Scientists from Cincinnati (Ohio) have developed the most complex stomach organoids to date, using embryonic stem cells.
The biology of tissues and organs is difficult to study in mammals, especially in humans. However, advances in stem cell culture have made it possible to generate tiny three-dimensional tissues in vitro, called organoids.
These organ models reproduce some of the anatomical and even functional hallmarks of real organs on a small scale (between a micrometer and a millimeter), allowing a multitude of studies to be performed without having to access the real organ in the body.
Both adult stem cells and pluripotent stem cells can be used to generate different types of organoids, which can model very diverse tissues and organs: retina, brain structures, gastric regions, small intestine, liver, pancreas, trachea, esophagus, prostate, kidney, and mammary glands, in addition to a long list of organoids that have already been generated.
Now, an article published in Cell Stem Cell reports the generation of complex mini-stomachs in vitro. As the article in Scientific American explains, many stomach organoids are made up of epithelial cells only; these cells form the basis of the tissue lining the body cavities. The novelty of the work in question is that the organoids obtained include nerves that coordinate muscle contraction and glands that make acid.
From an ethical point of view, there are several aspects to consider in the field of organoid generation, many of which have to do with sample treatment, such as informed consent from cell donors.
Additionally, a very sensitive issue is the type of stem cell used to develop the mini-organs. As in many other technologies involving the use of stem cells, an ethical dividing line is whether or not those stem cells are embryonic.
Obtaining embryonic stem cells implies, at least in the first instance, the destruction of human embryos, so their use is ethically unacceptable. In contrast, the use of adult stem cells or iPS cells (a type of cell similar to embryonic cells but obtained from adult cells) does not involve the destruction of embryos.
Both embryonic cells and human IPS cells were used in the article cited above. Although developments in this technology may be very useful both for basic research and for future medical applications, in no case should they involve the destruction of human embryos. While it is true that human embryos were not used in the study, but that previously established embryonic cell lines were purchased, this type of practice encourages the perpetuation of embryo research.
It is also notable that the study authors point out that they did not find any technical advantages in using one cell type over the other, so that even from a utilitarian perspective, the use of embryonic stem cells could not be justified in this case.
Institute of Life Sciences
Catholic University of Valencia