Renewal Bio’s exact technical plan remains secret, and the company’s website is just a business card. “It’s very little detail for a reason. We don’t want to promise too much and we don’t want to scare people,” said Omri Amirav-Drory, a partner at NFX who serves as CEO of the new company. .”
Some scientists say it will be difficult to grow human embryo models to an advanced stage and it would be better to avoid the controversy created by imitating real embryos too closely.
“It’s absolutely not necessary, so why would you do it?” says Nicolas Rivron, a stem cell scientist at the Institute of Molecular Biotechnology in Vienna. He argues that scientists only need to “create the minimal embryonic structure needed” to yield interesting cells.
For his part, Amirav-Drory says he hasn’t seen a technology with so much potential since CRISPR gene editing technology first emerged. “The ability to make a synthetic embryo from cells — no egg, no sperm, no uterus — it’s really amazing,” he says. “We think it could be a huge, transformative platform technology that can be applied to both fertility and longevity.”
To create the sequence of breakthroughs, Hanna’s lab has combined 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 culture natural mouse embryos outside of a female mouse for several days. The system includes rotating jars that keep the embryos in nutritious blood serum and oxygen.
Mouse embryos in mechanical uterus from the 2021 study
A. AGUILERA-CASTREJON ET AL., NATURE 2021
In the new research published this week, Hanna used the same mechanical uterus, but this time to grow similar-looking embryos made from stem cells.
Remarkably, when stem cells are grown together in specially shaped containers, they spontaneously come together and attempt to assemble an embryo, producing structures called embryoids, blastoids or synthetic embryo models. Many researchers maintain that these structures, despite appearances, have a limited relationship with real embryos and have no potential to fully develop.