Authors:H. Enginar, P. Unak, F. Biber Müftüler, F. Lambrecht, E. Medine, S. Yolcular, A. Yurt Kilcar, B. Seyitoğlu, and I. Bulduk
The aim of this study was to synthesize a glucuronide conjugated morphine derivative which could be labeled with 131I, as a radiopharmaceutical, and to investigate its radiopharmaceutical potential using biodistribution studies in male Albino
Wistar rats. Morphine was extracted from dry capsules of the opium poppy (Papaver somniferum L.). It was conjugated with UDP-glucuronic acid by using UDP-glucuronyl transferase (UDPGT) enzyme rich microsomes, purified
by high performance liquid chromatography (HPLC) and characterized by nuclear magnetic resonance (NMR), infrared (IR) spectroscopy
and liquid chromatography mass spectroscopy (LC-MS/MS). Normal and receptor blockage biodistribution studies were performed
in male Albino Wistar rats. The results of the tissue distribution studies showed that 131I labeled morphine glucuronide (131I-mor-glu) uptake in the small intestine, large intestine and urinary bladder was higher than in the other tissues of the
rats in the blocked receptor and unblocked receptor. A greater uptake of the radio labeled substance was observed in the hypothalamus
and mid brain than in the other branches of the rats’ brains.
Authors:H. Enginar, P. Unak, F. Müftüler, F. Lambrecht, A. Kilcar, S. Yolcular, B. Seyitoğlu, E. Medine, and I. Bulduk
In current study, ethyl-morphine (em) was synthesized from the morphine and glucuronidated via enzymatic mechanism. The conjugated
glucuronide ethyl-morphine (em-glu) was radiolabeled with 131I using iodogen method. The quality control studies of radiolabeled compound (131I-em-glu) were done with Thin Layer Radio Chromatography to confirm the radiolabeling efficiency. Biodistribution studies
of 131I labeled em-glu were run on healthy male Albino Wistar rats. The distribution figures demonstrated that 131I-em-glu was eliminated through the small intestine, large intestine and accumulated in urinary bladder both receptor blocked
and unblocked biodistribution studies. A greater uptake of the radiolabeled substance was observed in the m.pons, hypothalamus
and mid brain than in the other branches of the rats’ brains.
Authors:Yu-Ping Xu, Min Yang, Dong-Hui Pan, and Li-Zhen Wang
The aim of this study was to examine the radioiodinating condition of betulinic acid and understand the possibility of 131I–betulinic acid (131I–BA) as a potential tumor radiotherapy agent through in vitro uptake and in vivo biodistribution studies 131I–BA was prepared by the reaction of betulinic acid with Na131I in the presence of hydrogen peroxide, and then purified by HPLC. The labeling yield was about 80%, and the radiochemical
purity was greater than 95%. 131I–BA was found to be stable at 4 °C in saline containing 1% ethanol. In vitro studies showed that 131I–betulinic acid accumulated in the cancer cell lines (BEL-7402 and NCI-H446) in comparison with free 131I−. In vivo biodistribution study in KM mice bearing HepA tumor showed that 131I–BA stayed longer time in tumors than free 131I−. A significant differences were seen in tumor/muscle ratio at 4 h postinjection between 131I–BA and free 131I−. In vivo and in vitro studies showed the higher fraction of 131I–BA can be utilized for therapy and a higher dose will be delivered per targeting event. 131I–BA is a promising radiopharmaceutical in nuclear medicine, especially for hepatocellular tumor targeted radionuclide brachytherapy.
Authors:Veronika Kleinova, Hana Chaloupkova, Helena Svecova, and Miroslav Fiser
The ability of the monoclonal antibody TU-20 and its scFv fragment to bind specifically to the C-end of the class III β-tubulin
makes these substances useful as potential diagnostics for neurodegenerative diseases—especially peripheral neuropathies.
TU-20 and its scFv were labeled with 125I and 123I by chloramine-T (with radiochemical yield 75 and 50%, respectively). Radiochemical purity and stability was revealed by
gel filtration (decrease to 80 and 50% in 2 months, respectively). Immunoreactivity of the labeled TU-20 was determined by
ELISA—the range of the preserved immunoreactivity varies from 60 to 95% in accordance to the used radiolabeling process. RIA
and affinity coupling analytic methods were specifically designed with focusing on specifics of the antibody and its fragment.
