Copolymers and their use as contrast agents in magnetic resonance

Abstract

Novel compounds having use as contrast agents in magnetic resonance imaging, as well as other uses, are described. The compounds are comprised of a copolymer which comprises at least two of a first monomer of the formula X.sub.1 --(CHR.sub.2 CHR.sub.2 -Y).sub.n -(CHR.sub.2).sub.m --CHR.sub.2 CHR.sub.2 13 X.sub.2, wherein X.sub.1 and X.sub.2 are, independently, OH, NH.sub.2, NHR.sub.1, COOH, COOR.sub.1, SH, or Z, Y is O, NH, NR.sub.1, S, or CO, n is 0-10,000, m is 0 or 1, each Z is, independently, Cl, Br, or I, each R.sub.1 is, independently, a C.sub.1 -C.sub.20 substituted alkyl or cycloalkyl, and each R.sub.2 is, independently, H or OH, and at least one of a second monomer which is a polynitrilo chelating agent having at least two COOH, COOR.sub.1, or COZ groups, the first and second monomers being bound to one another to form a copolymer through an ester, amide, or carboxylic thioester linkage of at least one of the OH, NH.sub.2, NHR.sub.1, COOH, COOR.sub. 1, SH or Z groups of the first monomer, and at least one of the COOH, COOR.sub.1, or COZ groups of the second monomer. Optionally, the copolymer may also include at least one of a third monomer which is a targeting agent or a targeting agent ligand having an OH, NH.sub.2, NHR.sub.1, COOH, COOR.sub.1, SH, or COZ group, wherein R.sub.1 is described as above, and wherein the third monomer is also bound with the first and second monomers to form a copolymer through an ester, amide, or carboxylic thioester linkage. For magnetic resonance imaging, for example, the copolymer may further comprise a paramagnetic ion chelated to the chelating agent.