Amphiphilic Ditopic Bis-Aqua Gd-AAZTA-like Complexes Enhance Relaxivity of Lipidic MRI Nanoprobes.
Two amphiphilic mono- and dimeric GdAAZTA-like chelates composed of stable bis-aquo Gd(III) complexes (q=2) linked to one (for the monomer) or two dodecyl aliphatic chains (for the dimer) were synthesized. Both chelates showed high relaxivity when incorporated into the lipid bilayer of liposomes or after interaction with human serum albumin (HSA). The ditopic complex shows a significantly decreased internal motion relative to the monomeric complex, associated with an enhanced relaxivity (r1 ≈60 mm(-1)  s(-1) , at 30 MHz and 310 K). The presence of two metal-bound water molecules in fast exchange and the restricted rotational freedom make the relaxivity of this system the highest measured for paramagnetic liposomes.
Dipartimento di Scienze e Innovazione Tecnologica, Università degli Studi del Piemonte Orientale, Viale T. Michel 11, 15121, Alessandria, Italy.
Giuseppe
G
Gambino
Dipartimento di Scienze e Innovazione Tecnologica, Università degli Studi del Piemonte Orientale, Viale T. Michel 11, 15121, Alessandria, Italy.
Lorenzo
http://orcid.org/0000-0002-7027-8396
L
Tei
Dipartimento di Scienze e Innovazione Tecnologica, Università degli Studi del Piemonte Orientale, Viale T. Michel 11, 15121, Alessandria, Italy.
Fabio
F
Carniato
Dipartimento di Scienze e Innovazione Tecnologica, Università degli Studi del Piemonte Orientale, Viale T. Michel 11, 15121, Alessandria, Italy. mauro.botta@uniupo.it.
Mauro
http://orcid.org/0000-0003-4192-355X
M
Botta
amphiphiles; chelates; contrast agents; gadolinium; liposomes