Natural superglue slime shot decoded as prey

Animal superglue decrypted
Scientists at the University of Kassel have decoded the mode of action of a recyclable, animal superglue. The secretion of the so-called stub foot could be the template for the development of novel biomaterials for the medical and sustainable industries.

In a study that has now been published in the renowned journal Nature Communications, an international team of researchers led by Prof. Dr. Ing. Georg Mayer, Head of the Department of Zoology, and his colleague Alexander Bär, the operation and the structure of a glandular secret of an Australian stub-footed species. The over 300 million year old stubborn (onychophore) catches their prey using a fast and extremely tough sticky mucus, which the animals shoot from paired, specialized nozzles on the head.

Gland secretions of an Australian stub foot type decrypted. Image: Kzenon-fotolia

According to the investigations, the mucus of the stub-footed species Euperipatoides rowelli consists of tiny, uniformly sized, globular fat-protein structures. Upon touching the slime, these nano-spheres deform by shear forces and stiffen to microfibers from a tensile protein core and a sticky surface. As a result, the secretion adheres strongly and in a matter of seconds on almost all surfaces. However, if the bio-adhesive is exposed to water for a long time, the polymers dissolve again. As the original nano-globules regress, the secretion could be reused.

"To our surprise, we found a kind of reusable animal glue," says Mayer. "Our study provides important information on how recyclable polymers are formed in nature in a way never before known. An even better understanding of how these physicochemical processes work opens up interesting perspectives, especially in the area of ​​surgical medicine, but also for sustainable industrial polymer production. "The next goal of the researchers is now to synthetically replicate the bio-superglue.

In their experiments, the mucus of the onychophores was first collected. This was then examined for its structure and composition during microfiber formation. In addition to their experiments, researchers also used high-speed imaging.

The study, funded mainly by the German Research Foundation (DFG), also involved researchers from the Heinrich Heine University in Düsseldorf, the Max Planck Institute for Colloids and Interfaces in Potsdam, and McGill University in Montreal, Canada.

The onychophores, translated claw bearers, are invertebrates and resemble worm-shaped caterpillars with short legs and paired antennae. From two openings on the so-called mucus papillae next to the mouth, the animals, some of them up to 22 cm in size, emit a strongly adhesive weir secretion, which serves for defense and prey. They live mainly in the southern hemisphere and around the equator. So far, about 200 species are known and registered, but there are probably several thousand. The stubby feet live mainly in deadwood or in the Spreuschicht the forest floor. (Sb, pm)