Contrast Agents for Magnetic Resonance Imaging Synthesized with Ring-opening Metathesis Polymerization

A monomer for ring-opening metathesis polymerization (ROMP) has been developed that also functions as a portion of a GdIII chelating moiety for a magnetic resonance imaging contrast agent. An increase in per GdIII relaxivity was shown upon transition from monomer to polymer. Additionally, extremely large molecular relaxivities were achieved through incorporation of multiple GdIII ions per polymer. The nature of ROMP-derived polymers allows for functionalization of the monomer units and termini through orthogonal chemistry. This strategy is the basis for a new class of highly sensitive, targeted imaging agents.