Scientists have always been fascinated by the power of some organisms to regenerate whole body parts. One flatworm, called the planarian, is so good at regeneration that it can be cut up in several pieces that each of those pieces will generate a whole new worm. That regenerative power comes from stem cells that can become the cells that are needed for replacement. Which is why stem cell scientists study the planarian as a model.
The dream has been that harnessing the power of stem cells, humans could have this regenerative power to repair damaged limbs or organs as well. And scientists made a step toward that goal by growing a blood vessel in a little girl who needed one using stem cells from her own bone marrow.
Angela Irizarry was born with one functioning ventricle in her heart. It is a congenital condition called hypoplastic left heart syndrome. The ventricle is the chamber that pumps blood from the heart. The right ventricle pumps blood to the lungs. The left ventricle pumps the oxygen rich blood from the lungs to the body. In hypoplastic left heart syndrome, the one working ventricle had to pump blood not just to the lungs but to the rest of the body. Over time that causes strain on the right side of the heart.
Angela needed a new blood vessel to route blood from her lower body directly to her lungs to improve the oxygenation in her blood and allow the right ventricle to pump blood just to the body. Doctors grew one inside Angela’s body with her own stem cells. The Wall Street Journal reports:
Doctors at Yale University here implanted in Angela’s chest in August a bioabsorbable tube that is designed to dissolve over time. The tube was seeded with cells, including stem cells, that had been harvested from Angela’s bone marrow. Since then, the doctors say, the tube has disappeared, leaving in its place a conduit produced by Angela’s cells that functions like a normal blood vessel.
“We’re making a blood vessel where there wasn’t one,” says Christopher Breuer, the Yale pediatric surgeon who led the 12-hour procedure to implant the device. “We’re inducing regeneration.”
Angela, who had little stamina before the operation, now has the energy of a regular kid. She is on several medications, but Dr. Breuer and her parents think she’ll be able to start school in the fall.
What great news for little Angela and for adult stem cell research!