Near-infrared fluorescent probes for the detection of cancer-associated proteases

Proteases are enzymes capable of catalysing protein breakdown, which is critical across many biological processes. There are several families of proteases, each of which perform key functions through the degradation of specific proteins. As our understanding of cancer improves, it has been demonstrated that several proteases can be overactivated during the progression of cancer and contribute to malignancy. Optical imaging systems that employ near-infrared (NIR) fluorescent probes to detect protease activity offer clinical promise, both for early detection of cancer as well as for the assessment of personalised therapy. In this article, we review the design of NIR probes and their successful application for the detection of different cancer-associated proteases.