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More than two years ago, scientists at Vanderbilt University told of their intention to build an artificial kidney that could be implanted into the bodies of those suffering renal failure. Now it seems like they could be getting somewhere, with new advances in nanotechnology potentially putting such a lifesaving system within our grasps.
It’s obvious why doctors don’t want to depend on transplantation: there is a worldwide donor organ shortage, and after that there are issues of blood type matching and rejection. People with kidney disease can go on to dialysis – a procedure that cleans the blood, usually performed by machine – but the prospects aren’t good. The survival rate after three years is only about 50 percent. And the quality of life for those undergoing this treatment is poor – imagine being hooked up to tubes and having your blood swished around like clothes in a washing machine, for hours, several times a week.
So clearly there is a need for an alternative, which is what Vanderbilt researchers, in collaboration with the University of California, San Francisco, hope to ultimately achieve. A major part of the system they are developing is a nanofilter made of silicon that basically fishes out unwanted molecules from the blood, like waste products, excess water, and salt. This is the kidney’s main job, and also the role of dialysis machines, but progress in nanotechnology has led to better, more uniform pores that could mean more efficient filtering than the membranes across which molecules are exchanged in dialysis.
While we’ve used the word “nano” several times, this device is not exactly tiny; it’s about the size of a coffee cup, so probably not far off the size of an actual kidney. But there is no need to remove the kidneys to make room for it; the fake kidney is designed to be inserted nearby and hooked up to both the patient’s blood supply and bladder.
There’s still a lot to be done, but the group has just been given $6 million (£4 million) to play with, and said Tuesday at the American Society of Nephrology Kidney Week that human trials within this decade are on the agenda. But they’re not the only ones hoping to get this far. Other groups are working on 3D printed replacements, while some are opting for growing them using stem cells. One study has even managed to implant lab-grown kidneys into animals that could then pass urine, although they admit human studies are way off
Another promising solution is a recently trialed artificial kidney that’s kind of halfway between dialysis and this group’s design. It’s a wearable device that’s strapped around a patient’s waist, weighing a little over four kilograms (10 pounds). A diabetic man whose kidneys started failing two years ago has just become the first in the U.S. to have one strapped on, albeit a prototype that’s just proof-of-concept at the moment. Still, it seems there is progress being made, and the implantable artificial kidney project is set to be included in the FDA’s new fast-track program that will hopefully speed things along.
