Fast Dissolution Dynamic Nuclear Polarization NMR of 13C-Enriched 89Y-DOTA Complex: Experimental and Theoretical Considerations

Lumata, Lloyd; Merritt, Matthew E.; Malloy, Craig R.; Sherry, A. Dean

doi:10.1007/s00723-012-0335-8

Cited by 32 publications

(53 citation statements)

References 19 publications

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“…However, we note that it is also possible that the physics of DNP at 6.5 K or higher may be quite different for DNP done at T ~1K. As mentioned before, mounting experimental evidence 6,7,41,42 suggest the thermal mixing is the predominant DNP mechanism for low-γ nuclei such as 13 C, 89 Y, etc., at least at DNP conditions of 3.35 T and T ~1 K in which we have performed the experiments. Further combined DNP and ESR studies at these conditions may be needed to fully clarify these effects.…”

Section: Resultsmentioning

confidence: 64%

Impact of Ho³⁺-doping on ¹³C dynamic nuclear polarization using trityl OX063 free radical

Kiswandhi¹,

Niedbalski²,

Parish³

et al. 2016

Phys. Chem. Chem. Phys.

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We have investigated the effects of Ho-DOTA doping on the dynamic nuclear polarization (DNP) of [1-13 C] sodium acetate using trityl OX063 free radical at 3.35 T and 1.2 K. Our results indicate that addition of 2 mM Ho-DOTA on 3 M [1-13 C] sodium acetate sample in 1:1 v/v glycerol:water with 15 mM trityl OX063 improves the DNP-enhanced 13 C solid-state nuclear polarization by a factor of around 2.7-fold. Similar to the Gd 3+ doping effect on 13 C DNP, the locations of the positive and negative 13 C maximum polarization peaks in the 13 C microwave DNP sweep are shifted towards each other with the addition of Ho-DOTA on the DNP sample. W-band electron spin resonance (ESR) studies have revealed that while the shape and linewidth of the trityl OX063 ESR spectrum was not affected by Ho 3+ -doping, the electron spin-lattice relaxation time T 1 of trityl OX063 was prominently reduced at cryogenic temperatures. The reduction of trityl OX063 electron T 1 by Ho-doping is linked to the 13 C DNP improvement in light of the thermodynamic picture of DNP. Moreover, the presence of Ho-DOTA in the dissolution liquid at room temperature has negligible reduction effect on liquid-state 13 C T 1 , in contrast to Gd 3+ -doping which drastically reduces the 13 C T 1 . The results here suggest that Ho 3+ -doping is advantageous over Gd 3+ in terms of preservation of hyperpolarized state-an important aspect to consider for in vitro and in vivo NMR or imaging (MRI) experiments where a considerable preparation time is needed to administer the hyperpolarized 13 C liquid.

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Section: Resultsmentioning

confidence: 64%

Impact of Ho³⁺-doping on ¹³C dynamic nuclear polarization using trityl OX063 free radical

Kiswandhi¹,

Niedbalski²,

Parish³

et al. 2016

Phys. Chem. Chem. Phys.

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“…17,18,20,21,31,34,49 Trityl OX063, the stable organic radical used in this work, has a very narrow EPR linewidth that makes it ideal for polarizing low-γ nuclei such as 13 C. When using this free radical to polarize low-γ nuclei such as 13 C spins, DNP data at 3.35 T and temperatures close to 1 K have shown indications of thermal mixing (TM) as the predominant DNP mechanism. 24,[50][51][52][53] Other DNP data at similar conditions suggested that the mechanism could be a combination of the solid effect (SE) and cross effect (CE). [54][55][56] Unlike the solid effect (SE) 57 and the cross effect (CE), 54,58 TM is a many-spin model for polarization that treats spin interactions as thermodynamic reservoirs.…”

Section: Resultsmentioning

confidence: 94%

Influence of Dy3+ and Tb3+ doping on 13C dynamic nuclear polarization

Niedbalski

Parish

Kiswandhi

et al. 2017

The Journal of Chemical Physics

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Dynamic nuclear polarization (DNP) is a technique that uses a microwave-driven transfer of high spin alignment from electrons to nuclear spins. This is most effective at low temperature and high magnetic field, and with the invention of the dissolution method, the amplified nuclear magnetic resonance (NMR) signals in the frozen state in DNP can be harnessed in the liquid-state at physiologically acceptable temperature for in vitro and in vivo metabolic studies. A current optimization practice in dissolution DNP is to dope the sample with trace amounts of lanthanides such as Gd 3+ or Ho 3+ , which further improves the polarization. While Gd 3+ and Ho 3+ have been optimized for use in dissolution DNP, other lanthanides have not been exhaustively studied for use in 13 C DNP applications. In this work, two additional lanthanides with relatively high magnetic moments, Dy 3+ and Tb 3+ , were extensively optimized and tested as doping additives for 13 C DNP at 3.35 T and 1.2 K. We have found that both of these lanthanides are also beneficial additives, to a varying degree, for 13 C DNP. The optimal concentrations of Dy 3+ (1.5 mM) and Tb 3+ (0.25 mM) for 13 C DNP were found to be less than that of Gd 3+ (2 mM). W-band electron paramagnetic resonance shows that these enhancements due to Dy 3+ and Tb 3+ doping are accompanied by shortening of electron T 1 of trityl OX063 free radical. Furthermore, when dissolution was employed, Tb 3+ -doped samples were found to have similar liquid-state 13 C NMR signal enhancements compared to samples doped with Gd 3+ , and both Tb 3+ and Dy 3+ had a negligible liquid-state nuclear T 1 shortening effect which contrasts with the significant reduction in T 1 when using Gd 3+ . Our results show that Dy 3+ doping and Tb 3+ doping have a beneficial impact on 13 C DNP both in the solid and liquid states, and that Tb 3+ in particular could be used as a potential alternative to Gd 3+ in 13 C dissolution DNP experiments. Published by AIP Publishing.

