Synthesis and Evaluation of a Bifunctional Chelator for Thorium-227 Targeted Radiotherapy.

Thorium-227 (Th) is an α-emitting radionuclide currently under investigation for targeted alpha therapy. Available chelators used for this isotope suffer from challenging multistep syntheses. Here, we present the synthesis and preclinical evaluation of a novel bifunctional chelator, SCN-Bn-DOTHOPO, which contains an isothiocyanate group that is suitable for conjugation to biological molecules.

Siderocalin fusion proteins enable a new Y/Y theranostic approach.

The mammalian protein siderocalin binds bacterial siderophores and their iron complexes through cation-π and electrostatic interactions, but also displays high affinity for hydroxypyridinone complexes of trivalent lanthanides and actinides. In order to circumvent synthetic challenges, the use of siderocalin-antibody fusion proteins is explored herein as an alternative targeting approach for precision delivery of trivalent radiometals. We demonstrate the viability of this approach , using the theranostic pair Y (β, = 64 h)/Y (β, = 14.