A slug is a mollusk that belongs to the Gastropod class. This unique animal is adapted to life on ground and in the sea. The important role the slug plays cannot be overlooked as it helps in removing dead, decaying plant matter from our natural environment, and it also serves as a source of food for other animals.
The Slime of the Slug
Surgeons, have for long been searching for medical adhesives to assist in surgery and wound repair of body tissues, as many of the glues currently in use are toxic, and do not stick to wet tissues and as such cannot be used internally. Scientists have a found a way to address this issue by studying the slime released by a slug.
When a slug feels threatened, either by a predator or some other natural means, it releases a sticky slime that is strong enough to glue it (the slug) to a wet leaf. This defensive mechanism protects the slug, preventing it from being carried away by its predator. It also gives the slug a limited freedom of movement.
Inspired by this creature, scientists have been able to create a medical glue that is far stronger than the currently available medical adhesives. This glue is sticky, strong, stretchy, non-toxic and also has the ability to stick to a living organ.
The glue that was designed by the scientists is said to have two distinct layers. One layer is a sticky surface containing polymer. The polymers create strong chemical bonds with the underlying tissue, just as the proteins found in the slug’s glue, while the other layer is a strong and stretchable hydrogel.
The secret of the slug’s slime is that it can bond to surfaces in three different ways. It contains a chemical called a primary amine that has a positive charge. When it interacts with tissues and cells which are negatively charged, the two surfaces attract. The material can also bond chemically to tissue, and it can physically bind by intertwining surface proteins.
The strength of this glue was tested against the currently available medical glues, and in all scenarios, were found to be stronger and better that the commercially available medical adhesives. One of such scenarios is when they were tested against moving tissues, like a beating heart.
When tested with a beating heart, the new formulated glue from the slug was found to be stickier than the commercially available medical adhesives.
Even on expansion of the heart, the glue remained stuck as opposed to the commercially available medical adhesives. The researchers also used the glue to seal a hole in the wall of a rat’s liver and it worked perfectly without causing any harm to the rat.
Experts believe that this new formulated glue could become part of every surgeon’s tool kit, making the use of stitches and staples not relevant. Experts also believe that this glue could be used to repair cartilage and to attach medical devices to tissues.
Other Interesting Facts about the Slug
- Slugs do not have shells. Their whole body is strong, muscular foot covered in slime which aids movement on the ground and averts any injury from reaching the slug.
- The slug has two retractable tentacles on the head. An upper and lower tentacle. The lower tentacle is sensitive to smell, while both upper and lower tentacles are sensitive to touch.
- Slugs can grow up to 10inches long, depending on the species.
- Slugs have different colouration, ranging from whitish yellow, grey, brown, or black.
- Slugs possess an organ called a ‘Radula’. The radula is composed of thousands of tiny protrusions that help in grinding food.
- Slugs have the ability to flatten and elongate their body twenty times when they need to enter tiny holes.
- Slugs have the ability to breathe through their skin asides from their lungs.
- Most of the time of a slug is spent in underground tunnels that are moist and cold, surfacing only at night to feed on leaves, seed sprouts, roots and decaying vegetation.
- Slugs are hermaphrodites i.e a typical slug possesses both male and female reproductive organs.
- A slug can lay from 20 – 100 eggs on the surface of the soil, usually under leaves several times a year.
- Incubation period depends on weather conditions. Sometimes eggs hatch after some years of dormancy.
- The survival rate of an average slug in the wild is from 1 – 6 years, with females living longer than the males.