Scientists have developed a super strong, flexible adhesive material inspired by the glue secreted by slugs that stick to biological tissues – even when wet – without causing toxicity. Slugs secrete a special kind of mucus when threatened that glue it in place, making it difficult for a predator to pry it off its surface.
The new material is a double- layered hydrogel consisting of an alginate-polyacrylamide matrix supporting an adhesive layer that has positively- charged polymers protruding from its surface.
The polymers bond to biological tissues via three mechanisms – electrostatic attraction to negatively charged cell surfaces, covalent bonds between neighbouring atoms, and physical interpenetration – making the adhesive extremely strong.
The key feature of the new material is the combination of a very strong adhesive force and the ability to transfer and dissipate stress, which has historically not been integrated into a single adhesive.
The “tough adhesive” is biocompatible and binds to tissues with a strength comparable to the body’s own resilient cartilage.
It also causes no tissue damage or adhesions to surrounding tissues.
Such a high-performance material has numerous potential applications in the medical field, either as a patch that can be cut to desired sizes and applied to tissue surfaces or as an injectable solution for deeper injuries.