The ethics of human-embryoids model: a call for consistency

Abstract

In this article, we discuss the ethics of human embryoids, i.e., embryo-like structures made from pluripotent stem cells for modeling natural embryos. We argue that defining our social priorities is critical to design a consistent ethical guideline for research on those new entities. The absence of clear regulations on these emerging technologies stems from an unresolved debate surrounding natural human embryo research and one common opinion that one needs to solve the question of the moral status of the human embryo before regulating their surrogate. The recent NIH funding restrictions for research on human embryoids have made scientists even more unlikely to raise their voices. As a result, the scientific community has maintained a low profile while longing for a more favorable socio-political climate for their research. This article is a call for consistency among biomedical research on human materials, trying to position human embryoids within a spectrum of existing practice from stem cell research or IVF to research involving human subjects. We specifically note that the current practices in infertility clinics of freezing human embryos or disposing of them without any consideration for their potential benefits contradicts the assumption of special consideration for human material. Conversely, creating human embryoids for research purposes could ensure that no human material be used in vain, always serving humankind. We argue here that it is time to reconsider the full ban on embryo research (human embryos and embryoids) beyond the 14-day rule and that research on those entities should obey a sliding scale combining the completeness of the model (e.g., complete vs. partial) and the developmental stage: with more advanced completeness and developmental stage of the considered entity, being associated with more rigorous evaluation of societal benefits, statements of intention, and necessity of such research.

Human embryonic development: from peri-implantation to gastrulation

“…Therefore, studies based on in vitro culture of monkey embryos, which theoretically can be cultured in vitro until any developmental stage as long as the culture conditions allow, will continue to serve as one of the most integrated and reliable models for optimizing the culture conditions and elucidating human embryo development. Stem cell-based embryo models are experimental models that should not be given the same ethical considerations as natural embryos [14]. In the updated guidance, ISSCR proposed that nonintegrated and integrated models should be considered differently from an ethical point of view.…”

“…enhance the understanding of the mechanisms of human early embryonic development from blastocyst to gastrulation because these models are more scalable, versatile, and accessible than natural embryos (Figure 2 and Table S2 in the supplemental information online). The stem cell-based embryo models, either the nonintegrated or the integrated ones [13], can be produced via 2D micropatterning techniques, microfluidic devices, or 3D aggregation methods [14], and they exhibit self-organization similar to that of natural embryos during the in vitro culture process (Figure 2 and Table S2 in the supplemental information online).…”

Revisiting selected ethical aspects of current clinical in vitro fertilization (IVF) practice

“…pdf]. Now regarded by some researchers as outdated [16,17], it may be on the verge of being expanded [8,18,19].…”

Autonomy in the Development of Stem Cell-Derived Embryoids: Sprouting Blastocyst-Like Cysts, and Ethical Implications

“…at the primitive streak/14-day stage [31,32]. Specifically with regard to stem cell-derived embryoids, a broad discussion has now been started by various institutions, with the aim to arrive at a consensus on whether new legislation should be initiated, and whether such new laws could be more liberal as to permit producing even more complete and advanced stage human embryoids for research [6,[33][34][35][36], and which of the various embryoid models, and cultivation up to what stages, might be considered ethically permissible. This of course touches upon fundamental questions about the comparability of embryoids with real embryos and the dignity of embryos of various stages of development, about the respect they deserve, and whether there is reason enough to reconsider now the argumentation of the Warnock Report and perhaps even to change the derived regulations that are in force in the UK and in many other nations [31,32].…”