Japanese researchers have taken a step toward being able to grow organs from stem cells which could then be transplanted into humans.
A set of kidneys were successfully produced in a laboratory and then were implanted into an animal, where they were verified as functioning properly.
So far, such experiments have been performed with both rats and pigs. Results with the latter have greater impact, as pigs are more complex and more closely approximate the human physiology.
The new kidneys are grown complete with a drainage tube and bladder for the collection of urine. That part of the process presented the team with the biggest problems, as it’s vital to avoid the organs ballooning up under pressure. It is the function of the kidneys to remove excess organic molecules from the blood and waste products from the metabolism. Kidney organ transplantation has been viable for decades; however, the process requires a donor kidney which needs to be used within a short time period.
Laboratory grown kidneys could, in theory, overcome the common shortfall in which potential recipients often exceed available donor kidneys. Most donated kidneys come from deceased donors, and are the most in-demand organ for transplant, with long waiting lists.
Professor Chris Mason, an independent scientist based at University College London, said of this latest development: “This is an interesting step forward. The science looks strong and they have good data in animals.”
Although the test results are very promising, human trials remain a number of years away. A multitude of safety checks will be required before any attempt is made to implant one of the laboratory-produced kidneys into a human patient.
The research was led by Dr Takashi Yokoo of the Jikei University School of Medicine in Tokyo. The findings have been published in Proceedings of the National Academy of Sciences of the United States of America (PNAS). The paper is titled “Urine excretion strategy for stem cell-generated embryonic kidneys.”