A novel cholic acid-based contrast enhancement agent for targeted MRI.

The novel Gd(III) complexes of heptadentate ligands NE3TA and NE3TA-Bn were prepared, and their relaxivities were measured and favorably compared to the commercially available MRI contrast enhancement agent Gd(DOTA). NE3TA was conjugated with cholic acid (CA) to produce CA-NE3TA. TEM images of Gd(CA-NE3TA) indicate that the complex self-assembles forming nano-sized micelles and displays an over threefold increased relaxivity compared to Gd(DOTA). The new cholic acid-conjugated nanoparticle MR contrast enhancement agent, Gd(CA-NE3TA) possesses great promise for use in targeted MRI.