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Technetium-Labeled Compounds
Published in Garimella V. S. Rayudu, Lelio G. Colombetti, Radiotracers for Medical Applications, 2019
Suresh C. Srivastava, Powell Richards
The UV spectra of pertechnetate (Figure 8) show characteristic peaks that provide a simple means for determining the element. Measurements in the presence of perrhenate are possible since the absorption peak of perrhenate is reasonably well-separated. Absorption spectra for a number of technetium species are described in Table 12 and these provide useful methods for the spectrophotometric determination of technetium.
Radiochemistry for Preclinical Imaging Studies
Published in George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos, Handbook of Small Animal Imaging, 2018
Moreover, analytical and biological studies of the imaging agent may require a nonradioactive (“cold”) variant of the test item. Rhenium belongs to the same group in the periodic table as technetium, and due to the lanthanide contraction, many properties are similar. Therefore, nonradioactive Re and the therapeutic radioisotopes 186Re and 188Re form generally good surrogate coordination complexes of the corresponding 99mTc-labeled complexes and can be used for investigative studies. However, not all chelators form complexes with both 99mTc and Re such as bis(amine oxime) chelators. A small but significant difference between rhenium and technetium is observed in the redox potential (standard electrode potential) which is even lower for ReO4−/ReO2 in acidic solution at 0.51 V compared to 0.78 V for the corresponding TcO4−/TcO2 (Lide 2008). In other words, perrhenate is more difficult to reduce than pertechnetate to form a complex, and equally rhenium in a lower oxidation state in a complex is more easily oxidized compared to technetium. Ligands that can act in themselves as reducing agents, such as thiolates and phosphines, seem to stabilize ReV well (Carroll et al. 2012).
Antibody Radiolabeling with Isotopes of Rhenium
Published in David M. Goldenberg, Cancer Therapy with Radiolabeled Antibodies, 1995
The chemical properties of Re have been fully described in a standard text,53 The more pertinent properties of the element as they relate to its use in nuclear medicine have also been discussed.54 Chemically, the greatest difference between Re and Tc lies in the greater susceptibility of the former, once reduced, to return to the +7 oxidation state. It is in this +7 form, usually as sodium perrhenate , that irradiated, processed Re, or generator-derived Re is obtained. The anionic perrhenate species will not bind to organic ligands without reduction to a lower oxidation state. The +IV and +V oxidation states are most usually encountered in Re chemistry used in MoAb conjugation,55 with Re present as an oxorhenium core [Re=0].
Hydrogels for localized chemotherapy of liver cancer: a possible strategy for improved and safe liver cancer treatment
Published in Drug Delivery, 2022
Jianyong Ma, Bingzhu Wang, Haibin Shao, Songou Zhang, Xiaozhen Chen, Feize Li, Wenqing Liang
Peng et al. synthesized a chemotherapeutic drug (liposomal DOX) and therapeutic radionuclide (188Re-Tin colloid) containing thermosensitive hydrogel (Peng et al., 2013). Temperature changes cause a sol–gel phase transition in the thermosensitive PCL-PEG-PCL copolymer, which quickly forms a gel at body temperature while remaining liquid at room temperature. The hydrogel was slow to release radionuclide and DOX, and the system remained stable for almost 10 days. After intra-tumor injection of Lipo-Dox/188Re-Tin hydrogel in HCC bearing mice, the tumor's retention, distribution, and therapeutic effect were investigated. 188Re-Tin loaded hydrogel had a significantly longer residence time in the tumor than Na 188Re perrhenate (Na 188ReO4). When the hydrogel undergoes thermal transition, the radionuclide 188Re perrhenate (188ReO4) quickly diffused from the tumor. Compared to treatment with either 188Re-Tin hydrogel or Lipo-Dox hydrogel, treatment with Lipo-Dox/188Re-Tin hydrogel significantly reduced tumor growth (up to 80% regression of well-established tumors on day 32). It is possible that this biodegradable injectable hydrogel would therefore allow for more precise localization of radiotherapy and chemotherapy for the treatment of HCC (Table 3).
Anion inhibition studies of a beta carbonic anhydrase from the malaria mosquito Anopheles gambiae
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2018
Daniela Vullo, Leo Syrjänen, Marianne Kuuslahti, Seppo Parkkila, Claudiu T. Supuran
We report here an anion inhibition study of the β-class CA, AgaCA, from the mosquito Anopheles gambiae, the vector responsible of malaria transmission. A series of simple as well as complex inorganic anions, together with small molecules known to interact with CAs were included in the study. Bromide, iodide, bisulphite, perchlorate, perrhenate, perruthenate, and peroxydisulphate were ineffective AgaCA inhibitors, with KIs > 200 mM. Fluoride, chloride, cyanate, thiocyanate, cyanide, bicarbonate, carbonate, nitrite, nitrate, sulphate, stannate, selenate, tellurate, diphosphate, divanadate, tetraborate, selenocyanide, and trithiocarbonate showed KIs in the range of 1.80–9.46 mM, whereas N,N-diethyldithiocarbamate was a submillimolar AgaCA inhibitor, with a KI of 0.65 mM. The most effective AgaCA inhibitors were sulphamide, sulphamic acid, phenylboronic acid, and phenylarsonic acid, with inhibition constants in the range of 21–84 µM. The control of insect vectors responsible of the transmission of many protozoan diseases is rather difficult nowadays, and finding agents which can interfere with these processes, as the enzyme inhibitors investigated here, may arrest the spread of these diseases worldwide.
Personalized irradiation therapy for NMSC by rhenium-188 skin cancer therapy: a long-term retrospective study
Published in Journal of Dermatological Treatment, 2022
Cesidio Cipriani, Maria Desantis, Gerhard Dahlhoff, Shannon D. Brown, Thomas Wendler, Mar Olmeda, Gunilla Pietsch, Bernadette Eberlein
The carrier-free rhenium-188 (perrhenate) was obtained from a 188W/188Re generator (Oak Ridge National Laboratory, Oak Ridge, TN, USA; ITG GmbH, Garching, Germany) by elution with saline. A sterile nanocolloid (200–800 nm) of rhenium-188 results from a reaction of perrhenate with hydrogen sulfide. This nanocolloid is then thoroughly mixed with a synthetic acrylic resin (Max Meyer, Milan, Italy) to obtain a compound with a homogeneous distribution of the radioactive nanocolloid.