While a kidney transplant is the most exciting way to treat kidney failure, for the 661,000 Americans with kidney failure, approximately 468,000 survive using conventional dialysis machines. This may holdover patients until they can move up the transplant list, or in less severe cases, it may be a non-surgical way to handle kidney failure.
When a person’s kidneys are failing, they are unable to filter toxins out of the blood. To circumvent this, those who have kidney failure use a dialyzer, or a blood-cleaning machine, but the process is not easy. One type of dialysis requires 3-5 hours a day of getting one’s blood cleaned, multiple times a week. There is also a home option for kidney dialysis patients in which the lining of one’s stomach is used to inject cleaning fluids and clean the patients’ blood. However, this requires that users have a thin tube be placed in their abdomen, which can cause discomfort.
The objective of the Kidney Research Institute (KRI), a joint organization between Northwest Kidney Centers and UW Medicine is to reduce complications related to dialysis.
“What we’re trying to do is apply 21st century bioengineering, biomaterials, ideas, to innovating in dialysis technology in a way that will make it more accessible to patients, to be able to do their own dialysis or to reduce some of the complications that are associated with dialysis,” said Jonathan Himmelfarb, director of KRI and a professor of medicine at the UW.”So most of these are works in progress.”
Some of these developments involve investigating new biomaterials that are aimed to help heal scar tissue. According to Himmelfarb, some current projects at KRI will ideally reduce scar tissue for those who need vascular access for dialysis. Scar tissue results from multiple needle injections into a patient’s body. Needle injections are required for either at home dialysis or dialysis at a hospital, and can scar a person’s body. The abdominal dialysis in particular requires minor surgery, and can leave a scar on the person’s stomach.
Another issue with conventional dialysis machines is the lack of portability.
“The dialysis systems that we use today take up about 700 liters of water per day per patient,” said Buddy Ratner, joint professor of chemical and bioengineering. “Of course, it weighs tons.”
This makes the machine immobile, meaning patients have to travel to the nearest dialysis machine multiple times a week in order to receive lengthy treatments.
The KRI also oversaw the clinical trials of a Wearable Artificial Kidney (WAK), which is a mobile blood cleaner meant to serve as a possible replacement for the larger, traditional dialyzer in the future.
The WAK is worn around one’s waist and uses significantly less water than a conventional dialyzer. The need for a mobile dialyzer stems from the weight associated with each machine.
The initial clinical trials were considered successful, despite being halted early on to address issues with the prototype. Typical chemical waste products like urea, phosphorus, and creatinine were all removed from the patients’ bloodstreams, which a conventional dialyzer usually removes.
Excess salt and water were also taken out.
Another development in kidney dialysis is the regrowth of parts of a kidney. Benjamin Freedman, an assistant professor at the UW, is part of a team that grows organoids from stem cells.
“We potentially have a new source of kidney tissue that anyone could grow that would be compatible with their body,” Freedman said.
The first step of creating kidney organoids involves reprogramming adult cells into embryonic stem cells. This is important because embryonic stem cells can change into multiple different types of cells, such as a kidney cell. The final step involves the cells evolving into organoids. The organoids are roughly one-tenth of a millimeter.
However, there is still much work left to be done before new kidney dialysis machines like the WAK or regrown kidneys, will become part of conventional medicine.
“As exciting as [these new developments] are, they are not going to be a reality any time soon,” said Raj Mehrotra, professor of medicine at the UW and a section chief at Harborview Medical Center.
These new dialysis solutions will not be reaching hospitals any time soon, but scientists like Freedman are still excited about the potential for current research to one day become a reality.
“It’s hard to predict the future, but we do think that, we know that these cells have the potential to give rise to an entire kidney, and other organs as well,” Freedman said. “I’m optimistic based on what I’ve seen so far that we will be able to do this within the next couple of decades. I think that’s a very realistic approach.”
Reach contributing writer Christopher Leahy at firstname.lastname@example.org. Twitter: @chrisleahy227