Synthesis and Selective Radiolabeling Strategies for Production of [90Y-DOTA-βala-K-64Cu-NOTA-BBN(7–14) NH2] Conjugate; A Dual Negatron/Positron Emitting Radioligand

Herein the authors introduce the novel targeting agent, [DOTA-βala-K-NOTA-BBN(7–14)NH2], and its ability to be radiolabeled with 90Y (a pure β– emitting radionuclide) and 64Cu (a β+ emitting radionuclide) under typical radiolabeling conditions. [DOTA-βala-K-NOTA-BBN(7–14)NH2] was metallated with either 64Cu/90Y or natCu/natY to form the product, [(90Y/natY)-DOTA-βala-K-(64Cu/natCu)-NOTA-BBN(7–14)NH2]. All of the new targeting probes and metallated ligands were purified by RP-HPLC, characterized by ESI-MS, and evaluated for IC50. This new, two-step labeling procedure offers the opportunity to tailor a new radioligand that contains a high-energy pure β– emitting radionuclide and a highly resolvable β+ for molecular imaging investigatons.