Mn(II)-Based MRI Contrast Agent Candidate for Vascular Imaging
Ferenc K. Kálmán, Viktória Nagy, Balázs Váradi, Zoltán Garda, Enikő Molnár, György Trencsényi, János Kiss, Sandra Même, William Même, Éva Tóth, Gyula Tircsó
Abstract
Toxicity concerns related to Gd(III)-based magnetic resonance imaging (MRI) agents prompted an intensive research toward their replacement by complexes of essential metal ions, like Mn(II). Here, we report a macrocyclic chelate, [Mn(PC2A-BP)], which possesses high thermodynamic stability (log KMnL = 14.86 and pMn=8.35) and kinetic inertness (t1/2pH=7.4 = 286.2 h) as well as as remarkable relaxivity (r1p = 23.5 mM–1 s–1, 0.49 T, 37 °C) in the presence of human serum albumin, allowing a significant MRI signal intensity increase in the vasculature even at low dose (25 μmol/kg) of the complex.