Patients with renal failure require regular dialysis, which is an invasive and potentially risky treatment. But now researchers at the University of California, San Francisco (UCSF) have successfully demonstrated a prototype bioartificial kidney that can be implanted and worked without the need for drugs.
The kidney performs many important functions in the body, the most notable being to filter toxins and waste products in the blood, and also to regulate blood pressure, electrolyte concentration and other body fluids.
Therefore, when these organs begin to fail, it is very complicated to replicate these processes. Patients usually start with dialysis, but this is time-consuming and uncomfortable. A long-term solution is kidney transplantation, which can restore a higher quality of life, but is accompanied by the need to use immunosuppressive drugs to prevent the dangerous side effects of rejection.
For the UCSF kidney project, the team developed a bioartificial kidney that can be implanted in patients to perform the main functions of real things, but does not require immunosuppressive drugs or blood thinners, which are often required.
The device consists of two main parts. The blood filter is composed of a silicon semiconductor membrane, which can remove waste from the blood. At the same time, the bioreactor contains engineered renal tubular cells that can regulate water volume, electrolyte balance and other metabolic functions. The membrane also protects these cells from attack by the patient’s immune system.
Previous tests have allowed each of these components to work independently, but this is the first time the team has tested them to work together in a device.
The bioartificial kidney is connected to the two main arteries in the patient’s body – one carries the filtered blood into the body and the other carries the filtered blood back into the body – and to the bladder, where waste is deposited in the form of urine.
The team has now conducted a proof-of-concept experiment, showing that the bioartificial kidney only works under blood pressure and does not require a pump or external power source. The renal tubular cells survive and continue to function throughout the test.
Thanks to their efforts, researchers at the University of California, San Francisco have now received a KidneyX $650,000 prize as one of the winners of the first phase of the artificial kidney award.
Shuvo Roy, the lead researcher of the project, said: “Our team designed an artificial kidney that can sustainably support the cultivation of human kidney cells without causing an immune response.” With the feasibility of the reactor combination, we can focus on upgrading the technology for more rigorous pre-clinical testing and eventually clinical trials.”