Band-aid solutions

Humans, as you may have noticed, are covered with skin. This tissue, the largest organ of the body, is both waterproof and amazingly tough, but it isn’t impervious (unless you hail from the planet Krypton). Sharp objects can and do cut through it.

Cutting through the skin invariably involves cutting blood vessels, which leads to blood loss, which leads to death if it goes on too long. Fortunately, blood clots and tissues heal, but if the wound is large, you need a means of staunching the flow long enough for the body’s natural healing processes to take over.

As long as there have been people, they’ve had to try to treat wounds. For example, the ancient Egyptian Papyrus of Ebers, from around 1500 B.C., recommended the use of lint (the fibers helped promote the closing of the wound), animal grease (which kept out dirt) and honey (which prevented infection, although they didn’t know why).

Somewhat more recently–specifically, this week–has come news of an even better way to treat a wound. Rresearchers at the Massachusetts Institute of Technology (MIT) and Hong Kong University have come up with a simple biodegradable liquid that stops bleeding in wounded rats within 15 seconds.

The liquid is made up of fragments of protein, called peptides. Applied to an open wound, the peptides assemble themselves into a protective gel that seals the wound and halts bleeding. As the wound heals, the gel gets broken down into molecules that the cells can use as building blocks for new tissue. In rats, the liquid worked in many types of tissue–brain, liver, skin, spinal cord and intestine.

Such an effective way to stop bleeding could save thousands of lives, both through first-aid treatment of wounds and in surgery, where more than half of surgeons’ times is spent controlling bleeding using clamps, pressure, cauterization, sponges and the like. Reducing the length of surgery improves patient outcomes, and might even shorten waiting lists.

The researchers still aren’t entirely sure how the liquid works. They need to pin down the mechanism involved, but they hope to start human trials within three to five years.

A simple liquid that stoops bleeding certainly sounds more appealing than some other cutting-edge (sorry) bleeding treatments, but they do exist. For example, some U.S. police and military carry QuikClot. Discovered by accident by former NASA engineer Francis X. Hurvey (he cut himself shaving and applied an adsorptive agent–basically volcanic rock–he’d been working on for another project), it’s a porous, sand-like material that quickly adsorbs water when poured into a wound. This concentrates the blood’s clotting factors. In lab tests, blood treated with the substance clots in less than two minutes, compared to 10 minutes for untreated blood.

Unfortunately, as it adsorbs water it generates enough heat to sometimes cause second-degree burns. That’s made it a treatment of last resort, even for the U.S. military.

Their first option is called HemCon, a bandage containing ground-up shrimp shells. Shrimp shells contain chitosan, which binds strongly to tissue and thus seals wounds. But HemCon doesn’t work well on some gunshot wounds, because it’s too stiff to be packed into a hole tightly enough to control bleeding.

Researchers have come up with a new, improved QuikClot, a bioactive glass made of silica and calcium that has larger pores than QuickClot and a different consistency, and doesn’t generate the same amount of heat. It can also be squeezed out of a syringe like a paste, unlike QuikClot, and can be left in the body to be absorbed. The current QuikClot has to be painstakingly removed once bleeding has stopped.

“Ultimately, we hope everybody will have a first-aid kit with a pack in their car,” says a spokesman for Z-Medica, which makes QuikClot.

Maybe in the short term. But I’m hoping for the biodegradable liquid myself, which sounds like it could even make band-aids a thing of the past.

As the father of a five-year-old girl, though, I have to ask: is there some way to make the gel form a picture of Dora the Explorer?

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