1
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Molway MJ, Bales-Shaffer L, Ranta K, Ball J, Sparling E, Prince M, Cocking D, Basler D, Murphy M, Kidd BE, Gafar AT, Porter J, Albin K, Rosen MS, Chekmenev EY, Michael Snow W, Barlow MJ, Goodson BM. Dramatic improvement in the "Bulk" hyperpolarization of 131Xe via spin exchange optical pumping probed using in situ low-field NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 354:107521. [PMID: 37487304 DOI: 10.1016/j.jmr.2023.107521] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/04/2023] [Accepted: 07/06/2023] [Indexed: 07/26/2023]
Abstract
We report on hyperpolarization of quadrupolar (I=3/2) 131Xe via spin-exchange optical pumping. Observations of the 131Xe polarization dynamics via in situ low-field NMR show that the estimated alkali-metal/131Xe spin-exchange rates can be large enough to compete with 131Xe spin relaxation. 131Xe polarization up to 7.6±1.5% was achieved in ∼8.5×1020 spins-a ∼100-fold improvement in the total spin angular momentum-potentially enabling various applications, including: measurement of spin-dependent neutron-131Xe s-wave scattering; sensitive searches for time-reversal violation in neutron-131Xe interactions beyond the Standard Model; and surface-sensitive pulmonary MRI.
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Affiliation(s)
- Michael J Molway
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale 62901, IL, USA
| | - Liana Bales-Shaffer
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale 62901, IL, USA
| | - Kaili Ranta
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale 62901, IL, USA
| | - James Ball
- School of Medicine, University of Nottingham, Queens Medical Centre, Nottingham, UK
| | - Eleanor Sparling
- School of Medicine, University of Nottingham, Queens Medical Centre, Nottingham, UK
| | - Mia Prince
- School of Medicine, University of Nottingham, Queens Medical Centre, Nottingham, UK
| | - Daniel Cocking
- School of Medicine, University of Nottingham, Queens Medical Centre, Nottingham, UK
| | - Dustin Basler
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale 62901, IL, USA
| | - Megan Murphy
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale 62901, IL, USA
| | - Bryce E Kidd
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale 62901, IL, USA
| | - Abdulbasit Tobi Gafar
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale 62901, IL, USA
| | - Justin Porter
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale 62901, IL, USA
| | - Kierstyn Albin
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale 62901, IL, USA
| | - Matthew S Rosen
- A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston 02129, MA, USA; Department of Physics, Harvard University, Cambridge 02138, MA, USA
| | - Eduard Y Chekmenev
- Department of Chemistry, Integrative Biosciences (Ibio), Karmanos Cancer Institute (KCI), Wayne State University, Detroit 48202, MI, USA; Russian Academy of Sciences, Leninskiy Prospekt 14, 119991 Moscow, Russia
| | - W Michael Snow
- Department of Physics, Indiana University, Bloomington, IN, USA
| | - Michael J Barlow
- School of Medicine, University of Nottingham, Queens Medical Centre, Nottingham, UK
| | - Boyd M Goodson
- School of Chemical and Biomolecular Sciences, Southern Illinois University, Carbondale 62901, IL, USA.
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2
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Saul P, Schröder L, Schmidt AB, Hövener JB. Nanomaterials for hyperpolarized nuclear magnetic resonance and magnetic resonance imaging. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2023:e1879. [PMID: 36781151 DOI: 10.1002/wnan.1879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 01/03/2023] [Accepted: 01/07/2023] [Indexed: 02/15/2023]
Abstract
Nanomaterials play an important role in the development and application of hyperpolarized materials for magnetic resonance imaging (MRI). In this context they can not only act as hyperpolarized materials which are directly imaged but also play a role as carriers for hyperpolarized gases and catalysts for para-hydrogen induced polarization (PHIP) to generate hyperpolarized substrates for metabolic imaging. Those three application possibilities are discussed, focusing on carbon-based materials for the directly imaged particles. An overview over recent developments in all three fields is given, including the early developments in each field as well as important steps towards applications in MRI, such as making the initially developed methods more biocompatible and first imaging experiments with spatial resolution in either phantoms or in vivo studies. Focusing on the important features nanomaterials need to display to be applicable in the MRI context, a wide range of different approaches to that extent is covered, giving the reader a general idea of different possibilities as well as recent developments in those different fields of hyperpolarized magnetic resonance. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.
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Affiliation(s)
- Philip Saul
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel University, Kiel, Germany
| | - Leif Schröder
- Division of Translational Molecular Imaging, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany.,Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Andreas B Schmidt
- Intergrative Biosciences (Ibio), Department of Chemistry, Karmanos Cancer Institute (KCI), Wayne State University, Detroit, Michigan, USA.,German Cancer Consortium (DKTK), Partner Site Freiburg, German Cancer Research Center (DKFZ), Heidelberg, Germany.,Division of Medical Physics, Department of Radiology, Medical Center, University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Jan-Bernd Hövener
- Section Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel University, Kiel, Germany
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3
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Eills J, Budker D, Cavagnero S, Chekmenev EY, Elliott SJ, Jannin S, Lesage A, Matysik J, Meersmann T, Prisner T, Reimer JA, Yang H, Koptyug IV. Spin Hyperpolarization in Modern Magnetic Resonance. Chem Rev 2023; 123:1417-1551. [PMID: 36701528 PMCID: PMC9951229 DOI: 10.1021/acs.chemrev.2c00534] [Citation(s) in RCA: 64] [Impact Index Per Article: 64.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Magnetic resonance techniques are successfully utilized in a broad range of scientific disciplines and in various practical applications, with medical magnetic resonance imaging being the most widely known example. Currently, both fundamental and applied magnetic resonance are enjoying a major boost owing to the rapidly developing field of spin hyperpolarization. Hyperpolarization techniques are able to enhance signal intensities in magnetic resonance by several orders of magnitude, and thus to largely overcome its major disadvantage of relatively low sensitivity. This provides new impetus for existing applications of magnetic resonance and opens the gates to exciting new possibilities. In this review, we provide a unified picture of the many methods and techniques that fall under the umbrella term "hyperpolarization" but are currently seldom perceived as integral parts of the same field. Specifically, before delving into the individual techniques, we provide a detailed analysis of the underlying principles of spin hyperpolarization. We attempt to uncover and classify the origins of hyperpolarization, to establish its sources and the specific mechanisms that enable the flow of polarization from a source to the target spins. We then give a more detailed analysis of individual hyperpolarization techniques: the mechanisms by which they work, fundamental and technical requirements, characteristic applications, unresolved issues, and possible future directions. We are seeing a continuous growth of activity in the field of spin hyperpolarization, and we expect the field to flourish as new and improved hyperpolarization techniques are implemented. Some key areas for development are in prolonging polarization lifetimes, making hyperpolarization techniques more generally applicable to chemical/biological systems, reducing the technical and equipment requirements, and creating more efficient excitation and detection schemes. We hope this review will facilitate the sharing of knowledge between subfields within the broad topic of hyperpolarization, to help overcome existing challenges in magnetic resonance and enable novel applications.
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Affiliation(s)
- James Eills
- Institute
for Bioengineering of Catalonia, Barcelona
Institute of Science and Technology, 08028Barcelona, Spain,
| | - Dmitry Budker
- Johannes
Gutenberg-Universität Mainz, 55128Mainz, Germany,Helmholtz-Institut,
GSI Helmholtzzentrum für Schwerionenforschung, 55128Mainz, Germany,Department
of Physics, UC Berkeley, Berkeley, California94720, United States
| | - Silvia Cavagnero
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Eduard Y. Chekmenev
- Department
of Chemistry, Integrative Biosciences (IBio), Karmanos Cancer Institute
(KCI), Wayne State University, Detroit, Michigan48202, United States,Russian
Academy of Sciences, Moscow119991, Russia
| | - Stuart J. Elliott
- Molecular
Sciences Research Hub, Imperial College
London, LondonW12 0BZ, United Kingdom
| | - Sami Jannin
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Anne Lesage
- Centre
de RMN à Hauts Champs de Lyon, Université
de Lyon, CNRS, ENS Lyon, Université Lyon 1, 69100Villeurbanne, France
| | - Jörg Matysik
- Institut
für Analytische Chemie, Universität
Leipzig, Linnéstr. 3, 04103Leipzig, Germany
| | - Thomas Meersmann
- Sir
Peter Mansfield Imaging Centre, University Park, School of Medicine, University of Nottingham, NottinghamNG7 2RD, United Kingdom
| | - Thomas Prisner
- Institute
of Physical and Theoretical Chemistry and Center of Biomolecular Magnetic
Resonance, Goethe University Frankfurt, , 60438Frankfurt
am Main, Germany
| | - Jeffrey A. Reimer
- Department
of Chemical and Biomolecular Engineering, UC Berkeley, and Materials Science Division, Lawrence Berkeley National
Laboratory, Berkeley, California94720, United States
| | - Hanming Yang
- Department
of Chemistry, University of Wisconsin, Madison, Madison, Wisconsin53706, United States
| | - Igor V. Koptyug
- International Tomography Center, Siberian
Branch of the Russian Academy
of Sciences, 630090Novosibirsk, Russia,
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4
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Investigating Rubidium Density and Temperature Distributions in a High-Throughput 129Xe-Rb Spin-Exchange Optical Pumping Polarizer. Molecules 2022; 28:molecules28010011. [PMID: 36615208 PMCID: PMC9822042 DOI: 10.3390/molecules28010011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/09/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
Accurate knowledge of the rubidium (Rb) vapor density, [Rb], is necessary to correctly model the spin dynamics of 129Xe-Rb spin-exchange optical pumping (SEOP). Here we present a systematic evaluation of [Rb] within a high-throughput 129Xe-Rb hyperpolarizer during continuous-flow SEOP. Near-infrared (52S1/2→52P1/2 (D1)/52P3/2 (D2)) and violet (52S1/2→62P1/2/62P3/2) atomic absorption spectroscopy was used to measure [Rb] within 3.5 L cylindrical SEOP cells containing different spatial distributions and amounts of Rb metal. We were able to quantify deviation from the Beer-Lambert law at high optical depth for D2 and 62P3/2 absorption by comparison with measurements of the D1 and 62P1/2 absorption lines, respectively. D2 absorption deviates from the Beer-Lambert law at [Rb]D2>4×1017 m−3 whilst 52S1/2→62P3/2 absorption deviates from the Beer-Lambert law at [Rb]6P3/2>(4.16±0.01)×1019 m−3. The measured [Rb] was used to estimate a 129Xe-Rb spin exchange cross section of γ′=(1.2±0.1)×10−21 m3 s−1, consistent with spin-exchange cross sections from the literature. Significant [Rb] heterogeneity was observed in a SEOP cell containing 1 g of Rb localized at the back of the cell. While [Rb] homogeneity was improved for a greater surface area of the Rb source distribution in the cell, or by using a Rb presaturator, the measured [Rb] was consistently lower than that predicted by saturation Rb vapor density curves. Efforts to optimize [Rb] and thermal management within spin polarizer systems are necessary to maximize potential future enhancements of this technology.