The results of RIA differ in depandance on the type of the reaction vessel (glass or polystyrene) and the affinity coupling
results depend on the experimental arrangement—in the batch or on the column. Fragmentation of the labeled antibody and its
fragment was estimated by bis–tris gel electrophoresis followed by silver staining and autoradiography (over 95% of radioactivity
bound in the substances). The antibody binding in tissue slices was studied in vitro by immunohistochemistry. The Purkinje
cells were observed conjugated with the radiolabeled substances, either TU-20 or its ScFv fragment in the area of the cerebellum.
In vivo biodistribution of 125I-TU-20, 125I-scFv TU-20, 123I-scFv TU-20 and Na125I was proceeded in normal mice (wild type C57B/6/J). Both biomolecules labeled by 123I were also proved in an imaging biodistribution study with use of the SPECT camera. Finally, a transgene population G93A1
Gur was used for comparative study to show the different behaviour of the substances in a normal mouse and in the modified
organism with amyotrophic lateral sclerosis. The most part of differences is observed in the area of the muscles, rostal and
caudal spinal cord. In summary, the monoclonal antibody TU-20 and its scFv were successfully radioiodinated and afterwards
analysed by several quality control methods and biodistribution studies which confirmed their preserved or expected immunoanalytical
characteristics in normal and genetically modified organism.
This study reports the synthesis, radiolabeling and preliminary biodistribution results of [99mTc(CO)3(MN-TZ-BPA)]+ in tumor-bearing mice. The novel nitroimidazole derivative was successfully synthesized by conjugation of bis(pyridin-2-ylmethyl)amine
(BPA) to 2-methyl-5-niroimidazole via “click” reaction. The ligand could be labeled by [99mTc(CO)3]+ core in high yield to get [99mTc(CO)3(MN-TZ-BPA)]+, which was very hydrophilic and was stable at room temperature. Biodistribution studies in tumor-bearing mice showed that
[99mTc(CO)3(MN-TZ-BPA)]+ accumulated in the tumor with certain initial uptake while poor retention. The rapid clearance from normal organs with favorable
tumor/muscle ratios warrants further research to improve tumor targeting efficacy and pharmacokinetic profile of radiolabeled
nitroimidazoles by structural modification.
Authors:Xiaobei Zheng, Feng Dong, Jing Yang, Xiaojiang Duan, Tingting Niu, Wangsuo Wu, and Jianjun Wang
This work reports the synthesis and preliminary biodistribution results of [131I]SIB-PEG4-CHC in tumor-bearing mice. The tributylstannyl precursor ATE-PEG4-CHC was synthesized by conjugation of ATE to amino pegylated colchicine NH2-PEG4-CHC. [131I]SIB-PEG4-CHC was radiosynthesized by electrophilic destannylation of the precursor with a yield of ~44%. The radiochemical purity
(RCP) appeared to be >95% by a Sep-Pak cartridge purification. [131I]SIB-PEG4-CHC was lipophilic and was stable at room temperature. Biodistribution studies in tumor-bearing mice showed that [131I]SIB-PEG4-CHC cleared from background rapidly, and didn’t deiodinate in vivo. However, the poor tumor localization excluded it from
further investigations as a tumor-targeted radiopharmaceuticals.
In the current investigation radiosynthesis of the 99mTc-trovafloxacin (99mTc-TVN) complex and its biodistribution in male Wistar rats (MWR) artificially infected with live and heat killed methicillin
resistant Staphylococcus aureus (MRSA) was studied. Further the complex was evaluated in terms of the radiochemical stability in normal saline, in vitro
stability in serum and in vitro binding with MRSA. The complex showed radiochemical purity (RCP) in normal saline with a maximum
value of 97.30 ± 0.52% at 30 min after its reconstitution. The RCP value went down to 90.45 ± 0.48% within 4 h. In serum at
37 °C, the complex showed permanence up to 4 h but within 16 h of incubation the production of undesirable side product of
17.25% (free and radio-colloid) was observed. In buffer the labeled TVN showed saturated in vitro binding with live MRSA.
The uptake of the complex in the thigh of the MWR infected with live MRSA was almost five fold than those infected with heat
killed MRSA. The high RCP values, in vitro stability in serum, saturated in vitro binding with MRSA and promising biodistribution
with six fold higher accumulation in the infected organ of the MWR infected with live MRSA established the usefulness of the
99mTc-TVN as a promising MRSA infection radiotracer.
