Tobacco Hornworm Larvae Unveil Mechanism to Rapidly Stop Bleeding

Hemolymph, the blood-like fluid found in invertebrates like insects, lacks red blood cells, hemoglobin, and platelets. Instead, it contains hemocytes, amoeba-like cells. One intriguing aspect of hemolymph is its ability to rapidly clot outside the body, effectively stopping bleeding. However, the mechanism behind this process has remained a mystery. Recently, a team of materials scientists from Clemson University in the United States shed light on this phenomenon in a paper published in the journal "Frontiers in Soft Matter" on the 27th. Their research focused on tobacco hornworm larvae and their remarkable ability to halt bleeding quickly. This discovery holds promise for potential applications in human medicine and the development of new drugs.

Tobacco hornworm larvae can heal wounds within a minute, employing a two-step process. Within approximately 5 seconds after bleeding begins, the thin, watery hemolymph undergoes a transformation, becoming viscous and elastic. Within the next 10 seconds, significant changes occur: instead of dripping instantly, the hemolymph forms falling fluid drops connected by long bridges resembling slime strings. Due to its elasticity, the hemolymph at the lower end of the drop retracts into the wound.

To delve deeper into the cellular processes involved in forming crusts that stop bleeding, the researchers employed optical phase contrast and polarization microscopy, X-ray imaging, and materials science modeling. Interestingly, they discovered that the process of stopping bleeding is consistent across 18 other insect species as well.

These findings offer valuable insights into the development of fast-acting blood thickeners for humans. The researchers advocate for focusing on designing drugs that can convert blood into hemostatic viscoelastic materials, rather than attempting to replicate the precise biochemistry of insects.