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5
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Morik HA, Schuenke P, Schröder L. Rapid analytical CEST spectroscopy of competitive host-guest interactions using spatial parallelization with a combined approach of variable flip angle, keyhole and averaging (CAVKA). Phys Chem Chem Phys 2022; 24:12126-12135. [PMID: 35311881 DOI: 10.1039/d2cp01099b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A serious limitation of high resolution 129Xe chemical exchange saturation transfer (CEST) NMR spectroscopy for comparing competitive host-guest interactions from different samples is the long acquisition time due to step-wise encoding of the chemical shift dimension. A method of optimized use of 129Xe spin magnetization to enable the accelerated and simultaneous acquisition of CEST spectra from multiple samples or regions in a setup is described. The method is applied to investigate the host-guest system of commercially available cucurbit[7]uril (CB7) and xenon with competing guests: cis-1,4-bis(aminomethyl)cyclohexane, cadaverine, and putrescine. Interactions with the different guests prove that the observed CEST signal is from a CB6 impurity and that CB7 itself does not produce a CEST signal. Instead, rapid interactions between xenon and CB7 manifest in the spectrum as a broad saturation response that could be suppressed by cis-1,4-bis(aminomethyl)cyclohexane. This guest prevents interactions at the CB7 portals. The suggested method represents a type of spectroscopic imaging that is capable of capturing the exchange kinetics information of systems that otherwise suffer from shortened T2 times and yields multiple spectra for comparing exchange conditions with a reduction of >95% in acquisition time. The spectral quality is sufficient to perform quantitative analysis and quantifications relative to a CB6 standard as well as relative to a known blocker concentration (putrescine) that both reveal an unexpectedly high CB6 impurity of ca. 8%.
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Affiliation(s)
- Hen-Amit Morik
- Translational Molecular Imaging, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany. .,Molecular Imaging, Leibniz-Forschungs-Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
| | - Patrick Schuenke
- Molecular Imaging, Leibniz-Forschungs-Institut für Molekulare Pharmakologie (FMP), Berlin, Germany.,Biomedical Magnetic Resonance, Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - Leif Schröder
- Translational Molecular Imaging, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany. .,Molecular Imaging, Leibniz-Forschungs-Institut für Molekulare Pharmakologie (FMP), Berlin, Germany
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6
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Stäglich R, Kemnitzer TW, Harder MC, Schmutzler A, Meinhart M, Keenan CD, Rössler EA, Senker J. Portable Hyperpolarized Xe-129 Apparatus with Long-Time Stable Polarization Mediated by Adaptable Rb Vapor Density. J Phys Chem A 2022; 126:2578-2589. [PMID: 35420816 DOI: 10.1021/acs.jpca.2c00891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The extraordinary sensitivity of 129Xe, hyperpolarized by spin-exchange optical pumping, is essential for magnetic resonance imaging and spectroscopy in life and materials sciences. However, fluctuations of the polarization over time still limit the reproducibility and quantification with which the interconnectivity of pore spaces can be analyzed. Here, we present a polarizer that not only produces a continuous stream of hyperpolarized 129Xe but also maintains stable polarization levels on the order of hours, independent of gas flow rates. The polarizer features excellent magnetization production rates of about 70 mL/h and 129Xe polarization values on the order of 40% at moderate system pressures. Key design features include a vertically oriented, large-capacity two-bodied pumping cell and a separate Rb presaturation chamber having its own temperature control, independent of the main pumping cell oven. The separate presaturation chamber allows for precise control of the Rb vapor density by restricting the Rb load and varying the temperature. The polarizer is both compact and transportable─making it easily storable─and adaptable for use in various sample environments. Time-evolved two-dimensional (2D) exchange spectra of 129Xe absorbed in the microporous metal-organic framework CAU-1-AmMe are presented to highlight the quantitative nature of the device.
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Affiliation(s)
- Robert Stäglich
- Inorganic Chemistry III and Northern Bavarian NMR Centre, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Tobias W Kemnitzer
- Inorganic Chemistry III and Northern Bavarian NMR Centre, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Marie C Harder
- Inorganic Chemistry III and Northern Bavarian NMR Centre, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Adrian Schmutzler
- Inorganic Chemistry III and Northern Bavarian NMR Centre, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Marcel Meinhart
- Inorganic Chemistry III and Northern Bavarian NMR Centre, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Caroline D Keenan
- Department of Chemistry and Biochemistry, Carson-Newman University, 1645 Russel Avenue, Jefferson City, Tennessee 37760, United States
| | - Ernst A Rössler
- Inorganic Chemistry III and Northern Bavarian NMR Centre, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Jürgen Senker
- Inorganic Chemistry III and Northern Bavarian NMR Centre, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
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7
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Pilot Quality-Assurance Study of a Third-Generation Batch-Mode Clinical-Scale Automated Xenon-129 Hyperpolarizer. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27041327. [PMID: 35209116 PMCID: PMC8879294 DOI: 10.3390/molecules27041327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 11/28/2022]
Abstract
We present a pilot quality assurance (QA) study of a clinical-scale, automated, third-generation (GEN-3) 129Xe hyperpolarizer employing batch-mode spin-exchange optical pumping (SEOP) with high-Xe densities (50% natural abundance Xe and 50% N2 in ~2.6 atm total pressure sourced from Nova Gas Technologies) and rapid temperature ramping enabled by an aluminum heating jacket surrounding the 0.5 L SEOP cell. 129Xe hyperpolarization was performed over the course of 700 gas loading cycles of the SEOP cell, simulating long-term hyperpolarized contrast agent production in a clinical lung imaging setting. High levels of 129Xe polarization (avg. %PXe = 51.0% with standard deviation σPXe = 3.0%) were recorded with fast 129Xe polarization build-up time constants (avg. Tb = 25.1 min with standard deviation σTb = 3.1 min) across the first 500 SEOP cell refills, using moderate temperatures of 75 °C. These results demonstrate a more than 2-fold increase in build-up rate relative to previously demonstrated results in a comparable QA study on a second-generation (GEN-2) 129Xe hyperpolarizer device, with only a minor reduction in maximum achievable %PXe and with greater consistency over a larger number of SEOP cell refill processes at a similar polarization lifetime duration (avg. T1 = 82.4 min, standard deviation σT1 = 10.8 min). Additionally, the effects of varying SEOP jacket temperatures, distribution of Rb metal, and preparation and operation of the fluid path are quantified in the context of device installation, performance optimization and maintenance to consistently produce high 129Xe polarization values, build-up rates (Tb as low as 6 min) and lifetimes over the course of a typical high-throughput 129Xe polarization SEOP cell life cycle. The results presented further demonstrate the significant potential for hyperpolarized 129Xe contrast agent in imaging and bio-sensing applications on a clinical scale.
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8
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Khan AS, Harvey RL, Birchall JR, Irwin RK, Nikolaou P, Schrank G, Emami K, Dummer A, Barlow MJ, Goodson BM, Chekmenev EY. Enabling Clinical Technologies for Hyperpolarized 129 Xenon Magnetic Resonance Imaging and Spectroscopy. Angew Chem Int Ed Engl 2021; 60:22126-22147. [PMID: 34018297 PMCID: PMC8478785 DOI: 10.1002/anie.202015200] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Indexed: 11/06/2022]
Abstract
Hyperpolarization is a technique that can increase nuclear spin polarization with the corresponding gains in nuclear magnetic resonance (NMR) signals by 4-8 orders of magnitude. When this process is applied to biologically relevant samples, the hyperpolarized molecules can be used as exogenous magnetic resonance imaging (MRI) contrast agents. A technique called spin-exchange optical pumping (SEOP) can be applied to hyperpolarize noble gases such as 129 Xe. Techniques based on hyperpolarized 129 Xe are poised to revolutionize clinical lung imaging, offering a non-ionizing, high-contrast alternative to computed tomography (CT) imaging and conventional proton MRI. Moreover, CT and conventional proton MRI report on lung tissue structure but provide little functional information. On the other hand, when a subject breathes hyperpolarized 129 Xe gas, functional lung images reporting on lung ventilation, perfusion and diffusion with 3D readout can be obtained in seconds. In this Review, the physics of SEOP is discussed and the different production modalities are explained in the context of their clinical application. We also briefly compare SEOP to other hyperpolarization methods and conclude this paper with the outlook for biomedical applications of hyperpolarized 129 Xe to lung imaging and beyond.
