Water-stable Metal-Organic Framework for Hyperpolarized Xenon MRI in Aqueous Solution

Hyperpolarized 129Xe magnetic resonance imaging (MRI) is a
powerful tool for detecting respiratory system diseases. However,
129Xe is an inert gas and lacks specific detection capability.
Entrapping xenon within molecular cages to enable specific
detection is a challenging task, and numerous molecular cages
have been developed and evaluated to address this challenge.
Herein, we report that the aluminum-based metal-organic
framework, CAU-1, can effectively entrap xenon for
hyperpolarized 129Xe MRI in aqueous solutions. This platform
exhibits high water stability and good dispersibility, and shows
excellent xenon entrapment capability, even at a concentration as
low as 50 μg/mL. Importantly, it is responsive to pH changes across
a range from 6.6 to 5.0, making it promising for monitoring the
weakly acidic environment in tumors or metabolic abnormality.
Furthermore, the scalable and cost-effective production of this
molecular cage will facilitate future advancements in molecular
imaging and chemical sensing applications.

超极化129氙磁共振成像（Magnetic Resonance Imaging, MRI）是检测呼吸系统疾病的有力工具。然而，129氙属于惰性气体，缺乏特异性检测能力。将氙气封装于分子笼内以实现特异性检测是一项极具挑战性的课题，为此学界已开发并评估了多种分子笼以应对这一难题。本文报道，铝基金属有机框架CAU-1可在水溶液中有效封装氙气，用于超极化129氙磁共振成像。该平台具备优异的水稳定性与良好的分散性，即便在低至50 μg/mL的浓度下仍展现出出色的氙气封装能力。尤为重要的是，该平台可响应6.6至5.0区间内的pH变化，有望用于监测肿瘤微环境的弱酸性特征或代谢异常情况。此外，该分子笼可实现规模化且低成本制备，将推动分子成像与化学传感领域的未来发展与应用。