ATLANTA – Can the key to reducing hemorrhaging in a wounded patient be found in a single strand of hair? A group of researchers from Wake Forest Institute for Regenerative Medicine (Winston-Salem, North Carolina) are in the process of testing that theory and displayed their findings at the Society for Biomaterials (Mount Laurel, New Jersey) Translational Research Symposium held at the Hyatt this past weekend.
What researchers have found is that a keratin biomaterial gel derived from human hair can effectively stop hemorrhaging in an acute liver hemorrhage model. Keratin is an extremely strong protein which is a major component in skin, hair, nails, hooves, horns, and teeth. The amino acids which combine to form keratin have several unique properties, and depending on the levels of the various amino acids, keratin can be inflexible and hard, like hooves, or soft, as is the case with skin.
To extract the gel, the hair is oxidized and sits out at night to gel. The result is keratin which has hemostatic properties.
"Rapid voluminous hemorrhage instigates a cascade of events that are difficult to reverse in the absence of advanced medical care," said Luke Burnett PhD, a member of the research team developing this process. "First responders often arrive at scenes of traumatic injury well beyond the point when the transfusion trigger has been reached and they are unable to implement life saving measures."
He added that "On the battlefield, ballistic injuries often result in death within the first hour. Currently tourniquets and hemostatic agents can be used by those in the field but these technologies have limitations that don't address the many unique demands of administering aid at the point of injury."
Usually a hemostatic dressing for first responders should be easy to transport and to store, while also being able to be used by non medical personnel on the injured. "The beauty is its biodegrable," Burnett told the audience. "It forms a thick coating that can be scraped off and it's pretty tough and resilient."
Burnett played a brief film to demonstrate how the gel worked. The blackish pellet-like substance was applied to a rabbits liver. Within minutes (according to Burnett) the blood had stopped clotting and "As you can see blood loss decreases dramatically and in as little as five minutes," Burnett said.
Keratin also has a great deal of regenerative properties.
Using a variety of in vitro assays the research team found that keratins increase Schwann cell proliferation, migration and attachment. In addition, keratins have the ability to self-assemble into fibrous and highly porous scaffolds suitable for cell infiltration and axonal growth. To determine whether a keratin hydrogel scaffold could facilitate functional nerve regeneration in vivo, a tibial nerve axotomy mouse model was employed.
The laboratory studies showed that keratin actually sped up nerve regeneration. The research team used a keratin-filled tube to attempt to repair a 4 mm nerve gap in mice. The results from these animals were compared with animals treated with an empty nerve guidance conduit and with animals treated with a nerve graft.
After a month 100% of the animals in the keratin and nerve graft groups showed visible nerve regeneration across the gap, compared to only 50% who got the empty conduit. The speed of repair was best in the keratin group.
To date the application has only been used on rats, rabbits and pigs. It is nowhere close to being perfected to be used in humans.
"More studies are needed to obtain statistical data and to test the efficacy of Keratin in a model with a vascular size similar to humans," he said.
When and if the application ever makes it to market it will go head to head with other established hemostatic therapies such as HemCon Medical Technologies' (Portland, Oregon) HemCon Bandages and ChitoFlex dressings that are used by military and medical first responders as well as healthcare professionals around the globe. In May Hemcon teamed up with SanguiBioTech's (Witten, Germany) ChitoSkin technology platform to help further innovations in hemostatic bandages and wound care dressings for the acute care market (Medical Device Daily, May 29, 2008).
Z-Medica (Wallingford, Connecticut) makes hemostatic products as well with a QuikClot NoseBleed application, a product used to stop nasal bleeding.