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Affiliation(s)
- Alixander S Khan
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Rebecca L Harvey
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Jonathan R Birchall
- Intergrative Biosciences (Ibio), Wayne State University, Karmanos Cancer Institute (KCI), 5101 Cass Avenue, Detroit, MI, 48202, USA
| | - Robert K Irwin
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, NG7 2RD, UK
| | | | - Geoffry Schrank
- Northrup Grumman Space Systems, 45101 Warp Drive, Sterling, VA, 20166, USA
| | | | | | - Michael J Barlow
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Boyd M Goodson
- Department of Chemistry and Biochemistry, Southern Illinois University, 1245 Lincoln Drive, Carbondale, IL, 62901, USA
- Materials Technology Center, Southern Illinois University, 1245 Lincoln Drive, Carbondale, IL, 62901, USA
| | - Eduard Y Chekmenev
- Intergrative Biosciences (Ibio), Wayne State University, Karmanos Cancer Institute (KCI), 5101 Cass Avenue, Detroit, MI, 48202, USA
- Russian Academy of Sciences, Leninskiy Prospekt 14, Moscow, 119991, Russia
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9
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Khan AS, Harvey RL, Birchall JR, Irwin RK, Nikolaou P, Schrank G, Emami K, Dummer A, Barlow MJ, Goodson BM, Chekmenev EY. Enabling Clinical Technologies for Hyperpolarized
129
Xenon Magnetic Resonance Imaging and Spectroscopy. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202015200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Alixander S. Khan
- Sir Peter Mansfield Imaging Centre University of Nottingham Nottingham NG7 2RD UK
| | - Rebecca L. Harvey
- Sir Peter Mansfield Imaging Centre University of Nottingham Nottingham NG7 2RD UK
| | - Jonathan R. Birchall
- Intergrative Biosciences (Ibio) Wayne State University, Karmanos Cancer Institute (KCI) 5101 Cass Avenue Detroit MI 48202 USA
| | - Robert K. Irwin
- Sir Peter Mansfield Imaging Centre University of Nottingham Nottingham NG7 2RD UK
| | | | - Geoffry Schrank
- Northrup Grumman Space Systems 45101 Warp Drive Sterling VA 20166 USA
| | | | | | - Michael J. Barlow
- Sir Peter Mansfield Imaging Centre University of Nottingham Nottingham NG7 2RD UK
| | - Boyd M. Goodson
- Department of Chemistry and Biochemistry Southern Illinois University 1245 Lincoln Drive Carbondale IL 62901 USA
- Materials Technology Center Southern Illinois University 1245 Lincoln Drive Carbondale IL 62901 USA
| | - Eduard Y. Chekmenev
- Intergrative Biosciences (Ibio) Wayne State University, Karmanos Cancer Institute (KCI) 5101 Cass Avenue Detroit MI 48202 USA
- Russian Academy of Sciences Leninskiy Prospekt 14 Moscow 119991 Russia
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10
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Lee WT, Zheng G, Talbot CL, Tong X, D'Adam T, Parnell SR, de Veer M, Jenkin G, Polglase GR, Hooper SB, Thompson BR, Thien F, Egan GF. Hyperpolarised gas filling station for medical imaging using polarised 129Xe and 3He. Magn Reson Imaging 2021; 79:112-120. [PMID: 33600894 PMCID: PMC7882919 DOI: 10.1016/j.mri.2021.02.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/12/2021] [Accepted: 02/12/2021] [Indexed: 11/25/2022]
Abstract
We report the design, construction, and initial tests of a hyperpolariser to produce polarised 129Xe and 3He gas for medical imaging of the lung. The hyperpolariser uses the Spin-Exchange Optical Pumping method to polarise the nuclear spins of the isotopic gas. Batch mode operation was chosen for the design to produce polarised 129Xe and polarised 3He. Two-side pumping, electrical heating and a piston to transfer the polarised gas were some of the implemented techniques that are not commonly used in hyperpolariser designs. We have carried out magnetic resonance imaging experiments demonstrating that the 3He and 129Xe polarisation reached were sufficient for imaging, in particular for in vivo lung imaging using 129Xe. Further improvements to the hyperpolariser have also been discussed.
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Affiliation(s)
- Wai Tung Lee
- Australia Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234, Australia.
| | - Gang Zheng
- Monash Biomedical Imaging, Monash University, Melbourne, Victoria 3800, Australia
| | - Cavin L Talbot
- University of Queensland, St Lucia, Queensland 4072, Australia
| | - Xin Tong
- Spallation Neutron Source Science Center, Dongguan, 523803, China; Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Tim D'Adam
- Australia Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234, Australia
| | - Steven R Parnell
- Delft University of Technology, Mekelweg 15, 2629 JB, Delft, the Netherlands
| | - Michael de Veer
- Monash Biomedical Imaging, Monash University, Melbourne, Victoria 3800, Australia
| | - Graham Jenkin
- The Ritchie Centre, Monash University and Hudson Institute of Medical Research, Clayton, Victoria 3168, Australia
| | - Graeme R Polglase
- The Ritchie Centre, Monash University and Hudson Institute of Medical Research, Clayton, Victoria 3168, Australia; Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria 3168, Australia
| | - Stuart B Hooper
- The Ritchie Centre, Monash University and Hudson Institute of Medical Research, Clayton, Victoria 3168, Australia; Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria 3168, Australia
| | - Bruce R Thompson
- Swinburne University of Technology, Hawthorne, Victoria 3122, Australia
| | - Francis Thien
- Eastern Health Clinical School, Monash University, Clayton, Victoria 3168, Australia
| | - Gary F Egan
- Monash Biomedical Imaging, Monash University, Melbourne, Victoria 3800, Australia
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11
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Kunth M, Witte C, Schröder L. Mapping of Absolute Host Concentration and Exchange Kinetics of Xenon Hyper-CEST MRI Agents. Pharmaceuticals (Basel) 2021; 14:79. [PMID: 33494166 PMCID: PMC7909792 DOI: 10.3390/ph14020079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/11/2021] [Accepted: 01/16/2021] [Indexed: 12/14/2022] Open
Abstract
Xenon magnetic resonance imaging (MRI) provides excellent sensitivity through the combination of spin hyperpolarization and chemical exchange saturation transfer (CEST). To this end, molecular hosts such as cryptophane-A or cucurbit[n]urils provide unique opportunities to design switchable MRI reporters. The concentration determination of such xenon binding sites in samples of unknown dilution remains, however, challenging. Contrary to 1H CEST agents, an internal reference of a certain host (in this case, cryptophane-A) at micromolar concentration is already sufficient to resolve the entire exchange kinetics information, including an unknown host concentration and the xenon spin exchange rate. Fast echo planar imaging (EPI)-based Hyper-CEST MRI in combination with Bloch-McConnell analysis thus allows quantitative insights to compare the performance of different emerging ultra-sensitive MRI reporters.
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Affiliation(s)
- Martin Kunth
- Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125 Berlin, Germany;
| | - Christopher Witte
- Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125 Berlin, Germany;
| | - Leif Schröder
- Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Campus Berlin-Buch, Robert-Roessle-Str. 10, 13125 Berlin, Germany;
- Translational Molecular Imaging, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
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Plummer JW, Emami K, Dummer A, Woods JC, Walkup LL, Cleveland ZI. A semi-empirical model to optimize continuous-flow hyperpolarized 129Xe production under practical cryogenic-accumulation conditions. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 320:106845. [PMID: 33070086 PMCID: PMC7655637 DOI: 10.1016/j.jmr.2020.106845] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 10/02/2020] [Accepted: 10/04/2020] [Indexed: 05/05/2023]
Abstract
Continuous-flow spin exchange optical pumping (SEOP) with cryogenic accumulation is a powerful technique to generate multiple, large volumes of hyperpolarized (HP) 129Xe in rapid succession. It enables a range of studies, from dark matter tracking to preclinical and clinical MRI. Multiple analytical models based on first principles atomic physics and device-specific design features have been proposed for individual processes within HP 129Xe production. However, the modeling efforts have not yet integrated all the steps involved in practical, large volume HP 129Xe production process (e.g., alkali vapor generation, continuous-flow SEOP, and cryogenic accumulation). Here, we use a simplified analytical model that couples both SEOP and cryogenic accumulation, incorporating only two system-specific empirical parameters: the longitudinal relaxation time of the polycrystalline 129Xe "snow', T1snow, generated during cryogenic accumulation, and 2) the average Rb density during active, continuous-flow polarization. By fitting the model to polarization data collected from >140 L of 129Xe polarized across a range of flow and volume conditions, the estimates for Rb density and T1snow were 1.6 ± 0.1 × 1013 cm-3 and 84 ± 5 min, respectively - each notably less than expected based on previous literature. Together, these findings indicate that 1) earlier polarization predictions were hindered by miscalculated Rb densities, and 2) polarization is not optimized by maximizing SEOP efficiency with a low concentration 129Xe, but rather by using richer 129Xe-buffer gas blends that enable faster accumulation. Accordingly, modeling and experimentation revealed the optimal fraction of 129Xe, f, in the 129Xe-buffer gas blend was ~2%. Further, if coupled with modest increases in laser power, the model predicts liter volumes of HP 129Xe with polarizations exceeding 60% could be generated routinely in only tens of minutes.
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Affiliation(s)
- Joseph W Plummer
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States
| | | | | | - Jason C Woods
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati, Cincinnati, OH, United States
| | - Laura L Walkup
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati, Cincinnati, OH, United States
| | - Zackary I Cleveland
- Center for Pulmonary Imaging Research, Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States; Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States; Department of Pediatrics, University of Cincinnati, Cincinnati, OH, United States.
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13
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Kunth M, Schröder L. Binding site exchange kinetics revealed through efficient spin-spin dephasing of hyperpolarized 129Xe. Chem Sci 2020; 12:158-169. [PMID: 34163587 PMCID: PMC8178811 DOI: 10.1039/d0sc04835f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Spin exchange between different chemical environments is an important observable for characterizing chemical exchange kinetics in various contexts, including protein folding, chelation chemistry, and host-guest interactions. Such spins experience effective spin-spin relaxation rate, R 2,eff, that typically shows a dispersive behavior which requires detailed analysis. Here, we describe a class of highly simplified R 2,eff behavior by relying on hyperpolarized 129Xe as a freely exchanging ligand reporter. It provides large chemical shift separations that yield reduced expressions of both the Swift-Connick and the Carver-Richards treatment of exchange-induced relaxation. Despite observing a diamagnetic system, R 2,eff is dominated by large Larmor frequency jumps and thus allows detection of otherwise inaccessible analyte concentrations with a single spin echo train (only 0.01% of the overall hyperpolarized spins need to be transiently bound to the molecule). The two Xe hosts cryptophane-A monoacid (CrA-ma) and cucurbit[6]uril (CB6) represent two exemplary families of container molecules (the latter one also serving as drug delivery vehicles) that act as highly efficient phase shifters for which we observed unprecedented exchange-induced relaxivity r 2 (up to 866 s-1 mM-1). By including methods of spatial encoding, multiple data points can be collected simultaneously to isolate the exchange contribution and determine the effective exchange rate in partially occupied binding sites with a single delivery of hyperpolarized nuclei. The relaxivity is directly related to the guest turnover in these systems and temperature-dependent measurements yield an activation energy of E A = 41 kJ mol-1 for Xe@CrA-ma from simple relaxometry analysis. The concept is transferable to many applications where Xe is known to exhibit large chemical shifts.
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Affiliation(s)
- Martin Kunth
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V. (FMP) Campus Berlin-Buch, Robert-Roessle-Str. 10 13125 Berlin Germany +49 30 94793 121
| | - Leif Schröder
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie im Forschungsverbund Berlin e.V. (FMP) Campus Berlin-Buch, Robert-Roessle-Str. 10 13125 Berlin Germany +49 30 94793 121
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14
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Jayapaul J, Schröder L. Molecular Sensing with Host Systems for Hyperpolarized 129Xe. Molecules 2020; 25:E4627. [PMID: 33050669 PMCID: PMC7587211 DOI: 10.3390/molecules25204627] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/27/2020] [Accepted: 09/30/2020] [Indexed: 12/12/2022] Open
Abstract
Hyperpolarized noble gases have been used early on in applications for sensitivity enhanced NMR. 129Xe has been explored for various applications because it can be used beyond the gas-driven examination of void spaces. Its solubility in aqueous solutions and its affinity for hydrophobic binding pockets allows "functionalization" through combination with host structures that bind one or multiple gas atoms. Moreover, the transient nature of gas binding in such hosts allows the combination with another signal enhancement technique, namely chemical exchange saturation transfer (CEST). Different systems have been investigated for implementing various types of so-called Xe biosensors where the gas binds to a targeted host to address molecular markers or to sense biophysical parameters. This review summarizes developments in biosensor design and synthesis for achieving molecular sensing with NMR at unprecedented sensitivity. Aspects regarding Xe exchange kinetics and chemical engineering of various classes of hosts for an efficient build-up of the CEST effect will also be discussed as well as the cavity design of host molecules to identify a pool of bound Xe. The concept is presented in the broader context of reporter design with insights from other modalities that are helpful for advancing the field of Xe biosensors.
