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Performance and reproducibility of 13C and 15N hyperpolarization using a cryogen-free DNP polarizer. Sci Rep 2022; 12:11694. [PMID: 35803961 PMCID: PMC9270333 DOI: 10.1038/s41598-022-15380-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 06/23/2022] [Indexed: 12/02/2022] Open
Abstract
The setup, operational procedures and performance of a cryogen-free device for producing hyperpolarized contrast agents using dissolution dynamic nuclear polarization (dDNP) in a preclinical imaging center is described. The polarization was optimized using the solid-state, DNP-enhanced NMR signal to calibrate the sample position, microwave and NMR frequency and power and flip angle. The polarization of a standard formulation to yield ~ 4 mL, 60 mM 1-13C-pyruvic acid in an aqueous solution was quantified in five experiments to P(13C) = (38 ± 6) % (19 ± 1) s after dissolution. The mono-exponential time constant of the build-up of the solid-state polarization was quantified to (1032 ± 22) s. We achieved a duty cycle of 1.5 h that includes sample loading, monitoring the polarization build-up, dissolution and preparation for the next run. After injection of the contrast agent in vivo, pyruvate, pyruvate hydrate, lactate, and alanine were observed, by measuring metabolite maps. Based on this work sequence, hyperpolarized 15N urea was obtained (P(15N) = (5.6 ± 0.8) % (30 ± 3) s after dissolution).
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2
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Elliott SJ, Stern Q, Ceillier M, El Daraï T, Cousin SF, Cala O, Jannin S. Practical dissolution dynamic nuclear polarization. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2021; 126-127:59-100. [PMID: 34852925 DOI: 10.1016/j.pnmrs.2021.04.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 06/13/2023]
Abstract
This review article intends to provide insightful advice for dissolution-dynamic nuclear polarization in the form of a practical handbook. The goal is to aid research groups to effectively perform such experiments in their own laboratories. Previous review articles on this subject have covered a large number of useful topics including instrumentation, experimentation, theory, etc. The topics to be addressed here will include tips for sample preparation and for checking sample health; a checklist to correctly diagnose system faults and perform general maintenance; the necessary mechanical requirements regarding sample dissolution; and aids for accurate, fast and reliable polarization quantification. Herein, the challenges and limitations of each stage of a typical dissolution-dynamic nuclear polarization experiment are presented, with the focus being on how to quickly and simply overcome some of the limitations often encountered in the laboratory.
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Affiliation(s)
- Stuart J Elliott
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Quentin Stern
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Morgan Ceillier
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Théo El Daraï
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Samuel F Cousin
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Olivier Cala
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France
| | - Sami Jannin
- Centre de Résonance Magnétique Nucléaire à Très Hauts Champs - UMR 5082 Université de Lyon, CNRS, Université Claude Bernard Lyon 1, ENS de Lyon, 5 Rue de la Doua, 69100 Villeurbanne, France.
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Wang Q, Parish C, Niedbalski P, Ratnakar J, Kovacs Z, Lumata L. Hyperpolarized 89Y-EDTMP complex as a chemical shift-based NMR sensor for pH at the physiological range. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 320:106837. [PMID: 33039915 PMCID: PMC7895333 DOI: 10.1016/j.jmr.2020.106837] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/16/2020] [Accepted: 09/26/2020] [Indexed: 05/04/2023]
Abstract
Yttrium (III) complexes are interesting due to the similarity of their chemistry with gadolinium complexes that are used as contrast agents in nuclear magnetic resonance (NMR) spectroscopy or imaging (MRI). While most of the paramagnetic Gd3+-based MRI contrast agents are T1 or T2 relaxation-based sensors such as Gd3+-complexes for zinc or pH detection, a number of diamagnetic Y3+-complexes rely on changes in the chemical shift for potential quantitative MRI in biological milieu. 89Y, however, is a challenging nucleus to work with in conventional NMR or MRI due to its inherently low sensitivity and relatively long T1 relaxation time. This insensitivity problem in 89Y-based complexes can be circumvented with the use of dissolution dynamic nuclear polarization (DNP) which allows for several thousand-fold enhancement of the NMR or MRI signal relative to thermal equilibrium signal. Herein, we report on the feasibility of using hyperpolarized 89Y-complexes with phosphonated open-chain ligands, 89Y-EDTMP and 89Y-DTPMP, as potential chemical shift-based pH NMR sensors. Our DNP-NMR data show that hyperpolarized 89Y-DTPMP has an apparent pKa ~ 7.01 with a 4 ppm-wide chemical shift dispersion with the signal disappearing at pH below 6.2. On the other hand, pH titration data on hyperpolarized 89Y-EDTMP show that it has an apparent pKa of pH 6.7 and a 16-ppm wide chemical shift dispersion at pH 5-9 range. In comparison, the previously reported hyperpolarized pH NMR sensor 89Y-DOTP has a pKa of 7.64 and ~ 10-ppm wide chemical shift dispersion at pH 4-9 range. Overall, our data suggest that hyperpolarized 89Y-EDTMP is better than hyperpolarized 89Y-DOTP in terms of pH sensing capability at the physiological range.
