Engineered blood clots form faster to stop severe bleeding

Blood clotting is one of the body's oldest survival mechanisms-a biological defense that has protected humans from dangerous bleeding for millions of years.

But when severe injuries strike, nature's solution can sometimes fall short.

"We found the material to be 13 times tougher and four times more adhesive than native blood clots," Long said.

Strengthening nature's first responders

However, blood clotting is crucial in many situations, from a cut finger in the kitchen to a scraped knee from a bike fall.

Even during these routine situations, blood clotting is what prevents excessive blood loss. But according to the new study, that natural response isn't always fast or effective enough for more severe circumstances.

One day, Li-the senior author of the study- shared with Long a bold idea.

Li, alongside first author Shuaibing Jiang, a PhD student in Li's lab and now a postdoctoral associate at Harvard Medical School, showed Long a new type of blood clot that uses a novel technique to reinforce natural clots with a second network of red blood cells.

The natural and reinforced networks combined to create an engineered clotting system tougher and faster than any natural blood clot seen before.

"It was so exciting," Long said. "From there, we began building models and studying the mechanics behind this incredible material."

Creating a new biomaterial

Because the reaction doesn't interfere with normal blood chemistry, it can work alongside the body's natural clotting process. This allows the cell-based gel network to act as a second support system layered on top of the body's natural fibrin-platelet clot.

Previous efforts to recreate blood clots often used polymers and other synthetic materials foreign to the body. However, Li's cytogel clots are built from red blood cells-the body's own cellular building blocks.

That natural composition gives the engineered clots a unique advantage: they can easily degrade over time, transforming the stigma of blood clots from risky medical hazards into controlled, life-saving biomaterials.

"Blood cells have an 'expiration date.' Over time, they die just as all life eventually does," said Long. "Using red blood cells as the foundation of these reinforced clots makes them temporary. They can naturally break down in a short time, preventing blockages and other health issues that occur when they are in the body for too long."

But the researchers also believe the strategy of linking cells together could extend far beyond just blood clots.

Long envisions a day where Li's technology can be used to repair defected tissue or target localized areas of the body for drug delivery and treatment. And while the work is still in its early stages, the team thinks it points toward a broader shift in how biological materials can be engineered for medicine.

Source:

University of Colorado at Boulder

Journal reference:

Jiang, S., et al. (2026). Engineering tough blood clots for rapid haemostasis and enhanced regeneration. Nature. DOI: 10.1038/s41586-026-10412-y. https://www.nature.com/articles/s41586-026-10412-y