Artificial Kidney Could Free Thousands from Dialysis

An ambitious project is trying to create an artificial kidney using a combination of tissue engineering and micro-electromechanical systems (MEMS) technology.

Researchers at the University of California, San Francisco (UCSF; USA) are developing the groundbreaking artificial kidney, which will include thousands of microscopic filters, as well as a bioreactor to mimic the metabolic and water-balancing roles of an actual kidney. The two-stage system uses a hemofilter composed of thousands of nanoscale filters to remove toxins from the blood, while a biocartridge of renal tubule cells mimics the metabolic and water-balance roles of the human kidney. The process relies on the body's blood pressure (BP) to perform filtration, without needing pumps or an electrical power supply.


The first phase of the project, which has already been completed, focused on developing the technologies required to reduce the device from a larger external version to a size that could fit into the body, and the testing of individual components. The tests were a success, and the device was shown to be effective in an implantable animal model. In the second (current) phase, the team is attempting to apply silicon fabrication technology, along with specially engineered compartments for live kidney cells, to shrink the technology into a device the size of a coffee cup. The device would then be implanted in the body without the need for immune suppressant medications, allowing the patient to live a more normal life. The researchers hope that one day the device could actually be used in lieu of a kidney transplant, and not just as a stopgap measure.

"This device is designed to deliver most of the health benefits of a kidney transplant, while addressing the limited number of kidney donors each year,” said Shuvo Roy, Ph.D, an associate professor at the UCSF Department of Bioengineering and Therapeutic Sciences. "This could dramatically reduce the burden of renal failure for millions of people worldwide, while also reducing one of the largest costs in U.S. healthcare.”

End-stage renal disease (ESRD) affects more than 500,000 people each year in the United States alone, and currently it is treated fully only with a kidney transplant. This number has been rising between 5% - 7% annually, partly due to kidney damage associated with diabetes as well as a result of hypertension. However, kidney transplants are difficult to obtain; only 17,000 donated kidneys were available for transplant in 2009 in the U.S., while the number of patients on the transplant waiting list currently exceeds 85,000, and with over 350,000 patients remaining reliant on kidney dialysis for survival.

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