Mouse heart beats again thanks to human stem cells (taken from New Scientist)

http://www.newscientist.com/article/dn24042-mouse-heart-beats-again-thanks-to-human-stem-cells.html#.Ug0D4yi9Kc0

A newly beating heart is part-mouse, part-human. For the first time, a mouse heart has been made to pulse again by stripping it of its own cells and rebuilding it with human ones (see video above).

To create the hybrid heart, Lei Yang at the University of Pittsburgh and colleagues took the heart from a mouse and, in a process that lasted 10 hours, removed all its cells. The remaining protein scaffold was then repopulated with human heart precursor cells – stem cells that had differentiated into the three types of cell required for a heart. After a few weeks, the organ started to beat again. "Our engineered hearts contain about 70 per cent human heart precursor cells, which provide enough mechanical force for contraction," says Yang....