Generating contrast in hyperpolarized 13C MRI using ligand-receptor interactions

Analyst. 2012 Aug 7;137(15):3427-9. doi: 10.1039/c2an35406c. Epub 2012 Jun 1.

Abstract

We report the imaging of β-cyclodextrin-benzoic acid binding at 14T using hyperpolarized (13)C magnetic resonance (MR). Benzoic acid was polarized using a dynamic nuclear polarization (DNP) approach and combined with β-cyclodextrin in aqueous solution. As anticipated, decreases in the spin-lattice relaxation constant (T(1)) were observed with decreases in the ligand-receptor ratio. The calculated log K was approximately 1.7, similar to previously reported binding constants. Hyperpolarized [1-(13)C] benzoic acid was used to interrogate solutions of variable β-cyclodextrin concentrations, with the mixtures imaged at 14T using a 3D frequency-selective MR sequence. Differences in β-cyclodextrin concentration were easily visualized. These results suggest that hyperpolarized (13)C MR could be used in vivo to determine the presence and density of receptors for a given ligand-receptor pair.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Benzoic Acid / chemistry*
  • Carbon Isotopes
  • Contrast Sensitivity
  • Ligands
  • Magnetic Resonance Imaging / methods*
  • beta-Cyclodextrins / chemistry*

Substances

  • Carbon Isotopes
  • Ligands
  • beta-Cyclodextrins
  • Benzoic Acid
  • betadex