The first complete artificial model of a human embryo arrives

The researchers obtained this human embryo model, called iBlastoid, from reprogrammed skin cells. It can be used to study infertility, congenital diseases and the very first embryonic development. But it also opens up many bioethical questions

Images of iBlastoids with different colors (photo: Monash University) They are called blastoids and are the first human embryo models obtained from skin cells reprogrammed in the laboratory. To obtain them, for the first time with this formulation, is an international research group coordinated by Monash University, in Melbourne. The term blastoids - or rather iBlastoids, i.e. induced blastoids, to indicate that it is an artificial model - was chosen by the researcher and is traced back to the blastocyst, an embryonic phase typical of mammals. The models will be useful for analyzing infertility problems and conditions of spontaneous abortion (sometimes recurrent) in the laboratory and for studying the very early stages of human development. The findings are published in two independent studies in Nature.

A human embryo model

The human embryo prototypes were made from fibroblasts, particular skin cells, reprogrammed to form blastocyst-like structures. Fibroblasts are cells that isolate themselves from the skin, easy to collect and cultivate in vitro. The researchers reprogrammed them into a three-dimensional cellular structure that is similar in both morphology and molecular characteristics to human blastocysts. When it comes to medically assisted procreation, the blastocyst is an embryo with a development of 5-6 days and represents the last stage of pre-implantation development, while in a natural conception it is in this phase that the engraftment takes place inside the 'uterus. Returning to the study, these iBlastoids, explain the authors, "provide a model of the overall architecture of blastocysts and can give rise to pluripotent stem cells and trophoblastic stem cells", where the trophoblast is a cellular tissue that nourishes the embryo and is at the basis of the formation of the placenta and other elements of embryonic development.

The technique with which the human embryo model was obtained is called nuclear reprogramming and allows to modify the cellular identity of human skin cells which , when placed in a three-dimensional gelatinous structure (called an extracellular matrix), they can organize themselves into structures similar, but not the same, to blastocysts, or human embryos in a certain phase. Until now, research on these early embryonic stages was very limited and the result of blastocysts obtained with difficulty by IVF in vitro fertilization techniques.

The objectives of future research

The authors, moreover , have succeeded in creating a model for studying numerous aspects of the early stages of this development. "The iBlastoids", explains Jose Polo, "will allow scientists to study the earliest stages of human development and some causes of infertility, congenital diseases and the impact of toxins and viruses on early embryonic stages - without the use of human blastocysts. and, importantly, at an unprecedented level, accelerating the understanding and development of new therapies ”. The group also reports that this result represents a possible "significant turning point" for the future study of the aspects mentioned.

The differences with the human embryo

The authors note, however, that the iBlastoids should not be considered as an equivalent of human blastocysts, i.e. human embryos, with respect to which they have a number of differences. “They are not completely identical to blastocysts,” emphasizes Jose Polo, who coordinated the group. "For example, early stage blastocysts are encapsulated by the zona pellucida, a membrane that originates from the egg that interacts with the sperm during the fertilization process and which subsequently disappears. Since iBlastoids are derived from adult fibroblasts, they do not have a zona pellucida ”.

The ethical question

As expected, the reproduction of these blastoids in the laboratory reopens a deeply felt bioethical debate. "Since the protocols are optimized," write Yi Zheng and Jianping Fu of the University of Michigan, not involved in the work, in a commentary article, also in Nature, "these blastoids will mimic human blastocysts much more closely" and this will raise new bioethical questions. The guidelines on this particular research area are not yet well established and a definition is expected this year. The authors note that all the experiments carried out are in line with Australian and international legislation and ethical standards (for example, it is not possible to go beyond 14 days) and the culture did not go beyond 11 days.


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Abortion Bioethics Reproduction Health globalData.fldTopic = "Abortion, Bioethics, Reproduction , Health "

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