Researchers in the US have been carrying out pioneering experiments to grow human organs inside pigs and sheep in a bid to find a possible solution to transplant shortages.
Approximately 20 animals have been impregnated with hybrid embryos by research teams at several universities in the last year, according to MIT Technology Review. In a world first, more than 50 animals have been implanted with human-animal hybrid embryos. The aim is to develop fully functional human hearts, livers and other major organs to save the lives of patients waiting on the transplant list. More after cut…..
More than 6,000 people have died while waiting for an organ transplant on the NHS in the last decade. The development of the human-animal chimeras is controversial. It prompted outrage from animal welfare groups who denounced the experiments as “Frankenscience” and “the worst kind of medical adventurism”.
The first step involves genetically knocking out a major organ in an animal embryo. Scientists then inject human stem cells, which they hope will replace the missing organ, before placing the embryo in the womb of a female pig or sheep.
The idea is that surgeons would then later be able to harvest the human organ grown inside the animal in order to save the life of a patient. Around 20 livestock have been impregnated with the chimera embryos by researchers in the US in the last 12 months, according to MIT Technology Review. Another three dozen pregnancies are thought to have taken place in other countries.
The method is already used in mice, but using it in larger mammals marks a major step towards growing human organs for transplant. Bruce Whitelaw, professor of animal biotechnology at the University of Edinburgh’s Roslin Institute, said British scientists would be interested in carrying out their own experiments with humananimal chimeras.
He said: “It is scientifically fascinating and of potential commercial interest, and offers much for healthy, productive social debate.”
However, some organisations have expressed concerns about how far the experiments may go. The Academy of Medical Sciences has previously warned that any experiments introducing human brain cells into mammals had to be off-limits in case the resulting chimeras started acting like people.
Martin Bobrow, a former professor of medical genetics at the University of Cambridge, said the new work on chimeras could lead to “medical advances of considerable importance”.He added: “Without someone trying these experiments, we will not know whether the risks are huge, negligible, or in between.”
Julia Baines, science policy adviser to Peta UK, condemned the research as “Frankenscience”. She added: “Creating humananimal hybrids is bad for people and worse for animals. “To create animals containing human material, animal mothers undergo invasive procedures to harvest their eggs and implant embryos. “These animals have exactly the same capacity to feel pain and suffer as any other animal, including humans.”