Recent advances in biological-environment-responsive smart MRI contrast agents

随着生物医学领域的不断发展,人们对于在分子机理层面上研究生物体系中新陈代谢、疾病的发生和发展等过程的需求日益增长.磁共振成像因拥有其他成像方法所; 不具备的非侵入式、深层次的空间分辨能力,为生物体系分子层面的检测提供了有力的工具.分子层面的磁共振成像检测离不开生物环境智能响应磁共振造影剂的使; 用.生物环境智能响应磁共振造影剂的造影能力会随着特定生物环境变化而发生改变.此类造影剂使得人们可以根据磁共振图像上信号的改变分析得到生物体特定位; 置的pH、离子浓度、酶活力等相关信息.近20年来,生物环境智能响应磁共振造影剂得到了长足的发展.本文将按不同的响应对象分类总结近几年此类造影剂的; 研究进展,并对一些重要的研究成果进行较为详细的阐述和对比,分析目前生物环境智能响应磁共振造影剂研究中存在的困难和解决方案,最后对本领域的进一步发; 展进行展望.With the rapid advancement in biology and medicine, there is an urgent; need to study metabolisms in lives and mechanisms of diseases at; molecular levels. Magnetic resonance imaging (MRI), which is capable of; non-invasive and three-dimensional deep imaging, is a powerful tool to; meet this demand. Environment-responsive contrast agents, whose contrast; abilities change once stimulated, are necessary for this purpose. With; the use of these responsive contrast agents, related biological; information, such as pH, concentration of ions, activity of enzymes,; could be easily extracted and analyzed from MR images. Considerable; progress has been made in the field of biological-environment-responsive; smart MRI contrast agents over the two decades. In this review, we; describe achievements in recent years, discuss several representative; works in detail, summarize current difficulties that have been met and; possible solutions that have been formulated, and finally look into the; promising future of biological-environment-responsive smart MRI contrast; agents.科技部973项目; 国家自然科学基金; 霍英东教育基