Artificial kidneys may replace dialysis treatments

September 2, 2010 7:11:54 PM PDT
A breakthrough technology under development in the Bay Area could eventually free thousands of kidney patients from the bonds of dialysis. Instead, a device would handle kidney functions inside their own bodies.

After a transplanted kidney gave out in 2007, David Anderson spent three days a week hooked up to a dialysis machine.

"I don't leave San Francisco very often," he said.

But in the near future, thousands of patients like David could be freed from dialysis by technology being developed by researchers at UCSF.

"This is the device that will have filters that will remove toxins," Bioengineering Professor Shuvo Roy, PhD said.

Roy has a prototype of what could become the world's first, implantable, artificial kidney. The device uses sophisticated nano filters -- sheets of silicon etched with millions of microscopic pores.

"Only toxins and waste water will go through them, the rest of the blood will not," he said.

After it's purified, the blood flows through a second chamber, called a bio-reactor.

It's filled with bioengineered kidney cells that react with the blood. The living cells perform many of the same functions as a healthy kidney, including regulating blood pressure and producing Vitamin D.

Because of that ability, researchers believe the implantable device would not only free patients from dialysis, but it would treat them in ways traditional dialysis machines cannot.

"So the kidney does two main things, so one is it filters all the blood in the body and then it fine tunes the chemical levels in the body. What we do in dialysis is we do filtration part, but we can't really fine tune the chemistry very well," nephrologist and UCSF professor Dr. Lynda Frassetto said.

Frassetto said patients can experience a variety of symptoms in between dialysis sessions and some need drugs to perform functions normally handled by the kidneys.

"I think the most significant thing would be that we would d be able to adjust chemical levels all the time; that should make them feel a lot better," she said.

Unlike the mock-ups in his lab, Roy says the implantable model would work with the body's natural blood pressure, instead of using a pump and without using electricity it could theoretically be implanted in patients for the long term. It could potentially provide a breakthrough alternative to dialysis, which now accounts for $25 billion a year and 6 percent of all the money spent by Medicare.

"These things are very difficult and very expensive, but cheaper than $20,000 a month for dialysis," Anderson said.

Roy believes with adequate funding, his team could potentially have the artificial kidney ready for clinical trials within five years.

Written and produced by Tim Didion


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