Due to the critical shortage of donor organs to replace the ones damaged by accident or disease, it has been a goal of science to create human organs from stem cells. This can be possible, but it is a very complicated task. Scientists need to prompt stem cells to become kidney, liver or lung cells, which must then recreate the complex anatomy of a real organ in order to function in a human recipient. 

According to Relax News, the researchers from Australia and the Netherlands grew their kidney-prototype from Induced Pluripotent Stem (iPS) cells which are adult cells reprogrammed into a neutral state from which they can be influenced to develop into other types of cells. The tissue is not a usable organ, but may be used for other purposes such as replacing animals in drug toxicity tests.

The first part has proved most challenging, especially the organs that is composed of a number of different cell types. The kidney has more than 20. In the new study, published in the journal Nature, the team managed to transform iPS cells into two different adult cell types. As a result, the organoids exhibited different tissue types and were "similar" to the kidney of a human embryo, the researchers reported. The work characterized a very important step towards building stem-cell-derived kidneys University of Edinburgh anatomy expert Jamie Davies wrote in a comment, also published by Nature. But he stressed the product was "not a kidney, but an organoid."

Until a few years ago, the only way to obtain stem cells was to collect them from human embryos. Stem cells are basic cells that grow into different specialized cells that make up the different organs -- the brain, the heart, the kidney, and so on. However, this became very controversial because in order for the collection of stem cells to happen, the embryo needs to be eliminated.