Supramolecular and Biomacromolecular Enhancement of Metal-Free Magnetic Resonance Imaging Contrast Agents


Many contrast agents for magnetic resonance imaging are based on gadolinium, however side effects limit their use in some patients. Organic radical contrast agents (ORCAs) are potential alternatives, but are reduced rapidly in physiological conditions and have low relaxivities as single molecule contrast agents. Herein, we use a supramolecular strategy where cucurbit[8]uril binds with nanomolar affinities to ORCAs and protects them against biological reductants to create a stable radical in vivo. We further overcame the weak contrast by conjugating this complex on the surface of a self-assembled biomacromolecule derived from the tobacco mosaic virus.


Includes supplementary information


Radicals (Chemistry), Magnetic resonance imaging, Gadolinium, Contrast media (Diagnostic imaging), Tobacco mosaic virus

National Science Foundation [CAREER DMR-1654405]. the Welch Foundation [AT-1989-20190330 and AT-1877-20180324], National Science Foundation Graduate Research Fellows Program (1746053),


CC BY-NC 3.0 (Attribution-NonCommercial), ©2020 Royal Society of Chemistry