Renewal Bio’s precise technical plan remains secret, and the company’s website is just a calling card. “It’s very low on details for a reason. We don’t want to overpromise and we don’t want to scare people,” says Omri Amirav-Drory, an NFX partner who serves as the new company’s CEO. “Here the images are sensitive.”
Some scientists say it will be difficult to grow the human embryo models to an advanced stage and that it would be better to avoid the controversy it raises by mimicking too many real embryos.
“It’s absolutely not necessary, so why would you?” says Nicolas Rivron, a stem cell scientist at the Institute of Molecular Biotechnology in Vienna. He argues that scientists should create only the “minimum embryonic structure necessary” to produce cells of interest.
For his part, Amirav-Drory says he hasn’t seen a technology with so much potential since CRISPR gene-editing technology emerged. “The ability to create a synthetic embryo from cells, without eggs, without sperm, without a uterus, is really amazing,” he says. “We believe it can be a massive, transformative platform technology that can be applied to both fertility and longevity.”
To create the succession of breakthroughs, Hanna’s lab has been combining advanced stem cell science with new types of bioreactors.
A year ago, the stem cell specialist showed for the first time a “mechanical uterus” in which he managed to grow natural mouse embryos out of a female mouse for several days. The system consists of rotating jars that keep the embryos bathed in nutritious blood serum and oxygen.
In new research published this week, Hanna used the same mechanical womb, but this time to grow similar embryos created from stem cells.
Remarkably, when stem cells are grown together in specially shaped containers, they will spontaneously join together and attempt to assemble an embryo, producing structures called embryoids, blastoids, or synthetic embryo models. Many researchers insist that, despite appearances, these structures have a limited relationship to actual embryos and zero potential to fully develop.