Biomimicry, which involves creating solutions inspired by nature, has led to some incredible innovations in recent years. Now, researchers and engineers at the Massachusetts Institute of Technology (MIT) have designed a strong, biocompatible glue that can seal injured tissues and stop bleeding.
The new paste, inspired by the sticky substance that barnacles use to cling to rocks, can adhere to a surface even if it’s covered with blood, and can form a tight seal within about 15 seconds of application, an MIT news release explains. The researchers say such a glue could offer a much more effective way of treating traumatic injuries and help control bleeding during surgery.
Xuanhe Zhao, a professor of mechanical engineering and civil and environmental engineering at MIT, said the researchers are solving an adhesion problem in a “challenging environment” -- in the wet, dynamic environment of human tissues. “At the same time, we are trying to translate this fundamental knowledge into real products that can save lives,” said Zhao, one of the senior authors of the study, which appeared in the journal Nature Biomedical Engineering earlier this week.
Zhao explains in the release that finding ways to stop bleeding is a long-standing issue that has not been adequately solved. “Among members of the military, blood loss is the leading cause of death following a traumatic injury, and among the general population, it is the second leading cause of death following a traumatic injury,” the release adds.
While materials like hemostatic agents, that can stop the bleeding, have become commercially available in recent years, many of these consist of patches that contain clotting factors, which help blood to clot on its own. “However, these require several minutes to form a seal and don’t always work on wounds that are bleeding profusely,” the release explains.
Two years ago, Zhao’s lab had designed a double-sided tissue tape that could be used to close surgical incisions. This tape was inspired by the sticky material used by spiders to capture their prey in wet conditions. To make this new glue, the researchers turned their focus to barnacles. These small crustaceans attach themselves to rocks, ship hulls, and even other marine animals such as whales. These surfaces are wet and often dirty — conditions that make adhesion difficult, the release adds.
“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,” MIT research scientist and one of the lead authors of the study Hyunwoo Yuk explains. “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.”
When they analysed the barnacle glue, they discovered it had a unique composition: with sticky protein molecules and an oil-like substance. The MIT team decided to try to mimic this glue by adapting an adhesive they had previously developed, the release explains: “This sticky material consists of a polymer called poly(acrylic acid) embedded with an organic compound called an NHS ester, which provides adhesion, and chitosan, a sugar that strengthens the material. The researchers froze sheets of this material, ground it into microparticles, and then suspended those particles in medical grade silicone oil.”
In tests, the researchers were able to show that when this paste is applied to a wet surface, such as blood-covered tissue, the oil repels the blood and other substances that may be present, allowing the adhesive microparticles to crosslink and form a tight seal over the wound. One of the advantages of this new glue is that it is moldable and can be applied to a wound of any shape, a feature that was not possible with the previously-designed double-sided tape.
According to the release, the researchers are hoping this material can be used not only to treat traumatic injuries, but also in surgical procedures where controlling the bleeding is of utmost importance. They are now working on commercializing the glue, after a few more preclinical tests are concluded.