Chelating agents gadolinium

Low molecular weight gadolinium chelating agents have been coupled to high molecular weight polymers whether natural [22] (proteins such as HSA) or artificial [23] (polyaminoacids like polylysine, oligosaccharides such as dextrans, dendrimers). 

Gadolinium is a paramagnetic ion and is the most frequently used contrast agent. Gadolinium is chelated with other substances such as dimeglumine and diethylenetriaminepentaacetic add (DTPA) before intravenous use. The usual dose for children is 0.1 mmol/kg. 

Gadolinium(ni) chelates as magnetoresonance imaging (MRI) contrast agents 99CRV2293. 

Briicher E (2002) Kinetic Stabilities of Gadolinium (III) Chelates Used as MRI Contrast Agents. 221 103-122... 

This method represents one of the first attempts towards macromolecular agents.121-123 As many as 60-90 [Gd(DTPA)]2- or [Gd(DOTA)] chelates were first linked to a polylysine chain, then covalently conjugated to a HSA molecule.124 The increase in relaxivity per Gd, as compared with the monomeric chelate, was remarkable (two- to threefold), though far from optimal. However, the development of these albumin conjugates was abandoned at an early stage, since their synthesis is not easily controlled, and there are also toxicity concerns due to the retention of gadolinium observed in the bones and liver.125... 

Briicher, E. Kinetic Stabilities of Gadolinium(III) Chelates used as MRI Contrast Agents. In Contrast Agents I. Magnetic Resonance Imaging Krause, W., Ed. Topics in Current Chemistry Springer Berlin, 2002 Vol. 221, p 104. 

Figure 1.17 The texaphyrin-gadolinium chelate structure used as a photosensitizer and MRI contrast agent in the detection and treatment of cancer.

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