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Affiliation(s)
- Qing Wang
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, USA
| | - Christopher Parish
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, USA; Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695, USA
| | - Peter Niedbalski
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, USA; Pulmonary and Critical Care Medicine, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
| | - James Ratnakar
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 750390, USA
| | - Zoltan Kovacs
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 750390, USA.
| | - Lloyd Lumata
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, USA.
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Singh J, Suh EH, Sharma G, Khemtong C, Sherry AD, Kovacs Z. Probing carbohydrate metabolism using hyperpolarized 13 C-labeled molecules. NMR IN BIOMEDICINE 2019; 32:e4018. [PMID: 30474153 PMCID: PMC6579721 DOI: 10.1002/nbm.4018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 08/03/2018] [Accepted: 08/11/2018] [Indexed: 05/05/2023]
Abstract
Glycolysis is a fundamental metabolic process in all organisms. Anomalies in glucose metabolism are linked to various pathological conditions. In particular, elevated aerobic glycolysis is a characteristic feature of rapidly growing cells. Glycolysis and the closely related pentose phosphate pathway can be monitored in real time by hyperpolarized 13 C-labeled metabolic substrates such as 13 C-enriched, deuterated D-glucose derivatives, [2-13 C]-D-fructose, [2-13 C] dihydroxyacetone, [1-13 C]-D-glycerate, [1-13 C]-D-glucono-δ-lactone and [1-13 C] pyruvate in healthy and diseased tissues. Elevated glycolysis in tumors (the Warburg effect) was also successfully imaged using hyperpolarized [U-13 C6 , U-2 H7 ]-D-glucose, while the size of the preexisting lactate pool can be measured by 13 C MRS and/or MRI with hyperpolarized [1-13 C]pyruvate. This review summarizes the application of various hyperpolarized 13 C-labeled metabolites to the real-time monitoring of glycolysis and related metabolic processes in normal and diseased tissues.
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Affiliation(s)
- Jaspal Singh
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Eul Hyun Suh
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Gaurav Sharma
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Chalermchai Khemtong
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - A. Dean Sherry
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Chemistry and Biochemistry, The University of Texas at Dallas, Richardson, TX, USA
| | - Zoltan Kovacs
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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Parish C, Niedbalski P, Wang Q, Khashami F, Hayati Z, Liu M, Song L, Lumata L. Effects of glassing matrix deuteration on the relaxation properties of hyperpolarized 13C spins and free radical electrons at cryogenic temperatures. J Chem Phys 2019; 150:234307. [PMID: 31228902 PMCID: PMC6588520 DOI: 10.1063/1.5096036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/20/2019] [Accepted: 06/03/2019] [Indexed: 11/14/2022] Open
Abstract
Glassing matrix deuteration could be a beneficial sample preparation method for 13C dynamic nuclear polarization (DNP) when large electron paramagnetic resonance (EPR) width free radicals are used. However, it could yield the opposite DNP effect when samples are doped with small EPR width free radicals. Herein, we have investigated the influence of solvent deuteration on the 13C nuclear and electron relaxation that go along with the effects on 13C DNP intensities at 3.35 T and 1.2 K. For 13C DNP samples doped with trityl OX063, the 13C DNP signals decreased significantly when the protons are replaced by deuterons in glycerol:water or DMSO:water solvents. Meanwhile, the corresponding solid-state 13C T1 relaxation times of trityl OX063-doped samples generally increased upon solvent deuteration. On the other hand, 13C DNP signals improved by a factor of ∼1.5 to 2 upon solvent deuteration of samples doped with 4-oxo-TEMPO. Despite this 13C DNP increase, there were no significant differences recorded in 13C T1 values of TEMPO-doped samples with nondeuterated or fully deuterated glassing matrices. While solvent deuteration appears to have a negligible effect on the electron T1 relaxation of both free radicals, the electron T2 relaxation times of these two free radicals generally increased upon solvent deuteration. These overall results suggest that while the solid-phase 13C DNP signals are dependent upon the changes in total nuclear Zeeman heat capacity, the 13C relaxation effects are related to 2H/1H nuclear spin diffusion-assisted 13C polarization leakage in addition to the dominant paramagnetic relaxation contribution of free radical centers.
