Children with heart defects may someday receive perfectly-matched new heart valves built using stem cells from their umbilical cord blood, according to research presented at the American Heart Association's Scientific Sessions 2008.
When infants are born with malfunctioning heart valves that can't be surgically repaired, they rely on replacements from animal tissue, compatible human organ donations or artificial materials. These replacements are lifesaving, but don't grow and change shape as a child develops; so two or more surgeries may be needed to replace outgrown valves. The animal tissue may also stiffen over time as well and be less durable than a normal human valve. With artificial valves, children also must be treated with blood thinners.
"In our concept, if prenatal testing shows a heart defect, you could collect blood from the umbilical cord at birth, harvest the stem cells, and fabricate a heart valve that is ready when the baby needs it," said Ralf Sodian, M.D., lead author of the study and a cardiac surgeon at the University Hospital of Munich.
The tissue engineering of heart valves is still in its infancy, with various researchers investigating the possibility of using cells from blood, bone marrow or amniotic fluid.
In the study, the research team used stem cells (CD133+ cells) derived from umbilical cord blood. The cord blood was frozen to preserve it. After 12 weeks, the cells were seeded onto eight heart valve scaffolds constructed of a biodegradable material and then grown in a laboratory.