Scientists at the University of California are planning to grow human organs in pig by injecting human stem cells into pig embryos to produce chimeras (human-pig embryos), and then transplanting them into humans. To do so, the organ in the animal embryo has to be removed first by identifying and removing the gene for it, and then replacing the missing pig organ by injecting human stem cells. The embryo is then kept inside pig’s womb and is allowed to grow for 28 days before being analysed and terminated.  Also, since the size of pig organs are almost the same as humans, doctors even contemplated using pigs for humans transplants. But doctors, as iNews notes, feared the risk of passing animal viruses into humans and that the human body would reject the foreign tissue.

Now, this doesn’t seem to be a challenge because gene-editing technology known as CRISPR seems to have solved this. Organ is made mostly from human cells rather than a foreign species.

CRISPR allows scientists to edit genomes with remarkable precision and flexibility. With CRISPR, it’s theoretically possible to alter DNA of any animals, including humans. So, to create the chimeric embryos in this experiment, scientists used CRISPR to eliminate a section of the pig’s DNA necessary for the embryo to develop a pancreas.

Scientists are planning to grow human organs in pig by injecting human stem cells into pig embryos to produce chimeras (human-pig embryos)
Human stem cells being injected into a pig embryo. On the right side of the screen, you can see the cells travelling down the tube. Image ROSS/UC DAVIS via BBC

In the US, the embryos, which in this case is the chimeras, cannot be matured past 28 days. And, even if there are no such regulations, it would take years before a fully formed human pancreas can be created.

“Our hope is that this pig embryo will develop normally but the pancreas will be made almost exclusively out of human cells and could be compatible with a patient for transplantation.” said Pablo Ross, who led the research, in a statement at BBC.

Many stand against this experiment over fears that it could affect the animal’s behavior, IBT notes. Critics say the development of such hybrids is ‘offensive to human dignity,” and Julia Baines, Peta UK, describes the experiment as Frankenscience, saying that “Creating human-animal hybrids is bad for people and worse for animals.”

But anyway, human lives matter more. If the experiment is deemed successful, there would not be issue such as shortage of organs for transplants and this will eventually decrease death rate. And hopefully, CRISPR would one day hold the cure for any genetic diseases.