Adult stem cells from liposuction used to create blood vessels in the lab

Millions of cardiovascular disease patients are in need of small-diameter vessel grafts for procedures requiring blood to be routed around blocked arteries.

These liposuction-derived vessels, grown in a lab, could help solve major problems associated with grafting blood vessels from elsewhere in the body or from using artificial blood vessels that are not living tissue, said Matthias Nollert, Ph.D., the lead author of the study and associate professor at the University of Oklahoma School of Chemical, Biological and Materials Engineering, in Norman, Okla.

"Current small-diameter vessel grafts carry an inherent risk of clotting, being rejected or otherwise failing to function normally," Nollert said. "Our engineered blood vessels have good mechanical properties and we believe they will contract normally when exposed to hormones. They also appear to prevent the accumulation of blood platelets -- a component in blood that causes arteries to narrow."

In this study, adult stem cells derived from fat are turned into smooth muscle cells in the laboratory, and then "seeded" onto a very thin collagen membrane. As the stem cells multiplied, the researchers rolled them into tubes matching the diameter of small blood vessels. In three to four weeks, they grew into usable blood vessels.

Creating blood vessels with this technique has the potential for "off-the-shelf" replacement vessels that can be used in graft procedures, Nollert said.

The researchers hope to have a working prototype to test in animals within six months.

Co-authors are Jaclyn A. Brennan, M.S., and Julien H. Arrizabalaga, B.S.  Funding for this study was provided by the American Heart Association.