Instead of having to wait for one of the limited number of available donor kidneys, patients in need of a transplant may eventually be able to have a new kidney custom-grown for them. That possibility recently took one step closer to reality, as scientists at Australia's University of Queensland successfully grew a "mini-kidney" from stem cells.

The researchers created a proprietary new protocol, that prompts stem cells in a petri dish to self-organize into a miniature kidney. "During self-organization, different types of cells arrange themselves with respect to each other to create the complex structures that exist within an organ, in this case, the kidney," says project leader Prof. Melissa Little.

Stem cells, as many readers will already know, are essentially "blank slate" cells that are able to become any of a wide variety of specialized cells. Previous studies have coaxed them into becoming lung, retina and brain cells, among other types.

Little points out that while the work is indeed promising, human trials with full-size lab-grown kidneys are not likely to be happening anytime soon. In the meantime, however, the mini-kidneys could be used to test drug candidates without exposing human test subjects to harmful side effects.

A paper on the research was recently published in the journal Nature Cell Biology.

Earlier this year, scientists at the Massachusetts General Hospital Center for Regenerative Medicine created a functioning rat kidney. In their case, however, they did so by stripping the cells from an existing kidney, then "reseeding" the resulting collagen scaffold with endothelial cells.

Additionally, a team from Italy’s Mario Negri Institute for Pharmacological Research has created kidney-like “organoids” that perform the same functions as kidneys when implanted in rats.

Source: University of Queensland