Polyamine dendrimer‐based MRI contrast agents for functional kidney imaging to diagnose acute renal failure

To choose an efficacious renal functional MRI contrast agent to image early renal tubular damage. We synthesized and compared smaller polyamine dendrimer-based MRI contrast agents (<60 kD) that, unlike Gd-[DTPA], transiently accumulate in renal tubules and can be used to visualize renal structural and functional damage.Six dendrimer-based MRI contrast agents smaller than 60 kD were studied by high resolution dynamic micro-MRI and compared to Gd-[DTPA]-dimeglumine and Gadomer-17. The best agent, DAB-G2, was further tested in a mouse ischemia/reperfusion model to validate its efficacy.Despite unequal renal clearance rates, all polyamine dendrimer agents visualized the renal functional anatomy of the mice better than Gd-[DTPA]-dimeglumine and Gadomer-17. DAB-G2 was excreted most rapidly, yet was able to visualize mild renal tubular injury very early after injury.DAB-G2 was found to be the best candidate for functional kidney imaging and enabled early diagnosis of acute renal injury.