Researchers at University College London have succeeded in creating fragments of fetal organs from amniotic fluid. Technically speaking, they’re called organoids. This is a first. This technique may lead to important developments in the study of neonatal diseases.
Amniotic fluid surrounds the fetus during pregnancy and contains a mixture of nutrients, hormones and antibodies produced by the mother. As we know, it is currently used, by means of amniocentesis, or other techniques, to collect single cells shed by the fetus, to examine their genetic code and spot any abnormalities. However, the British researchers have now discovered that some of these cells (around 2% of the total) are, contrary to our previous understanding, still alive and can be grown into three-dimensional organoids (for example fragments of lung or kidney) using dedicated laboratory techniques. This provides us with a possible new tool for studying and diagnosing congenital diseases. The results of the study have been published in the scientific journal, Nature Medicine.
At the press briefing to present the study, the first author, biologist Mattia Gerli, commented: “For the first time, we can actually access the fetus without touching the fetus, which is quite exciting on my end”.
The cells that were isolated by the British scientists are epithelial cells (in other words, cells that line the surfaces of organs). Gerli clarified that these are not stem cells, but ‘progenitor’ cells, which are programmed by nature to become cells of the lung, small intestine and kidney (progenitor cells are, in essence, an intermediate between stem cells and specialised cells).
A gel matrix
The researchers collected amniotic fluid samples from women between the 16th and 34th week of gestation. They isolated the progenitor cells with sophisticated equipment and seeded them in a three-dimensional culture, using a gel matrix to support them and grow them into organoids.
As we mentioned earlier, this is a huge step forward. Until now, neonatal conditions (those that develop in pregnancy or during the first few days of the newborn’s life) have been studied almost exclusively on post-mortem fetal tissue, with major biological and even ethical limitations.
With organoids derived from amniotic fluid, on the other hand, in terms of basic research, it will be possible to study the fetus without even touching it. Moreover, this paves the way for new prenatal diagnostic procedures that are more reliable than those currently in use. Nevertheless, additional studies will of course be conducted to further validate this technique so that it can be used on a large scale.
Real-time monitoring of treatments
In the study carried out at University College London, the researchers found three developmental abnormalities in the 12 samples of amniotic fluid collected.
One of these was a diaphragmatic hernia, a condition where part of the diaphragm is missing, which means that the abdominal organs tend to move upwards, compressing the lungs. The disease is fatal in 30% of newborns and various surgical therapies are available to treat it. These include experimental therapies, such as placing a sort of balloon inside the windpipe of the fetus, by means of an intrauterine procedure, to allow the lung to maintain its pressure and expand against the abdominal organs.
The British researchers monitored the fetal lung situation using the organoids, and noticed an improvement after the placement of the balloon.
