A water-soluble triiodo amino acid and its dendrimer conjugate for computerized tomography (CT) imaging

Prolonging the circulation of an imaging agent is vital for making it suitable for blood pool (vascular) imaging. Medical applications of vascular imaging include cardiovascular disease, abnormal capillary permeability, and tumor neovascularity. As low molecular weight computerized tomography (CT) enhancement agents are characterized by inconveniently fast clearance, macromolecular compounds (both natural and synthetic) have gained a wide recongnition for possessing better characteristics for performing blood imaging tasks. Herein, the syntheses and characterization of a new water-soluble triiodo amino acid, 3-[(N,N-dimethylaminoacetyl) amino]-a-ethyl-2,4,6-triiodobenzenepropanoic acid (DMAA-IPA) and its Starburst PAMAMgeneration 4.0 dendrimer conjugate, G-4-(DMAA-IPA)37 are described. The applicability of G-4-(DMAA-IPA)37 as a potential macromolecular angiographic CT contrast agent is discussed. The linear relationship between organically bound iodine concentration and CT Hounsfield units has been established thus allowing for quantification uses of CT imaging as well.