About 25 percent of battlefield casualties are medically preventable, according to the Army Institute of Surgical Research. But what if there was something that could buy that wounded soldier time? One local company is working on doing just that.

In the pretend world of video games like Halo, humans battling aliens can sustain life-threatening wounds. That’s when you reach into your first-aid kit and inject yourself with a material called “biofoam.” Upon contact, this foam stops bleeding and keeps organs intact. Sounds impossible, right? Not for Watertown-based biomedical company Arsenal Medical, who is working on a real-life version of biofoam.

CEO Duke Collier and his team at Arsenal are in the business of buying time for those on the battlefield.

“We talk to the medics a lot and they talk about things like stuffing dirt up into wounds — anything they can think of to try and stabilize the patient,” Collier said.

Arsenal Medical has received a $15.5 million grant from the Defense Advanced Research Projects Agency —or DARPA, to develop an injectable foam that would be used in the battlefield to stop internal bleeding in the abdominal cavity.

Not your average foam

Upma Sharma, the head of foam technology at Arsenal, said this foam could prevent thousands of casualties.

“Liver injuries, gunshots to the liver are quite common,” Sharma said. “And right now there’s nothing you can do.”

Which means too many soldiers are bleeding to death from an injury that is easily fixable if they reach a surgeon sooner, or have some kind of intervention to stop the bleeding. Just ask David King, a trauma surgeon at Massachusetts General Hospital and the U.S. Army.

Ask the doctor

“The most frustrating thing is when you operate on those patients and you realize that the injury they have is easily surgically correctable and you correct it," King said. "But they’ve just been down too long already, and there’s no way to bring them back.”

King has worked in various emergency care conditions in Iraq and Afghanistan — from a sprawling military hospital in Baghdad to a small, mobile surgical unit in the middle of the desert. But regardless of how sophisticated or austere the hospital setting, King says a key factor in a soldier’s survivability is time. That’s where Arsenal’s injectable foam comes in.

“In the case of the polymer, it’s trying to convert those potentially salvageable deaths into survivors so they can arrive alive to a surgeon-- so they have a chance at getting their injury fixed,” King said. “Surgeons -- particularly combat surgeons -- have been looking for this kind of solution for a long time.”

King is advising the team at Arsenal Medical on the conditions they need to consider — the foam injector has to be small, portable, and fit in an Army medic’s kit. It has to withstand extreme temperatures, and be easy to use -- so easy that the medic doesn’t have to think too hard about assembling the device in the middle of combat — right before he injects it into the wounded soldier’s belly button. That’s right—the belly button, because as Duke Collier points out—it’s an easy entry because everyone has one.

“We’re going to go into the body at the same place every time but the wound could be anywhere in the abdomen,” Collier said. “It’s a very fancy caulking gun at one level.”

So how does it work?

Two separate solutions are loaded into what looks like a double-barreled caulking gun. The solutions mix when injected, and once the foam is inside, it expands inside the entire abdominal cavity and solidifies to a consistency that resembles a mattress foam topper. This blocks any blood from seeping out from the injury, potentially buying a soldier an hour -- maybe upwards of three hours -- until he or she is transported to a field hospital for surgery. But unlike the biofoam in the Halo videogame, it’s not meant to stay inside forever. After all, it’s a polymer and has to be removed.

Sharma said the only way to get it out is surgery.

“So you create an incision and then remove the foam," Sharma said. "That incision is going to be required anyway because of whatever repair you have to do for the person because of the severe injury. And then the foam comes out in a single piece. We compare the adhesion to a Post-It note. It comes right out.”

Not your average ham

So who on the Arsenal team is testing the foam out? Pigs. At MGH’s Knight Surgical Research Lab, Arsenal is using pigs because they are similar in size to humans. And the results have been good, with a high survivability rate of 75 percent to 80 percent. Arsenal’s next step is to begin discussions with the U.S. Food and Drug Administration, hopefully within the next few months, Collier said.

“Obviously, the Army feels enormous pressure to get this into the hands of medics," Collier said. "But the Army also feels enormous pressure to do it in a responsible way.”

Once the foam is in the kits of military medics, the next step is to place it in the hands of paramedics and first responders in our neighborhoods — a far-reaching goal for now, but not far-fetched.