Tracking Cell Viability for Adipose-Derived Mesenchymal Stem Cell-Based Therapy by Quantitative Fluorescence Imaging...

Area of Science:

• Regenerative Medicine
• Biomedical Engineering
• Nanotechnology

Background:

• Adipose-derived mesenchymal stem cell (ADSC) viability is critical for successful engraftment in regenerative medicine.
• Real-time *in vivo* monitoring of ADSC viability presents a significant challenge for effective ADSC therapy.

Purpose of the Study:

• To develop an activated near-infrared II (NIR-II) fluorescent nanoparticle for labeling and tracking ADSC viability *in vivo*.
• To establish a ratiometric fluorescent signal for precise and sensitive *in vivo* ADSC viability assessment.

Main Methods:

• Development of DCNP@IR786s nanoparticles utilizing lanthanide-based down-conversion nanoparticles (DCNPs) and IR786s.
• Utilizing laser excitation at 808 nm and 980 nm to detect changes in NIR-II fluorescence intensity correlating with cell viability.
• Application of the developed method to identify small molecules that enhance ADSC engraftment efficiency.

Main Results:

• The DCNP@IR786s nanoparticle demonstrated a ratiometric fluorescent signal sensitive to ADSC viability changes, particularly in response to reactive oxygen species (ROS).
• The nanoparticle enabled precise, real-time quantitative evaluation of stem cell viability *in vivo*.
• Glutathione and dexamethasone were identified as small molecules that improve stem cell engraftment and enhance ADSC therapy in a liver fibrosis model.

Conclusions:

• The developed activated NIR-II fluorescent nanoparticle offers a potential strategy for real-time *in vivo* quantitative tracking of stem cell viability.
• This technology can significantly advance ADSC-based regenerative medicine by optimizing cell engraftment and therapeutic efficacy.
• The findings provide a valuable tool for screening compounds that improve stem cell therapy outcomes.