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Affiliation(s)
- Christopher Parish
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, USA
| | | | - Qing Wang
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, USA
| | - Fatemeh Khashami
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, USA
| | | | | | - Likai Song
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA
| | - Lloyd Lumata
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, USA
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Niedbalski P, Kiswandhi A, Parish C, Wang Q, Khashami F, Lumata L. NMR Spectroscopy Unchained: Attaining the Highest Signal Enhancements in Dissolution Dynamic Nuclear Polarization. J Phys Chem Lett 2018; 9:5481-5489. [PMID: 30179503 DOI: 10.1021/acs.jpclett.8b01687] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Dynamic nuclear polarization (DNP) via the dissolution method is one of the most successful methods for alleviating the inherently low Boltzmann-dictated sensitivity in nuclear magnetic resonance (NMR) spectroscopy. This emerging technology has already begun to positively impact chemical and metabolic research by providing the much-needed enhancement of the liquid-state NMR signals of insensitive nuclei such as 13C by several thousand-fold. In this Perspective, we present our viewpoints regarding the key elements needed to maximize the NMR signal enhancements in dissolution DNP, from the very core of the DNP process at cryogenic temperatures, DNP instrumental conditions, and chemical tuning in sample preparation to current developments in minimizing hyperpolarization losses during the dissolution transfer process. The optimization steps discussed herein could potentially provide important experimental and theoretical considerations in harnessing the best possible sensitivity gains in NMR spectroscopy as afforded by optimized dissolution DNP technology.
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Affiliation(s)
- Peter Niedbalski
- Department of Physics , The University of Texas at Dallas , 800 West Campbell Road , Richardson , Texas 75080 , United States
| | - Andhika Kiswandhi
- Department of Physics , The University of Texas at Dallas , 800 West Campbell Road , Richardson , Texas 75080 , United States
| | - Christopher Parish
- Department of Physics , The University of Texas at Dallas , 800 West Campbell Road , Richardson , Texas 75080 , United States
| | - Qing Wang
- Department of Physics , The University of Texas at Dallas , 800 West Campbell Road , Richardson , Texas 75080 , United States
| | - Fatemeh Khashami
- Department of Physics , The University of Texas at Dallas , 800 West Campbell Road , Richardson , Texas 75080 , United States
| | - Lloyd Lumata
- Department of Physics , The University of Texas at Dallas , 800 West Campbell Road , Richardson , Texas 75080 , United States
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Parish C, Niedbalski P, Kiswandhi A, Lumata L. Dynamic nuclear polarization of carbonyl and methyl 13C spins of acetate using 4-oxo-TEMPO free radical. J Chem Phys 2018; 149:054302. [PMID: 30089385 DOI: 10.1063/1.5043378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Hyperpolarization of 13C-enriched biomolecules via dissolution dynamic nuclear polarization (DNP) has enabled real-time metabolic imaging of a variety of diseases with superb specificity and sensitivity. The source of the unprecedented liquid-state nuclear magnetic resonance spectroscopic or imaging signal enhancements of >10 000-fold is the microwave-driven DNP process that occurs at a relatively high magnetic field and cryogenic temperature. Herein, we have methodically investigated the relative efficiencies of 13C DNP of single or double 13C-labeled sodium acetate with or without 2H-enrichment of the methyl group and using a 4-oxo-TEMPO free radical as the polarizing agent at 3.35 T and 1.4 K. The main finding of this work is that not all 13C spins in acetate are polarized with equal DNP efficiency using this relatively wide electron spin resonance linewidth free radical. In fact, the carbonyl 13C spins have about twice the solid-state 13C polarization level of methyl 13C spins. Deuteration of the methyl group provides a DNP signal improvement of methyl 13C spins on a par with that of carbonyl 13C spins. On the other hand, both the double 13C-labeled [1,2-13C2] acetate and [1,2-13C2, 2H3] acetate have a relative solid-state 13C polarization at the level of [2-13C] acetate. Meanwhile, the solid-state 13C T1 relaxation times at 3.35 T and 1.4 K were essentially the same for all six isotopomers of 13C acetate. These results suggest that the intramolecular environment of 13C spins plays a prominent role in determining the 13C DNP efficiency, while the solid phase 13C T1 relaxation of these samples is dominated by the paramagnetic effect due to the relatively high concentration of free radicals.
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Affiliation(s)
- Christopher Parish
- Department of Physics, The University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, USA
| | - Peter Niedbalski
- Department of Physics, The University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, USA
| | - Andhika Kiswandhi
- Department of Physics, The University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, USA
| | - Lloyd Lumata
- Department of Physics, The University of Texas at Dallas, 800 West Campbell Road, Richardson, Texas 75080, USA
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Wang X, McKay JE, Lama B, van Tol J, Li T, Kirkpatrick K, Gan Z, Hill S, Long JR, Dorn HC. Gadolinium based endohedral metallofullerene Gd 2@C 79N as a relaxation boosting agent for dissolution DNP at high fields. Chem Commun (Camb) 2018; 54:2425-2428. [PMID: 29457159 DOI: 10.1039/c7cc09765d] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We show increased dynamic nuclear polarization by adding a low dosage of a S = 15/2 Gd based endohedral metallofullerene (EMF) to DNP samples. By adding 60 μM Gd2@C79N, the nuclear polarization of 1H and 13C spins from 40 mM 4-oxo-TEMPO increases by approximately 40% and 50%, respectively, at 5 T and 1.2 K. Electron-electron double resonance (ELDOR) measurements show that the high spin EMF shortens the electron relaxation times and increases electron spectral diffusion leading to the increased DNP enhancement.
