Xenotransplantation is the actual process of giving animal parts to people. It is the transplantation of one species organs into another species body. The most common animal we use for Xenotransplantation is the pig, which is strange seeing as a human can reject the organ of another human, but we are rebuilding peoples hearts with pig valves.
When people reject a transplant organ, it is a response of the immune system to the antigens in the foreign tissue. As far as pig tissue goes, we reject the antigen alpha gal. Even though chances of this happening are rare, scientists still managed to genetically engineer pigs that do not exhibit this specific sugar, leaving no chance for the human body to reject the tissue.
Scientists are always researching new ways to get more organs for transplants, and the advancement of using genetically engineered pig tissue has brought them a long way. They are looking into preventing the expression of multiple genes, so there is no chance of a foreign antigen being attacked by the immune system. There is also the possibility of inserting some human DNA into those pigs and seeing if we handled that better.
While research is well on its way, cloning enough cells for this to work is super expensive. It is too expensive to save lives with right now, but for the richest of the rich who need a new organ, they can now pay for a faster alternative to the waiting list. there is also the major fact that people aren’t comfortable with the idea of the use of animals purely for their supply in tissue and organs for people. These pigs are bred to match a human, when they’ve given up the organ or tissue sample needed, there is no further need for them.
As research continues, so do new ways to implement it, and hopefully one day not too far off we will see petri-dish grown organs that are very cheap to chuck straight into people in need.