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Öğe Bioavailability of Tc-99m-paclitaxel-glucuronide (Tc-99m-PAC-G)(Walter De Gruyter Gmbh, 2011) Muftuler, F. Z. Biber; Demir, I.; Unak, P.; Ichedef, C.; Kilcar, A. YurtAn antitumor agent paclitaxel (PAC) has been proved to be efficient in the treatment of breast and ovarian cancer. Glucuronic acid-derived paclitaxel compound (paclitaxel-glucuronide (PAC-G)) was enzymatically synthesized using microsome preparate separated from rat livers. The biodistribution mechanism of PAC-G in healthy female Albino Wistar rats has been investigated. The expected structure is confirmed according to LC/MS results, and the possible attachment is to C2-hydroxyl group. PAC-G was labeled with Tc-99m and the radiochemical yield of radiolabeled compound (Tc-99m-PAC-G) was 98.00 +/- 2.74% (n = 9). The range of the breast/blood and breast/muscle ratios is approximately between 3 and 35 in 240 min. All these experimental studies indicate that Tc-99m-PAC-G may potentially be used in breast tissue as an imaging agent.Öğe In vivo biological evaluation of I-131 radiolabeled-paclitaxel glucuronide (I-131-PAC-G)(Walter De Gruyter Gmbh, 2012) Aslan, O.; Muftuler, F. Z. Biber; Kilcar, A. Yurt; Ichedef, C.; Unak, P.Paclitaxel (PAC) is a natural occurring diterpene alkoloid originally isolated from the bark of Taxus Brevifolia. It is one of the most important antitumor agents for clinical treatment of ovarian, breast non-small cell lung and prostate cancers. It is known that these types of cancer cells have high beta-glucuronides enzyme which can catalyze the hydrolysis of glucuronides. This is why the synthesis compounds which undergo glucuronidation come into question in the imaging and therapy of these cancer cells. The aim of current study is conjugation of glucuronic acid (G) to the starting substance PAC, labeling with I-131 and to perform its in vivo biological evaluation. Glucuronic acid derived paclitaxel compound [paclitaxel-glucuronide (PAC-G)] was labeled with I-131 using iodogen method. According to thin layer radio chromatography (TLRC) method, the radio-chemical yield of I-131-PAC-G was 84.30 +/- 7.40% (n = 10). The biodistribution of I-131-PAC-G in healthy female and male Wistar Albino rats has been investigated. Imaging studies on male Balb-C mice were performed by using the Kodak FX PRO in vivo Imaging System. The range of the breast/blood, breast/muscle; ovary/blood, ovary/muscle ratios is approximately between 1.29 and 11.34 in 240 min, and between 0.71 and 8.24 in 240 min for female rats. The prostate/blood and prostate/muscle ratio is between 1.94 and 6.95 in 30 min for male rats. All these experimental studies indicate that I-131-PAC-G may potentially be used in breast, ovary and prostate tissues as an imaging agent. Also it is thought that (131)-PAC-G bears a theraphy potential because of the I-131 radionuclide and can be improved with further investigations.Öğe One-step conjugation of glycylglycine with [F-18]FDG and a pilot PET imaging study(Springer, 2018) Senisik, A. M.; Ichedef, C.; Kilcar, A. Y.; Ucar, E.; Ari, K.; Goksoy, D.; Parlak, Y.; Bilgin, Bedriye Elvan Sayit; Teksoz, S.This study describes a single step conjugation of Glycylglycine (GlyGly) which is a small peptide, with [F-18]FDG via oxime formation. Amiooxy-functionalization of GlyGly (AO-GlyGly) was accomplished through the reaction of Boc-aminooxy succinimide ester. Conjugation reaction was performed at 100 A degrees C for 30 min in a vial containing AO-GlyGly and [F-18]FDG solution. The radiolabeled product ([F-18]FDG-GlyGly) was obtained with 98.65 +/- 0.35% yield without any purification step which makes this method more attractive for F-18 radiolabeling. The present study is concluded with an in vivo pilot animal PET study to assess biodistribution and kinetics of chemoselectively [F-18]FDG tagged GlyGly in vivo.