In what's being hailed as a major scientific breakthrough, an Indian-origin researcher-led team claims to have created the world's first implantable "artificial kidney", no larger than a coffee cup.
Shuvo Roy and colleagues at University of California have developed the artificial kidney which they say not only filters toxins out of bloodstream, but also uses human kidney cells to perform other vital functions like regulating blood pressure and producing vitamin D.
The team has tested the new device on animals, and it now plans to test the same on humans.
"Dialysis is not only time-consuming, but it's also debilitating. Many patients don't feel good, because it's not doing all the functions of a normal, healthy kidney.
"The new kidney doesn't just filter toxins. It has metabolic functions and hormonal functions, and dialysis does not capture these abilities," Roy recently told 'Technology Review' published by Massachusetts Institute of Technology.
A prototype of the artificial kidney, unveiled recently, is a two-part system - half consists of a toxin-removing filter, in which thousands of silicon membranes are stacked together.
Their nano-pores are so dense, and so precisely shaped, that they can filter very precisely using only the force of the body's own blood pressure. Blood flows in through this filter, where the toxins, sugars, water, and salts are removed as a filtered solution.
The clean blood and watery filtrate are both shunted into the other half of the system - a separate cartridge.
Here, they flow over more silicon membranes, these ones coated with a single type of human kidney cell, which helps the device reabsorb some of the water, sugars, and salts, as well as produce vitamin D and help prevent blood pressure from sinking too low -- normal kidney functions that are not offered by dialysis, say the scientists.
The waste that's not reabsorbed is shunted to a tube attached to the bladder and removed as waste in the urine - just like a normal kidney would do.
Though the scientists have tested the implant in a dozen rats and a handful of pigs, they claim that they still have to scale up the device's efficiency to something that could work effectively in humans. They hope to start human trials in five to seven years.
Experts have welcomed the concept.
Allen Nissenson, the Chief Medical Officer of DaVita, one of America's largest dialysis provider, said: "It's a bioreactor kidney, an incredibly innovative concept, and really exciting if it proves to be workable on a larger scale."