Stemming the bleeding from a traumatic injury can save lives, but it’s hard to get adhesives to stick when blood is making everything wet. Now, MIT researchers have developed a new surgical glue that can halt bleeding within 30 seconds, inspired by the super-strong underwater adhesive used by barnacles.
Currently, bleeding is most commonly controlled during surgery or traumatic injury with materials called hemostatic agents. These contain factors that induce the blood to clot, but the process can take a few minutes to work and don’t always work if there’s too much blood.
The new glue, however, can seal up a wound in 15 to 30 seconds, the team says. In tests in rats and pigs, the glue stayed in place for weeks at a time, before it is slowly broken down by the body as the tissue heals. That said, if need be it can be removed earlier by applying a solution that dissolves it. The glue also didn’t induce much inflammation around the site as the tissue heals.
“The moldable paste can flow in and fit any irregular shape and seal it,” says Jingjing Wu, lead author of the study. “This gives freedom to the users to adapt it to irregular-shaped bleeding wounds of all kinds.”
The secret ingredient is (as is often the case) one that nature has already perfected. Barnacles are known to firmly attach themselves to rocks, ship hulls and other solid surfaces that are, obviously, wet and often dirty. So the researchers took a page out of their book.
“It's very interesting because to seal bleeding tissues, you have to fight with not only wetness but also the contamination from this outcoming blood,” says Hyunwoo Yuk, lead author of the study. “We found that this creature living in a marine environment is doing exactly the same thing that we have to do to deal with complicated bleeding issues.”
It turns out that barnacles secrete two different liquids to anchor themselves. The first is an oil that repels and displaces water, allowing the second liquid – a protein-based adhesive – a cleaner slate to stick to.
To mimic this stuff, the team built on previous medical adhesives they’ve developed. In 2019 they described a double-sided tape that could replace sutures in sealing a wound or incision in an organ or skin. This time, they froze sheets of their material, ground it into tiny particles then suspended those into a silicone oil.
This has the same effect as the barnacles, as the oil displaces the liquid – in this case blood – from the surface. The microparticles can then crosslink and quickly build up a seal. In their tests, the team found that it worked better than existing hemostatic agents, even stemming the flow of blood in test animals given strong blood thinners to prevent clots.
The team says that the next steps will involve testing the glue on larger wounds. In the longer run, they say that it could allow first responders to stop bleeding in injured patients as soon as they reach them, or for surgeons to more easily control bleeding during procedures.
The research was published in the journal Nature Biomedical Engineering.
Source: MIT