Öğe Radiochemical synthesis of Ag-105g-labelled silver nanoparticles(Springer, 2013) Ichedef, C.; Simonelli, F.; Holzwarth, U.; Piella Bagaria, J.; Puntes, V. F.; Cotogno, G.; Gilliland, D.; Gibson, N.A method for synthesis of radiolabelled silver nanoparticles is reported. The method is based on proton activation of silver metal powder, enriched in Ag-107, with a 30.7 MeV proton beam. At this proton energy Ag-105g is efficiently created, mainly via the 107 Ag(p,3n) Cd-105 -> Ag-105g reaction. Ag-105g has a half-life of 41.29 days and emits easily detectable gamma radiation on decay to Pd-105. This makes it very useful as a tracing radionuclide for experiments over several weeks or months. Following activation and a period to allow short-lived radionuclides to decay, the powder was dissolved in concentrated nitric acid in order to form silver nitrate (AgNO3), which was used to synthesise radiolabelled silver nanoparticles via the process of sodium borohydride reduction. For comparison, non-radioactive silver nanoparticles were synthesised using commercially supplied AgNO3 in order to check if the use of irradiated Ag powder as a starting material would alter in any way the final nanoparticle characteristics. Both nanoparticle types were characterised using dynamic light scattering, zeta-potential and X-ray diffraction measurements, while additionally the non-radioactive samples were analysed by transmission electron microscopy and UV-Vis spectrometry. A hydrodynamic diameter of about 16 nm was determined for both radiolabelled and non-radioactive nanoparticles, while the electron microscopy on the non-radioactive samples indicated that the physical size of the metal NPs was (7.3 +/- 1.4) nm.Öğe Synthesis And Radiolabeling Of Temozolomide Loaded Solid Lipid Nanoparticles(Springer, 2017) An, K.; Teksoz, S.; Ichedef, C.; Ucar, E.; Kilcar, A. YurtÖğe Synthesis of I-131/125 Labelled Diethylstilbestrol (DES) Glucuronide Conjugated Magnetic Nanoparticles and Investigation of Biological Affinities(Springer, 2011) Unak, P.; Yilmaz, T.; Muftuler, F. Z. Biber; Medine, E.; Ichedef, C.; Kilcar, A. Yurt; Unak, T.Öğe Synthesis, Radiolabeling and In Vivo Tissue Distribution of an Anti-Oestrogen Glucuronide Compound, Tc-99m-TOR-G(Int Inst Anticancer Research, 2010) Muftuler, F. Z. Biber; Unak, P.; Yolcular, S.; Kilcar, A. Yurt; Ichedef, C.; Enginar, H.; Sakarya, S.Toremifene (TOR) has been used as an anti-oestrogen drug for the treatment and prevention of human breast cancer. The aim of this study was the addition of the hydrophilic groups diethylenetriamine pentaacetic acid (DTPA) and glucuronic acid to the starting substance TOR and to label it with technetium-99m (Tc-99m) radionuclide and to investigate radiopharmaceutical potential of the new compound. The synthesis reactions are completed in four steps, including enzymatic reaction, with the following sub-steps; preparation of microsomal fraction from Hutu 80 cell line and subsequent purification of UDP-glucuronyl transferase (UDPGT), estimation of protein quantity in microsomal samples and glucuronidation reaction. The results indicate that Tc-99m-TOR-G may be proposed as a new anti-oestrogen glucuronide imaging agent for ovarian tumours.Öğe Thymidine kinase enzyme selective imaging radiopharmaceutical: Tc-99m(CO)(3)-Ganciclovir(Walter De Gruyter Gmbh, 2013) Gedik, B.; Teksoz, S.; Ichedef, C.; Kilcar, A. Y.; Medine, E. I.; Ucar, E.The aim of this study is to radiolabel ganciclovir, known as having selective antiviral properties against thymidine kinase, with technetium tricarbonylcore (Tc-99m(CO)(3)(+)) and to investigate the biological behavior of this complex in vitro and in vivo. Commercially provided Ganciclovir (GCV) was radiolabeled with Tc-99m(CO)(3)(+). Initially, optimum radiolabeling conditions were determined by analyzing factors such as temperature, pH and time. Quality control of the radiolabeled compound was performed. The radiolabeling yield was found to be 97%. The Tc-99m(CO)(3)-GCV complex also displayed good in vitro stability during the 24 h period. In vitro cell uptake studies showed that the Tc-99m(CO)(3)-GCV complex is highly uptaken in A-549, PC-3, HeLa cell lines according to the control group Tc-99m(I)-tricarbonyl core. The knowledge gained from in vivo and in vitro studies of Tc-99m(CO)(3)-GCV could contribute to the development of a new HSV1-tk gene imaging agent.
