An implantable artificial kidney could enhance prospects for individuals whose kidneys have failed and who have to depend on dialysis or the rare possibility of a transplant to remain alive. Now, investigators doing work on the first of its kind device that seeks to fulfill this need say they are hopeful of performing initial clinical studies within a year.
Kidneys are awesome organs that perform 24/7 to clean up the blood and remove waste. Daily, these filter about 150 liters of blood to generate 1-2 liters of urine.
Transplant is the best therapy for kidney failure but demand for organs is large in comparison with supply.
The US Organ Procurement and Transplantation Network say there are more than 100,000 sufferers on the waiting list for a kidney transplant, but previous year, only 17,108 obtained one.
In all, the National Kidney Foundation approximate that more than 460,000 Americans have an end-stage kidney condition, and each day, 13 individuals in the US die waiting for a kidney donor. They say the federal Medicare bill for caring for kidney condition patients – not including prescription drugs – was about $87 billion in 2012.
William H. Fissell IV, a kidney expert and associate professor and his team wish to put an end to this devastating situation, as he describes:
“We are developing a bio-hybrid system that can imitate a kidney to eliminate enough waste substances, salt and water to maintain a patient off dialysis.”
The objective is to develop a device that is small enough – about the size of a soda can – so it will fit within an individual’s body.
The implantable artificial kidney consists of microchip filters and living kidney cells and will be powered by the individual’s own heart.
Silicon nanotechnology plus living kidney cells
The microchip utilizes the same silicon nanotechnology that the microelectronics sector uses for computers.
Prof. Fissell states that the chips are low-cost, accurate and make ideal filters. Each system will consist of around 15 microchips, one on top of the other.
Each microchip filter consists of pores, each of which will consist of and work as a scaffold for a membrane of living kidney cells that imitate the natural features of the kidney. The research team is developing the filter one pore at a time to do accurately what they want each to do.
Prof. Fissell states that luckily the cells develop well in the lab dish. They can develop a membrane of kidney cells that can work out which substances in the blood reabsorb as nutrients that remain in the blood, and which need to be eliminated as waste products intended for disposal in urine.
This way, states Prof. Fissell, “we can leverage Mother Nature’s 60 million years of study and development,” to develop a bioreactor of living cells at the heart of the artificial kidney.
Powered by individual’s blood flow without danger of clots
The device does not need a supply of power because it utilizes the power of the patient’s heart – the normal pressure of blood flow in the blood vessels – to push the blood via the filters.
On the other hand, this function also provides a challenge: how to fine-tune the fluid dynamics so blood moves via the device without clotting.
Dr. Amanda Buck, a biomedical engineer with a fascination in fluid mechanics, is in charge of this portion of the project.
Dr. Buck uses computer designs to refine the shape of the channels within the device to accomplish the smoothest blood flow. Then, with the support of 3D printing, the research team creates a prototype and tests it to see how easily blood flows through it.
Prof. Fissell states because the bio-hybrid system will be out of reach of the body’s immune reaction, it is not likely to incur rejection. “The problem is not one of immune compliance, of matching, like it is with an organ transplant,” he describes.
The research team is expecting to run pilot clinical trials of the silicone filters by the end of 2017. Prof. Fissell states he has a long list of sufferers willing to take part, and he declares his admiration for them as he concludes:
“My sufferers are definitely my heroes. They come back all the time and they agree to a crushing burden of illness because they want to live. And they’re eager to put all of that at risk for the benefit of another sufferer.”