Scientists at Nanjing Medical University have created pigs that have been genetically modified to grow organs that can be transplanted into humans. The first litter of these GM pigs will be born within the next six months.
“The genetically modified piglets could bring hope to people who are in need of organ transplants but have failed to find a donor,” said Zhao Zijian, head of the Metabolic Disease Research Center at Nanjing Medical University. The research group has been working with GM technology since 1998 to replace pig genes that cause rejection of organs transplanted into humans.
“Just as people with different blood types cannot accept blood transfusions from one another, pig organs were rejected by all human recipients before I replaced a certain sugar molecule with a human gene,” said Dai Yifan, deputy director of the research center.
Dai successfully bred the transplantation-friendly GM pigs in a laboratory at Revivicor Inc in the United States and took cells back to China earlier this year from which he plans to clone thousands of pigs.
The first brood will be born in five or six months in Nanjing. They and their organs will be used for more experiments to verify suitability as donors of hearts, kidneys and livers.
Due to a shortage of organ donors only 10,000 out of 1 million people with kidney disease and 300,000 with liver disease awaiting a transplant are saved each year.
Organs from GM pigs have been tested in the United States since 2002. They have kept monkeys alive for up to 400 days. Such temporary transplants could potentially help keep human patients alive while waiting for human transplant organs.
Scientists from the Chinese Academy of Agricultural Sciences first bred GM pigs in November 2010. Clinical trials on humans have not been carried out anywhere in the world.
The Nanjing Medical Center research group will apply for permission to conduct human clinical experiments after the pigs have grown enough, said Dai. No one can say whether the government will allow the transplanting of pig organs into humans on an experimental basis.
Some transplant surgeons question whether transplanting pig organs won’t create risk of humans being infected with animal diseases.
The center is already constructing sterile pigsties that are “as clean as an operating room”, said Dai. “The sterile environment will mean there are no viruses on the pigs that could cause diseases among humans.”