Lab-Grown Mini Kidneys Are Bringing Science Closer to Custom Organs

Lab-Grown Mini Kidneys Are Bringing Science Closer to Custom Organs

A model of a human kidney.

(Photo by Robina Weermeijer on Unsplash)



Science's dream of creating perfect custom organs on demand as soon as a patient needs one is still a long way off. But tiny versions are already serving as useful research tools and stepping stones toward full-fledged replacements.

Although organoids cannot yet replace kidneys, they are invaluable tools for research.

The Lowdown

Australian researchers have grown hundreds of mini human kidneys in the past few years. Known as organoids, they function much like their full-grown counterparts, minus a few features due to a lack of blood supply.

Cultivated in a petri dish, these kidneys are still a shadow of their human counterparts. They grow no larger than one-sixth of an inch in diameter; fully developed organs are up to five inches in length. They contain no more than a few dozen nephrons, the kidney's individual blood-filtering unit, whereas a fully-grown kidney has about 1 million nephrons. And the dish variety live for just a few weeks.

An organoid kidney created by the Murdoch Children's Institute in Melbourne, Australia.

Photo Credit: Shahnaz Khan.

But Melissa Little, head of the kidney research laboratory at the Murdoch Children's Institute in Melbourne, says these organoids are invaluable tools for research. Although renal failure is rare in children, more than half of those who suffer from such a disorder inherited it.

The mini kidneys enable scientists to better understand the progression of such disorders because they can be grown with a patient's specific genetic condition.

Mature stem cells can be extracted from a patient's blood sample and then reprogrammed to become like embryonic cells, able to turn into any type of cell in the body. It's akin to walking back the clock so that the cells regain unlimited potential for development. (The Japanese scientist who pioneered this technique was awarded the Nobel Prize in 2012.) These "induced pluripotent stem cells" can then be chemically coaxed to grow into mini kidneys that have the patient's genetic disorder.

"The (genetic) defects are quite clear in the organoids, and they can be monitored in the dish," Little says. To date, her research team has created organoids from 20 different stem cell lines.

Medication regimens can also be tested on the organoids, allowing specific tailoring for each patient. For now, such testing remains restricted to mice, but Little says it eventually will be done on human organoids so that the results can more accurately reflect how a given patient will respond to particular drugs.

Next Steps

Although these organoids cannot yet replace kidneys, Little says they may plug a huge gap in renal care by assisting in developing new treatments for chronic conditions. Currently, most patients with a serious kidney disorder see their options narrow to dialysis or organ transplantation. The former not only requires multiple sessions a week, but takes a huge toll on patient health.

Ten percent of older patients on dialysis die every year in the U.S. Aside from the physical trauma of organ transplantation, finding a suitable donor outside of a family member can be difficult.

"This is just another great example of the potential of pluripotent stem cells."

Meanwhile, the ongoing creation of organoids is supplying Little and her colleagues with enough information to create larger and more functional organs in the future. According to Little, researchers in the Netherlands, for example, have found that implanting organoids in mice leads to the creation of vascular growth, a potential pathway toward creating bigger and better kidneys.

And while Little acknowledges that creating a fully-formed custom organ is the ultimate goal, the mini organs are an important bridge step.

"This is just another great example of the potential of pluripotent stem cells, and I am just passionate to see it do some good."

Ron Shinkman
Ron Shinkman is a veteran journalist whose work has appeared in the New England Journal of Medicine publication Catalyst, California Health Report, Fierce Healthcare, and many other publications. He has been a finalist for the prestigious NIHCM Foundation print journalism award twice in the past five years. Shinkman also served as Los Angeles Bureau Chief for Modern Healthcare and as a staff reporter for the Los Angeles Business Journal. He has an M.A. in English from California State University and a B.A. in English from UCLA.
MILESTONE: Doctors have transplanted a pig organ into a human for the first time in history

A surgeon at Massachusetts General Hospital prepares a pig organ for transplant.

Michelle Rose/Massachusetts General Hospital

Surgeons at Massachusetts General Hospital made history last week when they successfully transplanted a pig kidney into a human patient for the first time ever.

The recipient was a 62-year-old man named Richard Slayman who had been living with end-stage kidney disease caused by diabetes. While Slayman had received a kidney transplant in 2018 from a human donor, his diabetes ultimately caused the kidney to fail less than five years after the transplant. Slayman had undergone dialysis ever since—a procedure that uses an artificial kidney to remove waste products from a person’s blood when the kidneys are unable to—but the dialysis frequently caused blood clots and other complications that landed him in the hospital multiple times.

Keep Reading Keep Reading
Sarah Watts

Sarah Watts is a health and science writer based in Chicago.

The World’s First Longevity Charter City: An interview with Niklas Anzinger.

Niklas Anzinger is the founder of Infinita VC based in the charter city of Prospera in Honduras. Infinita focuses on a new trend of charter cities and other forms of alternative jurisdictions. Healso hosts a podcast about how to accelerate the future by unblocking “stranded technologies”.This spring he was a part of the network city experiment Zuzalu spearheaded by Ethereum founder Vitalik Buterin where a few hundred invited guests from the spheres of longevity, biotechnology, crypto, artificial intelligence and investment came together to form a two-monthlong community. It has been described as the world’s first pop-up city. Every morning Vitalians would descend on a long breakfast—the menu had been carefully designed by famed radical longevity self-experimenter Bryan Johnson—and there is where I first met Anzinger who told me about Prospera. Intrigued to say the least, I caught up with him later the same week and the following is a record of our conversation.

Keep Reading Keep Reading
Ingemar Patrick Linden
Driven by a passion to probe the fundamental questions we are confronted with, Dr. INGEMAR PATRICK LINDEN has been on a journey of discovery taking him from Lund University in Sweden, to UCL in London, to University of California, to New York, where he has taught philosophy for almost a decade. Death. It does not get more fundamental than that. One of the ideas that has remained a firm conviction of the author’s since childhood is that we do not have enough time. We are but the beginnings of complete humans, fragments of what we could be. It was the realization that not all share this view, in fact, surveys show that most do not, that inspired, and necessitated, the writing of THE CASE AGAINST DEATH.