Silver in Tiny Doses Kills Bacteria, Helps Wounds Heal
Posted Apr 04 2010 10:46am
NaturalNews) In a recent presentation before the annual American Chemical Society meeting held in Washington, D.C., scientist Ankit Agarwal revealed that he's come up with an approach to healing that can kill 99.9999 percent of bacteria in a wound using a natural substance -- silver. And he claims he's found a way to help skin heal by using tiny, targeted nanoparticles of the precious metal. The treatment could help save diabetics from amputations and help victims of severe burns heal with fewer complications from infections, too.
There's nothing new about the idea silver can be used as a healing tool. In fact, Hippocrates, the ancient Greek physician known as the father of modern medicine, wrote that silver has beneficial, anti-disease properties. And silver is often used today to prevent wound dressings from becoming contaminated with bacteria. However, the huge loads normally used by Western medicine can damage skin. That has made many doctors, especially those who treat burn victims, shy away from using silver to treat wounds.
But Agarwal, a postdoctoral researcher at the University of Wisconsin-Madison, believes he's come up with a way to take advantage of silver's anti-bacterial properties while at the same time avoiding skin damage and actually promoting the healing of damaged skin. The key? Extremely small doses delivered precisely.
Scientists have long known that cells in the bodies of humans and other mammals are sensitive to silver -- but bacteria are much more sensitive that cells. So the key to killing bacteria without killing or harming skin cells is to find the "sweet spot", a concentration of silver that kills infection-causing bacteria but doesn't harm the skin cells needed for healing. Agarwal appears to have done just that.
Combining 21st century high tech engineering with the ancient natural healing powers of silver, the researcher has created an ultra-thin material capable of carrying extraordinarily small amounts of the precious metal. One square inch of this material contains only a tiny amount -- about 0.4 percent -- of the silver found in the silver-treated antibacterial bandages now used in medicine that can damage skin.
Agarwal's approach is clearly an example of where less is more. In laboratory tests, he demonstrated that the low concentration of silver killed 99.9999 percent of the bacteria but didn't damage cells called fibroblasts that are needed to repair a wound. That means using silver at this extremely low level can zap disease-causing pathogens and actually help skin to heal at the same time.
This is important for several reasons. First, with the rise of superbugs, it is gratifying to see that a natural substance is effective against potentially serious wound infections. Second, diabetes has reached epidemic proportions both in the US and around the world, and wound healing is a particular problem in diabetics. Poor blood supply in people with diabetes can cause healing problems that result in amputations and silver appears to be a promising tool to help diabetic wounds heal. Another potentially life-changing application for the new silver treatment: treating or preventing burn victims' skin infections while allowing damaged skin to heal naturally.
Agarwal created the experimental material by alternately dipping a glass plate in two solutions of oppositely charged polymers and then adding a precise dose of silver. The resulting multilayers form a kind of sandwich of ultra-thin materials that stick together through electrical attraction. The final size of the silver-laced treatment material ranges from a few nanometers to several hundred nanometers in thickness (one nanometer is one-billionth of a meter; a human hair is about 60,000 nanometers in diameter.)
To kill bacteria, silver must take the form of charged particles, or ions, and the commercial wound dressings now in use contain a large dose of silver ions which are released quickly with little control. But the tiny silver nanoparticles that Agarwal embeds in his high tech silver sandwich material can be designed to release ions for days or weeks as needed. "We are putting the silver where we need it, so we can use a small loading of silver, which does not exhibit toxicity to mammalian cells because the silver is precisely targeted," Nicholas Abbott, a professor of chemical and biological engineering who works with Agarwal, explained in the media statement