USD researchers enhance Kevlar to aid emergency responders

VERMILLION, S.D. -- Developed in the 1960s for many uses, Kevlar is most widely used today to protect soldiers in battle, police officers on the street and firefighters in dangerous infernos. However, two researchers with the Biomedical Engineering Program at The University of South Dakota are hoping their design can take Kevlar protection one step further – to protect individuals from exposure to biochemical hazards.

Yuyu Sun, an associate professor in the biomedical engineering program at USD, and Jie Luo, a biomedical engineering research associate II at The U; have developed a process to create antimicrobial clothing. Their findings, which are featured in the American Chemical Society’s bi-weekly scientific journal Industrial & Engineering Chemistry Research (Aug. 6), include using acyclic N-Halamine to prevent the growth of microbes such as bacteria, fungi or viruses. N-Halamine is a potent germ-fighting substance.

The two researchers, who have been working on the antimicrobial project since 2005 when they were at the University of Texas, exposed Kevlar samples coated with N-Halamine and uncoated Kevlar samples to E. coli, Staphylococcus aureus (common cause of staph infections), Candida tropicalis (a fungus), M2 virus and Bacillus subtilis spores (to mimic anthrax). Over a short period of time, large amounts of microorganisms were attached to the untreated Kevlar samples, but the coated samples showed little to no evidence of the infected agents.

"Compared to other agents we’ve worked with, (N-Halamine) had all three components we were looking for," Sun, Ph.D., noted.

Sun described acyclic N-Halamine as powerful because of its ability to kill a wide range of infectious agents, including bacteria, viruses and even spores that cause anthrax; durable because the protection can last for months to years; and rechargeable because even if clothing is saturated by microbes, it can be recharged using a thorough bleach application.

"If a person is in a situation where there are hazardous materials," Sun explained, "they don’t want a false sense of security. The acyclic N-Halamine coating is long-lasting, can be easily re-applied and doesn’t alter the fabric’s comfort or strength."

Although the three-year project, which is being funded by the National Institute for Occupational Safety and Health (part of the Center for Disease Control), is receiving industry attention for its application to Kevlar, the benefits of this antimicrobial protection goes beyond protecting military and emergency personnel. Other possible uses for the acyclic N-Halamine include medical facilities, the hospitality industry as well as the packing industry. Sun and Luo are in the process of developing antimicrobial dental tubing using a very similar chemistry.

"This project is part of an ongoing development that we’ve been working on for quite some time," admitted Sun, who has been at USD since 2007. "We can combine these functions and create this clothing for other industries."

Despite ongoing development and successful testing, Sun said the process of mass producing coated Kevlar or other clothing for that matter is still several steps away. Confirming that the concept would work was only the first step, he said. “It’s possible to create this clothing, mainly for single hazards not multiple hazards,” he pointed out. “Our long-term goal is to develop something that can be multi-protective.”

To view the complete ACS Industrial & Engineering Chemistry Research article, please go to http://pubs.acs.org/cgi-bin/abstract.cgi/iecred/2008/47/i15/abs/ie800021p.html. For more information about Sun and Luo’s research, please contact the Office of Research and Sponsored Programs at The University of South Dakota at (605) 677-5370.