Separation of 99mTc from 99Mo by Using TOPO — Kerosene Supported Liquid Membrane

Transport of ^99mTcO₄ ^– ions across TOPO-kerosene based supported liquid membrane was investigated at different concentrations of phosphoric acid as a feed solution and different concentrations of TOPO in the membrane, where 0.9% NaCl aqueous solution was used as a stripping solution. The flux of TcO₄ ^– ions across this liquid membrane varied with the concentration of both H₃PO₄ and TOPO. The best permeability coefficient was obtained at concentrations, [H₃PO₄] = 3 mole·l^–1 and [TOPO] = 0.5 mole·l^–1 (P = 2.08·10^–9 m²·s^–1). The results were utilized for the separation of ^99mTc from ⁹⁹Mo, where a selective and effective separation was obtained since no ⁹⁹Mo transport across this liquid membrane was noticed while a high rate of ^99mTc transport took place.     

Integral cross section of the99Tc(γ,γ′)99mTc reaction at 4 MeV

^99mTc production was studied with the aid of photoexcitation by a 4 MeV endpoint energy bremsstrahlung from the LINAC of the Institute of Isotopes, Budapest. The intensity of the -flux was monitored by disc-shaped natural indium plates, placed in front of and behind the small cylindrical aluminium holders containing TcO₂ samples in a powder form. Isomeric activities were measured through the 140 keV -line by a Ge spectrometer. The integral cross section at 4 MeV was found to be 63.3±7.1 bMeV, which can be considered reasonable compared to the corresponding value of 55.3 bMeV established for the¹¹⁵In (,)^115mIn reaction. We also attempted the photoexcitation of^99mTc by irradiation with -rays from a 1.5×10¹⁵ Bq⁶⁰Co source, but no isomeric activity could be observed. This places the first activation level between 1.33 and 4 MeV.     

Polymerization of lactams. 99 Preparation of polyesteramides by the anionic copolymerization of ε-caprolactam and ε-caprolactone

Polyesteramides derived from the cyclic monomers ε-caprolactam and ε-caprolactone have been synthesized by the anionic polymerization and characterized. ε-Caprolactam magnesium bromide was employed as unique initiator giving high yield of copolymer across the whole range of monomer concentrations at 150 °C. Owing to a variation of the content of ester and amide component in polyesteramide backbone a large variety of materials having diverse physico-chemical and mechanical properties have been prepared. Materials prepared were examined for mechanical characteristic. Thermal properties were characterized using DSC, temperature modulated DSC, Hi-Res^TM TGA and DMA. Viscosity measurements were employed for molecular characterization.     

Studies on dynamic dissociation constant of 99Mo–insulin complex

In this article we studied the dynamic dissociation constant (k _d) of ⁹⁹Mo complexed with insulin molecule at various pH. The k _d values were determined by dialysis technique against deionised water. The T _1/2 of the molybdenum–insulin complexes were found to be 6.41, 5.25 and 3.5 h at pH 5, 6 and 7 respectively. The half-lives indicate that insulin may act as good carrier of ⁹⁹Mo to the intestine and may be useful in the field of nuclear medicine.     

Syntheses of Two Potential Ligands for Tc-99m Labeling as Diagnosis Agents of Alzheimer''''s Disease

Two types of ligands-biphenyl and stilbene derivatives, whichcan be labeled with Tc-99m for the diagnosis of Alzheimer'sdisease (AD) have been synthesized successfully. The key stepsin these two syntheses involved Suzuki reaction and Wittig reac-tion respectively. The new discovered debromination reactionmay be expanded to the compounds with double or triple bondadjacent to the carbon atom bearing the bromine atoms. Thesetypes of syntheses provide a route to a series of biphenyl andstilbene derivatives that will benefit the search of new imagingagents for AD.     

