激活型有机光声造影剂的应用

光声(PA)成像作为一种结合了光学和声学成像优势的新型成像方式,具有深层组织穿透和高空间分辨率等优点,在重大疾病的早期影像诊断方面有着巨大的应用前景。然而传统的PA造影剂依然存在信噪比低、选择性及特异性差等不足,容易产生假阳性诊断结果。激活型PA造影剂可以有效的降低背景噪声,并提升成像的灵敏度和特异性,是目前PA造影剂设计与构筑的主要趋势。本综述首先简单介绍了PA成像的原理,然后结合近几年在金属离子、酶、活性氮和活性氧等相关方面的生物成像应用,梳理了可激活探针在不同微环境中的响应方式。最后,对激活型探针在PA成像中的应用进行了总结和展望。

Applications of Activatable Organic Photoacoustic Contrast Agents

Photoacoustic(PA)imaging,as a new type of imaging technique that offers strong optical absorption contrast and high ultrasonic resolution,shows great application prospects in the early disease diagnosis for its characteristics of deep tissue penetration and high spatial resolution.However,traditional"always on"PA contrast agents have many disadvantages such as low signal-to-noise ratio,poor selectivity and specificity.In contrast,activatable PA contrast agents,where the imaging signal can be changed in response to pathologic parameters,have shown decreased background signal and improved selectivity and specificity in early disease diagnosis.Moreover,these contrast agents can obtain pathological parameters and information of various diseases at the molecular level by rational design to their structures,providing important guidelines for the optimization of treatment options.Therefore,activatable PA contrast agents hold greater promise in clinical practice than traditional"always on"PA contrast agents.In this review,we describe the recent advances in the development of activatable PA contrast agents.The design mechanisms and proof-of-concept applications of these activatable PA contrast agents are summarized in detail.The use of these activatable probes to detect different pathologic parameters(such as metal ions,enzymes,reactive nitrogen and reactive oxygen species)is highlighted.Finally,current challenges and future perspectives in this emerging field are also analyzed.