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Affiliation(s)
| | - Leif Schröder
- Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany;
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15
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Birchall JR, Irwin RK, Nikolaou P, Coffey AM, Kidd BE, Murphy M, Molway M, Bales LB, Ranta K, Barlow MJ, Goodson BM, Rosen MS, Chekmenev EY. XeUS: A second-generation automated open-source batch-mode clinical-scale hyperpolarizer. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 319:106813. [PMID: 32932118 DOI: 10.1016/j.jmr.2020.106813] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/20/2020] [Accepted: 08/24/2020] [Indexed: 06/11/2023]
Abstract
We present a second-generation open-source automated batch-mode 129Xe hyperpolarizer (XeUS GEN-2), designed for clinical-scale hyperpolarized (HP) 129Xe production via spin-exchange optical pumping (SEOP) in the regimes of high Xe density (0.66-2.5 atm partial pressure) and resonant photon flux (~170 W, Δλ = 0.154 nm FWHM), without the need for cryo-collection typically employed by continuous-flow hyperpolarizers. An Arduino micro-controller was used for hyperpolarizer operation. Processing open-source software was employed to program a custom graphical user interface (GUI), capable of remote automation. The Arduino Integrated Development Environment (IDE) was used to design a variety of customized automation sequences such as temperature ramping, NMR signal acquisition, and SEOP cell refilling for increased reliability. A polycarbonate 3D-printed oven equipped with a thermo-electric cooler/heater provides thermal stability for SEOP for both binary (Xe/N2) and ternary (4He-containing) SEOP cell gas mixtures. Quantitative studies of the 129Xe hyperpolarization process demonstrate that near-unity polarization can be achieved in a 0.5 L SEOP cell. For example, %PXe of 93.2 ± 2.9% is achieved at 0.66 atm Xe pressure with polarization build-up rate constant γSEOP = 0.040 ± 0.005 min-1, giving a max dose equivalent ≈ 0.11 L/h 100% hyperpolarized, 100% enriched 129Xe; %PXe of 72.6 ± 1.4% is achieved at 1.75 atm Xe pressure with γSEOP of 0.041 ± 0.001 min-1, yielding a corresponding max dose equivalent of 0.27 L/h. Quality assurance studies on this device have demonstrated the potential to refill SEOP cells hundreds of times without significant losses in performance, with average %PXe = 71.7%, (standard deviation σP = 1.52%) and mean polarization lifetime T1 = 90.5 min, (standard deviation σT = 10.3 min) over the first ~200 gas mixture refills, with sufficient performance maintained across a further ~700 refills. These findings highlight numerous technological developments and have significant translational relevance for efficient production of gaseous HP 129Xe contrast agents for use in clinical imaging and bio-sensing techniques.
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Affiliation(s)
- Jonathan R Birchall
- Department of Chemistry, Integrative Biosciences (Ibio), Wayne State University, Karmanos Cancer Institute (KCI), Detroit, MI 48202, United States
| | - Robert K Irwin
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | | | - Aaron M Coffey
- Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS), Nashville, TN 37232, United States
| | - Bryce E Kidd
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, United States
| | - Megan Murphy
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, United States
| | - Michael Molway
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, United States
| | - Liana B Bales
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, United States
| | - Kaili Ranta
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, United States
| | - Michael J Barlow
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Boyd M Goodson
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, United States; Materials Technology Center, Southern Illinois University, Carbondale, IL 62901, United States
| | - Matthew S Rosen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA 02129, United States; Department of Physics, Harvard University, Cambridge, MA 02138, United States
| | - Eduard Y Chekmenev
- Department of Chemistry, Integrative Biosciences (Ibio), Wayne State University, Karmanos Cancer Institute (KCI), Detroit, MI 48202, United States; Russian Academy of Sciences, Leninskiy Prospekt 14, Moscow 119991, Russia.
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16
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Birchall JR, Irwin RK, Nikolaou P, Pokochueva EV, Kovtunov KV, Koptyug IV, Barlow MJ, Goodson BM, Chekmenev EY. Pilot multi-site quality assurance study of batch-mode clinical-scale automated xenon-129 hyperpolarizers. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 316:106755. [PMID: 32512397 DOI: 10.1016/j.jmr.2020.106755] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/21/2020] [Accepted: 05/25/2020] [Indexed: 06/11/2023]
Abstract
We present a pilot quality assurance (QA) study of spin-exchange optical pumping (SEOP) performed on two nearly identical second-generation (GEN-2) automated batch-mode clinical-scale 129Xe hyperpolarizers, each utilizing a convective forced air oven, high-power (~170 W) continuous pump laser irradiation, and xenon-rich gas mixtures (~1.30 atm partial pressure). In one study, the repeatability of SEOP in a 1000 Torr Xe/900 Torr N2/100 Torr 4He (2000 Torr total pressure) gas mixture is evaluated over the course of ~700 gas loading cycles, with negligible decrease in performance during the first ~200 cycles, and with high 129Xe polarization levels (avg. %PXe = 71.7% with standard deviation σPXe = 1.5%), build-up rates (avg. γSEOP = 0.019 min-1 with standard deviation σγ = 0.003 min-1) and polarization lifetimes (avg. T1 = 90.5 min with standard deviation σT = 10.3 min) reported at moderate oven temperature of ~70 °C. Although the SEOP cell in this study exhibited a detectable performance decrease after 400 cycles, the cell continued to produce potentially useable HP 129Xe with %PXe = 42.3 ± 0.6% even after nearly 700 refill cycles. The possibility of "regenerating" "dormant" (i.e., not used for an extended period of time) SEOP cells using repeated temperature cycling methods to recover %PXe is also demonstrated. The quality and consistency of results show significant promise for translation to clinical-scale production of hyperpolarized 129Xe contrast agents for imaging and bio-sensing applications.
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Affiliation(s)
- Jonathan R Birchall
- Department of Chemistry, Integrative Biosciences (Ibio), Wayne State University, Karmanos Cancer Institute (KCI), Detroit, MI 48202, United States.
| | - Robert K Irwin
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | | | - Ekaterina V Pokochueva
- International Tomography Center SB RAS, Institutskaya Street 3A, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova Street 2, Novosibirsk 630090, Russia
| | - Kirill V Kovtunov
- International Tomography Center SB RAS, Institutskaya Street 3A, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova Street 2, Novosibirsk 630090, Russia
| | - Igor V Koptyug
- International Tomography Center SB RAS, Institutskaya Street 3A, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova Street 2, Novosibirsk 630090, Russia
| | - Michael J Barlow
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Boyd M Goodson
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, United States; Materials Technology Center, Southern Illinois University, Carbondale, IL 62901, United States
| | - Eduard Y Chekmenev
- Department of Chemistry, Integrative Biosciences (Ibio), Wayne State University, Karmanos Cancer Institute (KCI), Detroit, MI 48202, United States; Russian Academy of Sciences, Leninskiy Prospekt 14, Moscow 119991, Russia.
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17
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Birchall JR, Nikolaou P, Irwin RK, Barlow MJ, Ranta K, Coffey AM, Goodson BM, Pokochueva EV, Kovtunov KV, Koptyug IV, Chekmenev EY. Helium-rich mixtures for improved batch-mode clinical-scale spin-exchange optical pumping of Xenon-129. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 315:106739. [PMID: 32408239 DOI: 10.1016/j.jmr.2020.106739] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 06/11/2023]
Abstract
We present studies of spin-exchange optical pumping (SEOP) using ternary xenon-nitrogen-helium gas mixtures at high xenon partial pressures (up to 1330 Torr partial pressure at loading, out of 2660 Torr total pressure) in a 500-mL volume SEOP cell, using two automated batch-mode clinical-scale 129Xe hyperpolarizers operating under continuous high-power (~170 W) pump laser irradiation. In this pilot study, we explore SEOP in gas mixtures with up to 45% 4He content under a wide range of experimental conditions. When an aluminum jacket cooling/heating design was employed (GEN-3 hyperpolarizer), 129Xe polarization (%PXe) of 55.9 ± 0.9% was observed with mono-exponential build-up rate γSEOP of 0.049 ± 0.001 min-1 for the 4He-rich mixture (1000 Torr Xe/900 Torr He, 100 Torr N2), compared to %PXe of 49.3 ± 3.3% at γSEOP of 0.035 ± 0.004 min-1 for the N2-rich gas mixture (1000 Torr Xe/100 Torr He, 900 Torr N2). When forced-air cooling/heating was used (GEN-2 hyperpolarizer), %PXe of 83.9 ± 2.7% was observed at γSEOP of 0.045 ± 0.005 min-1 for the 4He-rich mixture (1000 Torr Xe/900 Torr He, 100 Torr N2), compared to %PXe of 73.5 ± 1.3% at γSEOP of 0.028 ± 0.001 min-1 for the N2-rich gas mixture (1000 Torr Xe and 1000 Torr N2). Additionally, %PXe of 72.6 ± 1.4% was observed at a build-up rate γSEOP of 0.041 ± 0.003 min-1 for a super-high-density 4He-rich mixture (1330 Torr Xe/1200 Torr 4He/130 Torr N2), compared to %PXe = 56.6 ± 1.3% at a build-up rate of γSEOP of 0.034 ± 0.002 min-1 for an N2-rich mixture (1330 Torr Xe/1330 Torr N2) using forced air cooling/heating. The observed SEOP hyperpolarization performance under these conditions corresponds to %PXe improvement by a factor of 1.14 ± 0.04 at 1000 Torr Xe density and by up to a factor of 1.28 ± 0.04 at 1330 Torr Xe density at improved SEOP build-up rates by factors of 1.61 ± 0.18 and 1.21 ± 0.11 respectively. Record %PXe levels have been obtained here: 83.9 ± 2.7% at 1000 Torr Xe partial pressure and 72.6 ± 1.4% at 1330 Torr Xe partial pressure. In addition to improved thermal stability for SEOP, the use of 4He-rich gas mixtures also reduces the overall density of produced inhalable HP contrast agents; this property may be desirable for HP 129Xe inhalation by human subjects in clinical settings-especially in populations with heavily impaired lung function. The described approach should enjoy ready application in the production of inhalable 129Xe contrast agent with near-unity 129Xe nuclear spin polarization.
