The embryo represents a certainty of life: human eggs mature with the help of sperm, presenting the early stage of development in the womb. But they also carry within an ineffable promise and possibility of discovery — even throwing open the question of the origins of life itself. Scientists grew synthetic embryos without the support of eggs, sperms, or the home of a womb in a world’s first, potentially paving a new way of recovery and healing for people.
Published in the journal Cell on Wednesday, the research details the discovery by scientists at Israel’s Weizmann Institute. They took stem cells — cells that work as raw material for all other cells with specialized functions to generate — from mice to assemble a structure that mimics an embryo in appearance and function. The tiny embryo-like organisms were developed over eight days in a Petri dish, with a beating heart, a gut tube, and the early stages of a brain.
“Remarkably, we show that embryonic stem cells generate whole synthetic embryos, meaning this includes the placenta and yolk sac surrounding the embryo,” said Prof Jacob Hanna, from the Weizmann Institute, who led the effort. “We are truly excited about this work and its implications.”
Hanna refers to two critical implications here: the synthetic embryo which is a living structure created without fertilized eggs offers insights into the way organs and tissues form in early stages. More importantly, the design of synthetic embryos in itself could be studied further to grow tissues and organs, which can be used for human transplantation in the future. “The embryo is the best organ-making machine and the best 3D bio-printer — we tried to emulate what it does,” Dr. Hanna said. The researchers found the synthetic model displayed a 95% similarity as compared to the natural mouse embryos; they were similar in shape, size, and even gene expression of cells.
The problem statement here is a shortage of organs for transplantations; countries the world over are struggling to perform life-saving transplants that could save millions of people. Within the scientific community, the answers involve exploring stem cell research and finding ways to grow living organs that could meet this need. Which explains efforts to create the world’s first monkey embryos containing human cells, or building mechanical wombs that allow natural mouse embryos to grow outside the uterus for several days.
But the use of artificial embryos, ones that are mechanical, birthed in tubes and dishes and not the human body, comes laden with several technical and ethical questions. One concerns the potential of exploiting animals for research purposes. The other is about affording a “moral status” to living creatures, and the subsequent rights and duties of an organism that develops mental capacities between those of ordinary animals and humans. How do we determine what is mortal, and what is not? Moreover, researchers are supposed to adhere to the requirement that lab-grown human embryos have to be destroyed within 14 days. But can science simply create or destroy something that is living?