What is wise in the production of 99Mo? A comparison of eight possible production routes

The present paper addresses eight possible routes of producing ⁹⁹Mo, and discusses both yield and ⁹⁹Mo specific activities (SA) in the context of anticipated worldwide demand. Target dimensions are modelled by considering both limits set by cooling and by inside-target radiation attenuation characteristics. Energy deposition profiles are set up by MCNP6, reaction probabilities are taken from TALYS/TENDL and JANIS codes, and both are used in arriving at the produced ⁹⁹Mo. The outcomes suggest that U neutron-fission may remain one of the most relevant and efficient means of producing ⁹⁹Mo at the world-demand level, but that within this domain new developments may surface, such as ADSR or AHR production modes. Accelerator-based ⁹⁹Mo production is discussed as asking for developments in both target cooling and new concepts in post-EOB upgrading of ⁹⁹Mo SA, and/or new concepts for ⁹⁹Mo/^99mTc-generators, the latter possibly in both volumes (mass) and ⁹⁹Mo capacities.     

Ascorbic acid as an eluent for99mTc in99Mo−99mTc generator system

A simple chromatographic procedure for clean separation of the important radionuclide,^99m Tc, in the equilibrium mixture,⁹⁹Mo−^99mTc, has been demonstrated. Separation of pure^99mTc has been achieved by preferential extraction of the radioisotope through an anion exchange resin column of Amberlite IRA-410 using Na-ascorbate solution at pH 7 as an eluent. The radiochemical purity of the separated radiotracer has been verified by taking recourse to γ-ray spectrometry. The potentiality of the developed procedure lies in the facts that the eluting agent, ascorbic acid, itself h got its own biomedical importance as Vitamin C and the concerned radioisotope can be obtained in both Tc(IV) and Tc(VII) states as per requirement for diagnostic purposes.     

Labeling of new formulation of tin–sucralfate freeze-dried kit with technetium-99m and its biological evaluation

The present investigation deals with a simple preparation of new formulation of tin?Csucralfate freeze-dried kit (F.D.K.), to be directly labeled with ^99mTc at optimal pH value of 7.0. The lyophilized form containing 100?mg sucralfate and 11.3?mg dihydrated stannous chloride. Other optimal pH values of the preparation were found to be from 4.0 to 11.0. The range of sucralfate amount studied (50?C500?mg) not affected the radiochemical purity of the labeled complex. The radiochemical purity and the stability of the labeled preparation that assessed by filtration were more than 95%. ^99mTc sucralfate was radiochemical stable up to a specific activity of 1,000?mCi per gram which was more stable than earlier published value (700?mCi per gram) without any radiolytic decomposition. The biological behavior of ^99mTc-pertechnetate was evaluated in two groups of animals, the first group (neither fasted nor ulcerated) and the second group (fasted and ulcerated mice). The data of organ distribution of ^99mTc?Csucralfate in ulcerated fasted mice showed that more than 99% of the administered dose was accumulated in the stomach (87.92%) and intestine (11.43%). The radioanalytical results together with the in vivo-biological behavior of the labeled preparation demonstrate it??s stability, efficacy and usefulness in medical applications for the detection of gastrointestinal ulcers.     

Synthesis and biological distribution of 99mTc–norfloxacin complex, a novel agent for detecting sites of infection

The optimization of the radiolabeling yield of ciprofloxacin analogous, norfloxacin, with technetium-99m (^99mTc) was described. Dependence of the labeling yield of ^99mTc–norfloxacin complex on the concentration of norfloxacin, SnCl₂·2H₂O content, pH of the reaction mixture and reaction time was studied. Norfloxacin was labeled with ^99mTc at pH 3 with a labeling yield of 95.4% by using 5 mg norfloxacin, 50 μg SnCl₂·2H₂O and 30 min reaction time. The formed ^99mTc–norfloxacin complex was stable for a time up to 3 h. Biological distribution of ^99mTc–norfloxacin complex was investigated in experimentally induced inflammation rats using Staphylococcus aureus (bacterial infection model) and heat killed Staphylococcus aureus and turpentine oil (sterile inflammation model). In case of bacterial infection, the T/NT value for ^99mTc–norfloxacin complex was found to be 6.9 ± 0.4 which was higher than that of the commercially available ^99mTc–ciprofloxacin under the same experimental condition.     

