MIT engineers designed a powerful, biocompatible glue that can seal injured tissue and stop bleeding, inspired by the sticky substance that barnacles use to stick to rocks. Credit: stock photos
A new adhesive that mimics the sticky substance used by barnacles to stick to rocks may provide a better way to treat trauma.
Inspired by the sticky substance that barnacles use to stick to rocks, MIT engineers designed a powerful biocompatible glue that can seal injured tissue and stop bleeding.
Even if the surface is covered by blood, this new paste can adhere to the surface and can form a tight seal within about 15 seconds after application. Researchers say that this glue can provide a more effective way to treat trauma and help control bleeding during surgery.
“We are solving the problem of adhesion in a challenging environment, that is, the humid, dynamic environment of human tissues. At the same time, we are trying to transform these basic knowledge into real products that can save lives,” MIT Machinery Said Zhao Xuanhe, a professor of engineering and civil and environmental engineering and one of the senior authors of the study.
Christoph Nabzdyk is a cardiac anesthesiologist and intensive care physician at the Mayo Clinic in Rochester, Minnesota, and the senior author of the paper, which was published in Nature Biomedical Engineering on August 9, 2021. MIT research scientist Hyunwoo Yuk and postdoctoral fellow Jingjing Wu are the main authors of the study.
Research group: Hyunwoo Yuk, Jingjing Wu, Xuanhe Zhao (from left to right), holding barnacle shell and barnacle gum hemostatic ointment in their hands. Credit: Provided by researcher
Finding a way to stop bleeding is a long-standing problem, but it has not yet been fully resolved, Zhao said. Sutures are usually used to close wounds, but sutures are a time-consuming process that first responders usually cannot do in an emergency. Among soldiers, blood loss is the leading cause of death after trauma, while in the general population, blood loss is the second leading cause of death after trauma.
In recent years, some materials that can stop bleeding, also called hemostatic agents, have been on the market. Many of these consist of patches containing clotting factors that help blood clot on its own. However, these take several minutes to form a seal and do not always work on heavily bleeding wounds.
Zhao’s laboratory has been committed to solving this problem for many years. In 2019, his team developed a double-sided tissue tape and showed that it can be used to close surgical incisions. This tape is inspired by the sticky material used by spiders to catch prey in humid conditions. It contains charged polysaccharides that can absorb water from the surface almost immediately, removing small dry spots that glue can stick to.
For their new tissue glue, the researchers once again drew inspiration from nature. This time, they focused their attention on barnacles, which are small crustaceans attached to other animals such as rocks, boat hulls and even whales. These surfaces are moist and usually very dirty-these conditions make adhesion difficult.
“This caught our attention,” Yuk said. “This is very interesting, because to seal the bleeding tissue, you have to deal with not only the moisture, but also the pollution of the blood flowing out. We found that this creature living in the marine environment is doing exactly the same thing that we have to do to deal with it. Complex bleeding problems.”
Researchers’ analysis of barnacle gum shows that it has a unique composition. The sticky protein molecules that help the barnacle attach to the surface are suspended in a kind of oil, which can repel water and any contaminants found on the surface, so that the sticky protein is firmly attached to the surface.
The MIT team decided to try to imitate this glue by adjusting the adhesive they had previously developed. This viscous material consists of a polymer called poly(acrylic acid) into which an organic compound called NHS ester is embedded to provide adhesion, while chitosan is a sugar that reinforces the material. Researchers freeze flakes of this material, grind them into particles, and then suspend these particles in medical-grade silicone oil.
When the resulting paste is applied to a wet surface (such as tissue covered with blood), the oil will repel blood and other substances that may be present, causing the viscous particles to crosslink and form a tight seal on the wound. Researchers’ tests on mice showed that within 15 to 30 seconds after applying the glue, gently applying pressure, the glue solidified and stopped bleeding.
The researchers said that compared to the double-sided tape designed by the researchers in 2019, one advantage of this new material is that the paste can be molded to fit irregular wounds, and the tape may be more suitable for sealing surgery Make an incision or attach a medical device to the tissue. “The moldable paste can flow into and fit any irregular shape and seal,” Wu said. “This allows users to freely adapt to various irregularly shaped bleeding wounds.”
In tests conducted on pigs, Nabzdyk and his colleagues at the Mayo Clinic found that this glue can stop bleeding quickly, and that it works faster and more effectively than the commercially available hemostatic agent they compared. It can even work when giving pigs a powerful blood thinner (heparin) so that the blood does not form clots spontaneously.
Their research shows that the seal remains intact for several weeks, allowing time for the tissue to heal on its own, and the glue causes little inflammation, similar to the inflammation caused by the hemostatic agents currently used. The glue will be slowly absorbed in the body within a few months. If the surgeon needs to repair the wound after the initial application, it can also be removed in advance by using a solution that dissolves it.
The researchers now plan to test the glue on larger wounds, and they hope this will prove that the glue can be used to treat trauma. They also envisioned that it might be useful during surgery, which usually requires the surgeon to spend a lot of time controlling bleeding.
“We are technically capable of performing many complex surgeries, but our ability to quickly control particularly severe bleeding has not really improved,” Nabzdyk said.
Another possible application is to help stop bleeding. These patients have plastic tubes inserted into their blood vessels, such as those used for arterial or central venous catheters or extracorporeal membrane oxygenation (ECMO). During ECMO, a machine is used to pump the patient’s blood out of the body to oxygenate it. It is used to treat people with severe heart or lung failure. The tube is usually inserted for several weeks or months, and bleeding at the insertion site can cause infection.
Reference: “Paste inspired by barnacle gum for rapid and coagulation-independent hemostatic sealing” Authors: Hyunwoo Yuk, Jingjing Wu, Tiffany L. Sarrafian, Xinyu Mao, Claudia E. Varela, Ellen T. Roche, Leigh G. Griffiths, Christoph S. Nabzdyk and Xuanhe Zhao, 9 August 2021, Nature Biomedical Engineering.DOI: 10.1038/s41551-021-00769-y
The researchers have received funding from the MIT Deshpande Center to help them commercialize the glue, which they hope to achieve after additional preclinical studies on animal models. The research also received funding from the National Institutes of Health, the National Science Foundation, and the Office of Army Research through the Soldier Nanotechnology Institute at the Massachusetts Institute of Technology and the Zoll Foundation.
Please, please commercialize it as soon as possible. My wife sealed my wound with glue. Sting like hell. Well, maybe I am a baby, as she said every time she applied.
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