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Affiliation(s)
- Xiaoling Wang
- National High Magnetic Field Laboratory, Tallahassee, FL 32310, USA.
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Niedbalski P, Parish CR, Wang Q, Hayati Z, Song L, Cleveland ZI, Lumata L. Enhanced Efficiency of 13C Dynamic Nuclear Polarization by Superparamagnetic Iron Oxide Nanoparticle Doping. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2017; 121:19505-19511. [PMID: 31768206 PMCID: PMC6876865 DOI: 10.1021/acs.jpcc.7b06408] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Attainment of high NMR signal enhancements is crucial to the success of in vitro or in vivo hyperpolarized NMR or imaging (MRI) experiments. In this work, we report on the use of a superparamagnetic iron oxide nanoparticle (SPION) MRI contrast agent Feraheme (ferumoxytol) as a beneficial additive in 13C samples for dissolution dynamic nuclear polarization (DNP). Our DNP data at 3.35 T and 1.2 K reveal that addition of 11 mM elemental iron concentration of Feraheme in trityl OX063-doped 3 M [1-13C] acetate samples resulted in a substantial improvement of 13C DNP signal by a factor of almost 3-fold. Concomitant with the large DNP signal increase is the narrowing of the 13C microwave DNP spectra for samples doped with SPION. W-band electron paramagnetic resonance (EPR) spectroscopy data suggest that these two prominent effects of SPION doping on 13C DNP can be ascribed to the shortening of trityl OX063 electron T 1 as explained within the thermal mixing DNP model. Liquid-state 13C NMR signal enhancements as high as 20,000-fold for SPION-doped samples were recorded after dissolution at 9.4 T and 297 K, which is about 3 times the liquid-state NMR signal enhancement of the control sample. While the presence of SPION in hyperpolarized solution drastically reduces 13C T 1, this can be mitigated by polarizing smaller aliquots of DNP samples. Moreover, we have shown that Feraheme nanoparticles (~30 nm in size) can be easily and effectively removed from the hyperpolarized liquid by simple mechanical filtration, thus one can potentially incorporate an in-line filtration for these SPIONS along the dissolution pathway of the hyperpolarizer-a significant advantage over other DNP enhancers such as the lanthanide complexes. The overall results suggest that the commercially-available and FDA-approved Feraheme is a highly efficient DNP enhancer that could be readily translated for use in clinical applications of dissolution DNP.
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Affiliation(s)
- Peter Niedbalski
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080 USA
| | - Christopher R. Parish
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080 USA
| | - Qing Wang
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080 USA
| | - Zahra Hayati
- National High Magnetic Field Laboratory, Florida State University, 1800 E Paul Dirac Drive, Tallahassee, FL 32310
| | - Likai Song
- National High Magnetic Field Laboratory, Florida State University, 1800 E Paul Dirac Drive, Tallahassee, FL 32310
| | - Zackary I. Cleveland
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH 45221
| | - Lloyd Lumata
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080 USA
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Kiswandhi A, Niedbalski P, Parish C, Wang Q, Lumata L. Assembly and performance of a 6.4 T cryogen-free dynamic nuclear polarization system. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:846-852. [PMID: 28593642 DOI: 10.1002/mrc.4624] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 06/03/2017] [Accepted: 06/05/2017] [Indexed: 06/07/2023]
Abstract
We report on the assembly and performance evaluation of a 180-GHz/6.4 T dynamic nuclear polarization (DNP) system based on a cryogen-free superconducting magnet. The DNP system utilizes a variable-field superconducting magnet that can be ramped up to 9 T and equipped with cryocoolers that can cool the sample space with the DNP assembly down to 1.8 K via the Joule-Thomson effect. A homebuilt DNP probe insert with top-tuned nuclear magnetic resonance coil and microwave port was incorporated into the sample space in which the effective sample temperature is approximately 1.9 K when a 180-GHz microwave source is on during DNP operation. 13 C DNP of [1-13 C] acetate samples doped with trityl OX063 and 4-oxo-TEMPO in this system have resulted in solid-state 13 C polarization levels of 58 ± 3% and 18 ± 2%, respectively. The relatively high 13 C polarization levels achieved in this work have demonstrated that the use of a cryogen-free superconducting magnet for 13 C DNP is feasible and in fact, relatively efficient-a major leap to offset the high cost of liquid helium consumption in DNP experiments.
