Supramolecular adducts between macrocyclic Gd (III) complexes and polyaromatic systems: a route to enhance the relaxivity through the formation of hydrophobic interactions

摘要

Introduction: MRI is the election imaging technique for the diagnosis and monitoring of numerous diseases. About 40-45% of MRI scans are performed with the use of Gadolinium based contrast agents (GBCAs). The recent findings related to NSF and Gd-retention strongly required caution in the use of GBCAs.1Chemistry becomes central in looking for i) more stable and ii) more efficient GBCAs (i.e. enhanced relaxivity). Different routes to enhance relaxivity were exploited as i) the set-up of non-covalent binding interactions with macromolecules present in solution (e.g. albumin), ii) the increase of the number of coordinated or second sphere water molecules, iii) the increasing of prototropic exchange rates.2Herein, we describe the increase of relaxivity attainable through reversible binding interactions between the hydrophobic region of macrocyclic GBCAs and SO_3~-/OH containing pyrene derivatives (Fig.1A).