(Nature) – Researchers have coaxed stem cells to grow into amniotic sacs filled with fluid. The model sacs, which grew to roughly the same size as a four-week-old sac surrounding a developing embryo, could be used to study the protective structure.

The amnion is a thin, transparent film that forms a fluid-filled sac that shields and cushions an embryo, potentially supporting its development. But researchers can’t easily access and study the tissue at early stages of pregnancy. Stem-cell models are a way to investigate early embryo development, but first researchers need to recreate in the laboratory what grows in the womb. The latest study, published in Cell today, is the most advanced model of the amniotic sac so far. (Read More)