy and biodistributional studies performed on the experimental animals have shown that radiopharmaceutical potentials of these compounds are completely different. At the same time, uptake of the 99mTc-BLMG was found to be better than that of 99mTc-BLM. © 2011, Mary Ann Liebert, Inc.Item Radiolabeling of bleomycin-glucuronide with 131I and biodistribution studies using xenograft model of human colon tumor in Balb/C mice(2012) Demiroǧlu H.; Avcibaşi U.; Ünak P.; Müftüler F.Z.B.; Içhedef Ç.A.; Gümüşer F.G.; Sakarya S.Bleomycin-glucuronide (BLMG) is the glucuronide conjugate of BLM. In the present study, BLMG was primarily enzymatically synthesized by using a microsome preparate separated from rat liver, labeled with 131I by iodogen method with the aim of generating a radionuclide-labeled prodrug, and investigated its bioaffinities with tumor-bearing Balb/C mice. Quality control procedures were carried out using thin-layer radiochromatography and high-performance liquid chromatography. Tumor growing was carried out by following Caco-2 cell inoculation into mice. Radiolabeling yield was found to be about 65%. Results indicated that 131I-labeled BLMG ( 131I-BLMG) was highly stable for 24 hours in human serum. Biodistribution studies were carried out with male Albino Wistar rats and colorectal adenocarcinoma tumor-bearing female Balb/C mice. The biodistribution results in rats showed high uptake in the prostate, the large intestine, and the spinal cord. In addition to this, scintigraphic results agreed with those of biodistributional studies. Xenography studies with tumor-bearing mice demonstrated that tumor uptakes of 131I-BLM and 131I-BLMG were high in the first 30 minutes postinjection. Tumor-bearing animal studies demonstrated that 131I-BLMG was specially retained in colorectal adenocarcinoma with high tumor uptake. Therefore, 131I-BLMG can be proven to be a promising imaging and therapeutic agent, especially for colon cancer in nuclear medical applications. © Copyright 2012, Mary Ann Liebert, Inc. 2012.Item Synthesis, radiolabeling and in vivo biodistribution of diethylstilbestrol phosphate derivative (DES-P)(2012) Ünak P.; Biber Müftüler F.Z.; Içhedef Ç.; Medine E.I.; Özmen K.; Ünak T.; Kilçar A.Y.; Gümüşer F.G.; Parlak Y.; Bilgin E.S.Diethylstilbestrol (DES) is a well known, nonsteroidal estrogen with high affinity for the estrogen receptor (ER). Today DES is used to treat breast and prostate cancers. A phosphate derivative of DES [Diethylstilbestrol diphosphate (DES-P)] which is specific to tumor cells consisting alkaline phosphatase enzyme was synthesized and labeled with 99mTc using tin chloride as reducing agent. In vivo biological activity of 99mTc labeled diethylstilbestrol phosphate compound ( 99mTc-DES-P) was examined by biodistribution studies on Wistar Albino rats. Statistical evaluation was performed using SPSS 13 program. The percentage (%) radiolabeling yield of 99mTc-DES-P and quality control studies were done by Thin Layer Radio Chromatography (TLRC). Results showed that, 99mTc-DES-P may be proposed as an imaging agent for ER enriched tumors such as uterus and prostate and their metastases in bones. © 2012 Akadémiai Kiadó.Item Investigation of therapeutic efficiency of bleomycin and bleomycin-glucuronide labeled with 131I on the cancer cell lines(Mary Ann Liebert Inc., 2013) Ediz M.; Avcibaşi U.; Ünak P.; Müftüler F.Z.B.; Medine E.I.; Yurt Kilçar A.; Demiroǧlu H.; Gümüşer F.G.; Sakarya S.The aim of this study is to determine the incorporations of radiolabeled bleomycin (131I-BLM) and bleomycin-glucuronide (131I- BLMGLU) on PC-3 (human prostate carcinoma cell line), Caco-2 (human colon adenocarcinoma cell line), Hutu-80 (Human Duodenum adenocarcinoma cell line), and A549 (Human lung adenocarcinoma epithelial cell line) cancerous cell lines. For this purpose, BLM and BLMGLU enyzmatically synthesized were labeled with 131I, quality control studies were done and the incorporation yields of 131I-BLM and 131I-BLMGLU on these cell lines were measured. Quality-control studies showed that the radiolabeling yields were obtained as 95% and 90% for 131I-BLM and 131I-BLMGLU, respectively. Also, as a result of the cell culture studies, it was found that 131I-BLM and 131I-BLMGLU had higher incorporation on PC-3 cells than that of other cell lines. In addition to this, it was reported that the incorporation yield of 131I-BLMGLU was higher than that 131I-BLM. At the end of the study, cytotoxicities of BLM and BLMGLU on PC-3 cancerous cell line were inspected and fluorescent images of BLM and BLMGLU were taken on PC-3 cells by using fluorescein isothiocyanate. In conclusion, cell culture studies demonstrated that the incorporation values of 131I-BLMGLU on the four cell lines were about five to six times higher than 131I-BLM. Radiolabeled glucuronide derivatives can be used in cancer therapy and tumor imaging, depending on the properties of radioiodine for the β-glucuronidase-rich tissues because glucuronidation leads to rapid and higher incorporation on adenocarcinoma cells. © Mary Ann Liebert, Inc.Item Investigation of therapeutic efficiency of phenytoin (PHT) labeled with radioactive 131I in the cancer cell lines(Springer Netherlands, 2016) Uzaras C.; Avcıbaşı U.; Demiroğlu H.; Medine E.