American scientists are attempting to grow a human pancreas inside a pig, in controversial research which could enable the harvesting of human organs for transplant patients.
A team from the University of California has created a “genetic niche” in the pigs’ DNA which will allow them to inject human stem cells into the pig embryos.
Researchers hope the resulting foetus will grow a pancreas made almost entirely of human cells -although in the current trials the pregnancies will be terminated after 28 days.
The work is controversial and last year the main US medical research agency imposed a funding limit because of concerns that the human cells might migrate to developing the foetal pig’s brain, making the animal more human.
Reproductive biologist Professor Pablo Ross, who is leading the research, said: “Our hope is that this pig embryo will develop normally but the pancreas will be made almost exclusively out of human cells and could be compatible with a patient for transplantation.
“We think there is a very low potential for a human brain to grow.”
Pigs are thought to be an ideal biological incubator for growing human organs, and could potentially be used to create not just a pancreas, but hearts, livers, kidneys lungs and corneas.
He said transplanting such organs to human patients in need of transplants could be done without the need for immunosuppressive drugs which can carry significant side-effects.
Britain is currently suffering an acute organ donor shortage , mainly due to medical advances which are saving more lives following accidents, and 429 people died in 2014 waiting for a transplant.
Experts believe the so-called “chimera” technique being developed in California is likely to be approved by the Home Office.
But animal rights campaigners are questioning the use of animals to grow human organs.
Peter Stevenson, from Compassion in World Farming, said: “I’m nervous about opening up a new source of animalfirst get many more people to donate organs.”