New York: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 lifespan of how long the tissue remains viable, for only a few hours after delivery, and the system that is used to perfuse the tissue and perform transport studies is complex," said one of the researchers Cassidy Blundell. Like other organs-on-chips, such as ones developed to simulate lungs, intestines and eyes, the placenta-on-a-chip provides a unique capability to mimic and study the function of that human organ in ways that have not been possible using traditional tools. The researchers' placenta-on-a-chip is a clear silicone device that contains two layers of human cells that model the interface between mother and fetus. Microfluidic channels on either side of those layers allow researchers to study how molecules are transported through, or are blocked by, that interface. "The placenta is arguably the least understood organ in the human body and much remains to be learned about how transport between mother and fetus works at the tissue, cellular and molecular levels," Professor Dan Huh, one of the lead researchers, said. While the placenta-on-a-chip, described in the journal Lab on a Chip, is still in the early stages of testing, the researchers are already planning to use it in studies on preterm birth. "This effort was part of the much larger Prematurity Research Center here at Penn, one of five centers around the country funded by the March of Dimes ( a non-profit organisation) to study the causes of preterm birth. The rate of preterm birth is about 10 to 11 percent of all pregnancies. That rate has not been decreasing, and interventions to prevent preterm birth have been largely unsuccessful," Professor Samuel Parry said.