Toward biocompatible nuclear hyperpolarization using signal amplification by reversible exchange: Quantitative in situ spectroscopy and high-field imaging

TY - JOUR

T1 - Toward biocompatible nuclear hyperpolarization using signal amplification by reversible exchange

T2 - Quantitative in situ spectroscopy and high-field imaging

AU - Hövener, J.-B.

AU - Schwaderlapp, N.

AU - Borowiak, R.

AU - Lickert, T.

AU - Duckett, S.B.

AU - Mewis, R.E.

AU - Adams, R.W.

AU - Burns, M.J.

AU - Highton, L.A.R.

AU - Green, G.G.R.

AU - Olaru, A.

AU - Hennig, J.

AU - Von Elverfeldt, D.

PY - 2014/2/4

Y1 - 2014/2/4

N2 - 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 ∼10 for 148 μmol of substance, a signal enhancement of 10 with respect to polarization transfer field of SABRE, or an absolute H-polarization level of ≈10 is achieved. In an important step toward biomedical application, we demonstrate H in situ NMR as well as H and C high-field MRI using hyperpolarized pyridine (d) and C 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.

AB - 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 ∼10 for 148 μmol of substance, a signal enhancement of 10 with respect to polarization transfer field of SABRE, or an absolute H-polarization level of ≈10 is achieved. In an important step toward biomedical application, we demonstrate H in situ NMR as well as H and C high-field MRI using hyperpolarized pyridine (d) and C 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.

UR - http://www.scopus.com/inward/record.url?scp=84893550286&partnerID=8YFLogxK

U2 - 10.1021/ac403653q

DO - 10.1021/ac403653q

M3 - Article

AN - SCOPUS:84893550286

SN - 0003-2700

VL - 86

SP - 1767

EP - 1774

JO - Analytical Chemistry

JF - Analytical Chemistry

IS - 3

ER -