High-field dissolution dynamic nuclear polarization of [1-<sup>13</sup>C]pyruvic acid

Yoshihara, Hikari A.I.; Can, Emine; Karlsson, Magnus; Lerche, Mathilde Hauge; Schwitter, Juerg; Comment, Arnaud

doi:10.1039/c6cp00589f

Cited by 47 publications

(99 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The liquid-state 13 C polarization obtained in the present work is severalfold lower than the maximum values obtained by dissolution DNP using the same polarizer and trityl radicals30. The narrower ESR line width of trityl radicals as compared to photo-induced radicals is expected to lead to higher 13 C polarization25, but the main reason for the lower polarization is the sub-optimal radical concentration, which also explains that the build-up time constant is larger than in an optimized PA sample prepared with trityl radical.…”

Section: Discussioncontrasting

confidence: 75%

Thermal annihilation of photo-induced radicals following dynamic nuclear polarization to produce transportable frozen hyperpolarized 13C-substrates

et al. 2017

Self Cite

View full text Add to dashboard Cite

Hyperpolarization via dynamic nuclear polarization (DNP) is pivotal for boosting magnetic resonance imaging (MRI) sensitivity and dissolution DNP can be used to perform in vivo real-time 13C MRI. The type of applications is however limited by the relatively fast decay time of the hyperpolarized spin state together with the constraint of having to polarize the 13C spins in a dedicated apparatus nearby but separated from the MRI magnet. We herein demonstrate that by polarizing 13C with photo-induced radicals, which can be subsequently annihilated using a thermalization process that maintains the sample temperature below its melting point, hyperpolarized 13C-substrates can be extracted from the DNP apparatus in the solid form, while maintaining the enhanced 13C polarization. The melting procedure necessary to transform the frozen solid into an injectable solution containing the hyperpolarized 13C-substrates can therefore be performed ex situ, up to several hours after extraction and storage of the polarized solid.

show abstract

Section: Discussioncontrasting

confidence: 75%

Thermal annihilation of photo-induced radicals following dynamic nuclear polarization to produce transportable frozen hyperpolarized 13C-substrates

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…The frozen glassy UV‐irradiated beads were loaded into a polytetrafluoroethylene sample cup together with frozen droplets of NaOH solution, the volume and concentration of which was calculated to balance the pH to 7 during dissolution. The polytetrafluoroethylene cup was then placed inside a 7T homebuilt polarizer, and the 13 C spins were polarized for 2 hours at 1.0 ± 0.1 K with the microwave frequency set to 196.75 GHz . Using an automated process, the sample was rapidly dissolved in 6 mL D 2 O and transferred within 2 seconds into a remotely controlled phase separator/injection pump, located inside the bore of the MR scanner (Figure ).…”

Section: Methodsmentioning

confidence: 99%

Probing cardiac metabolism by hyperpolarized 13C MR using an exclusively endogenous substrate mixture and photo‐induced nonpersistent radicals

Bastiaansen

Yoshihara

Capozzi

et al. 2018

Magnetic Resonance in Med

Self Cite

View full text Add to dashboard Cite

Purpose To probe the cardiac metabolism of carbohydrates and short chain fatty acids simultaneously in vivo following the injection of a hyperpolarized 13C-labeled substrate mixture prepared using photo-induced non-persistent radicals. Methods Droplets of mixed [1-13C]pyruvic and [1-13C]butyric acids were frozen into glassy beads in liquid nitrogen. Ethanol addition was investigated as a means to increase the polarization level. The beads were irradiated with ultraviolet (UV) light and the radical concentration was measured by ESR spectroscopy. Following dynamic nuclear polarization (DNP) in a 7T polarizer, the beads were dissolved, and the radical-free hyperpolarized solution was rapidly transferred into an injection pump located inside a 9.4T scanner. The hyperpolarized solution was injected in healthy rats to measure cardiac metabolism in vivo. Results UV-irradiation created non-persistent radicals in a mixture containing 13C-labeled pyruvic and butyric acids and enabled the hyperpolarization of both substrates by DNP. Ethanol addition increased the radical concentration from 16 to 26 mM. Liquid-state 13C polarization was 3% inside the pump at the time of injection, and increased to 5% by addition of ethanol to the substrate mixture prior to UV irradiation. In the rat heart, the in vivo 13C signals from lactate, alanine, bicarbonate and acetylcarnitine were detected following the metabolism of the injected substrate mixture. Conclusion Co-polarization of two 13C-labeled substrates and the detection of their myocardial metabolism in vivo was achieved without using persistent radicals. The absence of radicals in the solution containing the hyperpolarized 13C-substrates may simplify the translation to clinical use because no filtration is required prior to injection.

