Slime slime can stick wounds more securely with fewer scars

Viscous slime could create stronger glue to prevent scars and infections in surgery, scientists suggest.

Defensive mud is produced by a common garden slug found in the UK to foul the jaws of any potential predator.

The Dusky Arion slug, up to seven centimeters long, can be found in Britain's gardens, but it also produces a drool that can be used to help wounds heal.

Two studies have now provided a better understanding of how this glue achieved its high stickiness and flexibility, information that could be used to create better medical adhesives.

The stitches are strong but leave scars and can increase the risk of infection, and most medical adhesives are too weak or too rigid to keep wounds closed – but slime mud may be the solution

Undergraduate researcher Rebecca Falconer of Ithaca College in New York conducted the first study on possible medical uses of slime.

She said, "Typical sutures, such as staples and stitches, often result in scarring and holes in the skin that can increase the risk of infection after surgery.

"Understanding the role of adhesive proteins in slug glue would help create a medical adhesive that can move and stretch while retaining its strength and adhesive power."

Falconer analyzed 11 proteins created in the silt of the slug Dusky Arion and discovered that some proteins can bind together to form a strong and flexible three-dimensional network.

Christopher Gallego-Lazo, also an undergraduate researcher in Professor Andrew Smith's laboratory, has expanded his work. He studies the nature of adhesive secretions from a variety of molluscs.

Mr. Gallego-Lazo found that the double network structure that makes slug glue is incredibly strong and can withstand strong forces.

The glue has a rigid protein network that uses sacrificial bonds to absorb energy and protect an interwoven and deformable carbohydrate network.

Gallego-Lazo discovered that the strength of the slim can be adapted by modifying some of the chemical bonds within the protein network.

These bonds can be reformed naturally, allowing the glue to deform while maintaining its strength.

He said: "Few studies on biological adhesives have identified the exact nature of the bonds binding the glue.

"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 quickly and simply."

Professor Smith explained that slime muds are gels, made up of "a tangled web of diluted polymers".

He said: "These adhesives are not really strong, nor a cement, nor a fluid, like water under a sucker.

"For lack of a better term, they are often referred to as mucus.

The structure of these gels, however, varies greatly and the generic term "mucus" is probably inappropriate.

"The function of these gels also varies a lot. Some gels are exceptional lubricants. Some are excellent adhesives.

"Curiously, it appears that many molluscs can convert a slippery gel into a powerful adhesive.

"We therefore compare the structure of different adhesive gels in order to determine the functional significance of the structural features."

The results were presented at the annual meeting of the American Society of Biochemistry and Molecular Biology at the 2019 Experimental Biology Meeting in Orlando.