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Ultrasensitive Magnetic Resonance Research Group discovered a new method for enhancing gas MR signals in aqueous solutions (Hyper-SAME)

time:   2020-07-18 00:00    hits:4894

Recently, Ultrasensitive Magnetic Resonance Research Group and Wuhan University have developed a new method for enhancing gas MR signals in aqueous solutions (Hyper-SAME). This method can significantly enhance the MR signals of gases in aqueous solutions, thereby improving the sensitivity of the detection of MR molecules. Related research results were published in the Proceedings of the National Academy of Sciences (PNAS).

Magnetic resonance spectroscopy and imaging (NMR/MRI), as an important analysis and medical imaging technology, has been widely used in the detection of liquid, solid, and biological tissues, and has become one of the best imaging technologies to display the structure and function of the human body in vivo, It can image organs with no radiation and no imaging depth limitation. However, for the lungs, traditional MRI (1H MRI) technology is difficult to image the gas in the alveoli, so the lungs have become a "blind spot" in traditional MRI detection.

Gas MR can make up for the shortcomings of traditional MR. Ultrasensitive Magnetic Resonance Research Group enhanced the 129Xe gas MR signal by more than 50,000 times through hyperpolarization technology, and it has been applied to the detection of human lung structure and function, successfully "lighting up" the lung. However, the direct use of 129Xe MR for biological system detection has no specificity. In recent years, a series of molecular "cages" have been developed internationally, which can bind 129Xe atoms and endow the hyperpolarized 129Xe MR with specific detection capabilities. However, these molecular "cages" have poor water solubility and the problem of weak 129Xe signal in the "cage". Improving the signal strength of 129Xe in the "cage" is a major challenge in this field.

In this research, the water-stable metal-organic framework material (MOF), ZIF-8, was first proposed as a 129Xe nano-cage to load 129Xe, which can effectively increase the concentration of 129Xe in the “cage” in the aqueous solution. The developed hyperpolarized gas MR scientific instrument significantly enhances the MR signal of 129Xe in the "cage" in the aqueous solution, which is 200 times higher than the MR signal of 129Xe in the traditional molecular "cage". Furthermore, because the barrier of Xe signal intensity in the "cage" is broken, the chemical exchange between the signal in the cage" and the signal in the blood can be used in biological testing to amplify the weak signal in the blood, thereby enhancing the sensitivity of molecular detection in the blood.

This method is named "Hyperpolarized Xe Signal Advancement by Metal-organic framework Entrapment (Hyper-SAME)". Hyper-SAME can be combined with the Hyper-SAGE technology (PNAS, 2009) previously invented by the author to further optimize and amplify the 129Xe MR signal. This important research has significantly improved the sensitivity and resolution of gas MR in aqueous solutions, and represents a major step forward for gas MR as a major biomedical tool towards highly sensitive targeted detection.