Synthesis and investigation of anticancer potential of radiolabeled naphthalene monoimide bearing imidazolium salt.

Imidazolium salts and derivatives have antitumor efficacy and toxic effects in different micro-organisms. In this study, an imidazolium bromide salt (NMI) was synthesized, and its antitumor potential was investigated by in vitro studies. Radiolabeling of synthesized NMI was carried out by iodogen method using 131 I radionuclide. The yield of radiolabeling was determined as 98.5 ± 0.1%. After that, cytotoxicity and intracellular uptake studies were evaluated in various cell lines. The cytotoxicity of NMI was determined as 35, 20, 10, and 1 µm for HEK-293, PC-3, CaCo-2, and MCF-7 cells, respectively. In addition, the intracellular uptake of 131 I-NMI was investigated in the cell lines, and the uptake was significantly found as 4 hr for MCF-7 and 6 hr for PC-3. In future studies, antitumor efficacy of 131 I-NMI on tumor-bearing animal model might be studied in light of these results.

Nuclear imaging potential and in vitro photodynamic activity of symmetrical and asymmetrical zinc phthalocyanines.

Photodynamic therapy (PDT) is based on exposing a light-sensitive material that has been localized in target tissues with visible light. In the current study, symmetric Zn(II) octaoctadodecylphthalocyanine (1) and the asymmetrically substituted hydroxyhexyloxy derivative (2) were examined as a multifunctional agent for tumour nuclear imaging and for PDT potential. Zn(II)Pc 1 and Zn(II)Pc 2 were radiolabelled with (131) I using an iodogen method with high efficiency (93.5 ± 3.5% and 93.0 ± 2.8%, respectively) under the optimum conditions. Biodistribution study results showed that radiolabelled Zn(II)Pc 1 had a high uptake in the large intestine and unchanging uptake in the ovary. However, radiolabelled Zn(II)Pc 2 uptake was statically significant in the large intestine, pancreas, ovary and lung. For the PDT studies, EMT6/P (mouse mammary cell line) and HeLa (cervical adenocarcinoma cell line) with Zn(II)Pc 1 and Zn(II)Pc 2 were exposed to red light (650 nm) at 10-30 J/cm(2) . Zn(II)Pc 1 and Zn(II)Pc 2 had a good PDT efficacy in the EMT6/P cell line. In conclusion, radiolabelled Zn(II)Pc 1 might be a promising imaging agent for pancreas, ovary and colon tumours. However, the radiolabelled Zn(II)Pc 2 might be a promising nuclear imaging and PDT agent for colon, lung, pancreas and ovary tumours.

Evaluation of cancer imaging potential and photodynamic therapy efficacy of copper (II) benzyloxypheophorbide-a.

The biological potential of a synthetic copper chlorophyll derivative was investigated via in vivo and in vitro experiments. The Cu-chlorophyll derivative photosensitizer (Cu-PH-A) was labeled with (131)I with high efficiency (92.9 ± 4.2%) using the iodogen method. Cell culture studies were performed with the MCF-7 and MDAH-2774 cell lines after radiolabeling. The photosensitizing activity of Cu-PH-A was more effective in MDAH-2774 cells than in MCF-7 cells at a concentration of 50 µM. When the biodistribution in female Albino Wistar rats was examined, uptake of the radiolabeled photosensitizer was maximal in the liver and ovaries after 60 min. It is concluded that radiolabeled Cu-chlorophyll derivative photosensitizer has high uptake in ovaries in normal rats. In addition, the intercellular uptake and PDT efficacy of the Cu-PH-A in MDAH-2774 were good compared with MCF-7 cells. This photosensitizer could be useful for both ovary tumour imaging and PDT.

In vitro evaluation of (99m)Tc-EDDA/tricine-HYNIC-Q-Litorin in gastrin-releasing peptide receptor positive tumor cell lines.

Bombesin 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. (99m)Tc 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 (99m)Tc-EDDA-HYNIC-Q-Litorin and (99m)Tc-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.

Preparation of (131)I-Pyrimethamine and evaluation for scintigraphy of experimentally Toxoplasma gondii-infected rats.

We aimed to assess the ability of (131)I-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. (131)I-Pyrimethamine (specific activity: 7.08 MBq/µmol) 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, (131)I-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.

Radiolabeling of folate targeted multifunctional conjugate with Technetium-99m and biodistribution studies in rats.

Despite the progress in the diagnosis and management of early stage disease, the management of advanced prostate cancer remains an important problem. Prostate tissue expresses folate receptor (FR) which binds both folic acid and folate-linked drugs or imaging agents. Doxorubicin is the best known and most widely used member of the anthracycline antibiotic group of anticancer agents. The aim of this work is to develop a multifunctional nanoconjugate, (99m)Tc-folate-PEG-doxorubicin, in order to investigate its radiopharmaceutical potential as a prostate cancer imaging and real-time drug location imaging agent. Through this aim, biodistribution studies of (99m)Tc-folate-PEG-doxorubicin and control groups ((99m)Tc-doxorubicin and (99m)Tc-PEG-doxorubicin) in male rats were carried out. Obtained data showed that uptake of (99m)Tc-folate-PEG-doxorubicin in prostate was significantly higher than that of the control groups due to the affinity of folate ligand to folate receptor. As a consequence, it was indicated that (99m)Tc-FOL-PEG-DOX radiolabeled conjugate which has a great target/non-target organ ratio, is specific for target organ and has a high radiopharmaceutical potential as a prostate cancer and real-time drug location imaging agent.

Radiolabeling of morphine with (131)i and its biodistribution in rats.

This study was conducted to determine the possible radiopharmaceutical potential of morphin labeled with (131)I. Morphine was extracted from dry capsules of the opium poppy (Papaver somniferum L.), purified by high-performance liquid chromatography, and characterized with nuclear magnetic resonance and infrared spectroscopy. The purified compound was labeled with (131)I. Male Albino Wistar rats (18) were used for receptor blockage and unblockage biodistribution studies. Tissue distribution studies showed that radiolabeled morphine had higher uptake in lung, liver, small intestines, large intestines, and stomach than the other tissues. The highest uptake of radiolabeled compounds in rats' brain was found to be in the midbrain and hypothalamus. After receptor blockage with morphine, uptake of (131)I-morphine decreased in the lungs, liver, kidney, testis, prostate, spinal cord, cerebellum, hippocampus, striatum, and temporal cortex with respect to receptor unblockage studies of rats. This study concludes that the labeling yield of (131)I-morphine was high, high amount of (131)I-morphine was found in the hypothalamus, and (131)I-morphine has enough stability for diagnostic scanning.

Biological investigation of 131I-labeled new water soluble Ru(II) polypyridyl complex.

New [Ru(L1)(dcbpy)(NCS)2] complex was synthesized in a one-pot reaction starting from [RuCl2(p-cymene)]2, where the ligands (dcbpy=4,4'-dicarboxy-2,2'-bipyridine, L1=dipyrido[3,2-a:2',3'-c]phenazine-11-ylcarbonyl)-sodium) are introduced sequentially. The resulting complex was characterized by IR, NMR, and elemental analysis. The complex was labeled with I-131. Biodistribution study of the complex was carried out using 131I-labeled [Ru(L1)(dcbpy)(NCS)2] complex. The biodistribution study performed with albino Wistar male rats has shown that the complex has high uptake in the lung, small intestine, fat, and spleen.