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Affiliation(s)
- Andhika Kiswandhi
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Peter Niedbalski
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Christopher Parish
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Qing Wang
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Lloyd Lumata
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
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Kiswandhi A, Niedbalski P, Parish C, Ferguson S, Taylor D, McDonald G, Lumata L. Construction and 13 C hyperpolarization efficiency of a 180 GHz dissolution dynamic nuclear polarization system. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2017; 55:828-836. [PMID: 28407455 DOI: 10.1002/mrc.4597] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Revised: 04/05/2017] [Accepted: 04/06/2017] [Indexed: 06/07/2023]
Abstract
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 13 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 13 C polarization P levels of 64% and 31% were achieved for 3 M [1-13 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 13 C NMR signal enhancements as high as 240 000-fold (P=21%) were recorded in a nearby high resolution 13 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 13 C NMR or magnetic resonance imaging at least in the pre-clinical setting. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Andhika Kiswandhi
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Peter Niedbalski
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Christopher Parish
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Sarah Ferguson
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - David Taylor
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - George McDonald
- Department of Chemistry, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
| | - Lloyd Lumata
- Department of Physics, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080, USA
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Niedbalski P, Parish C, Wang Q, Kiswandhi A, Hayati Z, Song L, Lumata L. 13C Dynamic Nuclear Polarization Using a Trimeric Gd 3+ Complex as an Additive. J Phys Chem A 2017. [PMID: 28631929 DOI: 10.1021/acs.jpca.7b03869] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Dissolution dynamic nuclear polarization (DNP) is one of the most successful techniques that resolves the insensitivity problem in liquid-state nuclear magnetic resonance (NMR) spectroscopy and imaging (MRI) by amplifying the signal by several thousand-fold. One way to further improve the DNP signal is the inclusion of trace amounts of lanthanides in DNP samples doped with trityl OX063 free radical as the polarizing agent. In practice, stable monomeric gadolinium complexes such as Gd-DOTA or Gd-HP-DO3A are used as beneficial additives in DNP samples, further boosting the DNP-enhanced solid-state 13C polarization by a factor of 2 or 3. Herein, we report on the use of a trimeric gadolinium complex as a dopant in 13C DNP samples to improve the 13C DNP signals in the solid-state at 3.35 T and 1.2 K and consequently, in the liquid-state at 9.4 T and 298 K after dissolution. Our results have shown that doping the 13C DNP sample with a complex which holds three Gd3+ ions led to an improvement of DNP-enhanced 13C polarization by a factor of 3.4 in the solid-state, on par with those achieved using monomeric Gd3+ complexes but only requires about one-fifth of the concentration. Upon dissolution, liquid-state 13C NMR signal enhancements close to 20 000-fold, approximately 3-fold the enhancement of the control samples, were recorded in the nearby 9.4 T high resolution NMR magnet at room temperature. Comparable reduction of 13C spin-lattice T1 relaxation time was observed in the liquid-state after dissolution for both the monomeric and trimeric Gd3+ complexes. Moreover, W-band electron paramagnetic resonance (EPR) data have revealed that 3-Gd doping significantly reduces the electron T1 of the trityl OX063 free radical, but produces negligible changes in the EPR spectrum, reminiscent of the results with monomeric Gd3+-complex doping. Our data suggest that the trimeric Gd3+ complex is a highly beneficial additive in 13C DNP samples and that its effect on DNP efficiency can be described in the context of the thermal mixing mechanism.
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Affiliation(s)
- Peter Niedbalski
- Department of Physics, University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080 United States
| | - Christopher Parish
- Department of Physics, University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080 United States
| | - Qing Wang
- Department of Physics, University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080 United States
| | - Andhika Kiswandhi
- Department of Physics, University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080 United States
| | - Zahra Hayati
- National High Magnetic Field Laboratory, Florida State University , 1800 E. Paul Dirac Drive, Tallahassee, Florida 32310, United States
| | - Likai Song
- National High Magnetic Field Laboratory, Florida State University , 1800 E. Paul Dirac Drive, Tallahassee, Florida 32310, United States
| | - Lloyd Lumata
- Department of Physics, University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080 United States
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13
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Niedbalski P, Parish C, Kiswandhi A, Kovacs Z, Lumata L. Influence of 13C Isotopic Labeling Location on Dynamic Nuclear Polarization of Acetate. J Phys Chem A 2017; 121:3227-3233. [PMID: 28422500 DOI: 10.1021/acs.jpca.7b01844] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Dynamic nuclear polarization (DNP) via the dissolution method has alleviated the insensitivity problem in liquid-state nuclear magnetic resonance (NMR) spectroscopy by amplifying the signals by several thousand-fold. This NMR signal amplification process emanates from the microwave-mediated transfer of high electron spin alignment to the nuclear spins at high magnetic field and cryogenic temperature. Since the interplay between the electrons and nuclei is crucial, the chemical composition of a DNP sample such as the type of free radical used, glassing solvents, or the nature of the target nuclei can significantly affect the NMR signal enhancement levels that can be attained with DNP. Herein, we have investigated the influence of 13C isotopic labeling location on the DNP of a model 13C compound, sodium acetate, at 3.35 T and 1.4 K using the narrow electron spin resonance (ESR) line width free radical trityl OX063. Our results show that the carboxyl 13C spins yielded about twice the polarization produced in methyl 13C spins. Deuteration of the methyl 13C group, while proven beneficial in the liquid-state, did not produce an improvement in the 13C polarization level at cryogenic conditions. In fact, a slight reduction of the solid-state 13C polarization was observed when 2H spins are present in the methyl group. Furthermore, our data reveal that there is a close correlation between the solid-state 13C T1 relaxation times of these samples and the relative 13C polarization levels. The overall results suggest the achievable solid-state polarization of 13C acetate is directly affected by the location of the 13C isotopic labeling via the possible interplay of nuclear relaxation leakage factor and cross-talks between nuclear Zeeman reservoirs in DNP.
