For the first time, a kidney grown in a lab has been transplanted into the body of a living rat and begun to function normally. That makes the lucky recipient rat the home of the world's most complex lab-grown organ to date.
The story of how the kidney was created reads like something out of a science fiction novel. First, scientists at Boston's Massachusetts General Hospital took existing rat kidneys and washed away their native cells with some kind of terrifying, don't-let-it-touch-me soap. All that remained of the kidneys afterward was a protein scaffold, devoid of living cells.
Next the team of scientists, lead by Dr. Harald Ott, began the process of repopulating the kidneys with stem cells. To do this they sucked the stem cells through each kidney's network of tubules and ducts with a sort of cell-vacuum. After quite a few lab-kidneys "blew up in the jar," Ott and his team figured out just the right amount of pressure to deliver their new cells.
These newly re-formed kidneys were then put into beakers that "simulated the conditions within a body" and allowed to grow. After only a few days in this sort of an environment, the new kidneys began — somewhat miraculously — to function.
Yeah. The kidneys made urine while still outside of a living organism.
After that, the process of transplanting the first of these newly-reborn kidneys into a living rat was practically child's play. The transplanted kidney has shown no signs of rejection thus far. A wonderful thing, as well as one of the chief goals of the experiment. After all, one of the chief reasons for the kidney transplant waiting list is because of the need to match an organ to a patient. With grown-to-order kidneys, this goes away. And so does the need for immunosuppression medication.
While there is still need for a donor kidney, this process does allow for any kidney to match the needs of any patient — something that could surely save many lives. And who knows, maybe soon we won't even need donor kidneys at all.