Synthetic strategy for preparation of a folate corrole DOTA heterobimetallic Cu-Gd complex as a potential bimodal contrast agent in medical imaging

An efficient sequential route to synthesize heterobimetallic complexes is reported herein. A folate, Cu corrole, Gd DOTA complex that addresses the requirements of a potential contrast agent (CA) for bimodal imaging (e.g., MRI/PET) is reported. The over-expression of the folate receptor in a variety of malignant tumors, along with its limited expression in healthy tissues, makes this an attractive tumor-specific molecular target. Synthesis of a bimetallic ligand potentially targeting the folate receptor, was easily achieved in only a few steps. Interestingly, preliminary studies showed that the relaxivity of the folic heterobimetallic derivative was higher in comparison to a clinically used Gd DOTA MRI contrast agent. Their radiocomplexes may be useful as an in vitro tool and for in vivo tumor diagnosis by using, for example, PET imaging. (C) 2015 Elsevier Ltd. All rights reserved.