The Dusky Arion slug produces a defensive glue that fouls the mouthparts of any potential predator. Two new studies reveal more about how this glue achieves its strong sticking power and flexibility, which could be used to create better medical adhesives.

"Typical sutures like staples and stitches often lead to scarring and create holes in the skin that could increase the chance of infection after surgery," said Rebecca Falconer, one of the researchers. "Understanding the roles of adhesive proteins in the slug glue would aid in the creation of a medical adhesive that can move and stretch yet still retain its strength and adhesiveness."

The findings from the research will be presented at the American Society for Biochemistry and Molecular Biology annual meeting during the 2019 Experimental Biology meeting to be held in April of this year in Florida in the US.

Researchers analysed 11 proteins unique to the slug glue that had been identified from previous studies. Using recombinant DNA technology, they produced large amounts of each protein, a technique that could also be used to reproduce the proteins for a man-made glue.

The analysis revealed that some of the proteins can bind to themselves or with other proteins to form a 3D network. This suggests that this might be a necessary step for the proteins to be functional.  

Researchers also found that changing specific chemical bonds within the slug glue's protein network altered the strength of the glue. These bonds can be reformed naturally, enabling the glue to deform while keeping its strength.

"Few studies on biological adhesives have identified the exact nature of the bonds holding the glue together," said Gallego-Lazo, another researcher. "This knowledge can guide the development of an organic synthetic adhesive that would reduce the risk of infection and scarring compared to stitches and staples and could be applied rapidly and simply."