Scientists have successfully transplanted laboratory-made vaginas into four teenage girls whose own were absent because of a rare disease, marking a milestone in the quest to grow structurally complex body parts.
Some of the easiest organs to make are flat structures, like skin, typically composed of a single type of cell. Tubular body parts including windpipes, urethras and blood vessels are harder to fashion as some are typically made of two cell types. But in recent years several such organs have been successfully transplanted into patients.
Another step up in complexity are body parts such as the vagina, a highly elastic organ that also secretes mucus. And the final frontier is the quest to make solid organs—such as the heart and liver—that typically don’t have a cavity and have more complex functioning.