title: Expeditious dissolution dynamic nuclear polarization without glassing agents.
abstract: The hyperpolarization of metabolic substrates at low temperature using dynamic nuclear polarization (DNP), followed by rapid dissolution and injection into an MRSI or NMR system, allows in vitro or in vivo observation and tracking of biochemical reactions and metabolites in real time. This article describes an elegant approach to sample preparation which is broadly applicable for the rapid polarization of aqueous small-molecule substrate solutions and obviates the need for glassing agents. We demonstrate its utility for solutions of sodium acetate, pyruvate and butyrate. The polarization behavior of substrates prepared using rapid freezing without glassing agents enabled a 1.5-3-fold time savings in polarization buildup, whilst removing the need for toxic glassing agents used as standard for dissolution DNP. The achievable polarization with fully aqueous substrate solutions was equal to that observed using standard approaches and glassing agents. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA.
authors.forename: Bimala
authors.initials: B
authors.lastname: Lama
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA.
authors.forename: James H P
authors.initials: JH
authors.lastname: Collins
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Downes
authors.affiliation: Department of Chemistry, University of Florida, Gainesville, FL, USA.
authors.forename: Adam N
authors.initials: AN
authors.lastname: Smith
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA.
authors.forename: Joanna R
authors.initials: JR
authors.lastname: Long
mesh_terms: D002247:Carbon Isotopes; D005615:Freezing; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D012996:Solutions; D013997:Time Factors; D058989:Vitrification
chemical_list: D002247:Carbon Isotopes; D012996:Solutions
keywords: 13C MRS; DNP; glassing agents; hyperpolarization; in vivo; isopentane; toxicity; vitrified