Molecular imaging of enzyme activity in vivo using activatable probes

Precise measurement of enzyme activity in living systems with molecular imaging probes is becoming an important technique to unravel the functional roles of different enzymes in biological processes. Recent progress has been made in the development of a myriad of molecular imaging probes featuring different imaging modalities, including optical imaging, magnetic resonance imaging, nuclear imaging, and photoacoustic imaging, allowing for non-invasive detection of various enzyme activities in vivo with high sensitivity and high spatial resolution. Among these imaging probes, activatable or ＂smart＂ probes, whose imaging signal can be specifically switched from the ＂off＂ to ＂on＂ state upon interaction with a target enzyme, are particularly attractive due to their improved sensitivity and specificity. Here, recent advances in the development of activatable probes capable of imaging different enzyme activities in vivo are summarized based on different imaging modalities, and current challenges and future perspectives are discussed.

磁共振钆靶向对比剂的研究现状及展望

特异性MR靶向对比剂通过与体内特定的靶点结合显示活体分子靶点状态,为临床提供分子水平的信息。选择针对特定靶点的特异性运载体和良好的MR显像剂,是构建良好分子探针的一个关键因素。钆剂作为临床常用的MR对比剂,在构建分子探针上具有诸多优势,目前在MR分子成像领域进行了大量实验研究。就目前研究常用的分子靶点和分子探针,对MR钆靶向对比剂的研究现状及展望进行综述。