Novel candidate theranostic radiopharmaceutical based on strontium hexaferrite nanoparticles conjugated with azacrown ligand.

In this article, we report to the best of our knowledge the first modification of NPs with ligands for combined radiopharmaceuticals. Nanoparticles with suitable magnetic properties can be used both for diagnostics as a contrast for MRI and for therapy, including the insufficiently studied magneto-mechanical therapy. Strontium hexaferrite is one of the few hard-magnetic materials for which stable biocompatible colloidal solutions can be obtained. Strontium hexaferrite nanoparticles coated with silicon dioxide (SHF@SiO2) were modified with an amino silane coupling agent (3-aminopropyl)triethoxysilane and azacrown ether derivatives with six heteroatoms in rings were covalently linked to the amine group through the carboxyl group. The hard magnetic nanoparticles were then radiolabeled with 207Bi with a labelling yield of up to 99.8%. In vitro experiments showed that the complex SHF@SiO2-APTES-L2-207Bi is stable enough to be a potential theranostic radiopharmaceutical.

CeO2-Azacrown Conjugate as a Nanoplatform for Combined Radiopharmaceuticals.

This study is one of the first attempts to assess CeO2 nanoparticles as a nanoplatform for radiopharmaceuticals with radionuclides. The process of functionalization using a bifunctional azacrown ligand is described, and the resulting conjugates are characterized by IR and Raman spectroscopy. Their complexes with 207Bi show a high stability in medically relevant media, thus encouraging the further study of these conjugates in vivo as potential combined radiopharmaceuticals.

Zinc and copper complexes with azacrown ethers and their comparative stability in vitro and in vivo.

Copper-based radiopharmaceuticals are of high interest these days owing to the decay properties of copper radioisotopes. In contrast, labeled zinc compounds have been less studied for applications in nuclear medicine. In this study, the stability of labeled zinc and copper complexes with two azacrown ether ligands was investigated and compared. Then, the in vitro and in vivo stability of the studied zinc complexes was demonstrated, with the complexes showing promise for biomedical applications. In contrast, analogous copper complexes quickly dissociated in the presence of serum proteins. Furthermore, a simple method for the production of radiochemically pure 65Zn was proposed, and the opportunity for its use as a surrogate radionuclide for research into potential zinc-containing radiopharmaceuticals was demonstrated.

Benzoazacrown compound: a highly effective chelator for therapeutic bismuth radioisotopes.

A new benzoazacrown ligand H4BATA was synthesized and its complexation ability towards bismuth cations was evaluated. Binding of cation occurs at room temperature in a few minutes and formed complex exhibits the same level of inertness as highly stable complex with the well-known H4DOTA in biologically relevant and challenging media under in vivo conditions.