A New Method for Preparing Mesenchymal Stem Cells and Labeling with Ferumoxytol for Cell Tracking by MRI

Area of Science:

• Regenerative Medicine
• Biotechnology
• Medical Imaging

Background:

• Mesenchymal stem cells (MSCs) are vital for cell therapy and regenerative medicine.
• In-vivo cell tracking using magnetic resonance imaging (MRI) is essential to verify transplanted cell delivery.
• Superparamagnetic iron-oxide (SPIO) contrast agents combined with cellular MRI offer effective cell-tracking capabilities.

Purpose of the Study:

• To develop a novel bio-mimicry method for preparing native mesenchymal stem cells (MSCs) for enhanced ex-vivo labeling.
• To recover and expand the phagocytic activity of cultured MSCs for efficient labeling with Ferumoxytol.
• To re-size MSCs to a more native size for improved tracking in pre-clinical and clinical studies.

Main Methods:

• Utilized a "bio-mimicry" approach by leveraging the "in-vivo environment" of MSCs.
• Cultured MSCs for 7 days to regain phagocytic activity for Ferumoxytol uptake.
• Reduced MSC size from 32.0 ± 7.2 μm to 19.5 ± 5.2 μm.

Main Results:

• Expanded MSCs were successfully labeled ex-vivo with Ferumoxytol, the only FDA-approved SPIO for human use.
• Achieved an intracellular iron concentration of 2.50 ± 0.50 pg/MSC, comparable to other labeling methods.
• Successfully reduced MSC size to a more native state without transfection agents or electroporation.

Conclusions:

• The new bio-mimicry method effectively prepares MSCs for Ferumoxytol labeling and MRI tracking.
• This approach enhances MSCs' ability to uptake SPIO nanoparticles, crucial for regenerative medicine applications.
• The method facilitates MRI-based cell tracking in both pre-clinical and clinical settings without invasive cell modification.