Crosslinked shells for nano-assembled capsules: a new encapsulation method for smaller Gd(3+)-loaded capsules with exceedingly high relaxivities

Nano-assembled capsules can incorporate large payloads of high relaxivity Gd(3+), permitting the development of highly detectable molecular imaging agents for MRI. A new encapsulating shell, based upon cross-linked peptides, is found to afford smaller capsules (127 nm average diameter) with exceptionally high per-Gd(3+) relaxivities (70.7 s(-1) mmolal(-1)).