Melody Swartz, 37
Body Part Builder
She´s showing how a mysterious current inside the body could help us grow organs
Every paper cut is a reminder of the blood pulsing through our arteries, but Melody Swartz is about to demonstrate the importance of a lesser-known kind of flow, the slow currents of intercellular fluid pulsing through our tissues. With any luck, that flow will prove to be the long-sought-after key to growing organs in the lab.
At the Swiss Federal Institute of Technology of Lausanne, she points to the web of tubes on her monitor. "See those thin, spindly things?" asks Swartz, who is also a bioengineer at Northwestern University. "Those are the begin-
nings of a functional network"-the first biological system that she´s grown by exploiting the intercellular currents.
Previously, the processes driving organ growth were so poorly understood that bioengineers were able to create only a few simple tissue types, such as skin and heart muscle. Last year, however, Swartz´s experiments with human cells showed that during development, these currents redistribute proteins called morphogens, which then signal cells to create networks of capillaries that support growing tissue. She was the first to show that these slow streams are so crucial to development that when they are absent, specialized tissues degenerate into something of a biological casserole gone wrong.
Swartz´s driving force has always been her mechanical mind. As an undergraduate, she majored in engineering, not biology, and even today, she likens her discoveries to "taking apart a car and seeing how it works."
Her research is so novel that she sometimes has had trouble nailing down grants; her studies tend to defy predesignated award categories. According to her colleagues, this difficulty shows how revolutionary her approach is. Her work suggests, for instance, that creating transplantable organs in the lab will require reproducing the currents of intercellular flow. Understanding these currents could also help researchers invent new cancer-fighting drugs, since tumor cells use them to spread to the rest of the body. "She´s showing how sensitive cells are to small changes in flow," says Linda Griffith, a bioengineer at the Massachusetts Institute of Technology. "These are phenomena that will endure as foundational ideas."-Elizabeth Svoboda