Nav: Home

Advanced magnetic resonance imaging technology to track cells in the body

March 14, 2016

The need to non-invasively 'see' and track cells in living persons is indisputable - a boon to both research and development of future therapies. Emerging treatments using stem cells and immune cells are poised to most benefit from cell tracking, which would visualize their behavior in the body after delivery. Clinicians require such data to speed these cell treatments to patients.

Writing in the March 14, 2016 online issue of Nature Materials, researchers at University of California, San Diego School of Medicine describe a new, highly sensitive chemical probe that tags cells for detection by magnetic resonance imaging (MRI).

Specifically, a research team led by senior author Eric T. Ahrens, PhD, professor of radiology, and Roger Tsien, PhD, professor of pharmacology, chemistry and biochemistry (whose work with fluorescent proteins earned him a share of the 2008 Nobel Prize in chemistry) have synthesized a new cell labeling probe using fluorine-19, the stable isotope of the element fluorine. Agents are formulated as a "nanoemulsion" that contains microscopic droplets of an inert fluorine-based agent that is taken up by cells of interest. The fluorine agent in cells is directly detected by MRI, enabling one to observe movement of cell populations.

"Fluorine-19 tracer agents are an emerging approach that produces positive signal hot-spot images with no background signal because there's virtually no fluorine concentration in tissues," said Ahrens. "We have made a major leap in sensitivity. We have figured out how to dissolve and encapsulate metals inside the fluorine-based droplets. The net effect is to greatly amp up the MRI signal."

Ahrens, Tsien and Alex Kislukhin, a postdoctoral scholar in their labs, increased the sensitivity of the fluorine MRI agent by creating a new imaging medium that combines highly fluorinated nanoemulsions with the magnetic properties of metals - a technique that increases the visibility of fluorine by MRI. Unexpectedly and serendipitously, they also discovered that iron is particularly effective at enhancing the fluorine MRI signal.

"The chemist's iron hand has moved the field of biomedical imaging forward," said Ahrens. "To the best of our knowledge, iron has never been considered as an enhancer of 19F MRI signals, yet our analysis shows that iron is fundamentally magnetically superior to all other metal ions for enhancing fluorine MRI."

Added Tsien: "It's a wonderful coincidence that fluorine MRI benefits most from iron, which is biologically friendlier and cheaper than gadolinium, still the favorite for proton MRI."

While more research remains to be done, Ahrens said 19F MRI aided by iron represents a significant advance in tracking cells in many emerging therapeutic areas, such as immunotherapy, stem cells and treating inflammation.
-end-
Co-authors include Hongyan Xu, Stephen R. Adams and Kazim H. Narsinh, all at UC San Diego. Tsien is also a member of the Howard Hughes Medical Institute at UC San Diego.

Funding for this research came, in part, from the National Institutes of Health (grants T32-CA121938, R01-EB017271), Radiological Society of North America and the California Institute for Regenerative Medicine.

Disclosure: Dr. Ahrens is a co-founder and has an equity interest in Celsense, Inc. In addition, Dr. Ahrens is a member of Celsense, Inc.'s Board of Directors. The terms of this arrangement have been reviewed and approved by the University of California, San Diego in accordance with its conflict of interest policies.

University of California - San Diego

Related Stem Cells Articles:

Computer simulations visualize how DNA is recognized to convert cells into stem cells
Researchers of the Hubrecht Institute (KNAW - The Netherlands) and the Max Planck Institute in Münster (Germany) have revealed how an essential protein helps to activate genomic DNA during the conversion of regular adult human cells into stem cells.
First events in stem cells becoming specialized cells needed for organ development
Cell biologists at the University of Toronto shed light on the very first step stem cells go through to turn into the specialized cells that make up organs.
Surprising research result: All immature cells can develop into stem cells
New sensational study conducted at the University of Copenhagen disproves traditional knowledge of stem cell development.
The development of brain stem cells into new nerve cells and why this can lead to cancer
Stem cells are true Jacks-of-all-trades of our bodies, as they can turn into the many different cell types of all organs.
Healthy blood stem cells have as many DNA mutations as leukemic cells
Researchers from the Princess Máxima Center for Pediatric Oncology have shown that the number of mutations in healthy and leukemic blood stem cells does not differ.
New method grows brain cells from stem cells quickly and efficiently
Researchers at Lund University in Sweden have developed a faster method to generate functional brain cells, called astrocytes, from embryonic stem cells.
NUS researchers confine mature cells to turn them into stem cells
Recent research led by Professor G.V. Shivashankar of the Mechanobiology Institute at the National University of Singapore and the FIRC Institute of Molecular Oncology in Italy, has revealed that mature cells can be reprogrammed into re-deployable stem cells without direct genetic modification -- by confining them to a defined geometric space for an extended period of time.
Researchers develop a new method for turning skin cells into pluripotent stem cells
Researchers at the University of Helsinki, Finland, and Karolinska Institutet, Sweden, have for the first time succeeded in converting human skin cells into pluripotent stem cells by activating the cell's own genes.
In mice, stem cells seem to work in fighting obesity! What about stem cells in humans?
This release aims to summarize the available literature in regard to the effect of Mesenchymal Stem Cells transplantation on obesity and related comorbidities from the animal model.
TSRI researchers identify gene responsible for mesenchymal stem cells' stem-ness'
Researchers at The Scripps Research Institute recently published a study in the journal Cell Death and Differentiation identifying factors crucial to mesenchymal stem cell differentiation, providing insight into how these cells should be studied for clinical purposes.
More Stem Cells News and Stem Cells Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.