Synthetic embryos: a new venue in ethical research.

In Brief: Two independent groups have reported the development of 'artificial embryos'. Those are in vitro models made of mouse embryonic stem cells, without the need for egg or sperm, and grown ex utero without requiring implantation. This system might open new venues in bioethical research if human cells show the ability to replicate this system.

Abstract: The recent publications reported in 2022 reveal the possibility of obtaining mouse embryos without the need for egg or sperm. These 'artificial embryos' can recapitulate some stages of development ex utero - from neurulation to organogenesis - without implantation. Synthetic mouse embryos might serve as a valuable model to gain further insights into early developmental stages. Indeed, it is expected for these models to be replicated by employing human cells. This promising research raises ethical issues and expands the horizon of ethics in regard to the development of the human embryo. From this point of view, we state some of the new open venues for bioethical research.