Hyperpolarized Xenon-129 Chemical Exchange Saturation Transfer (HyperCEST) Molecular Imaging: Achievements and Future Challenges

Abstract

Molecular magnetic resonance imaging (MRI) is an emerging field that is set to revolutionize our perspective of disease diagnosis, treatment efficacy monitoring, and precision medicine in full concordance with personalized medicine. A wide range of hyperpolarized (HP) 129Xe biosensors have been recently developed, demonstrating their potential applications in molecular settings, and achieving notable success within in vitro studies. The favorable nuclear magnetic resonance properties of 129Xe, coupled with its non-toxic nature, high solubility in biological tissues, and capacity to dissolve in blood and diffuse across membranes, highlight its superior role for applications in molecular MRI settings. The incorporation of reporters that combine signal enhancement from both hyperpolarized 129Xe and chemical exchange saturation transfer holds the potential to address the primary limitation of low sensitivity observed in conventional MRI. This review provides a summary of the various applications of HP 129Xe biosensors developed over the last decade, specifically highlighting their use in MRI. Moreover, this paper addresses the evolution of in vivo applications of HP 129Xe, discussing its potential transition into clinical settings.

Water Molecules Confined in Cryptophane Nanocages: Structures and Dynamics Driven by Hydrogen Bonding and Water Chains

“…In XBSs, the abundant, spin-hyperpolarized , Xe in the bulk solution undergoes chemical exchange with the scarce, host-bound Xe, with an exchange rate of the order of 10 2 to 10 3 1/s. − ,,− The exchange allows a combination of the CEST and hyperpolarization methods in what is known as the hyper-CEST experiment . Hyper-CEST can increase the NMR signal intensity by up to 10 7 -fold, which enables chemical detection in down to picomolar concentration with XBSs.…”