Evaluation of bifunctional chelates for the development of gallium-based radiopharmaceuticals.

Ga radioisotopes, including the generator-produced positron-emitting isotope (68)Ga (t1/2 = 68 min), are of increasing interest for the development of new radiopharmaceuticals. Bifunctional chelates (BFCs) that can be efficiently radiolabeled with Ga to yield complexes with good in vivo stability are needed. To this end, we undertook a systematic comparison of four BFCs containing different chelating moieties: two novel BFCs, p-NO2-Bn-Oxo (1-oxa-4,7,10-triazacyclododecane-4,7,10-triacetic acid) and p-NO2-Bn-PCTA (3,6,9,15-tetraazabicyclo [9.

Evaluation of novel bifunctional chelates for the development of Cu-64-based radiopharmaceuticals.

Background: Currently available bifunctional chelates (BFCs) for attaching Cu-64 to a targeting molecule are limited by either their radiolabeling conditions or in vivo stability. With the goal of identifying highly effective BFCs, we compared the properties of two novel BFCs, 1-oxa-4,7,10-triazacyclododecane-S-5-(4-nitrobenzyl)-4,7,10-triacetic acid (p-NO(2)-Bn-Oxo) and 3,6,9,15-tetraazabicyclo[9.3.