Considering that “synthetic embryo models” (SCBEM[1]) raise scientific questions but also “of a practical, ethical, and legal nature”[2], a group of researchers “from around the world” indicates that they have developed “a reference framework for research, technological development, and regulation” in this area.
Their recommendations were developed in a white paper published in the journal Human Reproduction[3]. They specifically addressed ethical issues in an article published in the journal Nature Cell Biology[4].
Promoting comparison with embryos derived from IVF
“The remarkable diversity of SCBEM presents great advantages, but complicates reproducibility, regulatory oversight, and the achievement of clinical transfer goals,” the researchers assert. Therefore, they recommend publishing precise and detailed protocols, “drawing on best practices from the organoids community” (cf. Organoids: a promising path for research or ethical precipice?).
They also suggest the need for “a rigorous comparison of data on human SCBEM with those concerning human embryos derived from IVF at the pre-implantation stage and non-human primate embryos” (cf. Researchers implant human embryos in ‘synthetic embryo models’ of uterine mucosa).
The scientists also advocate for the creation of biobanks.
Promoting public-private interactions, similar to researchers working on ART
The researchers aim to “encourage interactions between researchers working on SCBEM and the assisted reproductive technology (ART) community,” as well as “interactions between the private and academic sectors”: “Clinical needs will strengthen this research field and guide resulting applications.” Specialized SCBEM platforms for infertility research should also be created.
The scientists call for the development of “high-quality, clinical-grade SCBEM.” They believe that this should form the basis for practical applications of SCBEM, especially those related to teratology and regenerative medicine.
An obsession: distinguishing these “models” from human embryos
In ethical and legal matters, several instances have debated in recent years the issues surrounding “synthetic embryos.” International guidelines and recommendations have been published by major scientific societies, such as the International Society for Stem Cell Research (ISSCR) and the European Society of Human Reproduction and Embryology (ESHRE) (cf. ‘Synthetic embryo models’ harder to distinguish: ISSCR updates its recommendations)[5]. These recommendations seem aimed primarily at giving researchers ample leeway (cf. ‘Unicells,’ ‘multiplex cells,’ or biologically derived from two parents of the same sex: ‘People may not realize how quickly science is evolving’).
However, the group of scientists proposes its own recommendations, starting with “establishing distinct legal and ethical status for SCBEM.” They believe that “due to their limited development potential, current SCBEM should not be considered human embryos, neither biologically nor legally” (cf. ‘Hematoids’: ‘synthetic embryo models’ produce blood cells). But do these “synthetic embryo models” always have a “limited development potential”? At the last biomedicine meetings in October, Professor Sophie Brouillet, head of the Reproductive Biology Laboratory-DPI-CECOS at the University Hospital of Montpellier, pointed out a photo of a “synthetic embryo” and said: “This blastocyst, if I put it back in a uterus, potentially it can give me a baby later. There are all the elements in any case to be able to do it.” She hastened to add: “Obviously it’s forbidden.”
Furthermore, researchers recommend prohibiting the transfer of human “synthetic embryo models” “into the uterus of a living human being, or into the uterus of a living non-human animal.” Attempts to achieve ectogenesis should also be explicitly banned, they argue (cf. Human uterus kept ‘alive’ outside body for 24 hours).
Towards international governance that “adapts” to scientific progress?
The group of scientists calls to “create an openly accessible registry listing relevant decisions made by different ethics committees” and to “establish an international group of consulting ethicists” that could then “assist” other committees.
“Specific limitations” – including culture deadlines – should be identified, implemented, and monitored, while remaining compliant with international standards, they recommend. It is also important to maintain “public trust.” But on these topics that may seem highly technical, does the general public still question?
The researchers conclude their recommendations by advocating for “implementing dynamic governance frameworks”: “Regular updates to guidelines related to SCBEM should be required as scientific capabilities evolve.” In embryo research, there is only one constant: the “framework,” whatever it may be initially, continues to expand (cf. Embryo research in France: 30 years of legislative flexibility; 30 years of bioethics laws: ‘change the rule to stay within the rule’).
