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Updated: Dec 8, 2025
Positron Emission Tomography Using 64-Copper as a Tracer for the Study of Copper-Related Disorders
Published on: April 28, 2023
Revisiting dithiadiaza macrocyclic chelators for copper-64 PET imaging
Sergey Shuvaev1, Elizaveta A Suturina2, Nicholas J Rotile1
1A. A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA. sshuvaev@mgh.harvard.edu.
Abstract:
Synthesis and characterisation of a dithiadiaza chelator NSNS2A, as well as copper complexes thereof are reported in this paper. Solution structures of copper(i/ii) complexes were calculated using density functional theory (DFT) and validated by both NMR and EPR spectroscopy. DFT calculations revealed a switch in the orientation of tetragonal distortion upon protonation, which might be responsible for poor stability of the Cu(II)NSNS2A complex in aqueous media, whilst the same switch in tetragonal distortion was experimentally observed by changing the solvent. The chelator was radiolabeled with 64Cu and evaluated using PET/MRI in rats. Despite a favorable redox potential to stabilize the cuprous state in vivo, the 64Cu(II)NSNS2A complex showed suboptimal stability compared to its tetraazamacrocyclic analogue, 64Cu(TE2A), with a significant 64Cu uptake in the liver.
