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Shchepin RV, Jaigirdar L, Theis T, Warren WS, Goodson BM, Chekmenev EY. Spin Relays Enable Efficient Long-Range Heteronuclear Signal Amplification By Reversible Exchange. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2017; 121:28425-28434. [PMID: 29955243 PMCID: PMC6017995 DOI: 10.1021/acs.jpcc.7b11485] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
A systematic experimental study is reported on the polarization transfer to distant spins, which do not directly bind to the polarization transfer complexes employed in Signal Amplification By Reversible Exchange (SABRE) experiments. Both, long-range transfer to protons and long-range transfer to heteronuclei i.e. 13C and 15N are examined. Selective destruction of hyperpolarization on 1H, 13C, and 15N sites is employed, followed by their re-hyperpolarization from neighboring spins within the molecules of interest (pyridine for 1H studies and metronidazole-15N2-13C2 for 13C and 15N studies). We conclude that long-range sites can be efficiently hyperpolarized when a network of spin-½ nuclei enables relayed polarization transfer (i.e. via short-range interactions between sites). In case of proton SABRE in the milli-Tesla regime, a relay network consisting of protons only is sufficient. However, in case 13C and 15N are targeted (i.e. via SABRE in SHield Enables Alignment Transfer to Heteronuclei or SABRE-SHEATH experiment), the presence of a heteronuclear network (e.g. consisting of 15N) enables a relay mechanism that is significantly more efficient than the direct transfer of spin order from para-H2-derived hydrides.
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Affiliation(s)
- Roman V. Shchepin
- Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee 37232-2310 United States
| | - Lamya Jaigirdar
- Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee 37232-2310 United States
- Vanderbilt University, School of Engineering, Nashville, Tennessee 37232 United States
| | - Thomas Theis
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Warren S. Warren
- Department of Chemistry, Duke University, Durham, North Carolina 27708, United States
| | - Boyd M. Goodson
- Department of Chemistry and Biochemistry and Materials Technology Center, Southern Illinois University, Carbondale, Illinois 62901, United States
| | - Eduard Y. Chekmenev
- Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology, Vanderbilt University Medical Center (VUMC), Nashville, Tennessee 37232-2310 United States
- Department of Biomedical Engineering, Vanderbilt University, Vanderbilt-Ingram Cancer Center (VICC), Nashville, Tennessee 37232-2310, United States
- Russian Academy of Sciences, Leninskiy Prospekt 14, Moscow, 119991, Russia
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Kovtunov KV, Kidd BE, Salnikov OG, Bales LB, Gemeinhardt ME, Gesiorski J, Shchepin RV, Chekmenev EY, Goodson BM, Koptyug IV. Imaging of Biomolecular NMR Signals Amplified by Reversible Exchange with Parahydrogen Inside an MRI Scanner. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2017; 121:25994-25999. [PMID: 30701013 PMCID: PMC6349396 DOI: 10.1021/acs.jpcc.7b10549] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The Signal Amplification by Reversible Exchange (SABRE) technique employs exchange with singlet-state parahydrogen to efficiently generate high levels of nuclear spin polarization. Spontaneous SABRE has been shown previously to be efficient in the milli-Tesla and micro-Tesla regimes. We have recently demonstrated that high-field SABRE is also possible, where proton sites of molecules that are able to reversibly coordinate to a metal center can be hyperpolarized directly within high-field magnets, potentially offering the convenience of in situ hyperpolarization-based spectroscopy and imaging without sample shuttling. Here, we show efficient polarization transfer from parahydrogen (para-H2) to the 15N atoms of imidazole-15N2 and nicotinamide-15N achieved via high-field SABRE (HF-SABRE). Spontaneous transfer of spin order from the para-H2 protons to 15N atoms at the high magnetic field of an MRI scanner allows one not only to record enhanced 15N NMR spectra of in situ hyperpolarized biomolecules, but also to perform imaging using conventional MRI sequences. 2D 15N MRI of high-field SABRE-hyperpolarized imidazole with spatial resolution of 0.3×0.3 mm2 at 9.4 T magnetic field and a high signal-to-noise ratio (SNR) of ~99 was demonstrated. We show that 1H MRI of in situ HF-SABRE hyperpolarized biomolecules (e.g. imidazole-15N2) is also feasible. Taken together, these results show that heteronuclear (15N) and 1H spectroscopic detection and imaging of high-field-SABRE-hyperpolarized molecules are promising tools for a number of emerging applications.
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Affiliation(s)
- Kirill V. Kovtunov
- International Tomography Center SB RAS, Novosibirsk, 630090, Russia
- Novosibirsk State University, Novosibirsk, 630090, Russia
- Corresponding Author, ,
| | - Bryce E. Kidd
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
- Corresponding Author, ,
| | - Oleg G. Salnikov
- International Tomography Center SB RAS, Novosibirsk, 630090, Russia
- Novosibirsk State University, Novosibirsk, 630090, Russia
| | - Liana B. Bales
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
| | - Max E. Gemeinhardt
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
| | - Jonathan Gesiorski
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
| | - Roman V. Shchepin
- Vanderbilt Institute of Imaging Science (VUIIS), Department of Radiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Eduard Y. Chekmenev
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
- Russian Academy of Sciences, Moscow, 119991, Russia
- Vanderbilt Institute of Imaging Science (VUIIS), Department of Radiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Boyd M. Goodson
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
- Materials Technology Center, Southern Illinois University, Carbondale, IL 62901, USA
| | - Igor V. Koptyug
- International Tomography Center SB RAS, Novosibirsk, 630090, Russia
- Novosibirsk State University, Novosibirsk, 630090, Russia
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