Noninvasive NIR Imaging of Senescence Labeling.

Cellular senescence, a process that arrests the cell cycle, is a cellular response mechanism for various stresses and is implicated in aging and various age-related diseases. However, the understanding of senescence in living organisms is insufficient, largely due to the scarcity of sensitive tools for the detection of cellular senescence . Herein, we describe the development of a self-immobilizing near-infrared (NIR) fluorogenic probe that can be activated by senescence-associated βgalactosidase (SA-βGal), the most widely used senescence marker. The NIR signal is turned on only in the presence of SA-βGal, and the fluorescence signal is retained to the site of activation labeling, significantly enhancing the sensitivity of the probe. We demonstrate its efficient noninvasive imaging of senescence in mice xenograft models.