show abstract

“…Recent studies have shown a trend in which DNP systems at higher field than 3.35 T yielded higher 13 C polarization levels. [20][21][22][23][25][26][27][28] In this work, we describe the development of a 180…”

Section: Introductionmentioning

confidence: 99%

Construction and ¹³C hyperpolarization efficiency of a 180 GHz dissolution dynamic nuclear polarization system

Kiswandhi

Niedbalski

Parish

et al. 2017

Magnetic Reson in Chemistry

View full text Add to dashboard Cite

Dynamic nuclear polarization (DNP) via the dissolution method has become one of the rapidly emerging techniques to alleviate the low signal sensitivity in nuclear magnetic resonance (NMR) spectroscopy and imaging. In this paper, we report on the development and C hyperpolarization efficiency of a homebuilt DNP system operating at 6.423 T and 1.4 K. The DNP hyperpolarizer system was assembled on a wide-bore superconducting magnet, equipped with a standard continuous-flow cryostat, and a 180 GHz microwave source with 120 mW power output and wide 4 GHz frequency tuning range. At 6.423 T and 1.4 K, solid-state C polarization P levels of 64% and 31% were achieved for 3 M [1- C] sodium acetate samples in 1 : 1 v/v glycerol:water glassing matrix doped with 15 mM trityl OX063 and 40 mM 4-oxo-TEMPO, respectively. Upon dissolution, which takes about 15 s to complete, liquid-state C NMR signal enhancements as high as 240 000-fold (P=21%) were recorded in a nearby high resolution C NMR spectrometer at 1 T and 297 K. Considering the relatively lower cost of our homebuilt DNP system and the relative simplicity of its design, the dissolution DNP setup reported here could be feasibly adapted for in vitro or in vivo hyperpolarized C NMR or magnetic resonance imaging at least in the pre-clinical setting. Copyright © 2017 John Wiley& Sons, Ltd.

show abstract

High-field dissolution dynamic nuclear polarization of [1-¹³C]pyruvic acid

Cited by 47 publications

References 29 publications

Thermal annihilation of photo-induced radicals following dynamic nuclear polarization to produce transportable frozen hyperpolarized 13C-substrates

Thermal annihilation of photo-induced radicals following dynamic nuclear polarization to produce transportable frozen hyperpolarized 13C-substrates

Probing cardiac metabolism by hyperpolarized 13C MR using an exclusively endogenous substrate mixture and photo‐induced nonpersistent radicals

Construction and ¹³C hyperpolarization efficiency of a 180 GHz dissolution dynamic nuclear polarization system

Contact Info

Product

Resources

About

High-field dissolution dynamic nuclear polarization of [1-13C]pyruvic acid

Cited by 47 publications

References 29 publications

Thermal annihilation of photo-induced radicals following dynamic nuclear polarization to produce transportable frozen hyperpolarized 13C-substrates

Thermal annihilation of photo-induced radicals following dynamic nuclear polarization to produce transportable frozen hyperpolarized 13C-substrates

Probing cardiac metabolism by hyperpolarized 13C MR using an exclusively endogenous substrate mixture and photo‐induced nonpersistent radicals

Construction and 13C hyperpolarization efficiency of a 180 GHz dissolution dynamic nuclear polarization system

Contact Info

Product

Resources

About

High-field dissolution dynamic nuclear polarization of [1-¹³C]pyruvic acid

Construction and ¹³C hyperpolarization efficiency of a 180 GHz dissolution dynamic nuclear polarization system