Researchers at the University of Pittsburgh School of Medicine have combined synthetic biology with a machine-learning algorithm to create human liver organoids with blood- and bile-handling systems. When implanted into mice with failing livers, the lab-grown replacement livers extended life. The study, published today in Cell Systems, shows that it's possible to trigger and speed up the maturation of a lab-grown organ without sacrificing precision or control. "Pregnancy is nine months--it takes that long and even months after birth for new organs to mature--but if a person needs a liver, they may not be able to wait that long," said study author Mo Ebrahimkhani, M.D., associate professor of pathology and bioengineering, and member of the Pittsburgh Liver Research Center and the McGowan Institute for Regenerative Medicine. "We showed it's possible to get human liver tissue with four main cell types and vasculature in 17 days. We can mature tissue almost to the third trimester in only three months."