Lab-Grown Kidneys Work in Rats

By Ashley Peterson

A team at Massachusetts General Hospital in Boston recently reached an important milestone in the field of regenerative medicine. For the first time, complete lab-grown kidneys have been successfully transplanted into rats, filtering and operating as natural kidneys would.

Regenerating the Kidneys

Harald C. Ott, MD, and his colleagues at Massachusetts General Hospital created bioengineered kidneys by using a decellularization technology Dr. Ott had previously developed. The team first stripped donor kidneys of their cells, leaving behind the underlying scaffold of connective tissues and blood vessels. They regenerated the kidneys by seeding or repopulating the decellurized organs with kidney and vessel cells from newborn rats. The kidneys produced urine but only about one-third as much as normal kidney transplants.

The Search for a New Alternative

The breakthrough marks an important step toward someday being able to grow human-scale organs virtually on demand.

Renal failure, which currently affects nearly one million people in the United States, is a medical condition in which the kidneys fail to adequately filter waste products from the blood and causes the body to retain excess water and waste products. Renal failure can be reversed by kidney transplants from well-matched donors. The problem is that there are currently not enough donated kidneys to meet the demand. An estimated 18,000 transplants are carried out each year, but 100,000 people remain on the waiting list to receive the surgery. Of those fortunate enough to receive the transplant surgery, approximately one in five experience organ rejection following the procedure.


Photo Credit: Ott Laboratory, Massachusetts General Hospital Center for Regenerative Medicine

According to Dr. Ott, “If this technology can be scaled to human-size grafts, patients suffering from renal failure, who are currently waiting for donor kidneys, could theoretically receive an organ grown on demand.” Ideally the lab-grown kidneys would be grown from the patient’s own cells so they would be less likely to be rejected by the recipient’s immune system.

A Promising Start

Dr. Ott and his team are now testing the approach with pig and human kidneys and improving the seeding process.

Though we are still a long way from being able to produce human-scale organs, bioengineered kidneys transplanted into rats filter blood and produce urine — an achievement that paves the way for growing replacement kidneys for humans.

Classroom Discussion

  • What would be some of the next steps toward making artificial kidneys possible for humans?
  • If you were a medical researcher working in a lab, what discovery or accomplishment would you make your primary mission?