Production and purification of Sc and Sc from enriched [Ti]TiO and [Ti]TiO targets.

The radioscandium isotopes, Sc and Sc, compose a promising elementally matched theranostic pair that can be used for the development of imaging and therapeutic radiopharmaceuticals with identical structures. This study aimed to investigate the production of high radionuclidic purity Sc from enriched [Ti]TiO targets and Sc from enriched [Ti]TiO targets and establish a target recycling technique. Enriched [Ti]TiO targets were irradiated with 18 MeV protons, and enriched [Ti]TiO targets were bombarded with 24 MeV protons.

Evaluation of Lu and Sc Picaga-Linked, Prostate-Specific Membrane Antigen-Targeting Constructs for Their Radiotherapeutic Efficacy and Dosimetry.

Lu-177-based, targeted radiotherapeutics/endoradiotherapies are an emerging clinical tool for the management of various cancers. The chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) remains the workhorse for such applications but can limit apparent molar activity or efficient charge modulation, which can impact target binding and, as a consequence, target efficacy. Previously, our lab had developed the small, rare earth selective bifunctional chelator, picaga, as an efficient bifunctional chelator for scandium and lutetium isotopes.

Accelerator Production of Scandium Radioisotopes: Sc-43, Sc-44, and Sc-47.

Scandium radioisotopes are increasingly considered viable radiolabels for targeted molecular imaging (Sc-43, Sc-44) and therapy (Sc-47). Significant technological advances have increased the quantity and quality of available radioscandium in the past decade, motivated in part by the chemical similarity of scandium to therapeutic radionuclides like Lu-177. The production and radiochemical isolation techniques applied to scandium radioisotopes are reviewed, focusing on charged particle and electron linac initiated reactions and using calcium and titanium as starting materials.

Homologous Structural, Chemical, and Biological Behavior of Sc and Lu Complexes of the Picaga Bifunctional Chelator: Toward Development of Matched Theranostic Pairs for Radiopharmaceutical Applications.

The radioactive isotopes scandium-44/47 and lutetium-177 are gaining relevance for radioimaging and radiotherapy, resulting in a surge of studies on their coordination chemistry and subsequent applications. Although the trivalent ions of these elements are considered close homologues, dissimilar chemical behavior is observed when they are complexed by large ligand architectures due to discrepancies between Lu(III) and Sc(III) ions with respect to size, chemical hardness, and Lewis acidity. Here, we demonstrate that Lu and Sc complexes of 1,4-bis(methoxycarbonyl)-7-[(6-carboxypyridin-2-yl)methyl]-1,4,7-triazacyclononane (Hmpatcn) and its corresponding bioconjugate picaga-DUPA can be employed to promote analogous structural features and, subsequently, biological properties for coordination complexes of these ions.

Cyclotron Production and Separation of Scandium Radionuclides from Natural Titanium Metal and Titanium Dioxide Targets.

Theranostic strategies involve select radionuclides that allow diagnostic imaging and tailored radionuclide therapy in the same patient. An example of a Food and Drug Administration-approved theranostic pair is the Ga- and Lu-labeled DOTATATE peptides, which are used to image neuroendocrine tumors, predict treatment response, and treat disease. However, when using radionuclides of 2 different elements, differences in the pharmacokinetic and pharmacodynamic profile of the agent can occur.

Harvesting V at the National Superconducting Cyclotron Laboratory.

As part of an effort to develop aqueous isotope harvesting techniques at radioactive beam facilities, V and a cocktail of primary- and secondary-beam ions created by the fragmentation reaction of a 160 MeV/nucleon Ni beam were stopped in an aqueous target cell. After collection, V was separated from the mixture of beam ions using cation-exchange chromatography. The extraction efficiency from the aqueous solution was (47.

Photonuclear production, chemistry, and in vitro evaluation of the theranostic radionuclide Sc.

Background: In molecular imaging and nuclear medicine, theranostic agents that integrate radionuclide pairs are successfully being used for individualized care, which has led to rapidly growing interest in their continued development. These compounds, which are radiolabeled with one radionuclide for imaging and a chemically identical or similar radionuclide for therapy, may improve patient-specific treatment and outcomes by matching the properties of different radionuclides with a targeting vector for a particular tumor type. One proposed theranostic radionuclide is scandium-47 (Sc, T = 3.

The surprisingly large neutron capture cross-section of Zr.

The probability that a nucleus will absorb a neutron-the neutron capture cross-section-is important to many areas of nuclear science, including stellar nucleosynthesis, reactor performance, nuclear medicine and defence applications. Although neutron capture cross-sections have been measured for most stable nuclei, fewer results exist for radioactive isotopes, and statistical-model predictions typically have large uncertainties. There are almost no nuclear data for neutron-induced reactions of the radioactive nucleus Zr, despite its importance as a diagnostic for nuclear security.

Harvesting (67)Cu from the Collection of a Secondary Beam Cocktail at the National Superconducting Cyclotron Laboratory.

Isotope harvesting is a promising new method to obtain isotopes for which there is no reliable continuous supply at present. To determine the possibility of obtaining radiochemically pure radioisotopes from an aqueous beam dump at a heavy-ion fragmentation facility, preliminary experiments were performed to chemically extract a copper isotope from a large mixture of projectile fragmentation products in an aqueous medium. In this work a 93 MeV/u secondary beam cocktail was collected in an aqueous beam stop at the National Superconducting Cyclotron Laboratory (NSCL) located on the Michigan State University (MSU) campus.

Feasibility of isotope harvesting at a projectile fragmentation facility: ⁶⁷Cu.

The work presented here describes a proof-of-principle experiment for the chemical extraction of (67)Cu from an aqueous beam stop at the National Superconducting Cyclotron Laboratory (NSCL). A 76 MeV/A (67)Cu beam was stopped in water, successfully isolated from the aqueous solution through a series of chemical separations involving a chelating disk and anion exchange chromatography, then bound to NOTA-conjugated Herceptin antibodies, and the bound activity was validated using instant thin-layer chromatography (ITLC). The chemical extraction efficiency was found to be 88 ± 3% and the radiochemical yield was ≥95%.