New gel to stop wounds from bleeding

Washington: Scientists have developed a new injectable polymer material that encourages faster, more durable blood clotting at wound sites to stop bleeding following life-threatening injuries.

The polymer could become a first line of defence in everything from battlefield injuries to rural car accidents to search and rescue missions deep in the mountains, researchers said.

Developed by the University of Washington researchers, the polymer called PolySTAT strengthens blood clots.

Administered in a simple shot, the polymer finds any unseen or internal injuries and starts working immediately.

It has been tested in rats, and researchers say it could reach human trials in five years.

In the initial study with rats, 100 per cent of animals injected with PolySTAT survived a typically-lethal injury to the femoral artery. Only 20 per cent of rats treated with a natural protein that helps blood clot survived.

"Most of the patients who die from bleeding die quickly," said co-author Dr Nathan White, an assistant professor of emergency medicine.

"This is something you could potentially put in a syringe inside a backpack and give right away to reduce blood loss and keep people alive long enough to make it to medical care," he said.

The UW team was inspired by factor XIII, a natural protein found in the body that helps strengthen blood clots.

Both PolySTAT and factor XIII strengthen clots by binding fibrin strands together and adding "cross-links" that reinforce the latticework of that natural bandage.

But the synthetic PolySTAT offers greater protection against natural enzymes that dissolve blood clots. Those help during the healing process, but they work against doctors trying to keep patients from bleeding to death.

The enzymes, which cut fibrin strands, don't target the synthetic PolySTAT bonds that are integrated into the clot. That helps keep the blood clots intact in the critical hours after an injury.

"We were really testing how robust the clots were that formed," said lead author Leslie Chan, a UW doctoral student in bioengineering.

"The animals injected with PolySTAT bled much less, and 100 per cent of them lived," said Chan.

The research was published in the journal Science Translational Medicine.