To better understand the causes of premature birth and devise ways to prevent it researchers at University of Pennsylvania have developed a placenta-on-a-chip that can fully model the transport of nutrients across the placental barrier. Prematurely born babies may experience lifelong debilitating consequences but the underlying mechanisms of this condition are not well understood due in part to the difficulties of experimenting with intact living human placentae. Donated placental tissue can be problematic for doing many of the types of studies necessary for fully understanding the structure and function of the placenta. Beyond the scarcity of samples there's a limited