Health security

IS IT ETHICAL TO GROW HUMAN ORGANS IN PIGS?

More than 120,000 Americans are currently on waiting lists for lifesaving organ transplants. Every day some 22 of them die before they can receive a transplant.

Wouldn't it be great if organs precisely matched to their recipients could be grown inside domesticated animals, such as pigs or sheep?

Scientists are trying to achieve just this goal, but some ethicists are opposed to the research.

At Stanford University, stem cell researcher Hiromitsu Nakauchi has made some significant steps toward growing human organs inside of animals. As a proof of principle experiment, he grew a rat pancreas in a mouse. He did this by disabling the gene for generating a pancreas in a mouse embryo, then injecting the embryo with stem cells from rats. The rat stem cells took up this vacated "organ niche" and differentiated into fully functioning pancreases.