Enhancing the Relaxivity of Gd-Based Liposomes and Micelles by Restricting the Local Motions

Mauro Botta¹, Filip Kielar¹, Lorenzo Tei¹, Enzo Terreno²

A novel GdDOTA derivative was prepared featuring two adjacent glutamic acid moieties. Reaction with dodecyl amine yields an amphiphilic complex that maintains the favorable properties of the parent complex in terms of stability, relaxivity and water exchange rate. The self-assembling process in aqueous solution results in micelles and liposomes of enhanced relaxivity (+ 140 % at 0.47 T; + 100 % at 1.5 T) over that of corresponding single-chain systems that is explained in terms of a strong limitation of the local rotation about the hydrophobic chains.