Scientist Break Records For Lab Grown Human Embryos, Kept Alive For 14 Days Outside Womb

Scientists have shattered a previous record of keeping grown human embryos in lab for 9 days by doing so for 13 days after fertilization, according to new reports. The recent achievement has enabled developmental biologists to discover new facets of early human growth, which includes aspects that have not yet been seen in a human embryo. The technique could also lead to an answer for failed pregnancies.

A team of scientists from UK's University of Cambridge used mouse embryos to develop the culture technique. Previously, many biologists have tried to create conditions in the womb by developing embryos on maternal cells' layer. However, for the recent study, the scientists used a gel matrix that had higher levels of oxygen. Subsequently, the mouse embryos lived past gastrulation, the stage at which layers of cells are formed that later become organs.  

The scientists adapted the process to work for human embryos donated by an in vitro fertilization (IVF) clinic. The progress of the embryos was then tracked by comparing the genes they exhibited with those shown in embryos of other animals in same stages. The team of researchers was then able to analyze the structural development of the embryos using data from a study conducted in 1956. The nearly 60 year old research had studied embryos of women going through hysterectomies and other medical procedures.

The team observed as the embryos' cells, human and mice, began to differentiate and the human embryos showed features unique to human development. In fact, the scientists discovered a group of cells that becomes present in the embryos on the 10th day but disappears after two days. However, the function of the cell cluster is still unclear. The culture method also showed that mice may not be good models for comprehending human development, because there is a vast difference between the genes revealed in mouse and human embryos.

The newly developed culture technology can have many implications in the future. The process could help scientists who are attempting the growth of stem cells into embryo type structures to understand the accuracy of their work. On achieving that feat, the researchers can use the structures to do more complicated and larger experiments that explore topics like toxic compounds effect and developments of birth defect.

According to a report in Nature journal, the development raises ethical questions, apart from technical challenges, because soon it might be possible for scientists to culture embryos to a more advanced phase. Many scientific organizations and countries have a ban on research involving human embryos that are more than two weeks old at present, because they enter the gastrulation period. Incidentally, the biologists who worked on the recent record ended their analytical work before hitting the 14 day mark. The team also believes that the embryos wouldn't survive beyond 14 days based on their previous work on mice embryos. Moreover, a further series of advanced techniques and processes are needed for such a course, though the scientists are starting preliminary rounds of experiments on cow and non human primates. In the wake of the new development, critics are of the opinion that the 14 day mark for keeping human embryos outside the womb should be re-examined, on ethical grounds.