Polyamine-substituted Gd-DTPA: intracellular, tumor-selective, high-retention MRI contrast agents
Wolf M, Hull W, Eisenhut M, Heiland S, Bauder-Wuest U
German Cancer Research Center (DKFZ)
Intracellular Gd(III) contrast agents with polyamine-substituted DTPA ligands have been synthesized. They exhibit relaxivities r1 of 2-8 s1 mM1, high uptake (10-100 M) via polyamine transporters into cultured B16 melanoma and MH3924A Morris hepatoma cells, and are retained within tumor cells for at least 24 h. In vivo MRI studies with subcutaneous MH3924A in the rat at 2.35 T demonstrate that the expected T1-wt. contrast enhancement in tumor is achieved with these novel agents, even at 24 h post Gd injection.