Today I will deviate quite a bit from Neuroscience and wander into tissue engineering as I just want to share a very informative and impressive video about heart transplants and engineering. Growing organs "out of the Petri dish" and successfully implanting them into the human body has already been achieved for several organs. However, most of those organs are of relatively simple architecture. Complex organs like the heart are causing much more headaches for researchers. Hence, they had to come up with new approaches to tackle the problem. Instead of growing the organ completely new, they took a heart from a recently diseased person, decellularized the heart and then repopulate the organ with functional stem cells. But the donor heart don't need to be human, it can be also from a pig. In fact, pig organs have been successfully implanted. But as with pig hearts or hearts from donor patients the main problem up to now has been the auto-immune reaction of the patients immune system. So it is not uncommon that the patients' body often rejects the donor graft. With the new technique this problem will be overcome. However, there is still a long way to go to fully regrow a new heart but for the moment even rebuilding and re-implanting parts like a heart valves is an important step forward. Check out now the video for a better picture...!