Densely packed Gd(III)-chelates with fast water exchange on a calix[4]arene scaffold: A potential MRI contrast agent

A pyridine-N-oxide functionalized DOTA analogue has been conjugated to a calix[4]arene and the corresponding Gd-complex was characterized with respect to its suitability as MRI contrast agent. The compound forms spherical micelles in water with a cmc of 35 mMand a radius of 8.2 nm. The relaxivity of these aggregates is 31.2 s-1 mM-1 at 25ºC and...