Synthesis and biodistribution of a Lipophilic 64Cu-labeled monocationic Copper(II) complex

The lipophilic, monocationic copper(II) complex of the diiminedioxime ligand 2,10-di-n-butyl-3,9-dimethyl-1,4,8,11-tetraazaundeca-1,3,8,10-tetraen-1,11-dione dioxime was synthesized and labeled with 64Cu. The biological properties of the 64Cu-labeled complex were measured in vivo and in vitro. In vivo, the complex shows uptake by the heart similar to that of 99mTc-tetrofosmin. In vitro, its uptake by multidrug resistant and non-resistant MES-SA tumor cells parallels that of 99mTc-MIBI, a well-characterized marker of multidrug resistance. These results suggest that this class of copper complexes may form the basis for the development of a 64Cu PET radiopharmaceutical for the functional imaging of multidrug resistance and/or myocardial perfusion.