Pravdivtsev Andrey N, Skovpin Ivan V, Svyatova Alexandra I, Chukanov Nikita V, Kovtunova Larisa M, Bukhtiyarov Valerii I, Chekmenev Eduard Y, Kovtunov Kirill V, Koptyug Igor V, Hövener Jan-Bernd
Section for Biomedical Imaging, Molecular Imaging North Competence Center (MOIN CC), Department of Radiology and Neuroradiology , University Medical Center Schleswig-Holstein (UKSH), Kiel University , Am Botanischen Garten 14 , 24118 Kiel , Germany.
International Tomography Center , Siberian Branch of the Russian Academy of the Sciences , Institutskaya st. 3 A , 630090 Novosibirsk , Russia.
J Phys Chem A. 2018 Nov 21;122(46):9107-9114. doi: 10.1021/acs.jpca.8b07163. Epub 2018 Nov 9.
Signal Amplification By Reversible Exchange (SABRE) is a new and rapidly developing hyperpolarization technique. The recent discovery of Spin-Lock Induced Crossing SABRE (SLIC-SABRE) showed that high field hyperpolarization transfer techniques developed so far were optimized for singlet spin order that does not coincide with the experimentally produced spin state. Here, we investigated the SLIC-SABRE approach and the most advanced quantitative theoretical SABRE model to date. Our goal is to achieve the highest possible polarization with SLIC-SABRE at high field using the standard SABRE system, IrIMes catalyst with pyridine. We demonstrated the accuracy of the SABRE model describing the effects of various physical parameters such as the amplitude and frequency of the radio frequency field, and the effects of chemical parameters such as the exchange rate constants. By fitting the model to the experimental data, the effective life time of the SABRE complex was estimated, as well as the entropy and enthalpy of the complex-dissociation reaction. We show, for the first time, that this SLIC-SABRE model can be useful for the evaluation of the chemical exchange parameters that are very important for the production of highly polarized contrast agents via SABRE.
可逆交换信号放大（SABRE）是一种新兴且发展迅速的超极化技术。自旋锁定诱导交叉SABRE（SLIC-SABRE）的最新发现表明，迄今为止开发的高场超极化转移技术是针对与实验产生的自旋态不一致的单重态自旋序进行优化的。在此，我们研究了SLIC-SABRE方法以及迄今为止最先进的定量理论SABRE模型。我们的目标是使用标准的SABRE系统（带有吡啶的IrIMes催化剂）在高场下通过SLIC-SABRE实现尽可能高的极化。我们证明了SABRE模型在描述各种物理参数（如射频场的幅度和频率）的影响以及化学参数（如交换速率常数）的影响方面的准确性。通过将模型与实验数据拟合，估计了SABRE配合物的有效寿命以及配合物解离反应的熵和焓。我们首次表明，这种SLIC-SABRE模型可用于评估对于通过SABRE生产高极化造影剂非常重要的化学交换参数。