The labeling of garenoxacin (GXN) with technetium-99m (99mTc) using different concentrations of GXN, sodium pertechnetate (Na99mTcO4), stannous chloride dihydrate (SnCl2·2H2O) at different pH was investigated and evaluated in terms of in-vitro stability in saline, serum, binding with multi-resistant
Staphylococcus aureus (MDRSA) and penicillin-resistant Streptococci (PRSC) and its biodistribution in artificially MDRSA and PRSC infected rats. 99mTc–GXN complex with 97.45 ± 0.18% radiochemical stability was prepared by mixing 3 mg of GXN with 3 mCi of Na99mTcO4 in the presence of 150 μL of SnCl2·2H2O (1 μg/μL in 0.01 N HCl) at a pH 5.6. The radiochemical stability of the complex was evaluated in normal saline up to 240 min
of reconstitution. It was observed that the complex showed maximum RCP values after 30 min of the reconstitution and remained
more than 90% up to 240 min. The complex showed radiochemical stability in normal saline at 37 °C up to 16 h with a 17.80%
de-tagging. The complex showed saturated in-vitro binding with living MDRSA and PRSC as compared to the insignificant binding
with heat killed MDRSA and PRSC. Biodistribution behavior of the complex was assessed in artificially infected with living
and heat killed MDRSA and PRSC rats. It was observed that the accumulation of the complex in the infected (live MDRSA and
PRSC) tissue of the rats was almost five fold than in the inflamed and normal tissue. The high radiochemical stability in
normal saline at room temperature, promising in-vitro stability in serum at 37 °C, saturated in-vitro binding with living
MDRSA and PRSC, specific biodistribution behavior and high infected (target) to normal (non-target) tissue and low inflamed
(non-target) to normal (non-target) tissue ratios we recommend 99mTc–GXN complex for in-vivo localization of infection caused by MDRSA and PRSC effective stains.
Authors:Ashok Behera, Kakali De, Susmita Chandra, Sankha Chattopadhyay, and Mridula Misra
In vivo imaging of tumours using radiolabelled somatostatin (SST) analogues has become an accepted clinical tool in oncology.
HYNIC-Tyr3 octreotide and Tyr3 octreotide were synthesized by FMOC solid-phase peptide synthesis using a semi-automated synthesizer. These were analyzed
and purified by RP-HPLC, mass spectroscopy, IR spectroscopy, 1H NMR and 13C NMR. The prochelator 6-BOC-HYNIC was also synthesised and characterised indigenously. HYNIC-Tyr3 octreotide was labelled with 99mTc using Tricine and EDDA as coligand by SnCl2 method. Labelling with 99mTc was performed at 100 °C for 15 min and radiochemical analysis by ITLC and HPLC methods. The radiochemical purity of the
complex was over 98% and log p value was found to be −1.27 ± 0.12. The stability of radiolabelled peptide complex was checked at 37 °C up to 24 h. Blood
clearance and protein-binding study was also performed. In vivo biodistribution studies in rat showed uptake of 99mTc-HYNIC-TOC in kidney than any other organs. The blood clearance was faster with rapid excretion through kidneys and relatively
low uptake in liver.
Authors:S. Fatahian, D. Shahbazi-Gahrouei, M. Pouladian, M. Yousefi, Gh. Amiri, and A. Noori
DMSA-coated Fe3O4 nanoparticles were synthesized by wet-chemical method. The chemical interaction between Fe3O4 and DMSA were investigated by FTIR. They were directly radiolabeled with 99mTc radioisotope (Fe3O4@DMSA–99mTc) at room temperature in the presence of stannous solution as a reducing agent. Magnetic and structure properties of Fe3O4@DMSA–99mTc nanoparticles were investigated by AGFM, TEM, and XRD. Biodistribution and toxicity assessment of Fe3O4@DMSA–99mTc were studied in mice by intravenous and intraperitoneally injections, respectively. Blood, kidney, and liver factors were
measured 4 days post injection and at the mean-while tissue sections were prepared from their kidney and liver. The results
indicate that, the Fe3O4@DMSA–99mTc nanoparticles were passed through the membrane of different cells but do not create any disorder in the kidney and liver
function even in high doses such as 300 mg/kg.