Cathepsin B and
matrix metalloproteinase (
MMP) play key roles in
tumor progression by controlled degradation of extracellular matrix. Consequently, these
proteases have been attracted in
cancer research, and many imaging probes utilizing these
proteases have been developed. Our groups developed
cathepsin B and
MMP imaging nanoprobes based on
polymer nanoparticle platform. Both
cathepsin B and
MMP imaging probes used near-infrared fluorescence (NIRF)
dye and dark-quencher to for high sensitivity, and
protease-sensitive
peptide sequence in each probe authorized high specificity of the probes. We compared the bioactivities of
cathepsin B and
MMP sensitive probes in
cancer-related environments to investigate the biological property of the probes. As a result,
cathepsin B probe showed fluorescence recovery after the probe entered the cytoplasm. This property could be useful to evaluate the cytoplasmic targeted delivery by using probe-conjugated nanoparticles in vivo. On the other hand,
MMP probe was superior in specificity in vivo and tissue study. This comparative study will provide precise information about
peptide-based optical probes, and allow their proper application to
cancer diagnosis.