Syntheses of Two Potential Ligands for Tc－99m Labeling as Diagnosis Agents of Alzheimer‘s Disease

Two types of ligands-biphenyl and stilbene derivatives, which can be labeled with Tc-99m for the diagnosis of Alzheimer‘ s disease (AD) have been synthesized successfully. The key steps in these two syntheses involved Suzuki reaction and Wittig reaction respectively. The new discovered debromination reaction may be expanded to the compounds with double or triple bond adjacent to the carbon atom bearing the bromine atoms. These types of syntheses provide a route to a series of biphenyl and stilbene derivatives that will benefit the search of new lmaging agents for AD.     

Preparation and bioevaluation of <Superscript>99m</Superscript>Tc–carbonyl complex of guanine

The aim of this study is to prepare radiolabeled guanine with ^99mTc(CO)₃⁺ core. For this purpose, guanine has been radiolabeled with ^99mTc(CO)₃⁺ core. Quality control study of radiolabeled guanine molecule with ^99mTc(CO)₃⁺ core was performed by thin layer radio chromatography (TLRC) and high performance liquid radio chromatography (HPLRC). The results showed that the radiolabeling yield was quite high (94 ± 3%). Beside that ^99mTc(CO)₃–Gua complex has showed good in vitro stability during the 24 h period. Radiopharmaceutical potential of this complex was evaluated in Wistar Albino Rats. It was concluded that ^99mTc(CO)₃–Gua could be used as a nucleotide radiopharmaceutical for in vivo applications.     

Effect of EDTA on the diffusion behavior of 99TcO4 − and ReO4 − in GMZ bentonite

Polyaminopolycarboxylate EDTA with powerful metal-binding property, which often presents in low and intermediate-level waste, can enhance the radionuclide migration. The effect of EDTA on the diffusion behavior of ⁹⁹TcO₄ ^? and ReO₄ ^? in Gaomiaozi (GMZ) bentonite was investigated by using through-diffusion method. For ⁹⁹TcO₄ ^? in present of EDTA, the D _e values was (1.2 ± 0.1) × 10^?11 m²/s, which was 4 times higher than that in absent of EDTA. It can be explained that the complexation between ⁹⁹TcO₄ ^? and EDTA might be formed. By contrast, the D _e values of ReO₄ ^? remained unchanged in present or absent of EDTA, indicating that ReO₄ ^? could not complex with EDTA. However, the diffusion of ReO₄ ^? could be increased in present of EDTA, the D _a value was found to be increased from 1.8 × 10^?10 to 5.4 × 10^?10 m²/s. It demonstrated that ReO₄ ^? need more drastic conditions to form the Re(VII)–EDTA complexes than those used for ⁹⁹TcO₄ ^?. For both ReO₄ ^? and ⁹⁹TcO₄ ^?, the rock capacity factor α is less than the total porosity ε _tot, indicating that they has little retention/sorption on the surface of bentonite.     

In vivo biological behavior of 99mTc(CO)3 labeled fullerol

The increase of environmental radiation dose rate during rainfall at environmental monitoring posts (MPs) was calculated by using the correlation relationship with the dose rate at the neighboring MP. The calculated dose rate agreed with the observed one within less than 20% of the maximum increase height of the observed one for each rainfall. Furthermore, when the dose rate increased due to Krypton-85 (⁸⁵Kr) discharged from the Tokai Reprocessing Plant (TRP) at the environmental monitoring station (MS) downwind of the stack during rainfall, the dose rate due to the ⁸⁵Kr was tried to discriminate. The discriminated dose rate agreed with that calculated by the atmospheric dispersion calculation code system, SIERRA-II, using stack monitor data and local meteorological observation data.     