İ.; Kılçar A.Y.; Müftüler F.Z.B.; Ünak P.The aim of this study is to determine the incorporations of PHT radiolabeled with 131I (131I-PHT) on U-87 MG, Daoy and A549 cancerous cell lines. For this, cold and radio-labeling studies were carried out. The radio-labeling yield of 131I-PHT was obtained about 95 %. Subsequently, cell culture studies were carried out and radio-labeling yields of 131I, 131I-PHT on U-87 MG, Daoy and A549 cancerous cells were investigated. Cell culture studies demonstrated that the incorporation values of 131I-PHT on the three cell lines decreased with increasing radioactivity. Consequently, 131I-PHT may be a good radiopharmaceutical for targeting radionuclide therapy of Central Nervous System Tumors. © 2015, Akadémiai Kiadó, Budapest, Hungary.Item Radiosynthesis and biodistribution of 99mTc-Sulfamethoxazole: a novel molecule for in-vivo infection imaging(Birkhauser Boston, 2017) Uyaroğlu Ö.; Demiroğlu H.; Topal G.; Parlak Y.; Gül Gümüşer F.; Uluer Türköz E.; Demir V.; Ateş B.; Ünak P.; Avcıbaşı U.The aim of this study was to prepare 99mTc-Sulfamethoxazole complex and evaluate its efficiency as an infection imaging agent. The Sulfamethoxazole was labeled with 99mTc and its biological efficacy as a potential radio tracer for Staphylococcus aureus infection was investigated in bacterially infected Albino Wistar rats. The radiolabeling yield was found to be 95 ± 3.07% and remained constant at more than 93 ± 0.1% even in serum for 240 min after radiolabeling. 99mTc-Sulfamethoxazole prepared with high yield localized well in the bacterially infected muscle of the rats. 99mTc-Sulfamethoxazole may be developed as a radiopharmaceutical agent to distinguish infection from inflammation by nuclear imaging. © 2017, Springer Science+Business Media, LLC.Item 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.Item 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.Item 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 LtdItem Thymoquinone glucuronide conjugated magnetic nanoparticle for bimo-dal imaging and treatment of cancer as a novel theranostic platform(Bentham Science Publishers, 2021) İnce İ.; Müftüler Z.B.; Medine E.İ.; Güldü Ö.K.; Takan G.; Ergönül A.; Parlak Y.; Yıldırım Y.; Çakar B.; Bilgin E.S.; Aras Ö.; Göker E.; Ünak P.Background: Theranostic oncology combines therapy and diagnosis and is a new field of medicine that specifically targets the disease by using targeted molecules to destroy the cancer-ous cells without damaging the surrounding healthy tissues. Objective: We aimed to develop a tool that exploits enzymatic TQ release from glucuronide (G) for the imaging and treatment of lung cancer. We added magnetic nanoparticles (MNP) to enable magnetic hyperthermia and MRI, as well as 131I to enable SPECT imaging and radionuclide thera-py. Methods: A glucuronide derivative of thymoquinone (TQG) was enzymatically synthesized and conjugated with the synthesized MNP and then radioiodinated with 131I. New Zealand white rab-bits were used in SPECT and MRI studies, while tumor modeling studies were performed on 6–7-week-old nude mice utilized with bioluminescence imaging. Results: Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectra confirmed the expected structures of TQG. The dimensions of nanoparticles were below 10 nm and they had rather polyhedral shapes. Nanoparticles were radioiodinated with 131I with over 95% yield. In imaging studies, in xenograft models, tumor volume was significantly reduced in TQGMNP-treated mice but not in non-treated mice. Among mice treated intravenously with TQGMNP, xenograft tumor models disappeared after 10 and 15 days, respectively. Conclusion: Our findings suggest that TQGMNP in solid, semi-solid and liquid formulations can be developed using different radiolabeling nuclides for applications in multimodality imaging (SPECT and MRI). By altering the characteristics of radionuclides, TQGMNP may ultimately be used not only for diagnosis but also for the treatment of various cancers as an in vitro diagnostic kit for the diagnosis of beta glucuronidase-rich cancers. © 2021 Bentham Science Publishers.