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Caterpillars can stop their bleeding and seal wounds in seconds

Meet the tobacco hornworm, a green caterpillar you might not find pretty, but its blood characteristics will surprise you. This caterpillar is a wound-healing wonder that can stop itself from bleeding with incredible speed, sealing up wounds in less than a minute.

Scientists have finally figured out how, and their discoveries could revolutionize the way we think about emergency blood clotting treatments.

Hemolymph: Caterpillar blood

Humans have blood. Insects sport a similar fluid known as hemolymph. Both are essential, circulating nutrients and crucial substances throughout the body. Yet, this is where their common ground largely ends.

Our blood boasts a rich composition, teeming with red blood cells and platelets. These components are vital for clotting, a natural defense against bleeding out from injuries.

On the flip side, insects navigate through life with a distinct setup. Their hemolymph lacks the red blood cells and platelets found in humans. Instead, it contains hemocytes. These cells are the insects’ multitaskers. They play a pivotal role in the immune system, combating infections and ensuring the insect remains healthy.

But their abilities stretch beyond defense against microbes. Hemocytes have another, equally crucial function. They’re key players in repairing damage. When an insect gets hurt, hemocytes spring into action. They converge at the injury site, working together to form a patch. This process is fast and efficient, sealing the wound and preventing further harm.

How caterpillars stop the bleeding

“These caterpillars, called tobacco hornworms, can seal the wounds in a minute,” said Dr. Konstantin Kornev, a professor specializing in materials science at Clemson University. So, how do they do it?

Here’s the step-by-step:

Insect hemolymph is typically watery. Yet, once it exits the body, an extraordinary transformation occurs. It morphs into a viscoelastic material. Imagine it becoming slimy and stretchable. “A good example of a viscoelastic fluid is saliva,” said Dr. Kornev.

“When you smear a drop between your fingers, it behaves like water: materials scientists will say it is purely viscous. But thanks to very large molecules called mucins in it, saliva forms a bridge when you move your fingers apart. Therefore, it’s properly called viscoelastic: viscous when you shear it and elastic when you stretch it.”

Then, the hemocytes spring into action. They converge on the injury, clustering to form a barrier atop the now gooey hemolymph. As time passes, this barrier crystallizes into a crust, effectively sealing the cut. This process is vital for an insect’s survival, preventing excessive loss of hemolymph and warding off infections.

Benefits of caterpillar blood

“Turning hemolymph into a viscoelastic fluid appears to help caterpillars and cockroaches to stop any bleeding, by retracting dripping droplets back to the wound in a few seconds,” explained Dr. Kornev.

“We conclude that their hemolymph has an extraordinary ability to instantaneously change its material properties. Unlike silk-producing insects and spiders, which have a special organ for making fibers, these insects can make hemolymph filaments at any location upon wounding.”

Why should we pay attention to caterpillar bleeding?

“Our discoveries open the door for designing fast-working thickeners of human blood,” explained Dr. Kornev. “We needn’t necessarily copy the exact biochemistry, but should focus on designing drugs that could turn blood into a viscoelastic material that stops bleeding.”

Imagine paramedics having access to a medicine that could temporarily thicken blood at the site of an injury. This could buy precious time for someone seriously hurt or even increase survival rates during complex surgeries.

Beyond emergency care, the study of caterpillar blood clotting mechanisms offers exciting possibilities for various medical fields. Here are a few applications:

Wound healing

Faster, controlled clotting can significantly enhance wound healing. For patients with chronic wounds or those recovering from surgery, a drug mimicking caterpillar hemolymph could speed up the healing process.

Hemophilia treatment

Individuals with hemophilia, a disorder that impairs blood clotting, could benefit immensely. A treatment derived from these findings might offer them a safer, more natural way to manage their condition, reducing the risk of bleeding episodes.

Cancer surgery

In cancer surgeries, precise blood management is crucial. A viscoelastic blood thickener could help surgeons operate more effectively, minimizing blood loss while excising tumors.

Transplant procedures

During organ transplants, managing the recipient’s blood properties is vital. This technology could stabilize patients, ensuring their bodies are in optimal condition to receive new organs.

Military medicine

In battlefield conditions, where rapid medical response is essential, such a drug could save lives. Medics could administer it to stabilize injured soldiers before evacuation, increasing survival rates in combat zones.

More about the tobacco hornworm

The tobacco hornworm, known scientifically as Manduca sexta, is a fascinating creature. It’s the larval stage of the Carolina sphinx moth. These caterpillars are easily recognized by their vibrant green color and the characteristic horn-like spike on their rear end.

Primarily, they feed on tobacco and tomato plants, which is where their name originates. Gardeners often find them munching on leaves, making them notorious pests in vegetable gardens. Yet, despite their bad reputation among gardeners, these caterpillars play a crucial role in the study of insect biology.

Tobacco hornworms grow rapidly, thanks to their high-protein diet of leaf material. This growth makes them an ideal subject for scientific research. Scientists study them to understand more about insect metabolism, physiology, and development. Additionally, their large size, reaching up to 10 centimeters in length, allows for easier handling and examination in laboratory settings.

Interestingly, when it’s time to pupate, the tobacco hornworm burrows into the ground. It transforms into a pupa, the stage before emerging as a Carolina sphinx moth. This metamorphosis is a stunning example of insect development and adaptation.

Moreover, researchers are fascinated by the hornworm’s defense mechanisms. Apart from their cryptic green coloration that camouflages them among leaves, they have a unique ability to metabolize nicotine from tobacco leaves. They convert it into a toxic compound, deterring predators.

Lessons from caterpillars

This study is a reminder that nature has a knack for finding elegant ways to overcome challenges. We humans are pretty smart, but sometimes the best solutions come from the unlikeliest places.

By paying close attention to the natural world – even the squirmy, crawly bits – we might unlock life-saving innovations we haven’t even imagined yet. From blood-stopping caterpillars to life-changing medicine, the possibilities are thrilling.

The study is published in the journal Frontiers in Soft Matter.


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