[Editors] EMBARGOED: MIT material stops bleeding in seconds

[Elizabeth Thomson]

EMBARGOED FOR RELEASE, TUESDAY, OCT. 10, 2006, 12:00 A.M. EDT

MIT News Office
Massachusetts Institute of Technology
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MIT material stops bleeding in seconds
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EMBARGOED FOR RELEASE
TUESDAY, OCT. 10, 2006, 12:00 A.M. EDT
Contact: Elizabeth A. Thomson, MIT News Office
Phone: 617-258-5402
Email: thomson at mit.edu

PHOTO AVAILABLE

CAMBRIDGE, Mass.--MIT and Hong Kong University researchers have shown 
that some simple biodegradable liquids can stop bleeding in wounded 
rodents within seconds, a development that could significantly impact 
medicine.

When the liquid, composed of protein fragments called peptides, is 
applied to open wounds, the peptides self-assemble into a nanoscale 
protective barrier gel that seals the wound and halts bleeding. Once 
the injury heals, the nontoxic gel is broken down into molecules that 
cells can use as building blocks for tissue repair.

"We have found a way to stop bleeding, in less than 15 seconds, that 
could revolutionize bleeding control," said Rutledge Ellis-Behnke, 
research scientist in the MIT Department of Brain and Cognitive 
Sciences.

This study will appear in the online edition of the journal 
Nanomedicine on Oct. 10 at http://www.nanomedjournal.com/inpress. It 
marks the first time that nanotechnology has been used to achieve 
complete hemostasis, the process of halting bleeding from a damaged 
blood vessel.

Doctors currently have few effective methods to stop bleeding without 
causing other damage. More than 57 million Americans undergo 
nonelective surgery each year, and as much as 50 percent of surgical 
time is spent working to control bleeding. Current tools used to stop 
bleeding include clamps, pressure, cauterization, vasoconstriction 
and sponges.

In their experiments on hamsters and rats, the MIT and HKU 
researchers applied the clear liquid containing short peptides to 
open wounds in several different types of tissue - brain, liver, 
skin, spinal cord and intestine.

"In almost every one of the cases, we were able to immediately stop 
the bleeding," said Ellis-Behnke, the lead author of the study.

Earlier this year, the same researchers reported that a similar 
liquid was able to partially restore sight in hamsters that had had 
their visual tract severed. In that case, the self-assembling 
peptides served as an internal matrix on which brain cells could 
regrow.

While experimenting with the liquid during brain surgery, the 
researchers discovered that some of the peptides could also stop 
bleeding, Ellis-Behnke said. He foresees that the material could be 
of great use during surgery, especially surgery that is done in a 
messy environment such as a battlefield. A fast and reliable way to 
stop bleeding during surgery would allow surgeons better access and 
better visibility during the operation.

"The time to perform an operation could potentially be reduced by up 
to 50 percent," said Ellis-Behnke.

Unlike some methods now used for hemostasis, the new materials can be 
used in a wet environment. And unlike some other agents, it does not 
induce an immune response in the animals being treated.

When the solution containing the peptides is applied to bleeding 
wounds, the peptides self-assemble into a gel that essentially seals 
over the wound, without harming the nearby cells. Even after excess 
gel is removed, the wound remains sealed. The gel eventually breaks 
down into amino acids, the building blocks for proteins, which can be 
used by surrounding cells.

The exact mechanism of the solutions' action is still unknown, but 
the researchers believe the peptides interact with the extracellular 
matrix surrounding the cells. "It is a completely new way to stop 
bleeding; whether it produces a physical barrier is unclear at this 
time," Ellis-Behnke said.


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Written by Anne Trafton, MIT News Office