Multi-sample/multi-nucleus parallel polarization and monitoring enabled by a fluid path technology compatible cryogenic probe for dissolution dynamic nuclear polarization

Abstract

Low throughput is one of dissolution Dynamic Nuclear Polarization (dDNP) main shortcomings. Especially for clinical and preclinical applications, where direct 13C nuclei polarization is usually pursued, it takes hours to generate one single hyperpolarized (HP) sample. Being able to hyperpolarize more samples at once represents a clear advantage and can expand the range and complexity of the applications. In this work, we present the design and performance of a highly versatile and customizable dDNP cryogenic probe, herein adapted to a 5 T “wet” preclinical polarizer, that can accommodate up to three samples at once and, most importantly, it is capable of monitoring the solid-state spin dynamics of each sample separately, regardless of the kind of radical used and the nuclear species of interest. Within 30 min, the system was able to dispense three HP solutions with high repeatability across the channels (30.0 ± 1.2% carbon polarization for [1-13C]pyruvic acid doped with trityl radical). Moreover, we tested multi-nucleus NMR capability by polarizing and monitoring simultaneously 13C, 1H and 129Xe. Finally, we implemented [1-13C]lactate/[1-13C]pyruvate polarization and back-to-back dissolution and injection in a healthy mouse model to perform multiple-substrate HP Magnetic Resonance Spectroscopy (MRS) at 14.1 T.

129Xe Dynamic Nuclear Polarization Demystified: The Influence of the Glassing Matrix on the Radical Properties

“…Finally, the vial was disconnected from the dispenser, sealed to the CFP using a new PTFE O-ring and prepared for the insertion into the DNP polarizer as previously described. 60 , 61 …”

“…Finally, 200 μL of the liquid sample were pipetted inside the vial, sealed to the CFP, leak-tested and prepared for DNP as previously described. 60 , 61 …”

“…Currently, one would need a SEOP polarizer and a dDNP polarizer to run both experiments in the same subject. 58 , 59 Pushing xenon DNP methods further by improving polarization level and augmenting the gas volume produced, combined with a dDNP polarizer with multisample capability, 60 would allow the use of the same machine for both purposes, saving financial resources and reducing the instrumentation footprint.…”