Hamachi Tomoyuki, Nishimura Koki, Sakamoto Keita, Kawashima Yusuke, Kouno Hironori, Sato Shunsuke, Watanabe Go, Tateishi Kenichiro, Uesaka Tomohiro, Yanai Nobuhiro
Department of Applied Chemistry, Graduate School of Engineering, Kyushu University 744 Moto-oka, Nishi-ku Fukuoka 819-0395 Japan
Department of Physics, School of Science, Kitasato University Sagamihara Kanagawa 252-0373 Japan.
Chem Sci. 2023 Nov 21;14(47):13842-13850. doi: 10.1039/d3sc04123a. eCollection 2023 Dec 6.
Dynamic nuclear polarization (DNP) significantly improves the sensitivity of magnetic resonance imaging, and its most important medical application is cancer diagnosis hyperpolarized C-labeled pyruvate. Unlike cryogenic DNP, triplet-DNP uses photoexcited triplet electrons under mild conditions. However, triplet-DNP of pyruvate has not been observed because of incompatibility of the hydrophobic polarizing agent with hydrophilic pyruvate. This work demonstrates that supramolecular complexation with β-cyclodextrin can disperse 4,4'-(pentacene-6,13-diyl)dibenzoate (NaPDBA), a pentacene derivative with hydrophilic substituents, even in the presence of high sodium pyruvate concentrations. The polarization of photoexcited triplet electron spins in NaPDBA was transferred to the C spins of sodium pyruvate triplet-DNP of H spins in water and H-to-C cross-polarization. This provides an important step toward the widespread use of ultra-sensitive MRI for cancer diagnosis.
动态核极化（DNP）显著提高了磁共振成像的灵敏度，其最重要的医学应用是癌症诊断——超极化碳标记的丙酮酸。与低温DNP不同，三线态-DNP在温和条件下使用光激发三线态电子。然而，由于疏水性极化剂与亲水性丙酮酸不相容，尚未观察到丙酮酸的三线态-DNP。这项工作表明，即使在高浓度丙酮酸钠存在的情况下，与β-环糊精的超分子络合也能分散4,4'-（并五苯-6,13-二基）二苯甲酸酯（NaPDBA），一种带有亲水性取代基的并五苯衍生物。NaPDBA中光激发三线态电子自旋的极化转移到丙酮酸钠的碳自旋上——水中氢自旋的三线态-DNP和氢到碳的交叉极化。这为超灵敏MRI在癌症诊断中的广泛应用迈出了重要一步。
