thedrifter
02-09-07, 12:49 PM
Shell-based blood clotter works without heat
By Kelly Kennedy - Staff writer
Posted : Friday Feb 9, 2007 9:54:34 EST
A scientist walking down a beach in Washington state noticed lots of crabs with no legs — but none of them showed any signs of bleeding.
Most animals that lose a limb tend to bleed again after the initial injury, so the scientist wondered why the crabs had such clean wounds.
The answer: Most animals don’t have shells.
“It was the chitosan in the shells,” explained Limor Shemer, chief executive officer for SAM Medical Products. “It stopped the bleeding.”
The crustaceans’ natural body armor now serves a similar purpose for soldiers and Marines in Iraq and Afghanistan through a new quick-clot agent, Shemer said.
“The feedback’s been very positive,” she said. “It works regardless of temperature, and it doesn’t heat up.”
Unlike other quick-clot products troops have been using in the battle zone, the seashell product — called Celox — doesn’t depend on the blood’s natural clotting agent to work. Instead, the seashells bind with the person’s blood to create a clot.
That’s important, because other blood-clotting agents, such as QuikClot, need the blood to be a certain temperature. The agents can heat up to temperatures of 230 degrees Fahrenheit — enough to cause a second-degree burn. Celox also can be used on heparinized blood, or blood that has been treated so that it won’t clot on its own.
While HemCon — which is standard issue for troops in combat zones — also uses chitosan, studies have shown it doesn’t work as well to prevent bleeding because it is a dressing. Celox, which comes in granules, is poured directly onto a wound, and therefore works well on deep or arterial wounds, Shemer said.
Scientists at the Portsmouth Naval Center, N.H., applied Celox granules, HemCon bandages or QuikClot granules to pigs with severed blood vessels in their thighs after letting the animals bleed for three minutes. The study found that Celox reduced bleeding to nothing, HemCon to 33 percent and QuikClot to 8 percent, as opposed to a standard dressing, which brought bleeding down by 50 percent.
“Although all three agents were superior to standard dressing with regard to re-bleed, only Celox improved survival in a lethal hemorrhagic groin injury compared to standard dressing,” wrote Lt. Cmdr. Buddy Kozen in a letter about the study.
Celox was approved by the FDA in June, and has been used in the war zones by Special Forces medics since September, Shemer said.
Studies also found that even if Celox gets wet or is kept in humid conditions, it may get clumpy, but it still works. It can also be easily rinsed from the wound, Shemer said.
Ellie
By Kelly Kennedy - Staff writer
Posted : Friday Feb 9, 2007 9:54:34 EST
A scientist walking down a beach in Washington state noticed lots of crabs with no legs — but none of them showed any signs of bleeding.
Most animals that lose a limb tend to bleed again after the initial injury, so the scientist wondered why the crabs had such clean wounds.
The answer: Most animals don’t have shells.
“It was the chitosan in the shells,” explained Limor Shemer, chief executive officer for SAM Medical Products. “It stopped the bleeding.”
The crustaceans’ natural body armor now serves a similar purpose for soldiers and Marines in Iraq and Afghanistan through a new quick-clot agent, Shemer said.
“The feedback’s been very positive,” she said. “It works regardless of temperature, and it doesn’t heat up.”
Unlike other quick-clot products troops have been using in the battle zone, the seashell product — called Celox — doesn’t depend on the blood’s natural clotting agent to work. Instead, the seashells bind with the person’s blood to create a clot.
That’s important, because other blood-clotting agents, such as QuikClot, need the blood to be a certain temperature. The agents can heat up to temperatures of 230 degrees Fahrenheit — enough to cause a second-degree burn. Celox also can be used on heparinized blood, or blood that has been treated so that it won’t clot on its own.
While HemCon — which is standard issue for troops in combat zones — also uses chitosan, studies have shown it doesn’t work as well to prevent bleeding because it is a dressing. Celox, which comes in granules, is poured directly onto a wound, and therefore works well on deep or arterial wounds, Shemer said.
Scientists at the Portsmouth Naval Center, N.H., applied Celox granules, HemCon bandages or QuikClot granules to pigs with severed blood vessels in their thighs after letting the animals bleed for three minutes. The study found that Celox reduced bleeding to nothing, HemCon to 33 percent and QuikClot to 8 percent, as opposed to a standard dressing, which brought bleeding down by 50 percent.
“Although all three agents were superior to standard dressing with regard to re-bleed, only Celox improved survival in a lethal hemorrhagic groin injury compared to standard dressing,” wrote Lt. Cmdr. Buddy Kozen in a letter about the study.
Celox was approved by the FDA in June, and has been used in the war zones by Special Forces medics since September, Shemer said.
Studies also found that even if Celox gets wet or is kept in humid conditions, it may get clumpy, but it still works. It can also be easily rinsed from the wound, Shemer said.
Ellie