Killer Clothing Bursts Bad Bacteria

Oct. 15, 2008 — -- It's the season for germs -- or at least worrying about germs.

With co-workers sneezing into your cubicle and coughing on the coffee cups, the microscopic world of bacteria and viruses can be difficult to ignore during cold and flu season. Is anything safe to touch?

Scientists and entrepreneurs are hoping to ease some of that worry with new technology -- some high tech, some low tech, several containing antimicrobial silver nanoparticles -- that can zap germs or resist bacteria and viruses from settling on their surfaces.

Still experts urge that consumers should keep a critical eye when considering these products and make informed choices before wielding the wallet.

The anti-microbials in these products can significantly kill microbes, acknowledged Dr. David Weber, an epidemiology professor at the University of North Carolina at Chapel Hill. But both Weber and colleague Dr. William Rutala, an infectious diseases professor, question whether there are any data that demonstrate these products are effective in reducing infection rates.

Dr. Neil Fishman, director of the health-care epidemiology and infection prevention and control at the University of Pennsylvania Medical Center, also questions the usefulness of some of the science backing these germ-resistant items.

"One of the big problems is that in order to make the claim anti-bacterial, they can kill bacteria on a petri plate, but they don't have to demonstrate they prevent infection from person to person," Fishman said.

"A lot of my skepticism stems from a lack of clinical data," Fishman added. "I think many of these can kill bacteria. I don't know if they'll make an impact on infection, but good hand hygiene does."

We invite you to examine these seven germ-resistant products along with Fishman and Weber.

In a study commissioned by a consumer advocacy group released in May, a microbiologist from the United Kingdom tested 33 keyboards for germs and found that four of those keyboards contained bacteria posing potential health hazards.

Several manufacturers have taken this study and others like it to produce keyboards and computer mice that are more convenient to clean.

Unotron, one such company, developed a keyboard and mouse that can withstand a soap-and-water session in the sink.

"Both products are laser-welded so the case itself is sealed ... so no liquid can penetrate," said Joe Caribella, a member of the board of directors for Unotron.

In addition to being water-resistant, the keyboard and mouse have an anti-microbial embedded in the plastic.

"The silver nitrate [in the keyboard and mouse] breaks down the cell walls of bacteria," Caribella said.

Wash-friendly items are turning up in hospitals and other health-care practices, where germs are a common concern. Fishman agrees that the ability to wash a keyboard is useful in such settings, but he is less enthused about the silver nitrate.

"My bigger concern is that they get dirty, not that they be anti-microbial," Fishman said. "You don't necessarily need the anti-microbial component."

The fabrics contained oft-researched silver nanoparticles that can be effective in killing bacteria and disrupting viruses from infection.

In order to make the fabric germ-resistant, the cotton fabric must first be given a positive charge, said Dr. Juan Hinestroza, assistant professor in the department of Fiber Science and Apparel Design in the College of Human Ecology at Cornell University.

Then, the silver nanoparticles are given a negative charge so that they attach to the fabric, added Hinestroza, who created the materials.

Although the fabric is currently not available to the public, it has the potential to be used in a variety of ways outside the fashion laboratory.

"[The nanofibers] can be commercialized. Several companies have called to ask about the use of the fabrics in surgical gowns," Hinestroza said.

Hinestroza said there have also been requests to use the germ-resistant fabrics in meatpacking uniforms, to help protect against E.coli.

Cornell is not the only institution working on the development of germ-protective clothing. Dr. Gang Sun, professor in the department of textiles and clothing at the University of California at Davis, has also been exploring fabrics that shield wearers from disease.

Sun is not only experimenting with nanoparticles, but also with anti-microbial polymers.

"I have been working in the area of biological and chemical protective textiles for the past 13 years, mostly focusing on producing biocidal polymers and fabrics that can kill germs rapidly," Sun said.

Sun's textiles are rechargeable and can be used for medical and military purposes. Specifically, the "materials could detoxify certain chemicals including pesticides and mustard gas upon contact," he said.

Sun's discovery is already in use in commercial products, including medical linens and reusable antibacterial wipes.

However, not everyone is sold on these germ-free materials for worker uniforms.

"Although you can culture bacteria from clothing, they have never been tied to transmission of infections," Fishman said. The germ-resistant clothing can "be useful in health-care settings [such as] the surgical drape to prevent surgical-site infections."

"The nanosilvers help to eliminate bacterial growth and [foot] odor," said Kim Amylon, a spokeswoman for Eurosocks, one company using anti-fungal technology.

