It shows for the first time that we can do regeneration at a scale that the world has never seen before, said Dr Charles Murry, professor of pathology and bioengineering, at the University of Washington.

"Before this study, it was not known if it is possible to produce sufficient numbers of these cells and use them to re-muscularise damaged hearts in a large animal whose heart size and physiology is similar to that of the human heart."

Weve shown that (stem cells) will survive and they will organise to form new heart muscle and they will connect with the surrounding cardiac muscle cells and beat in synchrony.

The green area shows the regenerated heart muscle

Currently heart muscle cannot be repaired and people with severe heart failure must wait for a heart transplant.

In the study the team induced heart attacks, in anesthetised macaque monkeys.

Over the course of two weeks they injected one billion heart muscle cells derived from human embryonic stem cells.

The researchers found that the stem cells infiltrated into the damaged heart tissue, matured, and knitted into muscle fibers, before beginning to beat in rhythm with the macaque heart cells.

After three months, the cells had fully integrated into the heart. On average the transplanted stem cells regenerated 40 percent of the damaged heart tissue and improve the ability of the heart to pump blood.

Although the study has been carried out on macaque monkeys, the researchers at the University of Washington said "the approach should be feasible in humans".

Originally posted here:
Stem cell injections may take place of heart swaps