Hemolymph, a blood-like fluid circulating within the hemocoel of invertebrates such as insects, notably lacks red blood cells, hemoglobin, and platelets, and contains amoeboid cells known as hemocytes. These hemolymph possess the ability to clot rapidly ex vivo, thereby stopping bleeding, yet the underlying mechanism has remained elusive. Recently, materials scientists at Clemson University in the United States elucidated the process by which tobacco hornworm caterpillars achieve rapid hemostasis, publishing their findings in the journal Frontiers in Soft Matter on the 27th. This discovery holds potential implications for human medicine, potentially aiding in the development of new drugs for human application.
Tobacco hornworm caterpillars.
Image source: Konstantin Kol'tsov/American Association for the Advancement of Science EurekAlert! website
Tobacco hornworm caterpillars can heal wounds within a minute. They achieve this through two steps: firstly, within about 5 seconds of bleeding, the thin watery lymph becomes viscous and elastic; in the next 10 seconds, there is a significant change in the lymph: instead of instantly dripping, they form a long bridge behind the falling droplet, similar to mucous drawing. Due to elasticity, the lymph dripping from one end recoils back to the wound.
Researchers further used techniques like differential interference contrast and polarized microscopy, X-ray imaging, and materials science modeling to study the cellular process of blood cell aggregation forming a clot at the wound. They found that the clotting process in 18 other insect species is similar.
This discovery provides insights for designing fast-acting human blood thickeners. The researchers suggest that instead of mimicking the exact biochemical process of insects, the focus should be on designing drugs that can transform blood into clotting viscoelastic materials.
