Wednesday, April 24, 2024

Implantable bioartificial kidney could free patients from dialysis

Chronic kidney failure, also known as end-stage renal disease, leads to the progressive and dangerous loss of kidney function. Most patients with kidney failure must visit dialysis clinics multiple times every week for dialysis – to have their blood filtered, a process that is time-consuming, uncomfortable, and risky. Some patients live with transplanted kidneys, which can restore a higher quality of life but comes with the risky side effect of requiring immune-suppressing drugs to prevent rejection.

Now, researchers at the University of California San Francisco (UCSF) have successfully demonstrated a functional prototype of its implantable artificial kidney that promises to free kidney disease patients from dialysis machines and transplant waiting lists.

UCSF’s Kidney Project is a nationwide collaboration led by Shuvo Roy, Ph.D. of UC San Francisco, and William Fissell, MD of Vanderbilt University Medical Center (VUMC). Its bioartificial kidney could be implanted into a patient to perform the main functions of the real thing, but without requiring immune-suppressing drugs or blood thinners, which are also often required.

The device combines the two essential parts of its artificial kidney, the hemofilter, and the bioreactor. The hemofilter is made of silicon semiconductor membranes that remove waste products and toxins from the blood. The bioreactor contains engineered renal tubule cells, which replicate other kidney functions, like the balance of electrolytes in the blood. The membranes also protect these cells from being attacked by the patient’s immune system.

In the last few years, The Kidney Project successfully tested these two parts in separate experiments. But this is the first time the team married the two units into a scaled-down version of the artificial kidney and evaluated its performance in a preclinical model.

The bioartificial kidney connects to two major arteries in the patient as well as to the bladder, where the waste products are deposited as urine. The units worked in tandem, powered by blood pressure alone and without the need for blood-thinning or immunosuppressant drugs.

For this advance, the UCSF research team has been awarded a $650,000 prize from KidneyX and was one of six winning teams selected out of an international field for the Phase 1 Artificial Kidney Prize.

According to the researchers, the Kidney Project’s artificial kidney will not only replicate the high quality of life seen in kidney transplant recipients – the “gold standard” of kidney disease treatment but also spare them from needing to take immunosuppressants.

“Our team engineered the artificial kidney to sustainably support a culture of human kidney cells without provoking an immune response,” said Roy. “Now that we have demonstrated the feasibility of combining the hemofilter and bioreactor, we can focus on upscaling the technology for more rigorous preclinical testing, and ultimately, clinical trials.”