Artificial kidneys may free patients from dialysis

Scientists at UC San Francisco are working on a new approach to treating kidney failure that could one day free people from needing dialysis or having to take harsh drugs to suppress their immune system after a transplant. They have shown for the first time that kidney cells, housed in an implantable device called a bioreactor, can survive inside the body of a pig and mimic several important kidney functions. The device can work quietly in the background, like a pacemaker, and does not trigger the recipient’s immune system to go on the attack.

Eventually, scientists plan to fill the bioreactor with different kidney cells that perform vital functions like balancing the body’s fluids and releasing hormones to regulate blood pressure – then pair it with a device that filters waste from the blood.

The aim is to produce a human-scale device to improve dialysis, which keeps people alive after their kidneys fail but is a poor substitute for having a real working organ. Roy and his colleagues engineered the bioreactor to connect directly to blood vessels and veins, allowing the passage of nutrients and oxygen, much like a transplanted kidney would. Silicon membranes keep the kidney cells inside the bioreactor safe from attack by the recipient’s immune cells.

The team used a type of kidney cell called a proximal tubule cell, which regulates water, as a test case. The team tracked the kidney cells and the recipient animals for seven days after transplantation and both did well.

Reference: Shuvo Roy et al, Journal: Nature Communications