A kidney-like organ grown from scratch in the lab has been shown to work in animals – an achievement that could be the prelude to growing spare kidneys for someone from their own stem cells. Donated kidneys are in huge demand worldwide. In the UK alone, there are 7200 people on the waiting list – a state of affairs that the new study takes a small step towards ending. Christodoulos Xinaris of the Mario Negri Institute for Pharmacological Research in Bergamo, Italy, and his colleagues extracted cells from the kidneys of mouse embryos as they grew in the mother. The cells formed clumps that could be grown for a week in the lab to become “organoids” containing the fine plumbing of nephrons – the basic functional unit of the kidney. A human kidney can contain over 1 million nephrons.
Kidneys are the latest of several lab-grown organs and replacement parts to be developed, including livers, windpipes, parts of voiceboxes and heartsMovie Camera.
The biggest question of all, however, is whether large enough grafts can be made to benefit patients. “We don’t know whether these little fetal kidneys could grow large enough to become fully functioning tissue in humans,” says Davies.