I don't post a lot of gee-whiz biomed stuff to LJ. I'm jaded. A lot of the stories that the pop-science press goes ga-ga about only amount to tiny twists on old ideas that have been around for years. And I know that for every thousand hot new lab techniques that are published, 999 will ultimately fail to find any use. Science is just like that.
This story, however, is a little different. This sounds like a technique that might move from the bench to the clinic within a decade, and might solve important problems. Need a new kidney or liver? Let us refurbish your old one, sir.
It's not quite *that* simple. One problem is that bad kidneys or livers not only have non-functioning kidney and liver cells, but the matrix for those cells is scarred down and contracted. I don't know how well that abnormal matrix will function even if you re-seed it with stem cells. Sort of like trying to rehab a house which has been abandoned so long that the roof has caved in, and water has rotted out the frame structure and the foundation has started to crumble. Or fixing up the convertible in the urban legend that someone filled with concrete.
Another other problem is that human hearts are unlike mouse and rat hearts in that they need constant perfusion. That is, they are so large that they cannot take oxygen and nutrients from the blood that passes through them (or the tissue culture medium -- probably the 'sterile setting' the article speaks of). They have their own blood vessels, the famous coronary arteries, that must be constantly perfused with blood or other nutrient solution. This makes the job of creating new hearts from old much, much harder.
Still, this is a promising development. And it's fascinating to think that stem cells can autonomously arrange and differentiate themselves into functional heart tissue, with proper electrical pathways, that starts to beat on its own.
Life wants to live.