What next? This wasn't a fully developed piece of heart muscle, but a thin strip. To be usable, it would have to be thicker, more three-dimensional, for more beating strength. It also needs a nourishing blood supply. So a next big challenge is pinpointing which daughter to those master heart stem cells will grow blood vessels.
The NIH's Nabel said the experiment also offers a possible new opportunity for cell therapy — that perhaps the precise muscle-generating cell injected directly into a damaged heart would have a better chance of sticking and working.
The Harvard team wants both methods tried.
“We're not saying this is going to happen tomorrow,” said Chien, who also is working on repeating the work with human cells. “I believe within five years,” it might be ready to try with people.