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Affiliation(s)
- Jonathan R Birchall
- Department of Chemistry, Integrative Biosciences (Ibio), Wayne State University, Karmanos Cancer Institute (KCI), 5101 Cass Ave, Detroit, MI 48202, United States
| | | | - Robert K Irwin
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Michael J Barlow
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Kaili Ranta
- Department of Chemistry and Biochemistry, Southern Illinois University, 1245 Lincoln Drive, Carbondale, IL 62901, United States
| | - Aaron M Coffey
- Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS), 1161 21st Ave South, Nashville, TN 37232, United States
| | - Boyd M Goodson
- Department of Chemistry and Biochemistry, Southern Illinois University, 1245 Lincoln Drive, Carbondale, IL 62901, United States; Materials Technology Center, Southern Illinois University, 1245 Lincoln Drive, Carbondale, IL 62901, United States
| | - Ekaterina V Pokochueva
- International Tomography Center SB RAS, Institutskaya Street 3A, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova Street 2, Novosibirsk 630090, Russia
| | - Kirill V Kovtunov
- International Tomography Center SB RAS, Institutskaya Street 3A, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova Street 2, Novosibirsk 630090, Russia
| | - Igor V Koptyug
- International Tomography Center SB RAS, Institutskaya Street 3A, Novosibirsk 630090, Russia; Novosibirsk State University, Pirogova Street 2, Novosibirsk 630090, Russia
| | - Eduard Y Chekmenev
- Department of Chemistry, Integrative Biosciences (Ibio), Wayne State University, Karmanos Cancer Institute (KCI), 5101 Cass Ave, Detroit, MI 48202, United States; Russian Academy of Sciences, Leninskiy Prospekt 14, Moscow 119991, Russia.
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18
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Birchall JR, Nikolaou P, Coffey AM, Kidd BE, Murphy M, Molway M, Bales LB, Goodson BM, Irwin RK, Barlow MJ, Chekmenev EY. Batch-Mode Clinical-Scale Optical Hyperpolarization of Xenon-129 Using an Aluminum Jacket with Rapid Temperature Ramping. Anal Chem 2020; 92:4309-4316. [PMID: 32073251 DOI: 10.1021/acs.analchem.9b05051] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We present spin-exchange optical pumping (SEOP) using a third-generation (GEN-3) automated batch-mode clinical-scale 129Xe hyperpolarizer utilizing continuous high-power (∼170 W) pump laser irradiation and a novel aluminum jacket design for rapid temperature ramping of xenon-rich gas mixtures (up to 2 atm partial pressure). The aluminum jacket design is capable of heating SEOP cells from ambient temperature (typically 25 °C) to 70 °C (temperature of the SEOP process) in 4 min, and perform cooling of the cell to the temperature at which the hyperpolarized gas mixture can be released from the hyperpolarizer (with negligible amounts of Rb metal leaving the cell) in approximately 4 min, substantially faster (by a factor of 6) than previous hyperpolarizer designs relying on air heat exchange. These reductions in temperature cycling time will likely be highly advantageous for the overall increase of production rates of batch-mode (i.e., stopped-flow) 129Xe hyperpolarizers, which is particularly beneficial for clinical applications. The additional advantage of the presented design is significantly improved thermal management of the SEOP cell. Accompanying the heating jacket design and performance, we also evaluate the repeatability of SEOP experiments conducted using this new architecture, and present typically achievable hyperpolarization levels exceeding 40% at exponential build-up rates on the order of 0.1 min-1.
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Affiliation(s)
- Jonathan R Birchall
- Department of Chemistry, Integrative Biosciences (Ibio), Wayne State University, Karmanos Cancer Institute (KCI), Detroit, Michigan 48202, United States
| | | | - Aaron M Coffey
- Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS), Nashville, Tennessee 37232, United States
| | | | | | | | | | | | - Robert K Irwin
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Michael J Barlow
- Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Eduard Y Chekmenev
- Department of Chemistry, Integrative Biosciences (Ibio), Wayne State University, Karmanos Cancer Institute (KCI), Detroit, Michigan 48202, United States.,Russian Academy of Sciences, Leninskiy Prospekt 14, Moscow, 119991, Russia
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19
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Skinner JG, Ranta K, Whiting N, Coffey AM, Nikolaou P, Rosen MS, Chekmenev EY, Morris PG, Barlow MJ, Goodson BM. High Xe density, high photon flux, stopped-flow spin-exchange optical pumping: Simulations versus experiments. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2020; 312:106686. [PMID: 32006793 PMCID: PMC7436892 DOI: 10.1016/j.jmr.2020.106686] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 01/07/2020] [Indexed: 05/13/2023]
Abstract
Spin-exchange optical pumping (SEOP) can enhance the NMR sensitivity of noble gases by up to five orders of magnitude at Tesla-strength magnetic fields. SEOP-generated hyperpolarised (HP) 129Xe is a promising contrast agent for lung imaging but an ongoing barrier to widespread clinical usage has been economical production of sufficient quantities with high 129Xe polarisation. Here, the 'standard model' of SEOP, which was previously used in the optimisation of continuous-flow 129Xe polarisers, is modified for validation against two Xe-rich stopped-flow SEOP datasets. We use this model to examine ways to increase HP Xe production efficiency in stopped-flow 129Xe polarisers and provide further insight into the underlying physics of Xe-rich stopped-flow SEOP at high laser fluxes.
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Affiliation(s)
- Jason G Skinner
- Division of Respiratory Medicine, School of Medicine, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Kaili Ranta
- Department of Chemistry and Biochemistry, Southern Illinois University Carbondale, Carbondale, IL, 62901, USA
| | - Nicholas Whiting
- Department of Physics & Astronomy and Department of Molecular & Cellular Biosciences, Rowan University, Glassboro, NJ 08028, USA
| | - Aaron M Coffey
- Vanderbilt University Institute of Imaging Science (VUIIS), Department of Radiology and Radiological Sciences, Vanderbilt-Ingram Cancer Center (VICC), Department of Biomedical Engineering, Department of Physics and Astronomy, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | | | - Matthew S Rosen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, 149 13th Street, Charlestown, MA 02129, USA; Department of Radiology, Harvard Medical School, Boston, MA 02115, USA; Department of Physics, Harvard University, Cambridge, MA 02138, USA
| | - Eduard Y Chekmenev
- Russian Academy of Sciences, Leninskiy Prospekt 14, 119991 Moscow, Russia; Department of Chemistry, Integrative Biosciences (Ibio), Wayne State University, Karmanos Cancer Institute (KCI), Detroit, MI, 48202, United States
| | - Peter G Morris
- Sir Peter Mansfield Imaging Centre, School of Physics & Astronomy, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Michael J Barlow
- Division of Respiratory Medicine, School of Medicine, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Boyd M Goodson
- Department of Chemistry and Biochemistry, Southern Illinois University Carbondale, Carbondale, IL, 62901, USA.
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20
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Jayapaul J, Schröder L. Probing Reversible Guest Binding with Hyperpolarized 129Xe-NMR: Characteristics and Applications for Cucurbit[ n]urils. Molecules 2020; 25:E957. [PMID: 32093412 PMCID: PMC7070628 DOI: 10.3390/molecules25040957] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 02/14/2020] [Accepted: 02/18/2020] [Indexed: 01/01/2023] Open
Abstract
Cucurbit[n]urils (CB[n]s) are a family of macrocyclic host molecules that find various applications in drug delivery, molecular switching, and dye displacement assays. The CB[n]s with n = 5-7 have also been studied with 129Xe-NMR. They bind the noble gas with a large range of exchange rates. Starting with insights from conventional direct detection of bound Xe, this review summarizes recent achievements with chemical exchange saturation transfer (CEST) detection of efficiently exchanging Xe in various CB[n]-based supramolecular systems. Unprecedented sensitivity has been reached by combining the CEST method with hyperpolarized Xe, the production of which is also briefly described. Applications such as displacement assays for enzyme activity detection and rotaxanes as emerging types of Xe biosensors are likewise discussed in the context of biomedical applications and pinpoint future directions for translating this field to preclinical studies.
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Affiliation(s)
| | - Leif Schröder
- Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany;
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21
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Jayapaul J, Schröder L. Nanoparticle-Based Contrast Agents for 129Xe HyperCEST NMR and MRI Applications. CONTRAST MEDIA & MOLECULAR IMAGING 2019; 2019:9498173. [PMID: 31819739 PMCID: PMC6893250 DOI: 10.1155/2019/9498173] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/15/2019] [Indexed: 02/06/2023]
Abstract
Spin hyperpolarization techniques have enabled important advancements in preclinical and clinical MRI applications to overcome the intrinsic low sensitivity of nuclear magnetic resonance. Functionalized xenon biosensors represent one of these approaches. They combine two amplification strategies, namely, spin exchange optical pumping (SEOP) and chemical exchange saturation transfer (CEST). The latter one requires host structures that reversibly bind the hyperpolarized noble gas. Different nanoparticle approaches have been implemented and have enabled molecular MRI with 129Xe at unprecedented sensitivity. This review gives an overview of the Xe biosensor concept, particularly how different nanoparticles address various critical aspects of gas binding and exchange, spectral dispersion for multiplexing, and targeted reporter delivery. As this concept is emerging into preclinical applications, comprehensive sensor design will be indispensable in translating the outstanding sensitivity potential into biomedical molecular imaging applications.
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Affiliation(s)
- Jabadurai Jayapaul
- Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - Leif Schröder
- Molecular Imaging, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
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22
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Zhang B, Guo Q, Luo Q, Zhang X, Zeng Q, Zhao L, Yuan Y, Jiang W, Yang Y, Liu M, Ye C, Zhou X. An intracellular diamine oxidase triggered hyperpolarized 129Xe magnetic resonance biosensor. Chem Commun (Camb) 2018; 54:13654-13657. [PMID: 30398489 DOI: 10.1039/c8cc07822j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Here, a novel method was developed for suppressing 129Xe signals in cucurbit[6]uril (CB6) until the trigger is activated by a specific enzyme. Due to its noncovalent interactions with amino-groups and CB6, putrescine dihydrochloride (Put) was chosen for blocking interactions between 129Xe and CB6. Upon adding diamine oxidase (DAO), Put was released from CB6 and a 129Xe@CB6 Hyper-CEST signal emerged. This proposed 129Xe biosensor was then tested in small intestinal villus epithelial cells.
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Affiliation(s)
- Bin Zhang
- State Key Laboratory for Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology (HUST), Wuhan 430071, China.
