A Caspase-3-Activatable Near-Infrared AIEgen for Tumor Apoptosis Imaging In Vivo

Area of Science:

• Biomedical Imaging
• Nanotechnology
• Chemical Biology

Background:

• Near-infrared (NIR) fluorescence imaging allows real-time monitoring of anticancer drug efficacy by detecting tumor caspase-3 activity.
• Aggregation-induced emission luminogens (AIEgens) are sensitive fluorophores, but NIR AIEgens for imaging caspase-3 activity are lacking.

Purpose of the Study:

• To develop an activatable NIR AIEgen for sensitive imaging of caspase-3 activity in apoptotic cells and tumors.
• To evaluate the potential of the developed AIEgen for real-time monitoring of anticancer drug therapeutic effects.

Main Methods:

• Synthesis of an activatable NIR AIEgen, Ac-Asp-Glu-Val-Asp-Pra-QMT (Ac-DEVD-Pra-QMT).
• In vitro and in vivo experiments to assess caspase-3 activity imaging in cisplatin-induced apoptotic cells and tumors.
• Measurement of NIR fluorescence intensity changes upon caspase-3 cleavage and aggregation.

Main Results:

• Ac-DEVD-Pra-QMT was successfully developed as an activatable NIR AIEgen.
• Upon caspase-3 cleavage in apoptotic cells, Ac-DEVD-Pra-QMT forms nanoparticles, activating NIR fluorescence.
• NIR fluorescence intensity showed a 14.9-fold increase in vitro and a 2.7-fold increase in vivo compared to controls.

Conclusions:

• Ac-DEVD-Pra-QMT effectively images caspase-3 activity in apoptotic cells and tumors.
• The developed NIR AIEgen shows significant potential for sensitive, real-time tracking of chemotherapeutic effects.
• This tool could aid in early monitoring of treatment responses in cancer therapy.