‘Injectable bandage’ with clay particles could reduce bleed time by almost 70%

A new clay-based ‘injectable bandage’ can reduce bleeding time by almost 70%, according to its developers, and future versions could one day be simple enough for patients to apply themselves.

Biomedical engineers at Texas A&M University are developing a suite of the injectable haemostatic bandages, which are designed to stop bleeding and promote blood to clot faster. The work is specifically targeting deep internal bleeding, where traditional methods like compression are not possible.

“Severe blood loss can rapidly lead to haemorrhagic shock,” said biomedical engineering professor Dr Akhilesh Gaharwar. “Many patients die within one to two hours of injury. This critical period is often referred to as the ‘golden hour’.”

Using funding from the US Department of Defense and the National Science Foundation, Gaharwar and his fellow researchers say they have found a way to extend that golden hour using clay.

“Under normal circumstances, human blood clots within six to seven minutes,” said Gaharwar. “Using these haemostatic dressings, we are able to reduce the clotting time to one to two minutes.”

The goal is a lifesaving device simple enough for self-application. “For a self-applied or in-the-field-applied device, you can’t use the fancy mechanics and apparatus that you would have in the operating room,” said researcher Dr Taylor Ware. “There can’t be any special tools. You have to have something that just works – and works quickly.”

Some naturally occurring clay minerals contain silicate-based particles that can accelerate blood coagulation. Inspired by their use in ancient civilisations, Gaharwar began to explore the use of a synthetic particle, which would avoid the potential risk of infection that comes with natural clays.

With the help of Dr Duncan Maitland’s lab, the researchers combined nanosilicate particles with an expanding foam. While completely stable in its applicator device, the particle-laced foam reacts to body heat. Once injected into a wound site, it expands to fill up the entire space, sealing severed blood vessels and holding the blood-clotting nanosilicate where it needs to be.

“Since the foam forms a single piece, there is no risk of particles breaking away and travelling to form dangerous blood clots in other areas of the body,” an A&M announcement said.

In Ware’s lab, the researchers instead developed a biomaterial formed of multiple ribbon-like structures, each covered in coagulation-promoting nanosilicate particles.

Like the foam, the micro-ribbons exploit the patient’s body heat to trigger a reaction once in place. Each ribbon is made of two different materials, only one of which reacts to body temperature. Once in contact with the patient’s body, one side of the ribbon contracts, causing it to curl. As multiple ribbons curl at the injury site, they tangle together to form a single foam-like structure.

“If these materials get into the first aid kits in an ambulance as well as a soldier’s backpack, they can save a lot of lives,” said Gaharwar. “If you can save 30-40% of haemorrhagic shock victims, that is a big achievement.”

The research was published in Advanced Science and Advanced Functional Materials.  

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