“…A substantial decrease in rotation can be achieved by using molecules with a higher molecular weight and size. Recent studies have demonstrated that linking contrast agents to large molecules and assemblies (i.e., dextran [ 20 ], dendrimers [ 21 , 22 , 23 ], liposomes [ 24 , 25 , 26 ], nanoparticles [ 27 , 28 ], fullerenes [ 29 ], micelles [ 30 , 31 ], peptides [ 32 , 33 , 34 ] and proteins [ 35 , 36 , 37 ]) can substantially increase T1 relaxivity. In addition, the integration of Gd(III) ions within various macromolecules can lead to the formation of multiple paramagnetic centers, thereby conferring enhanced sensitivity [ 38 , 39 , 40 , 41 ].…”