They've started to develop a foam that mixes the clotting agents with carbon dioxide and water. An emergency medic might shoot such a foam into an injured person's abdominal cavity in order to stop internal bleeding immediately. As in Hess' original concept, this powder would dissolve into a wound's moisture and start a clot. Such a tool might prove useful for large wounds or burns. All these applications demand considerable amounts of the clotting agents, and therein lies a challenge.
Scientists now purify the proteins from blood, a process both laborious and expensive.
Although hesitant to make an estimate before manufacturing expenses are known, MacPhee acknowledges that one large fibrin bandage might initially cost several hundred to more than a thousand dollars. To lower that price, the American Red Cross plans to genetically alter animals such as goats or cows so they will secrete large amounts of human fibrinogen or other clotting agents into their milk. Ultimately, says Drohan, the organization would like fibrin bandages to be cheap enough so that an average person can buy at least one for emergency use. Meanwhile, scientists are exploring whether fibrin sealants may have uses beyond halting blood loss. Creating new bone is one possible application.