Targeted Optical Imaging Agents in Cancer: Focus on Clinical Applications

Figure 7

Activatable probe. (a) LUM015 consists of GGRK cleavage site. The Cy5 fluorophore is quenched by QSY21 in native state. (b) Proteolytic cleavage of the quencher by cathepsins activates fluorescence from Cy5. (c) Significantly increased signal is seen in a preclinical model of sarcoma. (d) Representative ex vivo fluorescence images of resected normal human muscle and sarcoma along with corresponding histology ((c) and (d) reprinted with the permission from [89]).