Editorial: Questions over synthetic embryos

The importance of research cannot be overestimated, but ethical and legal issues must be addressed on priority

The scientific community is excited over the creation of the world’s first synthetic human embryos using stem cells, a ground-breaking advancement that could help researchers study the earliest stages of human development. What is fascinating, and also disquieting from an ethical perspective, is that the embryos were developed not from the union of sperms and eggs but by using stem cells in a lab. Two teams of scientists at the University of Cambridge, UK and California Institute of Technology in the United States, have announced that they have grown embryo-like structures made entirely from human stem cells that are more advanced than any previous efforts. The synthetic embryos develop to a stage equivalent to that of natural embryos about 14 days after fertilisation. While it is great news for medical researchers as it spurs further research into genetic disorders, it also raises ethical and legal questions. The moral questions pertain to the making of human embryos, especially beyond the 14-day period. Last year, Israel’s Weizmann Institute implanted embryo-like models made from stem cells of mice into a female mouse’s womb; a similar experiment in China on monkeys failed. However, their synthetic models had developed features such as an intestinal tract, the initial stages of brain cell development and a beating heart. The synthetic embryo holds the promise of shedding light on what is called the ‘black box’ period of the development of the foetus — the period before a pregnancy’s progress can be detected on a scan.

The stem cell-based models could provide a window to understanding cases of miscarriage and help study genetic disorders without having to use early embryos. The primitive embryos do not have a heart or a rudimentary brain but include cells that go on to form the placenta, the yolk-sac and the embryo itself. The latest breakthrough raises the possibility of further research into the subject that one day could lead to the development of a living creature out of the synthetic embryo. This makes a strong case for stringent legislation to curb malpractices. The breakthrough highlights how rapidly the science in this field has outpaced the law. The importance of advancements in research cannot be overestimated, but the related ethical and legal issues should be addressed on priority. There is also a significant unanswered question on whether these structures, in theory, have the potential to grow into a living creature. The synthetic embryos grown from mouse cells were reported to appear almost identical to natural embryos. But when they were implanted into the wombs of female mice, they did not develop into live animals. In the last few years, scientists have learned more about how to coax stem cells to develop into increasingly sophisticated structures. Artificial human kidneys, hearts and more have all been created in a lab, though they are still too rudimentary for medical use.

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