First artificial kidney implanted in rats

Artificial kidneys in the future as a replacement for donor organs?

04/15/2013

The first artificial kidneys were successfully implanted in rats. A research team led by Harald Ott of the Massachusetts General Hospital in Austria at Harvard Medical School in Boston has used a method for the biological reproduction of a kidney that has hitherto been used only for the production of artificial hearts, livers and lungs. The artificial kidneys were then used in rats and showed the ability to produce urine, even if their function was significantly behind that of a natural rat kidney. The results of their study, the researchers have in the journal „Nature Medicine“ released.

The method of producing the artificial kidney was based on the approach already used by Harald Ott in the biological reproduction of the heart and the lungs, which envisages a reduction of the organ to the original cell structure and a subsequent rebuilding with fresh cells in a so-called bioreactor. The artificial kidneys thus created proved to be quite functional in laboratory tests as well as after implantation in living rats. Thus, the researchers around Harald Ott arouse the hope that in the future kidneys can be artificially produced as needed. The long wait for a donor organ, would finally come to an end for those affected.

Artificial kidney reaches 23 percent of normal kidney function
The research team led by Harald Ott of the Massachusetts General Hospital used a special procedure to completely free the skeletal structure of the kidneys of deceased rats from the kidney cells, leaving only the collagenous structure of the organ in the end. Subsequently, fresh kidney cells were settled on this. The bioreactor developed after twelve days an artificial kidney, which achieved about 23 percent of full kidney function in laboratory tests. The researchers implanted the kidney-living rat, where the artificial organs still averaged five to ten percent of normal kidney function. Once the artificial kidney's blood supply was established, it began to produce urine, „without signs of bleeding or the formation of blood clots“, the researchers write.

Low risk of rejection in biological animals
„If this technique can be scaled to the human size of transplants, patients with kidney failure who are currently waiting for a donor kidney or who are not among the transplant candidates could theoretically receive new organs derived from their own cells“, explained the Austrian-born surgeon, Harald Ott. Not only availability (about 100,000 patients in the US, according to the researchers in the US, are currently waiting for a kidney transplant), but also the low risk of rejection of the organ or the high biocompatibility would be a major advantage of the new artificial kidneys. So far, even those lucky enough to receive a transplant will have to take immunosuppressants for a lifetime and end up with the risk of rejection after kidney transplantation.

Organs to order?
Commenting on the still relatively low functionality of the artificial kidneys, Harald Ott explained that „a further refinement of the cell types for sowing and further maturation“ in the bioreactor could bring significant improvements here. There is hope, „that one day biotechnological kidneys will be able to completely replace kidney function just as donor kidneys do.“Ideally, the necessary transplants could be used in the future „on demand“ From the patient's own cells, which could overcome the organ deficiency and the need for chronic immunosuppression, the researchers concluded. (Fp)

Picture: Martin Büdenbender