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23
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Kunth M, Lu GJ, Witte C, Shapiro MG, Schröder L. Protein Nanostructures Produce Self-Adjusting Hyperpolarized Magnetic Resonance Imaging Contrast through Physical Gas Partitioning. ACS NANO 2018; 12:10939-10948. [PMID: 30204404 DOI: 10.1021/acsnano.8b04222] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Signal amplification strategies are critical for overcoming the intrinsically poor sensitivity of nuclear magnetic resonance (NMR) reporters in noninvasive molecular detection. A mechanism widely used for signal enhancement is chemical exchange saturation transfer (CEST) of nuclei between a dilute sensing pool and an abundant detection pool. However, the dependence of CEST amplification on the relative size of these spin pools confounds quantitative molecular detection with a larger detection pool typically making saturation transfer less efficient. Here we show that a recently discovered class of genetically encoded nanoscale reporters for 129Xe magnetic resonance overcomes this fundamental limitation through an elastic binding capacity for NMR-active nuclei. This approach pairs high signal amplification from hyperpolarized spins with ideal, self-adjusting saturation transfer behavior as the overall spin ensemble changes in size. These reporters are based on gas vesicles, i.e., microbe-derived, gas-filled protein nanostructures. We show that the xenon fraction that partitions into gas vesicles follows the ideal gas law, allowing the signal transfer under hyperpolarized xenon chemical exchange saturation transfer (Hyper-CEST) imaging to scale linearly with the total xenon ensemble. This conceptually distinct elastic response allows the production of quantitative signal contrast that is robust to variability in the concentration of xenon, enabling virtually unlimited improvement in absolute contrast with increased xenon delivery, and establishing a unique principle of operation for contrast agent development in emerging biochemical and in vivo applications of hyperpolarized NMR and magnetic resonance imaging.
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Affiliation(s)
- Martin Kunth
- California Institute of Technology , Division of Chemistry and Chemical Engineering , Pasadena , California 91125 , United States
- Leibniz-Forschungsinstitut für Molekulare Pharmarkologie (FMP) , 13125 Berlin , Germany
| | - George J Lu
- California Institute of Technology , Division of Chemistry and Chemical Engineering , Pasadena , California 91125 , United States
| | - Christopher Witte
- Leibniz-Forschungsinstitut für Molekulare Pharmarkologie (FMP) , 13125 Berlin , Germany
| | - Mikhail G Shapiro
- California Institute of Technology , Division of Chemistry and Chemical Engineering , Pasadena , California 91125 , United States
| | - Leif Schröder
- Leibniz-Forschungsinstitut für Molekulare Pharmarkologie (FMP) , 13125 Berlin , Germany
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24
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Farhadi A, Ho G, Kunth M, Ling B, Lakshmanan A, Lu GJ, Bourdeau RW, Schröder L, Shapiro MG. Recombinantly Expressed Gas Vesicles as Nanoscale Contrast Agents for Ultrasound and Hyperpolarized MRI. AIChE J 2018; 64:2927-2933. [PMID: 30555168 DOI: 10.1002/aic.16138] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Ultrasound and hyperpolarized magnetic resonance imaging enable the visualization of biological processes in deep tissues. However, few molecular contrast agents are available to connect these modalities to specific aspects of biological function. We recently discovered that a unique class of gas-filled protein nanostructures known as gas vesicles could serve as nanoscale molecular reporters for these modalities. However, the need to produce these nanostructures via expression in specialized cultures of cyanobacteria or haloarchaea limits their broader adoption by other laboratories and hinders genetic engineering of their properties. Here, we describe recombinant expression and purification of Bacillus megaterium gas vesicles using a common laboratory strain of Escherichia coli, and characterize the physical, acoustic and magnetic resonance properties of these nanostructures. Recombinantly expressed gas vesicles produce ultrasound and hyperpolarized 129Xe MRI contrast at sub-nanomolar concentrations, thus validating a simple platform for their production and engineering.
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Affiliation(s)
- Arash Farhadi
- Division of Biology and Biological Engineering; California Institute of Technology; Pasadena CA 91125
| | - Gabrielle Ho
- Division of Chemistry and Chemical Engineering; California Institute of Technology; Pasadena CA 91125
| | - Martin Kunth
- Division of Chemistry and Chemical Engineering; California Institute of Technology; Pasadena CA 91125
- Dept. of Structural Biology, Molecular Imaging; Leibniz-Forschungsinstitute für Molekulare Pharmakologie (FMP); Berlin Germany
| | - Bill Ling
- Division of Chemistry and Chemical Engineering; California Institute of Technology; Pasadena CA 91125
| | - Anupama Lakshmanan
- Division of Biology and Biological Engineering; California Institute of Technology; Pasadena CA 91125
| | - George J Lu
- Division of Chemistry and Chemical Engineering; California Institute of Technology; Pasadena CA 91125
| | - Raymond W. Bourdeau
- Division of Chemistry and Chemical Engineering; California Institute of Technology; Pasadena CA 91125
| | - Leif Schröder
- Dept. of Structural Biology, Molecular Imaging; Leibniz-Forschungsinstitute für Molekulare Pharmakologie (FMP); Berlin Germany
| | - Mikhail G. Shapiro
- Division of Chemistry and Chemical Engineering; California Institute of Technology; Pasadena CA 91125
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Lakshmanan A, Lu GJ, Farhadi A, Nety SP, Kunth M, Lee-Gosselin A, Maresca D, Bourdeau RW, Yin M, Yan J, Witte C, Malounda D, Foster FS, Schröder L, Shapiro MG. Preparation of biogenic gas vesicle nanostructures for use as contrast agents for ultrasound and MRI. Nat Protoc 2017; 12:2050-2080. [PMID: 28880278 DOI: 10.1038/nprot.2017.081] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Gas vesicles (GVs) are a unique class of gas-filled protein nanostructures that are detectable at subnanomolar concentrations and whose physical properties allow them to serve as highly sensitive imaging agents for ultrasound and MRI. Here we provide a protocol for isolating GVs from native and heterologous host organisms, functionalizing these nanostructures with moieties for targeting and fluorescence, characterizing their biophysical properties and imaging them using ultrasound and MRI. GVs can be isolated from natural cyanobacterial and haloarchaeal host organisms or from Escherichia coli expressing a heterologous GV gene cluster and purified using buoyancy-assisted techniques. They can then be modified by replacing surface-bound proteins with engineered, heterologously expressed variants or through chemical conjugation, resulting in altered mechanical, surface and targeting properties. Pressurized absorbance spectroscopy is used to characterize their mechanical properties, whereas dynamic light scattering (DLS)and transmission electron microscopy (TEM) are used to determine nanoparticle size and morphology, respectively. GVs can then be imaged with ultrasound in vitro and in vivo using pulse sequences optimized for their detection versus background. They can also be imaged with hyperpolarized xenon MRI using chemical exchange saturation transfer between GV-bound and dissolved xenon-a technique currently implemented in vitro. Taking 3-8 d to prepare, these genetically encodable nanostructures enable multimodal, noninvasive biological imaging with high sensitivity and potential for molecular targeting.
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Affiliation(s)
- Anupama Lakshmanan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - George J Lu
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Arash Farhadi
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Suchita P Nety
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Martin Kunth
- Molecular Imaging, Department of Structural Biology, Leibniz-Forschungsinstitute für Molekulare Pharmakologie, Berlin, Germany
| | - Audrey Lee-Gosselin
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - David Maresca
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Raymond W Bourdeau
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Melissa Yin
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Judy Yan
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Christopher Witte
- Molecular Imaging, Department of Structural Biology, Leibniz-Forschungsinstitute für Molekulare Pharmakologie, Berlin, Germany
| | - Dina Malounda
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - F Stuart Foster
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Leif Schröder
- Molecular Imaging, Department of Structural Biology, Leibniz-Forschungsinstitute für Molekulare Pharmakologie, Berlin, Germany
| | - Mikhail G Shapiro
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
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26
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Piontek A, Witte C, May Rose H, Eichner M, Protze J, Krause G, Piontek J, Schröder L. A cCPE-based xenon biosensor for magnetic resonance imaging of claudin-expressing cells. Ann N Y Acad Sci 2017. [PMID: 28636798 DOI: 10.1111/nyas.13363] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The majority of malignant tumors originate from epithelial cells, and many of them are characterized by an overexpression of claudins (Cldns) and their mislocalization out of tight junctions. We utilized the C-terminal claudin-binding domain of Clostridium perfringens enterotoxin (cCPE), with its high affinity to specific members of the claudin family, as the targeting unit for a claudin-sensitive cancer biosensor. To overcome the poor sensitivity of conventional relaxivity-based magnetic resonance imaging (MRI) contrast agents, we utilized the superior sensitivity of xenon Hyper-CEST biosensors. We labeled cCPE for both xenon MRI and fluorescence detection. As one readout module, we employed a cryptophane (CrA) monoacid and, as the second, a fluorescein molecule. Both were conjugated separately to a biotin molecule via a polyethyleneglycol chemical spacer and later via avidin linked to GST-cCPE. Nontransfected HEK293 cells and HEK293 cells stably expressing Cldn4-FLAG were incubated with the cCPE-based biosensor. Fluorescence-based flow cytometry and xenon MRI demonstrated binding of the biosensor specifically to Cldn4-expressing cells. This study provides proof of concept for the use of cCPE as a carrier for diagnostic contrast agents, a novel approach for potential detection of Cldn3/-4-overexpressing tumors for noninvasive early cancer detection.
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Affiliation(s)
- Anna Piontek
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Structural Bioinformatics and Protein Design, Berlin, Germany
| | - Christopher Witte
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Molecular Imaging, Berlin, Germany
| | - Honor May Rose
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Molecular Imaging, Berlin, Germany
| | - Miriam Eichner
- Institute of Clinical Physiology Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jonas Protze
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Structural Bioinformatics and Protein Design, Berlin, Germany
| | - Gerd Krause
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Structural Bioinformatics and Protein Design, Berlin, Germany
| | - Jörg Piontek
- Institute of Clinical Physiology Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Leif Schröder
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Molecular Imaging, Berlin, Germany
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27
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Barskiy DA, Coffey AM, Nikolaou P, Mikhaylov DM, Goodson BM, Branca RT, Lu GJ, Shapiro MG, Telkki VV, Zhivonitko VV, Koptyug IV, Salnikov OG, Kovtunov KV, Bukhtiyarov VI, Rosen MS, Barlow MJ, Safavi S, Hall IP, Schröder L, Chekmenev EY. NMR Hyperpolarization Techniques of Gases. Chemistry 2017; 23:725-751. [PMID: 27711999 PMCID: PMC5462469 DOI: 10.1002/chem.201603884] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Indexed: 01/09/2023]
Abstract
Nuclear spin polarization can be significantly increased through the process of hyperpolarization, leading to an increase in the sensitivity of nuclear magnetic resonance (NMR) experiments by 4-8 orders of magnitude. Hyperpolarized gases, unlike liquids and solids, can often be readily separated and purified from the compounds used to mediate the hyperpolarization processes. These pure hyperpolarized gases enabled many novel MRI applications including the visualization of void spaces, imaging of lung function, and remote detection. Additionally, hyperpolarized gases can be dissolved in liquids and can be used as sensitive molecular probes and reporters. This Minireview covers the fundamentals of the preparation of hyperpolarized gases and focuses on selected applications of interest to biomedicine and materials science.
