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.
Get our top stories twice a month
Follow us on
Brain Cancer Chromosomes. Chromosomes prepared from a malignant glioblastoma visualized by spectral karyotyping (SKY) reveal an enormous degree of chromosomal instability -- a hallmark of cancer. Created by Thomas Ried, 2014

Glioblastoma is an aggressive and deadly brain cancer, causing more than 10,000 deaths in the US per year. In the last 30 years there has only been limited improvement in the survival rate despite advances in radiation therapy and chemotherapy. Today the typical survival rate is just 14 months and that extra time is spent suffering from the adverse and often brutal effects of radiation and chemotherapy.

Scientists are trying to design more effective treatments for glioblastoma with fewer side effects. Now, a team at the Department of Neurosurgery at Houston Methodist Hospital has created a magnetic helmet-based treatment called oncomagnetic therapy: a promising non-invasive treatment for shrinking cancerous tumors. In the first patient tried, the device was able to reduce the tumor of a glioblastoma patient by 31%. The researchers caution, however, that much more research is needed to determine its safety and effectiveness.

Keep Reading Keep Reading
Sarah Philip
Sarah Philip is a London-based freelance journalist who writes about science, film and TV. You can follow her on Twitter @sarahph1lip.

Astronaut and Expedition 64 Flight Engineer Soichi Noguchi of the Japan Aerospace Exploration Agency displays Extra Dwarf Pak Choi plants growing aboard the International Space Station. The plants were grown for the Veggie study which is exploring space agriculture as a way to sustain astronauts on future missions to the Moon or Mars.

Johnson Space Center/NASA

Astronauts at the International Space Station today depend on pre-packaged, freeze-dried food, plus some fresh produce thanks to regular resupply missions. This supply chain, however, will not be available on trips further out, such as the moon or Mars. So what are astronauts on long missions going to eat?

Going by the options available now, says Christel Paille, an engineer at the European Space Agency, a lunar expedition is likely to have only dehydrated foods. “So no more fresh product, and a limited amount of already hydrated product in cans.”

For the Mars mission, the situation is a bit more complex, she says. Prepackaged food could still constitute most of their food, “but combined with [on site] production of certain food products…to get them fresh.” A Mars mission isn’t right around the corner, but scientists are currently working on solutions for how to feed those astronauts. A number of boundary-pushing efforts are now underway.

Keep Reading Keep Reading
Payal Dhar
Payal is a writer based in New Delhi who has been covering science, technology, and society since 1998.