Human organs are short in supply, that is more people are waiting to receive organs than are available. There are too few donors, not in the least place because better road safety rules and better healthcare. So scientists and doctors are looking for alternatives.
One line of inquiry is xenotransplantation, i.e. the transfer of animal organs to humans. Most studies involves pigs, as their organs have a similar size as human ones. However, humans are not pigs and simply putting a pig kidney in a human will not work, as the human immune system will immediately reject the pig’s organ. Organ rejection is already a problem in human-to-human transplantation.
An approach to address this issue is to genetically engineer pigs in such way, that their organs are more “human-like”. As yet no such genetically engineered organ has been successfully implanted in humans.
Instead of genetic modification of pigs, other scientists have a different approach. A Californian team of researcher led by professor Pablo Ross has injected human stem cells into a pig embryo. The idea is that those human stem cells will form human organs, which could be used for transplantation.
Both lines of research raise ethical questions. Transgene pigs are problematic from an animal welfare perspective, while the creation of human-animal chimeras also adds to the ethical debates around stem cell research.
It is, however, doubtful whether either method will be necessary in the (near) future. For instance, Dutch scientists are working on a treatment to cure sick organs by injecting healthy stem cells – which could be obtained from living donors.
Also there is a lot of research to grow organs ex vivo from (induced pluripotent) stem cells – including the idea of 3D printing of organs. If those methods will prove to be successful than there will be no need to use animals to solve the shortage of donor organs.