Enabling Non-invasive Tracking of Vascular Endothelial Cells Derived from Induced Pluripotent Stem Cells Using...

Area of Science:

• Regenerative Medicine
• Vascular Biology
• Medical Imaging

Background:

• Clinical translation of stem cell therapies for vascular regeneration is hindered by the lack of continuous monitoring techniques.
• Non-invasive imaging is essential for tracking transplanted cells and assessing therapeutic efficacy in peripheral artery disease (PAD).

Purpose of the Study:

• To optimize a clinically applicable, non-invasive imaging technique for longitudinal monitoring of transplanted vascular endothelial cells (ECs) in PAD.
• To establish a reliable method for tracking ECs to improve vascular regeneration therapies.

Main Methods:

• Human induced pluripotent stem cells (HiPSCs) were differentiated into ECs (HiPSC-ECs) and transduced with lentiviral vectors encoding the human sodium iodide symporter (hNIS) and enhanced green fluorescent protein (eGFP).
• An optimal transduction protocol (multiplicity of infection of five) was determined using fluorescence microscopy and flow cytometry, achieving over 90% expression efficiency.
• Single-photon emission computed tomography (SPECT) was used for in vitro and in vivo imaging of hNIS-eGFP expressing HiPSC-ECs after transplantation in nude mice.

Main Results:

• Sustained co-expression of hNIS and eGFP was achieved in HiPSC-ECs post-differentiation with optimal transduction.
• Transduced cells (hNIS-eGFP+ HiPSC-ECs) demonstrated 99mTc uptake and were detectable via SPECT in vitro.
• In vivo SPECT/CT imaging allowed real-time tracking of transplanted cells, with signal reduction exceeding 80% within 7 days post-transplantation.

Conclusions:

• An optimized protocol for cell modification and imaging was established for tracking transplanted cells.
• This technique provides a foundation for monitoring cell survival and integration in vascular regeneration therapies.
• Future work will focus on improving cell delivery and survival to enhance therapeutic outcomes for PAD.