Scientists from the University Hospital of Munich have managed to grow the beginnings of a human heart valve using the stem cells from cord blood.
They constructed scaffolds in the shape of heart valves composed of a biodegradable material. Cells grew onto the scaffolding and became a layer of tissue. When this tissue was examined, it was found to contain:
• 77.9% of all the collagen needed for human cardiovascular tissue (a protein in connective tissue).
• 67% of all the elastin needed (another connective tissue protein).
• 85% of the glycosaminoglycan (a carbohydrate in connective tissue).
They also detected other proteins essential for the healthy development of muscles and for the growth of blood vessel linings.
“These markers all indicate that human cardiovascular tissue was grown in the lab,” said Ralf Sodian, M.D, lead author of the study and a cardiac surgeon at the University Hospital of Munich, “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.”
Currently, children with heart valve defects have to have their valves replaced with animal valves, by valves that are artificially constructed, or by valves taken from deceased organ donors. Although this usually works well, the valves do not grow as the child gets older, which means they need heart surgery two or more times over the course of their childhood. This is something that is painful and distressing for the child and has all the usual risks associated with surgery. There is also the risk of tissue rejection because it is foreign to the child’s body and immune suppressant anti-rejection medications will be required. These can reduce the quality of the child’s life.
If the heart valve has been grown from the cord blood of the affected child, from his/her own cells, then it will not be foreign to him/her; therefore, theoretically, tissue rejection would not be a risk and anti-rejection drugs would not be necessary.
“Tissue engineering provides the prospect of an ideal heart valve substitute that lasts throughout the patient’s lifetime and has the potential to grow with the recipient and to change shape as needed”, added Ralf Sodian.
It is hoped that in a year or two, scientists will be able to grow a whole valve. This will give children with heart problems a safer form of treatment and the prospect of a second chance at a healthy life.
Source: American Heart Association Press Release, November 10th 2008, Abstract 3087.
Joanna is a freelance health writer for The Mother magazine and Suite 101 with a column on infertility, http://infertility.suite101.com/. She is author of the book, 'Breast Milk: A Natural Immunisation,' and co-author of an educational resource on disabled parenting, in addition to running a charity for people damaged by vaccines or medical mistakes.