Toward Biocompatible Nuclear Hyperpolarization Using Signal Amplification by Reversible Exchange: Quantitative in Situ Spectroscopy and High-Field Imaging

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• 作者：Jan-Bernd H枚vener ; Niels Schwaderlapp ; Robert Borowiak ; Thomas Lickert ; Simon B. Duckett ; Ryan E. Mewis ; Ralph W. Adams ; Michael J. Burns ; Louise A. R. Highton ; Gary G. R. Green ; Alexandra Olaru ; J眉rgen Hennig ; Dominik von Elverfeldt
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：February 4, 2014
• 年：2014
• 卷：86
• 期：3
• 页码：1767-1774
• 全文大小：439K
• ISSN：1520-6882

文摘

Signal amplification by reversible exchange (SABRE) of a substrate and parahydrogen at a catalytic center promises to overcome the inherent insensitivity of magnetic resonance. In order to apply the new approach to biomedical applications, there is a need to develop experimental equipment, in situ quantification methods, and a biocompatible solvent. We present results detailing a low-field SABRE polarizer which provides well-controlled experimental conditions, defined spins manipulations, and which allows in situ detection of thermally polarized and hyperpolarized samples. We introduce a method for absolute quantification of hyperpolarization yield in situ by means of a thermally polarized reference. A maximum signal-to-noise ratio of 10³ for 148 渭mol of substance, a signal enhancement of 10⁶ with respect to polarization transfer field of SABRE, or an absolute ¹H-polarization level of 鈮?0^鈥? is achieved. In an important step toward biomedical application, we demonstrate ¹H in situ NMR as well as ¹H and ¹³C high-field MRI using hyperpolarized pyridine (d₃) and ¹³C nicotinamide in pure and 11% ethanol in aqueous solution. Further increase of hyperpolarization yield, implications of in situ detection, and in vivo application are discussed.