A New Way to Prepare Labeled Stem Cells

Researchers from Carnegie Mellon University in the laboratory of Chien Ho have designed a new method for preparing stem cells that can be easily detected on an magnetic resonance imaging (MRI) scan.

This new procedure not only can produce more native stem cells, but labels them with a FDA approval approved iron-oxide nanoparticle that is marketed under the name Feraheme (Ferumoxytol).

Mesenchymal stem cells extracted and isolated from bone marrow or other tissues can readily generate bone, cartilage, and fat in the laboratory. Mesenchymal stem cells (MSCs) are being tested in 360 registered clinical trials. The results of these trials have been mixed, and for these and other reasons, it is important to track implanted stem cells.

Tracking MSCs requires labeling the cells in some manner, and Dr Ho and his group discovered that superparamagnetic iron-oxide (SPIO) contrast agent, which are easily seen on MRI scans. Fortunately, MSCs have an intrinsic capacity to internalize SPIO under the right conditions. Ho and his coworkers devised a way to create the right conditions in culture so that MSCs in culture can readily take up ferumoxytol nanoparticles quite effectively.

Labeling MSCs with Feraheme

This new culture method takes MSCs extracted from bone marrow, isolates them, and then expands them in culture. Then the Carnegie group placed the MSCs into a culture system that mimics the environment cells normally experience inside someone’s body. This “in-vivo” culture method not only drives the MSCs to optimize their size, but it aggrandizes their SPIO internalization abilities.

Size optimization is very important, since smaller MSCs tend to be more effective for regenerative therapies than larger MSCs. This optimization produces high-quality cells that are also labeled and can be tracked after implantation into a patient’s body.

This impressive work was published in the journal Scientific Reports, 2016; 6: 26271 DOI: 10.1038/srep26271.


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Professor of Biochemistry at Spring Arbor University (SAU) in Spring Arbor, MI. Have been at SAU since 1999. Author of The Stem Cell Epistles. Before that I was a postdoctoral research fellow at the University of Pennsylvania in Philadelphia, PA (1997-1999), and Sussex University, Falmer, UK (1994-1997). I studied Cell and Developmental Biology at UC Irvine (PhD 1994), and Microbiology at UC Davis (MA 1986, BS 1984).