The Surprise Peptide

Researchers have accidentally found a promising way to stop bleeding

By Tom Mashberg

Monday, January 08, 2007

In 2001, Rutledge Ellis-Behnke, PhD '03, a research scientist in the Department of Brain and Cognitive Sciences, was doing surgical research on hamster brains. He and his colleagues were using a liquid made of protein fragments known as peptides to encourage the regeneration of neural tissue, a prospective treatment for stroke. In early experiments, the technique appeared to promote the strengthening and rewiring of traumatized neural regions in rodents. But in the lab one day, something seemed awry.

Rutledge Ellis-Behnke (left) and Gerald Schneider show off a transected liver that has been treated with their gel. Credit: Donna Coveney/MIT

"I kept saying to Rutledge, ‘Check the animal. He's not bleeding. Is he dead?'" says Gerald Schneider, an MIT professor of brain and cognitive sciences. "But no, he was still alive."

In that moment of serendipity, Ellis-Behnke saw that the peptide liquid had a second, equally profound effect: it halted bleeding almost immediately.

Through a string of experiments at the University of Hong Kong, he discovered that when the liquid is applied to a surgical wound in a mouse or hamster, the peptides self-assemble into a nanoscale barrier that seals the wound. Once the wound heals, the nontoxic gel is broken down into molecules that cells use for tissue repair, Ellis-Behnke explains.

The researchers (including Kwok-Fai So, PhD '77, head of the Department of Anatomy at the University of Hong Kong) published the results in October 2006 in the journal Nanomedicine, noting that this was the first time nanotechnology had been used to halt bleeding in damaged blood vessels without clotting. "We have found a way to stop bleeding in less than 15 seconds that could revolutionize bleeding control," Ellis-Behnke says.

Ellis-Behnke and So are now carrying out experiments on pigs. They hope that their gel will prove useful for humans and might replace the saline, clamps, and sponges used during surgery, cutting down on operating-room time spent stanching bleeding. Peptides could also be applied to battlefield wounds or used as what the researchers call a "molecular band-aid" in the brains of stroke patients.

The researchers are also pushing ahead with their work on regenerating neural networks. That's led to 20-hour days for Ellis-Behnke, not to mention exhausting shuttling from his home in Canton, MA, to China. But there's an upside: along the way, his fertile mind has absorbed talents like microsurgery ("It's basically plumbing") and speaking Chinese ("It's mostly the taxi-restaurant variety").