By Edwin L. Aguirre
On any given day, about one in 31 hospital patients in the U.S. picks up at least one health-care-associated infection, according to the Centers for Disease Control and Prevention (CDC).
People get exposed to bacteria, fungi and viruses, including multidrug-resistant pathogens, while they are receiving medical treatment. The resulting infections have led to the loss of tens of thousands of lives and have cost the country’s health care system billions of dollars each year. In addition, health care personnel are exposed to a high occupational burden of infectious agents, causing illness and affecting the workers’ well-being.
To help combat this health threat, a team of UMass Lowell researchers has developed a way to treat hospital garments worn by nurses and other health care personnel with special antimicrobial function that offers not only long-lasting protection, but its potency can also be easily monitored and recharged as needed.
Prof. Yuyu Sun
, in collaboration with Assoc. Prof. Nancy Goodyear
of Biomedical and Nutritional Sciences
, is using N-halamine – a biocide with proven germ-killing property – to reduce the occupational burden of exposure by protecting the staff from harmful microorganisms that can cause various infections. This will also prevent serious complications among patients due to cross-contamination.
The team’s research is supported by a two-year grant totaling more than $417,000 from the U.S. National Institute of Occupational Safety and Health, with Sun and Goodyear as principal investigators.
“N-halamines are widely used water and food disinfectants with antimicrobial efficacy similar to that of hypochlorite bleach, but they are much more stable and safer to use,” Sun says.
Users can periodically check the N-halamine level on the fabric with potassium iodine test strips. If the tests show that all of the active N-halamine on the fabric surface is used up, the antimicrobial function can be recharged by rinsing the fabric in a dilute bleach solution during laundering.
“The recharging process can be repeated as needed through the entire service life of the textiles,” says Sun.
According to Goodyear, preliminary studies have demonstrated N-halamine-treated fabrics to be effective against pathogens such as E. coli, Pseudomonas aeruginosa, MRSA, vancomycin-resistant enterococci, Staphylococcus aureus and Candida albicans. “Many more species will be tested in this study,” she says.
Early lab tests have shown the N-halamine fabrics to be cytocompatible – that is, harmless to living cells. “Animal and human tests will be performed in future, larger-scale studies,” says Sun.
Assisting Sun in his lab at the Olney Science Center on North Campus are research scientist Jianchuan Wen and chemistry senior Jake B. Sartorelli. Goodyear is assisted by graduate student Adorrah-Le Khan at her lab at Weed Hall on South Campus.
Extensive studies have shown that in general practice, “clean” hospital textiles like curtains, blankets, bed sheets and pillowcases are rapidly and heavily contaminated/recontaminated with harmful bacteria, including multidrug-resistant organisms that can survive for weeks on soft fabrics and easily transfer onto the nurses’ hands and other clean surfaces.
“Reducing bacterial contamination of health care personnel’s clothing made of conventional, untreated fabrics would require them to change work clothes every few hours,” notes Goodyear.
According to Goodyear, about 37 percent of hospital facilities laundered their privacy curtains only when they were visibly soiled with blood or body fluids; white coats were washed every 11.3 to 13.5 days and scrubs every 1.6 to 1.8 days (some were even laundered at home).
Sun and Goodyear stress that while textile contamination puts the health and safety of hospital workers (and also patients) at risk, the impact of such contamination is underestimated, they say, “because of a lack of point-source investigations of textiles during outbreaks and cases of infection or illness.”
From Dentures to Textile Dyes
Throughout his career, Sun has used his background in polymer chemistry and biomedical engineering to battle preventable infections as well as protect the environment.
Sun has been developing dentures that can be infused with anti-fungal medications
to treat denture-related stomatitis – inflamed, painful gums caused by a common yeast that builds up between the hard dentures and soft tissue. Homeless veterans and those with post-combat disabilities are highly susceptible to stomatitis. If left untreated, it can lead to open sores, systemic infection and even death. Sun and his collaborator from the South Texas VA Health Care System received $1.5 million in grants from the National Institutes of Health and the Department of Veterans Affairs to pursue their research. Sun has a U.S. patent on the technology.
Sun also won a three-year, $490,000 grant from the Walmart Foundation to develop cleaner, environmentally sustainable technology for dyeing fabrics
. He is using a magnetic field to pull the dyes modified with nanoparticles into the fabrics more efficiently – and then remove most of the remaining dye from the wastewater before it gets discharged. Sun already had preliminary success with two of the most commonly used classes of dyes – dispersed dyes, used on polyester fabrics, and reactive dyes, used for cotton. His team is now exploring the use of new technology in printing.