However, researchers in Arizona found the nanoparticles don't necessarily last long enough to disappear from the dryer.

"The idea was to purchase socks that contain silver, [and find out] how much of it comes off through washing," said Troy Benn, a doctoral candidate in the department of civil and environmental engineering at Arizona State University

Benn found that some of the socks -- he did not test Eurosocks -- released the silver after multiple washings. The findings are published in Environmental Science and Technology, the American Chemical Society's journal.

Still, Amylon stands by the durability of fungus-fighting socks: "A sock is a consumable product. Italian craftsmanship reinforces the durability of our sock, but any item will age and wear over time."

Benn also expressed some concern that the shed nanosilver particles might accumulate in wastewater systems.

"Nanosilver might be able to persist longer in surface waters," Benn said. "There could be an accumulation in the wastewater treatment biosolids, which could render them unusable as an agricultural fertilizer. Or the nanosilver could travel through a wastewater treatment plant back out into our surface waters."

There is ongoing debate about the possible environmental impacts of silver nanoparticles.

In addition to concerns about biodegradability, others question whether microbes may adapt to the silver's lethality.

"One issue is: Is it doing any good? Is it doing any harm? Could you get a silver-resistant organism?" Weber said.

"There were so many of them," Song said. "After 48 hours, the smell was so bad. There were well over 500 species of bacteria."

That research led to Song's invention of a toothbrush sterilization device. Essentially a mini-autoclave for the toothbrush, the Germ Terminator uses steam and dry heat to kill germs that breed on the bristles.

The Germ Terminator also "makes the bristles [of the toothbrush] nice and soft," Song claimed, so that they won't puncture the gumline.

But after considering the Germ Terminator apparatus, Fishman was perplexed.

"This one befuddled me," Fishman said. "Mouths are filled with bacteria -- some of them are good bacteria and some of them are bad bacteria. Usually, we don't worry about bacteria in the mouth because they don't spread anywhere."

Fishman added that the acid in our stomachs generally kills a lot of the bad bacteria that traverses through our bodies.

Song, though, said he believes it's important to be educated about what we put into our mouths with our toothbrushes.

"We are our own dentists every single time we brush," he noted.

So how is the plasma pencil supposed to help eliminate bacteria? When emitted from the pencil-shaped device, the plasma charges the surrounding air molecules and creates free radicals, thereby once again poking holes in the bacterial cell walls and killing the microbe.

The device is not supposed to affect human skin, said Laroussi, who pointed out that human skin cells have a more sophisticated cell wall structure than bacteria. The complexity of skin cells is what prevents them from breaking apart when hit by the low-temperature plasma.

Another planned application of the plasma pencil is healing wounds.

"Let's say you have a patient with a cut and burn. Instead of using liquid, you can apply the plasma and kill the bacteria without leaving residue," Laroussi said.

Fishman said he believes the plasma pencil seems like promising technology, especially with regard to its function as a wound healer. However, he noted that more research needs to be done on the device.

"I think there needs to be a lot more work done on this," said Fishman. "More work on the safety."

But what if you just don't touch anything? The Handler, a key chain-sized device that releases a rubber hook to grip door handles and press buttons, is advertised as an alternative to more traditional cold and flu prevention methods.

"The idea with the Handler is that it basically puts a barrier in between your hands and surfaces like ATM buttons and the keypads at checkout lanes," said Bill Schlueter of Launchpad Public Relations, which promotes the device.

But what about the germs that latch onto the Handler? Nanosilver.

"The Handler has a minute amount of nanosilver infused in the plastic," said Schlueter. "It's a self-sanitizing device."

However, Fishman was less than enthused.

"This borders on the obsessive-compulsive," Fishman said. "Other than reinforce phobias, I don't think this is a useful product to significantly decrease infections."

Fishman asserted that the routine washing of hands is better at stopping the spread of disease.

Schlueter said that the Handler is meant to prevent sicknesses at the individual level and that each person has his or her own "degree of germ-consciousness. The whole idea behind the Handler is that you don't take the chance of getting [germs] on your hand in the first place."

Photos: Unotron, Inc. (Keyboard and Mouse); Dr. Juan Hinestroza, Cornell University (Fabrics); Eurosocks North America (Socks); Germ Terminator, Inc. (The Germ Terminator); M. Laroussi, Old Dominion University (The Plasma Pencil); Bill Schlueter, Launchpad PR (The Handler)

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