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 Stem Cells show promise for a new generation of tissue-engineered vascular grafts which could improve the success rate of surgery for peripheral arterial disease. 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 bypass surgery. 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 endothelial cells 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."
The Stem Cell paper is titled "Toward Engineering a Human Neoendothelium With Circulating Progenitor Cells." In addition to Ameer, other authors are Josephine B. Allen, Sadiya Khan and Karen A. Lapidos, all of Northwestern.
The work was funded by the Illinois Regenerative Medicine Institute, the Department of Defense and the American Heart Association.
Kyle Delaney | EurekAlert!
Plant mothers talk to their embryos via the hormone auxin
17.07.2018 | Institute of Science and Technology Austria
Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides
16.07.2018 | Tokyo Institute of Technology
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
16.07.2018 | Physics and Astronomy
16.07.2018 | Life Sciences
16.07.2018 | Earth Sciences