Reopening blocked blood vessels can mean the difference between life and death for many patients, including children with pulmonary hypertension and adults with coronary artery disease. But the procedure used for restoring blood flow can cause extensive vascular injury, wiping away an essential protective layer of cells lining the walls of arteries and veins: the endothelium.

It may take the body weeks or months to heal that damage. Some long stretches of damaged vessels may never fully regrow the endothelium, which naturally propagates inward from the healthy edge toward the center of the wiped-out area.

“Our idea is that if we could put some seeds of endothelium regrowth within the boundaries of this denuded arterial segment, so that the endothelium can grow from those foci, we could speed up the process dramatically,” said Michael Chorny, PhD, a researcher at The Children’s Hospital of Philadelphia and research assistant professor of Pediatrics at the Perelman School of Medicine at the University of Pennsylvania, who specializes in developing delivery systems for therapies. “By changing the pattern of endothelium recovery, we may in practice restore it on scale of days.”