High-relaxivity magnetic resonance imaging (MRI) contrast agent based on supramolecular assembly between a gadolinium chelate, a modified dextran, and poly-beta-cyclodextrin.

Nanosized contrast agents have great potential in magnetic resonance molecular imaging applications for clinical diagnosis. This study proposes new nanoparticles spontaneously formed under mild conditions and composed of a noncovalent adduct between a gadolinium complex, a polymer of beta-cyclodextrin (pbetaCD: MW 1.5 x 10(6) g mol(-1)) and a dextran grafted with alkyl chains (MD).

Molecular recognition of sugars by lanthanide (III) complexes of a conjugate of N, N-bis[2-[bis[2-(1, 1-dimethylethoxy)-2-oxoethyl]amino]ethyl]glycine and phenylboronic acid.

A novel conjugate of phenylboronic acid and an Ln(DTPA) derivative, in which the central acetate pendant arm was replaced by the methylamide of L-lysine, was synthesized and characterized. The results of a fit of variable (17)O NMR data and a (1)H NMRD profile show that the water residence lifetime of the Gd(III) complex (150 ns) is shorter than that of the parent compound Gd(DTPA)(2-) (303 ns). Furthermore, the data suggest that several water molecules in the second coordination sphere of Gd(III) contribute to the relaxivity of the conjugate.

Magnetic resonance imaging visualization of targeted cells by the internalization of supramolecular adducts formed between avidin and biotinylated Gd3+ chelates.

The high binding affinity between avidin and biotin has been exploited to develop a procedure for magnetic resonance imaging (MRI) visualization of target cells. SHIN3 and PANC1 tumor cell lines have been used as target cells because they possess on their membranes galactosyl receptors able to bind avidin molecules. Avidin-Gd chelate adducts have been built by using two Gd complexes containing one (Gd-I) and two (Gd-II) biotin residues, respectively.