2 research outputs found
Gd Complexes of DO3A-(Biphenyl-2,2′-bisamides) Conjugates as MRI Blood-Pool Contrast Agents
We report the synthesis of DO3A derivatives of 2,2′-diaminobiphenyl
(<b>1a</b>,<b>b</b>) and their Gd complexes of the type
[GdÂ(<b>1</b>)Â(H<sub>2</sub>O)]·<i>x</i>H<sub>2</sub>O (<b>2a</b>,<b>b</b>) for use as new MRI blood-pool
contrast agents (BPCAs) that provide strong and prolonged vascular
enhancement. Pharmacokinetic inertness of <b>2</b> compares
well with that of structurally related Dotarem, a DOTA-based MRI CA
currently in use. The <i>R</i><sub>1</sub> relaxivity in
water reaches 7.3 mM<sup>–1</sup> s<sup>–1</sup>, which
is approximately twice as high as that of Dotarem (<i>R</i><sub>1</sub> = 3.9 mM<sup>–1</sup> s<sup>–1</sup>).
They show interaction with HSA to give association constants (<i>K</i><sub>a</sub>) in the order of two (∼10<sup>2</sup>), revealing the existence of the blood-pool effect. The in vivo
MR images of mice obtained with <b>2</b> are coherent, showing
strong signal enhancement in both heart, abdominal aorta, and small
vessels. Furthermore, the brain tumor is vividly enhanced for an extended
period of time
Gadolinium Complex of 1,4,7,10-TetraazacycloÂdodecane-1,4,7-trisacetic Acid (DO3A)–Ethoxybenzyl (EOB) Conjugate as a New Macrocyclic Hepatobiliary MRI Contrast Agent
We report the synthesis of a macrocyclic
Gd chelate based on a 1,4,7,10-tetraazacycloÂdodecane-1,4,7-trisacetic
acid (DO3A) coordinationn cage bearing an ethoxybenzyl (EOB) moiety
and discuss its use as a <i>T</i><sub>1</sub> hepatobiliary
magnetic resonance imaging (MRI) contrast agent. The new macrocyclic
liver agent shows high chelation stability and high <i>r</i><sub>1</sub> relaxivity compared with linear-type Gd chelates, which
are the current clinically approved liver agents. Our macrocyclic,
liver-specific Gd chelate was evaluated in vivo through biodistribution
analysis and liver MRI, which demonstrated its high tumor detection
sensitivity and suggested that the new Gd complex is a promising contrast
agent for liver cancer imaging