Traumatic blood loss is the main killer of emergency room patients, and it is relatively easy to treat in hospital settings. The problem is that it can happen suddenly, and first responders don’t have the tools like the emergency room. Now, scientists at Harvard University have developed a new blood clotting material that is portable and easy to store, potentially helping people survive long enough to reach the hospital.
In the human body, platelets are specialized cells that circulate in the blood and are always alert to damage that can lead to bleeding. When they find a wound, they activate and rush to the injured area to trigger a blood clot. This is an important biological process that keeps us from bleeding to death from every small wound and bruise.
But the effectiveness of natural processes for more serious injuries is limited. In a hospital environment, doctors can use clotting agents, including donated platelets, to help with the process. Unfortunately, this type of treatment needs to be refrigerated, and even this does not last long, so it does not allow people to carry them to the site where they are most needed.
“Our goal is to provide first responders with a tool to stop internal bleeding that can be easily stored in a backpack or stored in an ambulance, and once given intravenously in a bleeding patient, it can stop the internal bleeding for long enough to take the patient to the hospital,” said Samir Mitragotri, senior author of the study.
The Harvard team’s solution is a clotting agent that can be injected into the blood, freeze-drying, giving it marshmallow-like consistency and being stored at room temperature for months at a time. When needed, it can be combined with physiological saline and can be injected at any time.
The researchers call their creation saucy, an acronym for Hemostatic Agents via Polymer Peptide Interfusion. It binds to activated platelets at the injured site, helping more platelets gather there. Since it binds only to activated platelets, not those that roam in the blood, HAPPI can inject it anywhere in the body and only help clot at the wound.
In tests on mice, the team found that HAPPI was able to reduce bleeding time by 99 percent and blood loss by 97 percent. In the case of trauma, the material can increase the median survival rate to more than one hour, which is enough to allow medical staff to take the injured patient to hospital for further treatment.
“A lot of trauma-related deaths occur within the first hour, when there is a lot of blood loss and no intervention,” said Gao Yongsheng, a postdoctoral research assistant at SEAS and co-lead author of the paper. “A key goal for first responders is to keep trauma patients alive in this so-called prime time and to take them to the hospital during that time, because once they get to the hospital, it’s a completely different state.”
The team says the next step is to scale up the production of materials made for THE HAPPI and test it on larger animals.
Other similar clotting agents are also under study, including a clotting agent made from snake venom that can be injected into the wound site, and a form of binding to fibrin to strengthen blood clots in a manner similar to WHEREe’s binding to platelets.
The study was published in the journal Science Advances.