Method: Grown on a polymer framework
When: 10–20 years
His artificial bladder breakthrough in 2006 grabbed all the headlines, but Anthony Atala of the Wake Forest Institute for Regenerative Medicine is forging ahead on other artificial organs. In 2002, when he transplanted artificial kidneys into cows, the organs survived for months and even produced their own urine, albeit not very efficiently. But to build one for humans, he has to figure out the precise combination of seeder cells that will transform a lab-built scaffold into a fully functioning, transplantable organ.