Real time, high resolution video imaging of apoptosis in single cells with a polymeric nanoprobe.

We report a new apoptosis nanoprobe (Apo-NP) designed on the basis of a polymer nanoparticle platform. This simple one-step technique is capable of boosting fluorescence signals upon apoptosis in living cells, enabling real-time imaging of apoptosis in single cells and in vivo. The Apo-NP efficiently delivers chemically labeled, dual-quenched caspase-3-sensitive fluorogenic peptides into cells, allowing caspase-3-dependent strong fluorescence amplification to be imaged in apoptotic cells in real-time and at high resolution. The design platform of the Apo-NP is flexible and can be fine-tuned for a wide array of applications such as identification of caspase-related apoptosis in pathologies and for monitoring therapeutic efficacy of apoptotic drugs in cancer treatment.