Pig Parts

There is a human tissue crisis. According to OrganDonor.org, there are over 100,000 people that go onto a waitlist each year in hopes of getting an organ transplant. However, more than half of the people on the list won't receive an organ. Because of this shortage scientists have turned to ”xenotransplantations,” specifically the transplantation of organs from pigs to humans. Xenotransplantation originally started as a concept in the 17th century and was first tried with blood transfusions. Needless to say, it failed in most cases as the body rejected the blood. Later down the line, during the 19th century, xenotransplants were more focused around skin grafts tried from various animals. However, there was little prep done to the skin, meaning animal hair was often left on the grafted skin. These also reported a high failure rate, though some successes were also reported. During this time several organ transplants were also attempted, though these also didn’t work. Eventually, the first heart transplant was attempted by James Hardy in 1964. Hardy used a chimpanzee heart, however, he witnessed the patient die two hours after the transplant, as the heart was too small to pump the blood.

This brings us to modern day trials or studies. Currently, animal scientists are experimenting with pigs. This is because pigs can bear litters of up to 9 piglets. Also, pig DNA is similar to humans and they share similar organ size. Previously, transplants between humans and pigs were failures, as the organs were rejected by the human bodies. This was due to the fact that pig cells contain a sugar that is forgien to human bodies. This sugar causes the human body to see the organ as a foreign object that must be taken out. Using the technique of genetic engineering, scientists have removed this sugar as well as added human DNA to pig DNA to make the cells more compatible. Thanks to these efforts, a successful heart transplant has occurred. This procedure was done on David Bennett, a 57-year-old man. Bennett lived with a pig's heart for two months before he died of what was dubbed a “pig virus,” which led to the eventual rejection of the heart. Despite this failure, the transplant was ultimately seen as a huge breakthrough, as it showed how much closer humans are to being able to get organ transplants from pigs.

Another example of how close we are to achieving this goal is another experiment done on a person who was brain dead but their body was kept alive. The subject underwent a procedure in which a pig's kidney was attached to their leg and scientists observed how the body reacted to the kidney’s presence. This was a success, as the kidney did all of its functions successfully, filtering out blood, creating urine, and there was no rejection from the body. However, the experiment was short-lived, ending after 72 hours, when the body was finally unplugged.

In the future, in addition to successful xenotransplantations, we also hope to achieve blood transfusions from pigs to humans (using ideal conditions and clean blood of course). Humans are getting ever closer to achieving successful and long term xenotransplantation from pigs to humans, and within the next few years our tissue crisis could potentially be solved by this solution.