Hopkins researchers develop new way to track migration of stem cells used to treat damaged hearts

September 05, 2005

A team of scientists from the Johns Hopkins Department of Radiology and Institute of Cell Engineering has used a non-invasive imaging technique, called SPECT/CT, to successfully trace stem cells' destinations after being injected into the body to treat animal hearts damaged by myocardial infarction, or heart attack.

In the study, researchers surgically induced acute myocardial infarctions in seven dogs, six of which later received canine mesenchymal stem cells (MSCs) labeled with a radioactive tracer and magnetic resonance imaging (MRI) contrast agent to enhance image quality. Both the tracer and contrast agent are widely used in research and routine clinical practice.

The internal distribution of the injected stem cells was tracked with SPECT/CT and MRI scanners immediately after injection as well as at multiple time points over seven days to assess whether the MSCs preferentially migrated or "homed" in on damaged cardiac tissue. Previous studies in animals were only able to demonstrate homing by examining the tissue microscopically after death.

The team's results, reported in the Sept. 6, 2005, issue of Circulation, revealed redistribution of the radiolabeled MSCs from the initial localization in the lungs to the target organ, the heart, at 24 hours post-injection. Moreover, the cells remained visible in SPECT/CT images until seven days after the injection.

SPECT/CT also found redistribution of the MSCs to non-target organs, such as the liver, kidney and spleen. Measuring the radiation levels in tissues obtained from the animals after their death validated these findings.

MRI, because of its lower sensitivity, was unable to demonstrate targeted cardiac localization of MSCs.

"Our study demonstrates that SPECT/CT imaging is well suited to dynamically track the biodistribution and movement of stem cells to both target and non-target organs," says lead investigator Dr. Dara L. Kraitchman, an associate professor of radiology at the Johns Hopkins Russell H. Morgan Department of Radiology and Radiological Science. "Such a non-invasive means of studying stem cell movement could be very helpful in monitoring therapeutic safety and efficacy in clinical trials." With her co-workers, Drs. Jeff W.M. Bulte, Mark F. Pittenger, Benjamin M.W. Tsui, Randell G. Young, and Richard L. Wahl, she anticipates that this technique will useful in developing customized therapies for future patient trials.

SPECT, or single photon emission computed tomography, is a special type of emission computed tomography (ECT) scan in which a small amount of a radioactive tracer is injected into a vein, and a scanner is used to make detailed images that are highly sensitive to the location of the radioactive materials inside the body. CT, or computed tomography, uses X-rays to produce high-resolution images of the anatomical structure of the body's interior. Combining the two techniques greatly enhances anatomical mapping and localization, permitting researchers to know more precisely what cells or organs are taking up the radiolabeled tracer.
-end-
Photographs and videos of the SPECT/CT images can be viewed online at http://www.hopkinsmedicine.org/Press_releases/2005/08_30a_05.html

Johns Hopkins Medicine

Related Stem Cells Articles from Brightsurf:

SUTD researchers create heart cells from stem cells using 3D printing
SUTD researchers 3D printed a micro-scaled physical device to demonstrate a new level of control in the directed differentiation of stem cells, enhancing the production of cardiomyocytes.

More selective elimination of leukemia stem cells and blood stem cells
Hematopoietic stem cells from a healthy donor can help patients suffering from acute leukemia.

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.

Read More: Stem Cells News and Stem Cells Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.