After successfully bioengineering hearts and livers, scientists have now managed to engineer kidneys, growing them from donor cells. The kidneys appear to be functioning as they should.
Scientists at the Massachusetts General Hospital have managed to bioengineer kidneys which function to produce urine, both in laboratory experiments and when implanted in rats. The method used to produce the kidneys involves growing them from living cells which had been scraped off of donor organs, something previously used to experimentally produce both livers and hearts. "If this technology can be scaled to human-sized grafts, patients suffering from renal failure who are currently waiting for donor kidneys or who are not transplant candidates could theoretically receive new organs derived from their own cells." Says Dr. Harold Ott, the lead author on the study which is being published in Nature Medicine.
Currently, end stage kidney disease still requires an actual organ donation. Currently, there are 18,000 such kidneys available for transplant in the US with almost 100,000 Americans in need of one. If you are lucky enough to receive a kidney, you’ll still need immunosuppressive drugs to prevent organ rejection, though such drugs cannot guarantee the organ will be accepted. In addition, immunosuppressive drugs can be damaging for your health. Employing the new method thus has the potential of saving thousands of lives, and could effectively grow you a brand new kidney from your own cells.
A brand new man-made kidney
The approach was discovered by Dr. Ott while he was a research fellow at the University of Minnesota and involves stripping living cells from a donor organ with a detergent solution. The cells are then implanted into a “collagen scaffold”, which in this case was the lining of the vascular system and kidney cells in rats. To ensure the right cells went to the right place, the new vascular cells were delivered through the renal artery while the kidney cells were injected through the ureter; the “outflow pipe” of the kidney. Adjusting the pressure of the injected cells ensured they dispersed evenly throughout the kidney.
After culturing in a bioreactor for 12 days, the new kidney was tested. Blood was circulated through the kidney and shown to exhibit filtering of the blood and production of urine. After being transplanted into rats which had previously had a kidney removed, the new organs began functioning, filtering blood without any clot formation or bleeding, as soon as the blood flow was restored. The kidney had limited function however; something Dr. Ott and his team believe have to do with the cells used for the transplant: "Further refinement of the cell types used for seeding and additional maturation in culture may allow us to achieve a more functional organ."