Stem-cell patch may fix damaged hearts

By Ben Hirschler

LONDON (Reuters) - Scientists have made two significant advances in developing a stem-cell patch to repair the damage caused to the heart after an attack.

Sian Harding of London's Imperial College said on Thursday her team had successfully matured beating heart cells in a laboratory dish for up to seven months and developed a biocompatible scaffold to form the basis of a patch.

The idea is to stitch or glue a patch of new tissue derived from embryonic stem cells over the damaged area of the heart to make the muscle viable again.

During a heart attack, or myocardial infarct, part of the heart muscle loses its blood supply and the oxygen-starved cells die, causing scarring.

"We really would like to cover the area of the infarct scar as much as possible, so it might be quite a large patch," Harding said in an interview.

"We think the patch itself will stop the scar expanding, which is one of the big problems when you have a myocardial infarction because the scar becomes weak and can bulge out."

The biomaterial developed for the patch is designed to have the same elasticity as heart muscle and can also be programmed to degrade safely in anything from two weeks upwards.

Several groups around the world are working on different ways to use stem cells in heart repair but a key challenge is to get cells to function properly.