Researchers have developed a new kind of bandage that helps blood to clot and doesn’t stick to the wound. They tested various superhydrophobic materials — which are, like Teflon, extremely good at repelling liquids such as water and blood. The goal was to find coatings for devices that come into contact with blood; for example, heart-lung machines or artificial heart devices.
One of the materials not only repelled blood but also aided the clotting process. Although this made the material unsuitable for use as a coating for blood pumps and related devices, it was ideally suited for a bandage.
Repelling blood and achieving fast clotting are two different properties that are both beneficial in bandages: blood-repellent bandages do not get soaked with blood and do not adhere to the wound, so they can be removed easily, which avoids secondary bleeding. Substances and materials that promote clotting, on the other hand, are used in medicine to stop bleeding as quickly as possible; however, to date, no materials that simultaneously repel blood and also promote clotting have been available.
The researchers took a conventional cotton gauze and coated it with the new material — a mix of silicone and carbon nanofibers. They were able to show in laboratory tests that blood in contact with the coated gauze clotted in only a few minutes. Exactly why the new material triggers blood clotting is still unclear and requires further research but the team suspects that it is due to the interaction with the carbon nanofibers. They were also able to show that the coated gauze has an antibacterial effect, as bacteria have trouble adhering to its surface.
With the superhydrophobic material, the wound does not reopen when the bandage is changed. Reopening wounds increases the risk of infection including from dangerous hospital germs — a risk that is especially high when changing bandages.