A Heart from Spare Parts
Roadworthy on a rebuilt title: a functioning heart made from stem cells and the outer body of a donor heart; in this case, a rat's.
The stripped-out shell of a heart has been made to work again - using brand new cells planted inside it.
Scientists removed all the muscle cells in a rat heart, leaving just a "scaffold" of other tissues such as blood vessels and valves.
When the University of Minnesota team added heart cells, they quickly grew and produced a pumping action.
It is hoped the Nature Medicine study will ultimately mean human or animal hearts can be crafted for transplant.
By the eight day, the home-grown hearts were capable of pumping, albeit at only 2% of the power of a normal rat heart.
Dr Doris Taylor, who led the experiment, suggested that it might change the way scientists think about producing artificial organs.