MERLN Develops the First Model for Monozygotic Twinning
Scientists at Maastricht UMC+ and the MERLN Institute have succeeded in growing an embryo structure of human identical twins purely from stem cells, bypassing the need for egg or sperm cells. This advancement makes it possible, for the first time, to glimpse into the processes of how identical twins form: accelerated expansion of the blastocyst—a type of sac made of placenta cells that contains the stem cells in it from which new life emerges—splits the embryo into two. This new scientific achievement has been published in the renowned scientific journal Advanced Materials (Dorian Luijkx et al.) and is the result of a technological platform which for several years has been unravelling increasingly complex biological secrets, enabling the controlled growth of cells, tissues, organs and embryos. The current research initially focuses on the healthy implantation and development of embryos. The synthetic embryos make it possible to study the first crucial micro-processes, which previously remained hidden in the womb. The aim is to use this research to make improved biomedical care accessible and affordable on a large scale.
Medical applications
The synthetic embryo grown from stem cells appears to be sufficiently true to reality that it can provide valuable information about biological embryos. The current research focuses on practical applications: it increases understanding of miscarriages and infertility and can help solve fertility problems or improve contraception. Three-quarters of all identical twins share the same placenta during pregnancy. Until now it has not been clear how this natural phenomenon came about, but this discovery helps to solve that mystery. In addition, pregnancies with twins are more often accompanied by complications that arise during early implantation. These can now be studied and possibly prevented or treated.
Research platform: high throughput and implantation-on chip
In the laboratory research, the early synthetic embryos – grown for a maximum of 14 days – are tested in thousands of high-throughput parallel experiments. Each individual parallel test has its own characteristic combination of growth factors and signalling molecules, which determine experimentally what factors, hormones and other substances provide the right conditions for the optimal growth of the embryo in the first week, as well as the exact timings. ‘For growth in the second week, we have developed an implantation platform, implantation-on-chip, with which we can grow and study a small sample of uterine tissue from a patient on a microfluidic chip to find the conditions for the most viable implantation of the embryo in the uterus,’ says lead researcher Erik Vrij. ‘This will allow us to predict whether treatments after IVF and PGT will be successful.’
Better care on a larger scale
‘Through robotisation and machine learning, we are simulating biological processes with increasing accuracy, and with the high-throughput method we increase our chances in this case of creating a rare twin embryo,’ says founder of MERLN Professor Clemens van Blitterswijk. ‘And using the “identified formulas”, we can also create tissue-specific stem cells, tissues and parts of organs to treat patients. The idea is that in the future this will be possible on a scale that will help a large number of people while keeping costs low.’
This research is part of the PhD thesis of Dorian Luijkx directed by Erik Vrij, Stefan Giselbrecht, and Clemens van Blitterswijk and in collaboration with Asli Ak and Ge Guo from the University of Exeter.
Want to learn more? Please visit Advanced Materials, our Vimeo page and www.vrijlab.org.
