Scientists 'Grow' Kidney in Lab Engineered rat kidneys a step toward helping humans By Rob Quinn, Newser Staff Posted Apr 15, 2013 4:20 AM CDT 11 comments Comments The engineered kidneys weren't as effective as normal ones, but they could be enough to get many patients off dialysis. (Shutterstock) (Newser) – In a breakthrough with the potential to save many thousands of lives, scientists have "grown" a kidney that produced urine both in the lab and after being transplanted into a rat. The new kidneys were created by stripping old kidneys of their cells and pumping the remaining "scaffold" with new cells that regrew the organ, the New York Times reports. Vast amounts of research still needs to be done, but scientists believe this is a major step toward creating replacement kidneys for people. The lab-grown kidneys were only about 5% as effective as normal ones, but researchers say that restoring a fraction of function could be enough for many patients. "If you're on hemodialysis then kidney function of 10% to 15% would already make you independent of hemodialysis. It's not that we have to go all the way," the lead researcher says, describing the potential as huge. "If you think about the United States alone, there's 100,000 patients currently waiting for kidney transplants and there's only around 18,000 transplants done a year," he tells the BBC, which notes that people are already walking around with bladders and windpipes grown with the same technique, but livers, kidneys, and hearts are much more difficult to produce.