Scientists want to enable studies on human embryos for more than 14 days to develop treatments

The study of human embryos provided new scientific knowledge useful for understanding new diseases and treatments. Inside it are stem cells that haven’t yet differentiated to play a role in some part of the body. Some of these embryos come from fertility clinics that have the consent of donor couples. In other cases, embryos are intentionally produced in the laboratory for scientific purposes. In some countries, the use of human embryos is regulated by law. In other countries, as in most of Latin America, there remains a legal vacuum regarding borders.

right Now, International Society for Stem Cell Research, a non-profit organization of more than 4,000 researchers and physicians from around the world, He came out to argue that human embryo research should be allowed past the 14-day deadline.

Entity The world argued that He suggested extending the term by taking into account “developments in the culture of human embryos and the potential for such research to obtain useful knowledge that enhances human health and well-being”. With this argument, the National Academies of Sciences, academic societies, financiers and regulators have been asked to lead public conversations about scientific importance and the social and ethical issues raised by authorizing such research.

“If broad public support is achieved in a jurisdiction, and if local policies and regulations allow, a specialized process of scientific and ethical oversight can weigh whether the scientific goals need and justify an increase in time beyond 14 days,” Ensure that only a minimum number of embryos are used to achieve research goals, ”defined the new guidelines of the International Society for Stem Cell Research. In other words, it relaxed the 14-day rule.

The new evidence updates a debate that erupted decades ago. Since the first successful births through in vitro fertilization technique in the late 1970s, Human embryo research is subject to time limits and developmental criteria.

“Many national international guidelines, laws and standards have prohibited scientists from implanting embryos to conduct research that exceeds 14 consecutive days, or beyond the emergence of a structure called the primordial streak, which determines the beginning of the formation of the main tissues of the body and the end of the period in which an embryo can divide into identical twins.” Scientists Ensu Hyun and Sigal Klebstein from the United States, Anelian Bridenward, from the Netherlands, said last March; James Brisco from UK; And Tao Tan from China in an article in the magazine Science.

The 14-day limit was set 40 years ago when there were no methods for growing embryos on a plate for a period of approximately two weeks. But research since 2016 shows that it is possible to grow research human embryos beyond the two-week limit. They suggested that doing so would lead to scientific insights that might be important to human health and fertility, ”the scientists wrote, and also called in March for the guidelines to be updated with a cautious and gradual approach to scientific exploration after 14 days. Finally, the International Society followed suit and now accepted it.

So far, scientists have not exceeded the 14-day limit, not only for legal and ethical reasons, but also for technical reasons: You cannot keep growing embryos in laboratory dishes for a long time. However, scientists have recently perfected cell culture techniques and found ways to preserve embryos throughout this time.

These developments – along with other milestones in the world of stem cell research, where scientists are now converting cells into droplets that resemble early embryos or injecting human cells into animals – They have held complex ethical debates about the extent to which biomedical research should go in its search for knowledge and possible treatments.

“We have relaxed the guidelines in this regard, but we have not abandoned them,” developmental biologist Robin Lovell-Badge of the Francis Crick Institute in England said at a press conference. This scientist chaired the working group on the guidelines. The change is not expected to trigger much research into human embryos. But In some countries, such as Australia and the United Kingdom, implementing the change in term usage of embryos requires a change in legislation.

consultation InfobaeAnd the The Fabiana Arzwaga, Coordinator of the Ministerial Committee for Advanced Research and Treatments, commented: “In Argentina, there is only one rule regarding assisted fertilization as part of medical practice. But the use of embryos in research has not been regulated. In some fertility clinics they have voluntary laws for the use of embryos. “

For Dr Arzuaga, the new International Society for Stem Cell Research guidelines “open a window for research into embryos after 14 days, but it is not a mandatory rule. It will depend on the legislative powers of the countries to make the decision. Evenly, The Society’s guidelines are recommended in contexts where there is an ethics committee and a justification for socially valuable research“.

“This is not a green light for groups to move forward in expanding human cultures for more than 14 days,” said biologist Cathy Nyakan of the University of Cambridge. One of the experts who worked on the guidelines. “It would be irresponsible, and in many jurisdictions it would be illegal, to do so. What we are doing, instead, is that the guidelines are a call to proactively engage in a two-way dialogue with the public to review the 14-day limit for human embryo implantation.”

The international community’s guidance does not detail what such public discussions should look like or what levels of public support should be required before an experiment is allowed. But Nyakan said the process could be different in each country depending on local perspectives in this type of research. “It should not be run for the convenience of a country with this,” he said.

Scientists say studying human embryos for a little longer could allow them to peek into the “black box” of days 14 to 28 of development, the time when different types of cells emerge, body tissues tend toward specialization and the placenta begins to take shape. It can help researchers understand what goes wrong with miscarriages or what causes birth defects. It can also verify whether the models that scientists use to mimic human embryonic development, such as animal embryos, are legitimate surrogates and, if not, then not.

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