US scientists have grown kidneys that produce rudimentary urine in the lab and also after being transplanted into rats. They hope to refine the approach so one day it is possible to grow human kidneys in the lab that work as well as donor kidneys in transplant patients but without the need for them to take drugs to suppress their immune system.

Nature Medicine

3D, collagen scaffold of the correct shape and size, with the organ’s complex and intricate architecture intact


They found that the while the “urine” was far from perfect, there was evidence that the new organ was trying to filter the blood.