Synthesis and biological evaluation of a novel 99mTc labeled 2-nitroimidazole derivative as a potential agent for imaging tumor hypoxia

Tumor hypoxia plays a major role in reducing the efficacy of therapeutic modalities like chemotherapy and radiation therapy in combating cancer. In order to target hypoxic tissues, a tripeptide ligand having a 2-nitroimidazole moiety, as a bioreductive species, was synthesized. The latter was radiolabeled with 99mTc for imaging hypoxic regions of tumors and was characterized by means of its rhenium analogue. The biodistribution and scintigraphic image of the corresponding 99mTc-complex showed accumulation in tumor and these results suggest that it could be a marker for imaging tumor hypoxia.