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Affiliation(s)
- Peter Niedbalski
- Department of Physics, University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080 United States
| | - Christopher Parish
- Department of Physics, University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080 United States
| | - Andhika Kiswandhi
- Department of Physics, University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080 United States
| | - Zoltan Kovacs
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center , 5323 Harry Hines Boulevard, Dallas, Texas 75390 United States
| | - Lloyd Lumata
- Department of Physics, University of Texas at Dallas , 800 West Campbell Road, Richardson, Texas 75080 United States
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14
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Jähnig F, Kwiatkowski G, Däpp A, Hunkeler A, Meier BH, Kozerke S, Ernst M. Dissolution DNP using trityl radicals at 7 T field. Phys Chem Chem Phys 2017; 19:19196-19204. [DOI: 10.1039/c7cp03633g] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Characterization of direct 13C DNP at 1.4 K and 7 T field using trityl radicals.
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Affiliation(s)
- Fabian Jähnig
- Physical Chemistry
- ETH Zürich
- Vladimir-Prelog-Weg 2
- 8093 Zürich
- Switzerland
| | - Grzegorz Kwiatkowski
- Institute for Biomedical Engineering
- University and ETH Zürich
- Gloriastrasse 35
- 8092 Zürich
- Switzerland
| | - Alexander Däpp
- Physical Chemistry
- ETH Zürich
- Vladimir-Prelog-Weg 2
- 8093 Zürich
- Switzerland
| | - Andreas Hunkeler
- Physical Chemistry
- ETH Zürich
- Vladimir-Prelog-Weg 2
- 8093 Zürich
- Switzerland
| | - Beat H. Meier
- Physical Chemistry
- ETH Zürich
- Vladimir-Prelog-Weg 2
- 8093 Zürich
- Switzerland
| | - Sebastian Kozerke
- Institute for Biomedical Engineering
- University and ETH Zürich
- Gloriastrasse 35
- 8092 Zürich
- Switzerland
| | - Matthias Ernst
- Physical Chemistry
- ETH Zürich
- Vladimir-Prelog-Weg 2
- 8093 Zürich
- Switzerland
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15
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Niedbalski P, Parish C, Kiswandhi A, Lumata L. 13 C dynamic nuclear polarization using isotopically enriched 4-oxo-TEMPO free radicals. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2016; 54:962-967. [PMID: 27377643 DOI: 10.1002/mrc.4480] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 06/12/2016] [Accepted: 06/29/2016] [Indexed: 06/06/2023]
Abstract
The nitroxide-based free radical 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) is a widely used polarizing agent in NMR signal amplification via dissolution dynamic nuclear polarization (DNP). In this study, we have thoroughly investigated the effects of 15 N and/or 2 H isotopic labeling of 4-oxo-TEMPO free radical on 13 C DNP of 3 M [1-13 C] sodium acetate samples in 1 : 1 v/v glycerol : water at 3.35 T and 1.2 K. Four variants of this free radical were used for 13 C DNP: 4-oxo-TEMPO, 4-oxo-TEMPO-15 N, 4-oxo-TEMPO-d16 and 4-oxo-TEMPO-15 N,d16 . Our results indicate that, despite the striking differences seen in the electron spin resonance (ESR) spectral features, the 13 C DNP efficiency of these 15 N and/or 2 H-enriched 4-oxo-TEMPO free radicals are relatively the same compared with 13 C DNP performance of the regular 4-oxo-TEMPO. Furthermore, when fully deuterated glassing solvents were used, the 13 C DNP signals of these samples all doubled in the same manner, and the 13 C polarization buildup was faster by a factor of 2 for all samples. The data here suggest that the hyperfine coupling contributions of these isotopically enriched 4-oxo-TEMPO free radicals have negligible effects on the 13 C DNP efficiency at 3.35 T and 1.2 K. These results are discussed in light of the spin temperature model of DNP. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Peter Niedbalski
- Department of Physics, University of Texas at Dallas, Richardson, TX, USA
| | - Christopher Parish
- Department of Physics, University of Texas at Dallas, Richardson, TX, USA
| | - Andhika Kiswandhi
- Department of Physics, University of Texas at Dallas, Richardson, TX, USA
| | - Lloyd Lumata
- Department of Physics, University of Texas at Dallas, Richardson, TX, USA
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16
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Kiswandhi A, Niedbalski P, Parish C, Kaur P, Martins A, Fidelino L, Khemtong C, Song L, Sherry AD, Lumata L. Impact of Ho(3+)-doping on (13)C dynamic nuclear polarization using trityl OX063 free radical. Phys Chem Chem Phys 2016; 18:21351-9. [PMID: 27424954 PMCID: PMC5199769 DOI: 10.1039/c6cp03954e] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
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 T1 of trityl OX063 was prominently reduced at cryogenic temperatures. The reduction of trityl OX063 electron T1 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 T1, in contrast to Gd(3+)-doping which drastically reduces the (13)C T1. 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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Affiliation(s)
- Andhika Kiswandhi
- Department of Physics, University of Texas at Dallas, Richardson, TX 75080, USA.