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Affiliation(s)
- Danila A Barskiy
- Department of Radiology, Department of Biomedical Engineering, Department of Physics, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University, Nashville, TN, 37232, USA
| | - Aaron M Coffey
- Department of Radiology, Department of Biomedical Engineering, Department of Physics, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University, Nashville, TN, 37232, USA
| | - Panayiotis Nikolaou
- Department of Radiology, Department of Biomedical Engineering, Department of Physics, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University, Nashville, TN, 37232, USA
| | | | - Boyd M Goodson
- Southern Illinois University, Department of Chemistry and Biochemistry, Materials Technology Center, Carbondale, IL, 62901, USA
| | - Rosa T Branca
- Department of Physics and Astronomy, Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - George J Lu
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Mikhail G Shapiro
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | | | - Vladimir V Zhivonitko
- International Tomography Center SB RAS, 630090, Novosibirsk, Russia
- Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Igor V Koptyug
- International Tomography Center SB RAS, 630090, Novosibirsk, Russia
- Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Oleg G Salnikov
- International Tomography Center SB RAS, 630090, Novosibirsk, Russia
- Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Kirill V Kovtunov
- International Tomography Center SB RAS, 630090, Novosibirsk, Russia
- Novosibirsk State University, Pirogova St. 2, 630090, Novosibirsk, Russia
| | - Valerii I Bukhtiyarov
- Boreskov Institute of Catalysis SB RAS, 5 Acad. Lavrentiev Pr., 630090, Novosibirsk, Russia
| | - Matthew S Rosen
- MGH/A.A. Martinos Center for Biomedical Imaging, Boston, MA, 02129, USA
| | - Michael J Barlow
- Respiratory Medicine Department, Queen's Medical Centre, University of Nottingham Medical School, Nottingham, NG7 2UH, UK
| | - Shahideh Safavi
- Respiratory Medicine Department, Queen's Medical Centre, University of Nottingham Medical School, Nottingham, NG7 2UH, UK
| | - Ian P Hall
- Respiratory Medicine Department, Queen's Medical Centre, University of Nottingham Medical School, Nottingham, NG7 2UH, UK
| | - Leif Schröder
- Molecular Imaging, Department of Structural Biology, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Eduard Y Chekmenev
- Department of Radiology, Department of Biomedical Engineering, Department of Physics, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University, Nashville, TN, 37232, USA
- Russian Academy of Sciences, 119991, Moscow, Russia
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28
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Korchak S, Kilian W, Schröder L, Mitschang L. Design and comparison of exchange spectroscopy approaches to cryptophane-xenon host-guest kinetics. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2016; 265:139-145. [PMID: 26896869 DOI: 10.1016/j.jmr.2016.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 02/04/2016] [Accepted: 02/07/2016] [Indexed: 06/05/2023]
Abstract
Exchange spectroscopy is used in combination with a variation of xenon concentration to disentangle the kinetics of the reversible binding of xenon to cryptophane-A. The signal intensity of either free or crytophane-bound xenon decays in a manner characteristic of the underlying exchange reactions when the spins in the other pool are perturbed. Three experimental approaches, including the well-known Hyper-CEST method, are shown to effectively entail a simple linear dependence of the signal depletion rate, or of a related quantity, on free xenon concentration. This occurs when using spin pool saturation or inversion followed by free exchange. The identification and quantification of contributions to the binding kinetics is then straightforward: in the depletion rate plot, the intercept at the vanishing free xenon concentration represents the kinetic rate coefficient for xenon detachment from the host by dissociative processes while the slope is indicative of the kinetic rate coefficient for degenerate exchange reactions. Comparing quantified kinetic rates for hyperpolarized xenon in aqueous solution reveals the high accuracy of each approach but also shows differences in the precision of the numerical results and in the requirements for prior knowledge. Because of their broad range of applicability the proposed exchange spectroscopy experiments can be readily used to unravel the kinetics of complex formation of xenon with host molecules in the various situations appearing in practice.
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Affiliation(s)
- Sergey Korchak
- Physikalisch-Technische Bundesanstalt Braunschweig und Berlin, Division of Medical Physics and Metrological Information Technology, Abbestr. 2 - 12, 10587 Berlin, Germany
| | - Wolfgang Kilian
- Physikalisch-Technische Bundesanstalt Braunschweig und Berlin, Division of Medical Physics and Metrological Information Technology, Abbestr. 2 - 12, 10587 Berlin, Germany
| | - Leif Schröder
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125 Berlin, Germany
| | - Lorenz Mitschang
- Physikalisch-Technische Bundesanstalt Braunschweig und Berlin, Division of Medical Physics and Metrological Information Technology, Abbestr. 2 - 12, 10587 Berlin, Germany.
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29
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Kunth M, Witte C, Hennig A, Schröder L. Identification, classification, and signal amplification capabilities of high-turnover gas binding hosts in ultra-sensitive NMR. Chem Sci 2015; 6:6069-6075. [PMID: 30090222 PMCID: PMC6055117 DOI: 10.1039/c5sc01400j] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 07/05/2015] [Indexed: 12/20/2022] Open
Abstract
Nuclear Magnetic Resonance (NMR) can be a powerful tool for investigating exchange kinetics of host-guest interactions in solution. Beyond conventional direct NMR detection, radiofrequency (RF) saturation transfer can be used to enhance the study of such chemical exchange or to enable signal amplification from a dilute host. However, systems that are both dilute and labile (fast dissociation/re-association) impose specific challenges to direct as well as saturation transfer detection. Here we investigate host-guest systems under previously inaccessible conditions using saturation transfer techniques in combination with hyperpolarized nuclei and quantitative evaluation under different RF exposure. We further use that information to illustrate the consequences for signal amplification capabilities and correct interpretation of observed signal contrast from comparative exchange data of different types of hosts. In particular, we compare binding of xenon (Xe) to cucurbit[6]uril (CB6) with binding to cryptophane-A monoacid (CrA) in water as two different model systems. The Xe complexation with CB6 is extremely difficult to access by conventional NMR due to its low water solubility. We successfully quantified the exchange kinetics of this system and found that the absence of Xe signals related to encapsulated Xe in conventional hyperpolarized 129Xe NMR is due to line broadening and not due to low binding. By introducing a measure for the gas turnover during constant association-dissociation, we demonstrate that the signal amplification from a dilute pool of CB6 can turn this host into a very powerful contrast agent for Xe MRI applications (100-fold more efficient than cryptophane). However, labile systems only provide improved signal amplification for suitable saturation conditions and otherwise become disadvantageous. The method is applicable to many hosts where Xe is a suitable spy nucleus to probe for non-covalent interactions and should foster reinvestigation of several systems to delineate true absence of interaction from labile complex formation.
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Affiliation(s)
- Martin Kunth
- ERC Project BiosensorImaging , Leibniz-Institut für Molekulare Pharmakologie (FMP) , 13125 Berlin , Germany . ; Tel: +49 30 947 93 121
| | - Christopher Witte
- ERC Project BiosensorImaging , Leibniz-Institut für Molekulare Pharmakologie (FMP) , 13125 Berlin , Germany . ; Tel: +49 30 947 93 121
| | - Andreas Hennig
- Jacobs University Bremen , Department of Life Sciences and Chemistry , Campus Ring 1 , 28759 Bremen , Germany
| | - Leif Schröder
- ERC Project BiosensorImaging , Leibniz-Institut für Molekulare Pharmakologie (FMP) , 13125 Berlin , Germany . ; Tel: +49 30 947 93 121
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30
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Kunth M, Witte C, Schröder L. Continuous-wave saturation considerations for efficient xenon depolarization. NMR IN BIOMEDICINE 2015; 28:601-606. [PMID: 25900330 DOI: 10.1002/nbm.3307] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 03/06/2015] [Accepted: 03/18/2015] [Indexed: 06/04/2023]
Abstract
The combination of hyperpolarized Xe with chemical exchange saturation transfer (Hyper-CEST) is a powerful NMR technique to detect highly dilute concentrations of Xe binding sites using RF saturation pulses. Crucially, that combination of saturation pulse strength and duration that generates the maximal Hyper-CEST effect is a priori unknown. In contrast to CEST in proton MRI, where the system reaches a steady-state for long saturation times, Hyper-CEST has an optimal saturation time, i.e. saturating for shorter or longer reduces the Hyper-CEST effect. Here, we derive expressions for this optimal saturation pulse length. We also found that a pulse strength, B1, corresponding to five times the Xe exchange rate, k(BA) (i.e. B1 = 5 k(BA)/γ with the gyromagnetic ratio of (129)Xe, γ), generates directly and without further optimization 96% of the maximal Hyper-CEST contrast while preserving spectral selectivity. As a measure that optimizes the amplitude and the width of the Hyper-CEST response simultaneously, we found an optimal saturation pulse strength corresponding to √2 times the Xe exchange rate, i.e. B1=√2k(BA)/γ. When extremely low host concentration is detected, then the expression for the optimum saturation time simplifies as it approaches the longitudinal relaxation time of free Xe.
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Affiliation(s)
- Martin Kunth
- ERC Project BiosensorImaging, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Christopher Witte
- ERC Project BiosensorImaging, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Leif Schröder
- ERC Project BiosensorImaging, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
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31
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Schnurr M, Sydow K, Rose HM, Dathe M, Schröder L. Brain endothelial cell targeting via a peptide-functionalized liposomal carrier for xenon hyper-CEST MRI. Adv Healthc Mater 2015; 4:40-5. [PMID: 24985966 DOI: 10.1002/adhm.201400224] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/02/2014] [Indexed: 12/17/2022]
Abstract
A nanoparticulate carrier system is used to efficiently deliver a contrast agent for highly sensitive xenon Hyper-CEST MRI. The carrier system not only improves the biocompatibility and solubility of the contrast agent, it also allows selective cell targeting as demonstrated by the discrimination of human brain capillary and aortic endothelial cells.
