Researchers characterize stem cell function

Mar 11, 2010

The promise of stem cells lies in their unique ability to differentiate into a multitude of different types of cells. But in order to determine how to use stem cells for new therapeutics, scientists and engineers need to answer a fundamental question: if a stem cell changes to look like a certain type of cell, how do we know if it will behave like a certain type of cell?

Researchers at Northwestern University's McCormick School of Engineering are the first to fully characterize a special type of stem cell, endothelial progenitor cells (EPCs) that exist in circulating blood, to see if they can behave as endothelial cells in the body when cultured on a bioengineered surface.

The results, published online in the journal show promise for a new generation of tissue-engineered vascular grafts which could improve the success rate of surgery for . Peripheral arterial disease is estimated to affect one in every 20 Americans over the age of 50, a total of 8 to 12 million people.

"Normally, stem cells are not studied in the context of improving vascular grafts for . Therefore, we had to develop new tests to assess their use in this application," says Guillermo Ameer, senior author of the paper and associate professor of biomedical engineering and surgery. "We looked at the function of the cells on a citric acid-based polymer, which will be the basis for a new generation of bioengineered vascular grafts."

In the study, Josephine Allen, then a graduate student in Ameer's lab, and colleagues isolated endothelial progenitor cells from eight tablespoons of blood. In approximately half of the attempts, the team was able to isolate the EPCs to expand to make millions of that can behave like the cells of a blood vessel.

Once the endothelial-like cell colonies were established, the research team performed a battery of tests to examine the properties and functionality of the cell.

"These new tests show that these endothelial-like cells can inhibit blood clotting and can prevent platelets from adhering to their surface," says Ameer. "But if you antagonize the cells or stimulate them, they will also respond the same way that an endothelial cell would and will clot blood if needed."

The study is an important step in identifying methods to build a tissue-engineered vascular graft. Synthetic grafts, used to treat common diseases such as peripheral arterial disease, have lower success rates when used in small-diameter arteries, such as those found in the leg.

"These small-diameter synthetic grafts are more prone to blood clots and other complications, especially over time," Ameer says. "It's thought that a tissue-engineered graft would allow us to preserve many of the body's natural defenses against these complications."

Explore further: Mycologist promotes agarikon as a possibility to counter growing antibiotic resistance

More information: The Stem Cell paper is titled "Toward Engineering a Human Neoendothelium With Circulating Progenitor Cells."

add to favorites email to friend print save as pdf

Related Stories

Deciphering the body's healing secrets

Feb 12, 2009

Healthy blood vessels play a key role in the prevention and treatment of diseases such as cardiovascular disease and diabetes. Endothelial cells line the blood vessels and are critical to the regulation of blood vessel growth ...

Scientists create blood vessel cells from stem cells

Jan 22, 2010

New York Stem Cell Foundation (NYSCF)-Druckenmiller Fellow, Daylon James, PhD, of Weill Cornell Medial College, is lead author on a study defining conditions for generating a plentiful supply of endothelial (vessel lining) ...

Engineered Blood Vessels Function like Native Tissue

Jul 05, 2007

Blood vessels that have been tissue-engineered from bone marrow adult stem cells may in the future serve as a patient's own source of new blood vessels following a coronary bypass or other procedures that require vessel replacement, ...

Recommended for you

YEATS protein potential therapeutic target for cancer

Oct 23, 2014

Federal Express and UPS are no match for the human body when it comes to distribution. There exists in cancer biology an impressive packaging and delivery system that influences whether your body will develop cancer or not.

Precise and programmable biological circuits

Oct 23, 2014

A team led by ETH professor Yaakov Benenson has developed several new components for biological circuits. These components are key building blocks for constructing precisely functioning and programmable bio-computers.

User comments : 0