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17
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Jähnig F, Kwiatkowski G, Ernst M. Conceptual and instrumental progress in dissolution DNP. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:22-29. [PMID: 26920827 DOI: 10.1016/j.jmr.2015.12.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 12/16/2015] [Accepted: 12/16/2015] [Indexed: 05/15/2023]
Abstract
We discuss conceptual and instrumental progress in dissolution DNP since its introduction in 2003. In our view there are three critical steps in the dissolution DNP process: (i) The achievable polarization level in a sample. (ii) The time required to build up the polarization. (iii) The transfer of the sample to the measurement system with minimum loss of polarization. In this review we describe in detail these steps and the different methodological and instrumental implementations, which have been proposed to optimize them.
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Affiliation(s)
- Fabian Jähnig
- Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Grzegorz Kwiatkowski
- Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland; Institute for Biomedical Engineering, University and ETH Zürich, Gloriastrasse 35, 8092 Zürich, Switzerland
| | - Matthias Ernst
- Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland.
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18
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Ardenkjaer-Larsen JH. On the present and future of dissolution-DNP. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 264:3-12. [PMID: 26920825 DOI: 10.1016/j.jmr.2016.01.015] [Citation(s) in RCA: 164] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 01/04/2016] [Accepted: 01/05/2016] [Indexed: 05/03/2023]
Abstract
Dissolution-DNP is a method to create solutions of molecules with nuclear spin polarization close to unity. The many orders of magnitude signal enhancement have enabled many new applications, in particular in vivo MR metabolic imaging. The method relies on solid state dynamic nuclear polarization at low temperature followed by a dissolution to produce the room temperature solution of highly polarized spins. This work describes the present and future of dissolution-DNP in the mind of the author. The article describes some of the current trends in the field as well as outlines some of the areas where new ideas will make an impact. Most certainly, the future will take unpredicted directions, but hopefully the thoughts presented here will stimulate new ideas that can further advance the field.
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Affiliation(s)
- Jan Henrik Ardenkjaer-Larsen
- Technical University of Denmark, Department of Electrical Engineering, Kgs Lyngby, Denmark; GE Healthcare, Brøndby, Denmark
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19
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Krajewski M, Wespi P, Busch J, Wissmann L, Kwiatkowski G, Steinhauser J, Batel M, Ernst M, Kozerke S. A multisample dissolution dynamic nuclear polarization system for serial injections in small animals. Magn Reson Med 2016; 77:904-910. [DOI: 10.1002/mrm.26147] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 01/04/2016] [Accepted: 01/11/2016] [Indexed: 02/01/2023]
Affiliation(s)
- Marcin Krajewski
- Institute for Biomedical EngineeringUniversity and ETH Zurich Switzerland
- Laboratory of Physical ChemistryETH Zurich Switzerland
| | - Patrick Wespi
- Institute for Biomedical EngineeringUniversity and ETH Zurich Switzerland
| | - Julia Busch
- Institute for Biomedical EngineeringUniversity and ETH Zurich Switzerland
| | - Lukas Wissmann
- Institute for Biomedical EngineeringUniversity and ETH Zurich Switzerland
| | | | - Jonas Steinhauser
- Institute for Biomedical EngineeringUniversity and ETH Zurich Switzerland
| | - Michael Batel
- Laboratory of Physical ChemistryETH Zurich Switzerland
| | | | - Sebastian Kozerke
- Institute for Biomedical EngineeringUniversity and ETH Zurich Switzerland
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20
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Kiswandhi A, Lama B, Niedbalski P, Goderya M, Long J, Lumata L. The effect of glassing solvent deuteration and Gd3+ doping on 13C DNP at 5 T. RSC Adv 2016. [DOI: 10.1039/c6ra02864k] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report the influence of glassing solvent deuteration and Gd3+ doping on 13C dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) performed on [1-13C] sodium acetate at B0 = 5 T and 1.2 K.
