The Tungara frog, aka Engystomops pustulosus When the tiny Tungara frog lays its eggs, it also secretes a protein cocktail that it beats into a foam using its back legs. Surrounding the eggs, that foam protects them from predators, germs and environmental stress. As it turns out, a synthetic version of the substance may also one day have another use – delivering medication to serious skin wounds. Led by Dr. Paul Hoskisson, a team from the University of Strathclyde has discovered that the natural version of the foam is not only highly stable and long-lasting, but also capable of taking up and then releasing pharmaceuticals. In lab tests, it was able to release dyes steadily for 72 to 168 hours. More relevantly, it was also able to release the antibiotic vancomycin for 48 hours, preventing growth of the pathogenic bacterium Staphylococcus aureus as it did so. Importantly, the non-toxic foam also caused no harm to human keratinocytes (skin cells), even after they were exposed to it for a period of 24 hours. Given that harvesting the foam from frogs could be just a little impractical, the researchers are now looking at recreating it in the lab. Already, they've successfully engineered E. coli bacteria to produce two of its main proteins. Ultimately, it is hoped that a completely synthetic version could be used topically on wounds such as severe burns, releasing a consistent stream of antibiotics. "Foams are usually very short-lived so they're not considered for long-term drug release, even though they have great potential for topical treatments," says researcher Sarah Brozio. "This foam comes from a tiny frog and yet offers us a whole new approach that could prevent wound infections, and with increasing antibiotic resistance it's important that all new tactics are explored." Source
