Re-creating A Rat's Heart

It sounds gross, but it's potentially ground-breaking:

Decellularization is the process of removing all of the cells from an organ -- in this case an animal cadaver heart -- leaving only the extracellular matrix, the framework between the cells, intact.

After successfully removing all of the cells from both rat and pig hearts, researchers injected them with a mixture of progenitor cells that came from neonatal or newborn rat hearts and placed the structure in a sterile setting in the lab to grow.

A science blogger responds:

I wonder about whether the new organ actually works. They say that it starts pumping, but does it really function?

Their idea is predicated on the premise that the cells differentiate on the new scaffold into a relatively functional state. They mention in the abstract that the cardiac function of the new heart is reduced: "equivalent to about 2% of adult or 25% of 16-week fetal heart function." Thus, whether a fully functional organ can be created is still speculation.

That being said, if this works out the applications are essentially limitless. All solid organs have an ECM scaffold of some kind. If this technology could be paired with embryonic or adult stem cells, we could create a nearly limitless supply of replacement human organs using the scaffolds of some related species like pigs. For that reason, this is some brilliant work.