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Affiliation(s)
- Matthias Schnurr
- ERC Project BiosensorImaging; Leibniz-Institut für Molekulare Pharmakologie; Robert-Rössle-Str. 10 13125 Berlin Germany
| | - Karl Sydow
- Peptide-Lipid Interaction; Leibniz-Institut für Molekulare Pharmakologie; Robert-Rössle-Str. 10 13125 Berlin Germany
| | - Honor May Rose
- ERC Project BiosensorImaging; Leibniz-Institut für Molekulare Pharmakologie; Robert-Rössle-Str. 10 13125 Berlin Germany
| | - Margitta Dathe
- Peptide-Lipid Interaction; Leibniz-Institut für Molekulare Pharmakologie; Robert-Rössle-Str. 10 13125 Berlin Germany
| | - Leif Schröder
- ERC Project BiosensorImaging; Leibniz-Institut für Molekulare Pharmakologie; Robert-Rössle-Str. 10 13125 Berlin Germany
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32
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Kunth M, Witte C, Schröder L. Quantitative chemical exchange saturation transfer with hyperpolarized nuclei (qHyper-CEST): Sensing xenon-host exchange dynamics and binding affinities by NMR. J Chem Phys 2014; 141:194202. [DOI: 10.1063/1.4901429] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M. Kunth
- ERC Project BiosensorImaging, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - C. Witte
- ERC Project BiosensorImaging, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
| | - L. Schröder
- ERC Project BiosensorImaging, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin, Germany
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Nikolaou P, Coffey AM, Barlow MJ, Rosen MS, Goodson BM, Chekmenev EY. Temperature-ramped (129)Xe spin-exchange optical pumping. Anal Chem 2014; 86:8206-12. [PMID: 25008290 PMCID: PMC4139178 DOI: 10.1021/ac501537w] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 06/26/2014] [Indexed: 12/12/2022]
Abstract
We describe temperature-ramped spin-exchange optical pumping (TR-SEOP) in an automated high-throughput batch-mode (129)Xe hyperpolarizer utilizing three key temperature regimes: (i) "hot"-where the (129)Xe hyperpolarization rate is maximal, (ii) "warm"-where the (129)Xe hyperpolarization approaches unity, and (iii) "cool"-where hyperpolarized (129)Xe gas is transferred into a Tedlar bag with low Rb content (<5 ng per ∼1 L dose) suitable for human imaging applications. Unlike with the conventional approach of batch-mode SEOP, here all three temperature regimes may be operated under continuous high-power (170 W) laser irradiation, and hyperpolarized (129)Xe gas is delivered without the need for a cryocollection step. The variable-temperature approach increased the SEOP rate by more than 2-fold compared to the constant-temperature polarization rate (e.g., giving effective values for the exponential buildup constant γSEOP of 62.5 ± 3.7 × 10(-3) min(-1) vs 29.9 ± 1.2 × 10(-3) min(-1)) while achieving nearly the same maximum %PXe value (88.0 ± 0.8% vs 90.1% ± 0.8%, for a 500 Torr (67 kPa) Xe cell loading-corresponding to nuclear magnetic resonance/magnetic resonance imaging (NMR/MRI) enhancements of ∼3.1 × 10(5) and ∼2.32 × 10(8) at the relevant fields for clinical imaging and HP (129)Xe production of 3 T and 4 mT, respectively); moreover, the intercycle "dead" time was also significantly decreased. The higher-throughput TR-SEOP approach can be implemented without sacrificing the level of (129)Xe hyperpolarization or the experimental stability for automation-making this approach beneficial for improving the overall (129)Xe production rate in clinical settings.
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Affiliation(s)
- Panayiotis Nikolaou
- Department
of Radiology, Vanderbilt University Institute of Imaging
Science, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Aaron M. Coffey
- Department
of Radiology, Vanderbilt University Institute of Imaging
Science, Vanderbilt University, Nashville, Tennessee 37232, United States
- Department of Biomedical
Engineering, Department of Biochemistry, and Vanderbilt-Ingram
Cancer Center, Vanderbilt University, Nashville, Tennessee 37205, United States
| | - Michael J. Barlow
- Sir Peter Mansfield
Magnetic Resonance Centre, University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Matthew S. Rosen
- Athinoula A. Martinos
Center for Biomedical Imaging, Massachusetts General
Hospital, Boston, Massachusetts 02129, United States
- Department
of Physics, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Boyd M. Goodson
- Department
of Chemistry and Biochemistry, Southern
Illinois University, Carbondale, Illinois 62901, United States
| | - Eduard Y. Chekmenev
- Department
of Radiology, Vanderbilt University Institute of Imaging
Science, Vanderbilt University, Nashville, Tennessee 37232, United States
- Department of Biomedical
Engineering, Department of Biochemistry, and Vanderbilt-Ingram
Cancer Center, Vanderbilt University, Nashville, Tennessee 37205, United States
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Freeman MS, Emami K, Driehuys B. Characterizing and modeling the efficiency limits in large-scale production of hyperpolarized 129Xe. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 2014; 90:023406. [PMID: 25400489 PMCID: PMC4228970 DOI: 10.1103/physreva.90.023406] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The ability to produce liter volumes of highly spin-polarized 129Xe enables a wide range of investigations, most notably in the fields of materials science and biomedical MRI. However, for nearly all polarizers built to date, both peak 129Xe polarization and the rate at which it is produced fall far below those predicted by the standard model of Rb metal vapor, spin-exchange optical pumping (SEOP). In this work, we comprehensively characterized a high-volume, flow-through 129Xe polarizer using three different SEOP cells with internal volumes of 100, 200 and 300 cc and two types of optical sources: a broad-spectrum 111-W laser (FWHM = 1.92 nm) and a line-narrowed 71-W laser (FWHM = 0.39 nm). By measuring 129Xe polarization as a function of gas flow rate, we extracted peak polarization and polarization production rate across a wide range of laser absorption levels. Peak polarization for all cells consistently remained a factor of 2-3 times lower than predicted at all absorption levels. Moreover, although production rates increased with laser absorption, they did so much more slowly than predicted by the standard theoretical model and basic spin exchange efficiency arguments. Underperformance was most notable in the smallest optical cells. We propose that all these systematic deviations from theory can be explained by invoking the presence of paramagnetic Rb clusters within the vapor. Cluster formation within saturated alkali vapors is well established and their interaction with resonant laser light was recently shown to create plasma-like conditions. Such cluster systems cause both Rb and 129Xe depolarization, as well as excess photon scattering. These effects were incorporated into the SEOP model by assuming that clusters are activated in proportion to excited-state Rb number density and by further estimating physically reasonable values for the nanocluster-induced, velocity-averaged spin-destruction cross-section for Rb (<σcluster-Rbv> ≈4×10-7 cm3s-1), 129Xe relaxation cross-section (<σcluster-Xev> ≈ 4×10-13 cm3s-1), and a non-wavelength-specific, photon-scattering cross-section (σcluster ≈ 1×10-12 cm2). The resulting modified SEOP model now closely matches experimental observations.
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Affiliation(s)
- M S Freeman
- Center for In Vivo Microscopy, Department of Radiology, Duke University, 311 Research Drive, Durham, NC, 27710, USA ; Medical Physics Graduate Program, Duke University, 2424 Erwin Rd, Ste. 101, Durham, NC, 27710, USA
| | - K Emami
- Polarean, Inc., 2500 Meridian Pkwy #175, Durham, NC 27713, USA
| | - B Driehuys
- Center for In Vivo Microscopy, Department of Radiology, Duke University, 311 Research Drive, Durham, NC, 27710, USA ; Medical Physics Graduate Program, Duke University, 2424 Erwin Rd, Ste. 101, Durham, NC, 27710, USA
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35
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Development of an antibody-based, modular biosensor for 129Xe NMR molecular imaging of cells at nanomolar concentrations. Proc Natl Acad Sci U S A 2014; 111:11697-702. [PMID: 25071165 DOI: 10.1073/pnas.1406797111] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Magnetic resonance imaging (MRI) is seriously limited when aiming for visualization of targeted contrast agents. Images are reconstructed from the weak diamagnetic properties of the sample and require an abundant molecule like water as the reporter. Micromolar to millimolar concentrations of conventional contrast agents are needed to generate image contrast, thus excluding many molecular markers as potential targets. To address this limitation, we developed and characterized a functional xenon NMR biosensor that can identify a specific cell surface marker by targeted (129)Xe MRI. Cells expressing the cell surface protein CD14 can be spatially distinguished from control cells with incorporation of as little as 20 nM of the xenon MRI readout unit, cryptophane-A. Cryptophane-A serves as a chemical host for hyperpolarized nuclei and facilitates the sensitivity enhancement achieved by xenon MRI. Although this paper describes the application of a CD14-specific biosensor, the construct has been designed in a versatile, modular fashion. This allows for quick and easy adaptation of the biosensor to any cell surface target for which there is a specific antibody. In addition, the modular design facilitates the creation of a multifunctional probe that incorporates readout modules for different detection methods, such as fluorescence, to complement the primary MRI readout. This modular antibody-based approach not only offers a practical technique with which to screen targets, but one which can be readily applied as the xenon MRI field moves closer to molecular imaging applications in vivo.
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Nikolaou P, Coffey AM, Ranta K, Walkup LL, Gust BM, Barlow MJ, Rosen MS, Goodson BM, Chekmenev EY. Multidimensional mapping of spin-exchange optical pumping in clinical-scale batch-mode 129Xe hyperpolarizers. J Phys Chem B 2014; 118:4809-16. [PMID: 24731261 PMCID: PMC4055050 DOI: 10.1021/jp501493k] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
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We present a systematic, multiparameter
study of Rb/129Xe spin-exchange optical pumping (SEOP)
in the regimes of high xenon
pressure and photon flux using a 3D-printed, clinical-scale stopped-flow
hyperpolarizer. In situ NMR detection was used to study the dynamics
of 129Xe polarization as a function of SEOP-cell operating
temperature, photon flux, and xenon partial pressure to maximize 129Xe polarization (PXe). PXe values of 95 ± 9%, 73 ± 4%, 60
± 2%, 41 ± 1%, and 31 ± 1% at 275, 515, 1000, 1500,
and 2000 Torr Xe partial pressure were achieved. These PXe polarization values were separately validated by ejecting
the hyperpolarized 129Xe gas and performing low-field MRI
at 47.5 mT. It is shown that PXe in this
high-pressure regime can be increased beyond already record levels
with higher photon flux and better SEOP thermal management, as well
as optimization of the polarization dynamics, pointing the way to
further improvements in hyperpolarized 129Xe production
efficiency.
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Affiliation(s)
- Panayiotis Nikolaou
- Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS) , Nashville, Tennessee 37232, United States
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