Abstract
The promise of hyperpolarized glucose as a non-radioactive imaging agent capable of reporting on multiple metabolic routes has led to recent advances in its dissolution-DNP (dDNP) driven polarization using UV-light induced radicals and trityl radicals at high field (6.7 T) and 1.1 K. However, most preclinical dDNP polarizers operate at the field of 3.35 T and 1.4–1.5 K. Minute amounts of Gd3+ complexes have shown large improvements in solid-state polarization, which can be translated to improved hyperpolarization in solution. However, this Gd3+ effect seems to depend on magnetic field strength, metal ion concentration, and sample formulation. The effect of varying Gd3+ concentrations at 3.35 T has been described for 13C-labeled pyruvic acid and acetate. However, it has not been studied for other compounds at this field. The results presented here suggest that Gd3+ doping can lead to various concentration and temperature dependent effects on the polarization of [13C6,2H7]glucose, not necessarily similar to the effects observed in pyruvic acid or acetate in size or direction. The maximal polarization for [13C6,2H7]glucose appears to be at a Gd3+ concentration of 2 mM, when irradiating for more than 2 h at the negative maximum of the DNP intensity profile. Surprisingly, for shorter irradiation times, higher polarization levels were determined at 1.50 K compared to 1.45 K, at a [Gd3+]=1.3 mM. This was explained by the build-up time constant and maximum at these temperatures.
Original language | English |
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Pages (from-to) | 251-256 |
Number of pages | 6 |
Journal | ChemPhysChem |
Volume | 21 |
Issue number | 3 |
DOIs | |
State | Published - 4 Feb 2020 |
Keywords
- build-up time constant
- carbon-13 labeled pyruvate
- hyperpolarized glucose
- microwave frequency intensity profile
- solid-state polarization
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry