Fig. 8.

Schematic representation of local and global mobility processes relevant to Gd³⁺-chelates (brown spheres) in (a) cross-linked polymeric nanoparticles, (b) dendrites, (c) enosomes, and (d) memsomes with τ_RG and τ_RL representing global and local rotational correlation times, respectively. Paramagnetic chelates are covalently bound in (a) and (b); for the paramagnetic chelates encapsulated (in (c) and (d)) in the membrane or aqueous phase of a liposome, τ_io denotes water exchange rate between the interior and exterior and τ_Ri the rotational correlation time of the internalised complex.