Figure 7. Confirmation of therapeutic inhibition of the enzyme matrix metalloproteinase-2 (MMP-2) in a murine tumour model using near infrared (NIR) imaging and a "smart" fluorescent probe. In the absence of the MMP inhibitor the NIR probe binds to its MMP target and is converted to a fluorescent substrate. The smart NIR probe will not be activated without binding to the enzyme. Reproduced with permission [60].