0000000001142348
AUTHOR
Valery Radchenko
showing 10 related works from this author
Desferrioxamine as an appropriate chelator for 90Nb: Comparison of its complexation properties for M-Df-Octreotide (M=Nb, Fe, Ga, Zr)
2014
The niobium-90 radioisotope ((90)Nb) holds considerable promise for use in immuno-PET, due to its decay parameters (t½ = 14.6h, positron yield=53%, Eß(+)(mean) = 0.35 MeV and Eß(+)(max) = 1.5 MeV). In particular, (90)Nb appears well suited to detect in vivo the pharmacokinetics of large targeting vectors (50-150 kDa). In order to be useful for immuno-PET chelators are required to both stabilize the radionuclide in terms of coordination chemistry and to facilitate the covalent attachment to the targeting vector. Different chelators were evaluated for this purpose in terms of radiolabelling efficiency and stability of the radiolabelled Nb(V) complex and in order to determine the most suitable…
Behavior of Actinium, Alkaline, and Rare Earth Elements in Sr-Resin/Mineral Acid Systems
2015
In this work, the interactions between the divalent alkaline earth elements (AEE) (Sr, Ba, Ra), the trivalent rare earth elements (REE) (Ce-Lu, Y), and Ac(III) with Sr-resin were investigated in the presence of HNO3, HCl, HBr, HClO4, and HPF6. Distribution coefficients of these ions on the Sr-resin were determined under batch-loading conditions. Lastly, online column separations were performed to demonstrate the utility of these systems. Substantial differences in the behavior of the ions in solutions comprised of the five different acids were observed. These differences can partly be explained by a combination of ion exchange (primary) and extraction (solvation) mechanisms. From a practica…
Direct flow separation strategy, to isolate no-carrier-added 90Nb from irradiated Mo or Zr targets
2016
Abstract 90Nb has an intermediate half-life of 14.6 h, a high positron branching of 53% and optimal β + emission energy of only E mean 0.35 MeV per decay. These favorable characteristics suggest it may be a potential candidate for application in immuno-PET. Our recent aim was to conduct studies on distribution coefficients for ZrIV and NbV in mixtures of HCl/H2O2 and HCl/oxalic acid for anion exchange resin (AG 1 × 8) and UTEVA resin to develop a “direct flow” separation strategy for 90Nb. The direct flow concept refers to a separation accomplished using a single eluent on multiple columns, effectively streamlining the separation process and increasing the time efficiency. Finally, we also …
Radiolabeling of a polypeptide polymer for intratumoral delivery of alpha-particle emitter, 225Ac, and beta-particle emitter, 177Lu
2021
Introduction: Radiotherapy of cancer requires both alpha- and beta-particle emitting radionuclides, as these radionuclide types are efficient at destroying different types of tumors. Both classes of radionuclides require a vehicle, such as an antibody or a polymer, to be delivered and retained within the tumor. Polyglutamic acid (pGlu) is a polymer that has proven itself effective as a basis of drug-polymer conjugates in the clinic, while its derivatives have been used for pretargeted tumor imaging in a research setup. trans-Cyclooctene (TCO) modified pGlu is suitable for pretargeted imaging or therapy, as well as for intratumoral radionuclide therapy. In all cases, it becomes indirectly ra…
Separation and purification of no-carrier-added arsenic from bulk amounts of germanium for use in radiopharmaceutical labelling
2010
AbstractRadioarsenic labelled radiopharmaceuticals could add special features to molecular imaging with positron emission tomography (PET). For example the long physical half-lives of72As (T1/2=26 h) and74As (T1/2=17.8 d) in conjunction with their high positron branching rates of 88% and 29%, respectively, allow the investigation of slow physiological or metabolical processes, like the enrichment and biodistribution of monoclonal antibodies in tumour tissue or the characterization of stem cell trafficking. A method for separation and purification of no-carrier-added (nca) arsenic from irradiated metallic germanium targets based on distillation and anion exchange is developed. It finally con…
Separation of 90Nb from zirconium target for application in immuno-PET
2014
Abstract Fast progressing immuno-PET asks to explore new radionuclides. One of the promising candidates is 90Nb. It has a half-life of 14.6 h that allows visualizing and quantifying biological processes with medium and slow kinetics, such as tumor accumulation of antibodies and antibodies fragments or drug delivery systems and nanoparticles. 90Nb exhibits a positron branching of 53% and an average kinetic energy of emitted positrons of E mean =0.35 MeV. Currently, radionuclide production routes and Nb V labeling techniques are explored to turn this radionuclide into a useful imaging probe. However, efficient separation of 90Nb from irradiated targets remains in challenge. Ion exchange based…
Determination of distribution coefficients (Kd) of various radionuclides on UTEVA resin
2016
Abstract Using radioisotope markers the distribution coefficients (Kd) of the following elements In, Sn, Sb, Te, Bi, Co, Fe, Nb, Sr, Ba, Ag, Cd, Zr, Hf and Ti were determined with different concentrations of HCl, H2SO4 and HNO3 for the extraction chromatographic resin Uranium and TEtraValent Actinides (UTEVA). This data can be used for separation of elements in complex mixtures, as well as for correct assessment of the elements chemistry with higher valences such as 3, 4, 5 or 6.
Labeling and preliminary in vivo assessment of niobium-labeled radioactive species: A proof-of-concept study.
2016
Abstract The application of radionuclide-labeled biomolecules such as monoclonal antibodies or antibody fragments for imaging purposes is called immunoscintigraphy . More specifically, when the nuclides used are positron emitters, such as zirconium-89, the technique is referred to as immuno-PET . Currently, there is an urgent need for radionuclides with a half-life which correlates well with the biological kinetics of the biomolecules under question and which can be attached to the proteins by robust labeling chemistry. 90 Nb is a promising candidate for in vivo immuno-PET , due its half-life of 14.6h and low β + energy of E mean =0.35MeV per decay. 95 Nb on the other hand, is a convenient …
Nb-90 - a potential PET nuclide: production and labeling of monoclonal antibodies
2012
Abstract Fast progressing immuno-PET gives reasons to develop new potential medium-long and long-lived radioisotopes. One of the promising candidates is 90Nb. It has a half-life of 14.6 h, which allows visualizing and quantifying processes with medium and slow kinetics, such as tumor accumulation of antibodies and antibodies fragments or polymers and other nanoparticles. 90Nb exhibits a high positron branching of 53% and an optimal energy of β + emission of E mean=0.35 MeV only. Consequently, efficient radionuclide production routes and NbV labeling techniques are required. 90Nb was produced by the 90Zr(p,n) 90Nb nuclear reaction on natural zirconium targets. No-carrier-added (n.c.a.) 90Nb …
Behavior of Actinium, Alkaline, and Rare Earth Elements in Sr-Resin/Mineral Acid Systems
2015
In this work, the interactions between the divalent alkaline earth elements (AEE) (Sr, Ba, Ra), the trivalent rare earth elements (REE) (Ce-Lu, Y), and Ac(III) with Sr-resin were investigated in the presence of HNO3, HCl, HBr, HClO4, and HPF6. Distribution coefficients of these ions on the Sr-resin were determined under batch-loading conditions. Lastly, online column separations were performed to demonstrate the utility of these systems. Substantial differences in the behavior of the ions in solutions comprised of the five different acids were observed. These differences can partly be explained by a combination of ion exchange (primary) and extraction (solvation) mechanisms. From a practica…