Scientists have grown a kidney in a laboratory and shown that it works when implanted into a living animal. The work is an important step towards the longer-term goal of growing personalised replacement organs that could be transplanted into people with kidney failure…Finding a new source of replacement organs that could be grown using the patient’s own cells and that could last a lifetime would, therefore, be a big leap forward.

In the latest work, Harald Ott of Massachusetts General hospital led a team of scientists who grew a kidney by using an experimental technique that has previously been used to create working hearts, lungs and livers. Ott first took a rat kidney and stripped out its functional cells using a solution of detergent. That left behind a white cellular matrix, the collagen scaffold that gives the organ its three-dimensional structure. His team then introduced kidney and blood vessel cells from newborn rats onto the scaffold and cultured the growing organs for 12 days, until the cells had grown to cover the scaffold. The team then implanted the organ into a living rat, where it successfully filtered the animal’s blood and produced urine.

According to Ott, further refinement of the technique would be needed, but it could lead to bioengineered kidneys one day replacing diseased or damaged kidneys in the same way that donor kidneys via transplant do now. Ideally, the engineered kidneys would be grown from a patient’s own cells, thereby removing the need for the patient to take immunosuppressant drugs for the rest of their lives.