Transplantation is a very helpful, yet ethically ambiguous practice. Despite its betterment of millions of lives worldwide, transplantation is an elusive treatment: only 10% of patients in need of a transplant actually receive it, according to the Global Observatory on Donation and Transplantation (GODT).
The demand for transplants is steadily increasing, while the supply is limited and swiftly declining; this creates a surge in human trafficking with the purpose of unlawfully obtaining organs. In addition to that, whether or not you receive the treatment depends on a series of factors. Those include age, gender (with women being more likely to be living donors while men are the vast majority of recipients), socioeconomic status, ethnicity, place of residence, according to the European Public Health Alliance. What can be done to mend this disparity?
One solution is growing humanised organs in animal embryos. Although growing mouse organs inside rat embryos was possible, the growth of human organs inside pigs was seen as unmanageable, until recently. Researchers have found a way to grow human embryo kidneys inside pig chimeras. That is, “an organism containing a mixture of genetically different tissues, formed by processes such as fusion of early embryos, grafting, or mutation”, according to Oxford Languages. This is an outstanding feat since pig cells and human cells have different physiological needs. Moreover, the pig cells compete with the human cells for resources, thus inhibiting the growth of the latter.
Innovation in genetic engineering
The way the researchers came over this issue truly is astounding. First, they genetically engineered a single-cell embryo that was missing the genes needed for kidney development. Thus, they created a space in which the human cells could grow uninhibited by the pig cells. Then, they engineered human pluripotent cells (cells that have the capacity to form any other cell type). They increased the cell’s ability to integrate into a different organism. At the same time this decreased its chances to self-destruct. The researchers grew the chimeras in an environment that provided the specific nutrients for both pig and human cells. Last but not least, they implanted the chimeras in the surrogate sows. After 25 to 28 days they terminated the gestation.
The researchers found that after this period the embryos had structurally normal kidneys, in the mesonephros stage. The kidneys were composed of 50-60% human cells. They also assessed whether human cells migrated to neural or germinal tissues. It was found that the human cells were mostly localised in the kidneys. The next step is to let the embryos develop further and to assess the kidneys at every stage.
However, it is still a long way before this study may be used clinically: the kidneys developed in the chimeras still have pig blood vessels, meaning they are not suitable for transplantation. Read the full text here. As always, if you found this study interesting, stay tuned and stay curious with us!
About the author…
Hello 🙂 My name is Ilinca and I am a third year medical student that dabbles in a little bit of everything. I have an undying thirst for knowledge and a great talent for procrastination. Oh and I love hairless cats with all my heart!