The director of the Bioethics Committee of the Catholic University of Valencia dissects the ethical aspects of the creation of synthetic embryos from stem cells
The creation of synthetic embryos from stem cells to investigate what the first 14 days after conception are like caused a stir two weeks ago in the field of bioethics. Although the idea of the creators is that, in the long run, their findings have a medical application –in the field of transplants or to avoid unwanted abortions, for example–, doubts about the methodology used are something that worries experts. like Julio Tudela. For this reason, the researcher, professor and director of the Bioethics Observatory of the San Vicente Mártir Catholic University of Valencia calls for legislative changes that delimit and protect embryos in all aspects of this type of research.
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Although it has been widely publicized in many media, the production of embryo-like structures in both animals and humans is not new, and the track record in this field is extensive.
Generally, it is about using pluripotent stem cells, commonly called stem cells, coming in turn from other embryos obtained from the surplus of assisted reproduction techniques, which are sacrificed in order to cultivate their cells under certain conditions so that they continue the process. maturational process until the formation of an «embryoid» or incomplete embryo, which will not develop certain structures, but which may be useful for investigating the complex cellular mechanisms that occur in the initial stages of life. In any case, we are talking about the first 14 days of the embryo’s life.
The novelty that is hidden in the two investigations that we have learned about last week is that new techniques have been implemented to ensure that these embryoids are capable of developing all the embryonic structures of the individual, which would allow, if it were legal because today it is not that is, to continue with its gestation until birth.
But this is at a theoretical level, because the modifications introduced into these «synthetic embryos» make them, to this day, unfeasible in the long term, and this is one of the objectives of this research, to be able to reproduce embryonic genesis in the laboratory as as it occurs after natural fertilization. It is not possible to assess the news, as I am asked, without calibrating the bioethical edges that accompany it: these processes require the sacrifice of multiple human embryos that are thawed from the banks where they remain cryopreserved as they are left over from assisted reproduction techniques. This difficulty is bioethically insurmountable: biomedical research does not justify the extermination of numerous human embryos, human beings in their initial stages of development, don’t forget, for the sake of improving knowledge about embryogenesis, implantation, or any other.
What advantages and disadvantages do you appreciate in what has been achieved?
Behind the striking news, there is a paradox that is difficult to explain: real human embryos are destroyed in order to partially recompose other embryonic structures from the cells resulting from said destruction. It seems to place us before the challenge of creating new individuals outside the natural reproduction process, designing them and experimenting with them. Not everything can be justified for the sake of research.
Legislation must return to the embryo the rights that should never have been denied
Other investigations have taken different paths to obtain these embryoids, starting not from human embryonic stem cells, but from reprogrammed adult cells, known as iPS cells, in which their genome is modified to revert them to an immature state, susceptible to differentiation into different structures. In this case, the sacrifice of human embryos is not used as a source of stem cells, but it is also intended to obtain structures similar to embryos, which pose the same problem as in the previous case: are they human embryos or not? How similar or different must they be from the authentic embryos obtained by fertilization? Is it enough to say that since they cannot develop until birth, they cannot be considered human?
Because many human embryos do not complete their development until birth, but they do not stop being so because of that. Therefore, both in the origin of the research and in the end pursued, there are serious ethical difficulties that make them rejectable. However, the production of those more rudimentary embryonic models, therefore, further removed from the nature of an individual of the human species, and which only reproduce some embryonic structures, could be considered ethically acceptable when stem cells are not used to obtain them. from human embryos.
What does the regulation say about it? Do you think it should be modified in the face of this type of project?
–The legislation, very permissive with the handling of human embryos for research, condemned to be destroyed in any case, establishes time limits for the handling of these embryos: no more than 14 days, explicitly prohibiting the continuation of their development in the laboratory beyond this period. This limit is due to the erroneous belief, inherited since the end of the last century, of the existence of a pre-embryo, which would not be human, and which would allow its manipulation without negative ethical connotations.
But science has amply demonstrated that this is not the case. The biological identity of the zygote, the first stage of the embryo after fertilization, is not different from that of the 14-day-old embryo or that of the fetus or neonate. They have the same biological identity, they are the same individual, but located in different maturational stages, so the same respect that their human identity deserves must be demanded in the treatment that is provided to them in any of these stages.
But this is not protected by law, rather it discriminates against immature human beings of less than 14 days so that they can be investigated causing their death, or with fetuses of up to 14 weeks so that they can be freely aborted by their mothers, for being immature The law does not protect the lives of the most defenseless, placing itself at the opposite end of what legislative activity should guide: first defend those who cannot defend themselves.
A paradigm shift is essential, returning to the human embryo the rights that should never have been denied, and the right to life is the first of them.
