University of Pittsburgh researchers have grown arteries that exhibit the elasticity of natural blood vessels at the highest levels reported, a development that could overcome a major barrier to creating living-tissue replacements for damaged arteries, the team reports in the Proceedings of the National Academy of Sciences.

The team used smooth muscle cells from adult baboons to produce the first arteries grown outside the body that contain a substantial amount of the pliant protein elastin, which allows vessels to expand and retract in response to blood flow. Lead researcher Yadong Wang, a professor of bioengineering in Pitt’s Swanson School of Engineering, his postdoctoral researcher Kee-Won Lee, and Donna Stolz, a professor of cell biology and physiology in Pitt’s School of Medicine, cultured the baboon cells in a nutrient-rich solution to bear arteries with approximately 20 percent as much elastin as an inborn artery.

The Pitt process is notable for its simplicity, Wang said. Elastin—unlike its tougher counterpart collagen that gives vessels their strength and shape—has been notoriously difficult to reproduce. The only successful methods have involved altering cell genes with a virus; rolling cell sheets into tubes; or culturing elastin with large amounts of transforming growth factor, Wang said. And still these previous projects did not report a comparison of elastin content with natural vessels.