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“…In the solid effect regime where the ESR linewidth D is much smaller than the nuclear Larmor frequency ν n these optimum polarization peaks are expected to appear at ν e ± ν n [4, 5]. However, considering the ESR linewidths of these free radicals are wider than or comparable to the 13 C ν n , the expected predominant DNP mechanism for 13 C samples here is the thermal mixing process [28, 29]. The shape of the microwave DNP spectra in this regime can be approximated by the Borghini model, which predicts the nuclear spin temperature as a function of the ESR line shape [30].…”

Section: Discussionmentioning

confidence: 99%

Development and performance of a 129-GHz dynamic nuclear polarizer in an ultra-wide bore superconducting magnet

Lumata

Martin

Jindal

et al. 2014

Magn Reson Mater Phy

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Objective We sought to build a dynamic nuclear polarization system for operation at 4.6 T (129 GHz) and evaluate its efficiency in terms of 13C polarization levels using free radicals that span a range of ESR linewidths. Materials and methods A liquid helium cryostat was placed in a 4.6 T superconducting magnet with a 150-mm warm bore diameter. A 129-GHz microwave source was used to irradiate 13C enriched samples. Temperatures close to 1 K were achieved using a vacuum pump with a 453-m3/h roots blower. A hyperpolarized 13C nuclear magnetic resonance (NMR) signal was detected using a saddle coil and a Varian VNMRS console operating at 49.208 MHz. Samples doped with free radicals BDPA (1,3-bisdipheny-lene-2-phenylallyl), trityl OX063 (tris{8-carboxyl-2,2,6,6-benzo(1,2-d:4,5-d)-bis(1,3)dithiole-4-yl}methyl sodium salt), galvinoxyl ((2,6-di-tert-butyl-α-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadien-1-ylidene)-p-tolyloxy), 2,2-diphenylpicrylhydrazyl (DPPH) and 4-oxo-TEMPO (4-Oxo-2,2,6,6-tetramethyl-1-piperidinyloxy) were assayed. Microwave dynamic nuclear polarization (DNP) spectra and solid-state 13C polarization levels for these samples were determined. Results 13C polarization levels close to 50 % were achieved for [1-13C]pyruvic acid at 1.15 K using the narrow electron spin resonance (ESR) linewidth free radicals trityl OX063 and BDPA, while 10–20 % 13C polarizations were achieved using galvinoxyl, DPPH and 4-oxo-TEMPO. Conclusion At this field strength free radicals with smaller ESR linewidths are still superior for DNP of 13C as opposed to those with linewidths that exceed that of the 1H Larmor frequency.

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Fast Dissolution Dynamic Nuclear Polarization NMR of 13C-Enriched 89Y-DOTA Complex: Experimental and Theoretical Considerations

Cited by 32 publications

References 19 publications

Impact of Ho³⁺-doping on ¹³C dynamic nuclear polarization using trityl OX063 free radical

Impact of Ho³⁺-doping on ¹³C dynamic nuclear polarization using trityl OX063 free radical

Influence of Dy3+ and Tb3+ doping on 13C dynamic nuclear polarization

Development and performance of a 129-GHz dynamic nuclear polarizer in an ultra-wide bore superconducting magnet

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Fast Dissolution Dynamic Nuclear Polarization NMR of 13C-Enriched 89Y-DOTA Complex: Experimental and Theoretical Considerations

Cited by 32 publications

References 19 publications

Impact of Ho3+-doping on 13C dynamic nuclear polarization using trityl OX063 free radical

Impact of Ho3+-doping on 13C dynamic nuclear polarization using trityl OX063 free radical

Influence of Dy3+ and Tb3+ doping on 13C dynamic nuclear polarization

Development and performance of a 129-GHz dynamic nuclear polarizer in an ultra-wide bore superconducting magnet

Contact Info

Product

Resources

About

Impact of Ho³⁺-doping on ¹³C dynamic nuclear polarization using trityl OX063 free radical

Impact of Ho³⁺-doping on ¹³C dynamic nuclear polarization using trityl OX063 free radical