Recently, the Institute of Precision Measurement Science and Technology Innovation of the Chinese Academy of Sciences has cooperated with Wuhan University and other units to develop a new method for enhancing the gas magnetic resonance signal in aqueous solution. This method can significantly enhance the gas magnetic resonance signal in aqueous solution, thus improving the sensitivity of magnetic resonance molecular detection. The relevant research results were published in the Proceedings of the National Academy of Sciences (PNAS) in the United States.
Magnetic resonance spectroscopy and imaging (NMR/MRI), as an important analytical and medical imaging technique, has been widely used in the detection of liquid, solid, and biological tissues. It has become an imaging technology that displays the structure and function of the human body in a living state, and can image solid organs without radiation or imaging depth limitations. However, for the lungs, traditional magnetic resonance imaging (1H MRI) techniques are difficult to achieve gas imaging inside the alveoli, making the lungs a "blind spot" for traditional magnetic resonance detection.
Gas magnetic resonance can compensate for the shortcomings of traditional magnetic resonance. The research group led by Zhou Xin from the Precision Measurement Institute has enhanced the 129Xe gas magnetic resonance signal by more than 50000 times through hyperpolarization technology, and has been applied to the detection of human lung structure and function, successfully "illuminating" the lungs. This technology is non-invasive and has advantages over other technologies in the diagnosis and treatment evaluation of major lung diseases. However, directly using 129Xe magnetic resonance imaging for biological system detection lacks specificity. In recent years, a series of molecular "cages" have been developed that can bind to 129Xe atoms, endowing hyperpolarized 129Xe with the ability for magnetic resonance specific detection. However, these molecular "cages" all have poor water solubility and weak 129Xe signal inside the cages. Improving the signal strength of 129Xe inside the cages is a major challenge facing this field.
In this study, researchers proposed a water stable metal organic framework material (MOF) - ZIF-8- as a nano "cage" of 129Xe to load 129Xe, which can effectively increase the concentration of 129Xe in the "cage" in aqueous solution. Using the self-developed hyperpolarized gas magnetic resonance scientific instrument by the research group, the magnetic resonance signal of 129Xe in the "cage" in aqueous solution was significantly enhanced, which was 200 times higher than that of traditional molecular "cages", achieving an important breakthrough in the field of hyperpolarized 129Xe magnetic resonance molecular imaging. In addition, by breaking through the barrier of Xe signal intensity inside the "cage", the chemical exchange between this signal and the signal in the blood can be utilized in biological detection to amplify weak signals in the blood, thereby improving the sensitivity of molecular detection in the blood.
This method is named "Hyperpolarized Xe Signal Advancement by Metal organic Framework Entrancement (Hyper SAME)". Hyper SAME can be combined with the Hyper SAGE technology previously invented by the author (PNAS, 2009) to further optimize and amplify the magnetic resonance signal of 129Xe. This study significantly improves the sensitivity and resolution of gas magnetic resonance in aqueous solutions, representing a step forward for gas magnetic resonance as a primary biomedical tool towards high-sensitivity targeted detection.
Dr. Zeng Qingbin from the Institute of Precision Measurement and Dr. Bi Binglin from Wuhan University are co authors, while researchers Zhou Xin and Guo Qianyi from the Institute of Precision Measurement and Professor Deng Hexiang from Wuhan University are co corresponding authors. This research has received support from the Ministry of Science and Technology, the National Natural Science Foundation of China, and the Chinese Academy of Sciences.