Is the creation of synthetic human embryos for research morally justified?
This is the question scientists and ethicists are now debating following the recent announcement that a developmental biologist had created the first human embryos without eggs or sperm.
Instead, this breakthrough was achieved by reprogramming embryonic stem cells, according to Professor Magdalena Żernicka-Goetz of the University of Cambridge and the California Institute of Technology.
As first reported by The Guardian last week, these synthetic structures do not have a heart or brain but did include cells that would form the placenta, yolk sac and the embryo itself.
While the results of the experiment are yet to be published in a peer-reviewed journal, Professor Żernicka-Goetz described the creations as “beautiful” ahead of her talk at the International Society for Stem Cell Research’s (ISSCR) annual meeting in Boston.
Her team also went one step further by growing the embryos to the gastrulation stage — otherwise known as the ‘black box’ of human development — that occurs just after the current 14-day threshold at which lab-grown embryos are destroyed.
The news prompted others to reveal similar breakthroughs, including a UK team who created an embryo model with a heartbeat but lacking other vital tissues to form the placenta or yolk sac.
It also reignited a debate about the ethics of stem cell research, specifically whether model embryos are fundamentally different to human embryos.
Professor Rachel Ankeny, a philosopher and bioethics expert from the University of Adelaide’s School of Humanities, said that while model embryos “originate from different sources and processes”, they shared characteristics with ‘natural’ embryos.
“[This] makes the issue about how we view and treat them much more complex,” she said.
“Most importantly, it is critical that researchers be transparent about this type of research and what is known and unknown, in order to ensure that our regulatory processes address the necessary issues and that the public is assured that there are adequate oversight mechanisms and safeguards.”
Professor Ankeny added that the research would likely spark further debate about the 14-day rule that was introduced decades ago and has informed legislation in many countries including Australia.
But two years ago, the ISSCR updated its guidelines with a relaxed stance on the issue in a bid for the 14-day limit to be debated and reconsidered.
According to Dr Kathryn MacKay (PhD), senior lecturer and bioethicist at the University of Sydney, there is also the moral issue of “creating something for research that may or may not have the potential to live as its own full entity”.
“If they [synthetic embryos] could live as their own full entities, then we must ask whether it is morally permissible to create living beings purely for research purposes,” she said.
However, there is also recognition of the promise this breakthrough might offer for future research.
Scientists are hopeful that it will help to provide greater understanding around infertility and early pregnancy loss, as well as answering some questions around longevity and ageing.
Melbourne public health scientist Dr Evie Kendal, from Swinburne University of Technology, said that if synthetic embryos were deemed to not be equivalent to human embryos, they could be used for research “currently considered too risky”.
“For example, artificial womb technology research is currently hampered by the 14-day rule and … [the lack of] data regarding how a fetus might develop in an artificial environment between this stage of development and that of the youngest known premature infants to survive via existing neonatal incubation systems.”
“A synthetic alternative to human embryo experimentation might help advance this, and many other, reproductive technologies.”
But as Professor Ankeny points out, this would first require a decision on whether the use of such embryos in clinical research is morally permissible to begin with.
“We need to engage various publics about their understandings of and expectations from this sort of research, and more generally about their views on early human development, as these biological processes are deeply tied to our values and what we think counts as human life.”