(n,n′) production of99mTc by252Cf fission neutrons

Activation technique was employed to determine the²⁵²Cf spectrum averaged cross section of the⁹⁹Tc(n,n)^99mTc reaction. Two different -spectrometric methods were applied. One of the measurements was relative to that of the cross-section value of¹¹⁵In (n,n)^115mIn reaction, while the other one was absolute. The measured values are 179±49 mb and 195±43 mb for the relative and absolute measurement, respectively.     

Long-lived γ-radionuclidic impurities in spent99Mo/99mTc generators

The long-lived -radionuclidic impurities in the columns of spent⁹⁹Mo/^99mTc generators one year after the calibration date have been determined by -spectrometry. Three radionuclidic impuritiesfission products (¹⁰³Ru,¹⁰⁶Ru and¹²⁵Sb) were detected. Also in the majority of samples three radioisotopes of tungsten (¹⁸¹W,¹⁸⁵W and¹⁸⁸W) were also present. The contents of the impurities were found to vary greatly. According to the activity, energy and half-life, the main contribution to the residual activity in the spent generators is due to the presence of¹²⁵Sb.     

Synthesis of techentium-99m labeled clinafloxacin (99mTc�CCNN) complex and biological evaluation as a potential Staphylococcus aureus infection imaging agent

In the present study synthesis of the ^99mTc?CCNN complex and its efficacy as a prospective Staphylococcus aureus (S. aureus) infection imaging agent was assessed. The ^99mTc?CCNN complex was characterized in terms of stability in saline, serum, in vitro binding with S. aureus and in vivo percent absorption in male Wister rats (MWR) infected with live and heat killed S. aureus. Radiochemically the ^99mTc?CCNN complex showed stable behavior in saline and serum at different intervals. At 30 min after reconstitution the complex showed maximum radiochemical purity (RCP) yield of 97.55 ± 0.22%. The RCP yield decreased to 90.50 ± 0.18% within 240 min. In serum, 18.15% unwanted side product was appeared within 16 h of the incubation. In vitro saturated binding with S. aureus was observed at different intervals with a 62.00% maximum at 90 min. Normal percent in vivo uptake was observed in MWR artificially infected with live S. aureus with a five times higher in the infected muscle as compared to the inflamed and normal muscles. No difference in the percent uptake of the complex in MWR infected with heat killed S. aureus in the infected, inflamed and normal muscles were observed. Based on the promising in vitro and in vivo radiochemical and biological characteristics, we recommend the ^99mTc?CCNN complex for in vivo localization of the S. aureus infectious foci.     

Experimental and numerical investigations of 99TcO4− diffusion in compacted SPV 200 bentonite

Journal of Radioanalytical and Nuclear Chemistry - Diffusion characteristics in bentonite are essential to quantify the transport of radionuclides through buffer/backfill materials in waste...     

Bioevaluation of 99mTc(CO)3–Guanine in vitro and in vivo

The aim of this study is to examine biological behaviour of radiolabeled guanine with [Tc(CO)₃]⁺ core in vitro and in vivo. In vitro biological behavior of ^99mTc(CO)₃–Gua was evaluated on Lung (A-549), Breast (MCF-7), Colonic (Caco) carcinoma cell lines and normal human bronchial epithelial (NHBE). ^99mTc(CO)₃–Gua compound showed high uptake on A-549 cell line when compared to NHBE cell line. Biodistribution characteristics of ^99mTc(CO)₃–Gua was evaluated using New Zeland Rabbits. Scintigraphic results showed that a high level of radioactivity was observed in the lungs and liver shortly after administration of the ^99mTc(CO)₃–Gua and excretion takes place via both renal and hepatobiliary route. It was concluded that ^99mTc(CO)₃–Gua could be used as a nucleotide radiopharmaceutical for imaging purposes.