According to the World Health Organization, snakes bite an estimated 5 million people each year, killing more than 100,000 of those victims and permanently injuring hundreds of thousands more. Current antivenoms might not be saving lives as efficiently as they could be, given that they're difficult and expensive to produce, distribute and administer. Now, researchers at the University of California, Irvine (UCI) have developed a synthetic alternative with a long shelf-life that can neutralize the venom from several species of snakes.
Although existing antivenom treatments are effective at preventing death or long-term disability like amputation, they aren't easy to make, store or ship. One of the most common ways is to inject a horse or sheep with a non-lethal dose of a venom, wait for the animal to develop antibodies against the toxins, and then harvest and process those antibodies into an antivenom.
That technique is problematic for several reasons. For one, it's expensive, which means that it isn't accessible in the poorer rural areas of the world where the majority of snake bites occur. It also needs to be refrigerated, making storage and shipping tricky, and most antivenoms are only effective against bites from a single species of snake. The UCI team says their synthetic solution could solve all of these issues.
"Current antivenom is very specific to certain snake types," says Jeffrey O'Brien, lead author of the study. "Ours seems to show broad-spectrum ability to stop cell destruction across species on many continents, and that is quite a big deal. Our treatment costs pennies on the dollar and, unlike the current one, requires no refrigeration. It feels pretty great to think this could save lives."
The team's treatment, which they call a "nanodote," is built around a specially-designed polymer nanogel. When injected, nanoparticles in the material absorb the venom by binding to certain protein toxins that are common to several species of deadly snakes. These particles sequester and neutralize the toxins, keeping the poison from attacking red blood cells and causing the serious haemorrhaging that can sometimes be fatal.
Since the nanodote ingredients are easy to obtain, it's much cheaper to produce than the current antidotes, and can sit unrefrigerated for much longer. That means it could be shipped at low-cost to remote areas as part of a standard medical package to treat bites from a variety of snake species.
"The military has platoons in the tropics and sub-Saharan Africa, and there are a variety of toxic snakes where they're traipsing around," says Ken Shea, senior author of the study. "If soldiers are bitten, they don't have a hospital nearby; they've got a medic with a backpack. They need something they can use in the field to at least delay the spread of the venom."
The researchers are preparing for clinical trials and have applied for patents for their treatment. In future, the nanodote could also be modified to work on the venom of spiders, scorpions and bees.
The research was published in the Journal of the American Chemical Society.
Source: University of California, Irvine