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Affiliation(s)
| | - Bimala Lama
- Department of Biochemistry and Molecular Biology
- University of Florida
- Gainesville
- USA
| | | | - Mudrekh Goderya
- Department of Physics
- University of Texas at Dallas
- Richardson
- USA
| | - Joanna Long
- Department of Biochemistry and Molecular Biology
- University of Florida
- Gainesville
- USA
| | - Lloyd Lumata
- Department of Physics
- University of Texas at Dallas
- Richardson
- USA
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21
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Chaumeil MM, Najac C, Ronen SM. Studies of Metabolism Using (13)C MRS of Hyperpolarized Probes. Methods Enzymol 2015; 561:1-71. [PMID: 26358901 DOI: 10.1016/bs.mie.2015.04.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
First described in 2003, the dissolution dynamic nuclear polarization (DNP) technique, combined with (13)C magnetic resonance spectroscopy (MRS), has since been used in numerous metabolic studies and has become a valuable metabolic imaging method. DNP dramatically increases the level of polarization of (13)C-labeled compounds resulting in an increase in the signal-to-noise ratio (SNR) of over 50,000 fold for the MRS spectrum of hyperpolarized compounds. The high SNR enables rapid real-time detection of metabolism in cells, tissues, and in vivo. This chapter will present a comprehensive review of the DNP approaches that have been used to monitor metabolism in living systems. First, the list of (13)C DNP probes developed to date will be presented, with a particular focus on the most commonly used probe, namely [1-(13)C] pyruvate. In the next four sections, we will then describe the different factors that need to be considered when designing (13)C DNP probes for metabolic studies, conducting in vitro or in vivo hyperpolarized experiments, as well as acquiring, analyzing, and modeling hyperpolarized (13)C data.
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Affiliation(s)
- Myriam M Chaumeil
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Chloé Najac
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Sabrina M Ronen
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.
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22
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Hyperpolarized (13)C Magnetic Resonance and Its Use in Metabolic Assessment of Cultured Cells and Perfused Organs. Methods Enzymol 2015; 561:73-106. [PMID: 26358902 DOI: 10.1016/bs.mie.2015.04.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Diseased tissue is often characterized by abnormalities in intermediary metabolism. Observing these alterations in situ may lead to an improved understanding of pathological processes and novel ways to monitor these processes noninvasively in human patients. Although (13)C is a stable isotope safe for use in animal models of disease as well as human subjects, its utility as a metabolic tracer has largely been limited to ex vivo analyses employing analytical techniques like mass spectrometry or nuclear magnetic resonance spectroscopy. Neither of these techniques is suitable for noninvasive metabolic monitoring, and the low abundance and poor gyromagnetic ratio of conventional (13)C make it a poor nucleus for imaging. However, the recent advent of hyperpolarization methods, particularly dynamic nuclear polarization (DNP), makes it possible to enhance the spin polarization state of (13)C by many orders of magnitude, resulting in a temporary amplification of the signal sufficient for monitoring kinetics of enzyme-catalyzed reactions in living tissue through magnetic resonance spectroscopy or magnetic resonance imaging. Here, we review DNP techniques to monitor metabolism in cultured cells, perfused hearts, and perfused livers, focusing on our experiences with hyperpolarized [1-(13)C]pyruvate. We present detailed approaches to optimize the DNP procedure, streamline biological sample preparation, and maximize detection of specific metabolic activities. We also discuss practical aspects in the choice of metabolic substrates for hyperpolarization studies and outline some of the current technical and conceptual challenges in the field, including efforts to use hyperpolarization to quantify metabolic rates in vivo.
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23
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Comment A, Merritt ME. Hyperpolarized magnetic resonance as a sensitive detector of metabolic function. Biochemistry 2014; 53:7333-57. [PMID: 25369537 PMCID: PMC4255644 DOI: 10.1021/bi501225t] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
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Hyperpolarized magnetic resonance
allows for noninvasive measurements
of biochemical reactions in vivo. Although this technique
provides a unique tool for assaying enzymatic activities in intact
organs, the scope of its application is still elusive for the wider
scientific community. The purpose of this review is to provide key
principles and parameters to guide the researcher interested in adopting
this technology to address a biochemical, biomedical, or medical issue.
It is presented in the form of a compendium containing the underlying
essential physical concepts as well as suggestions to help assess
the potential of the technique within the framework of specific research
environments. Explicit examples are used to illustrate the power as
well as the limitations of hyperpolarized magnetic resonance.
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Affiliation(s)
- Arnaud Comment
- Institute of Physics of Biological Systems, Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland
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