The work entails planting human stems cells
into the embryo of animals to make a 'chimeric embryo' which will then be planted into an animal's womb. The intention is to grow them inside the animals and then kill the animals and harvest
the human organs for transplants. Livers, pancreas and hearts are among the organs they intend to grow.
There is widespread support for this work in Japan but in other countries there are questions about such experimentation. Japanese scientists can now only develop chimeric embryos in a laboratory for 14 days and scientists say they've been working hard to get those guidelines changed.
“This recommendation is a very important step forward and one that has taken us three years to achieve,” the head of the centre for stem cell biology and regenerative medicine at the University of Tokyo, Professor Hiromitsu Nakauchi told The Daily Telegraph. "We can apply the same principles to human stem cells and pigs, although the guidelines have not permitted us to do this yet."
The first organ they intend to grow will be a pancreas.