Washable bandages containing silver nanoparticles that are able to assist in the treatment of wounds are among the potential uses arising from new technology developed in the United States.
For more than a century, clothing and medical supplies have included silver as an antimicrobial agent. However, washing tends to remove silver’s powerful antimicrobial properties.
Scientists with the Agricultural Research Service (ARS) have developed technology that effectively traps silver nanoparticles inside cotton fiber.
They found that the nanoparticles embedded in the cotton were still killing bacteria after 50 washings.
The amount of silver nanoparticles required to kill bacteria is extremely small, making them cost efficient.
ARS materials engineer Sunghyun Nam developed an inexpensive, effective and environmentally friendly way to kill bacteria by creating silver nanoparticles inside cotton fibers.
Nam and her colleagues at the service’s Southern Regional Research Center in New Orleans, Louisiana, used a new process to create a silver-cotton nanocomposite fiber for use in applications such as bandages, disposable undergarments, shoe liners, upholstery and bedding.
Since the nanoparticles are trapped inside the fabric and not on the surface, they release slowly, thus protecting against harmful bacteria longer and increasing cotton fiber strength, according to Nam.
Silver nanoparticles, which range from 1 to 100 nanometers in size, kill more than 600 kinds of bacteria, including the common kitchen microbe E. coli. A human hair is about 80,000 to 100,000 nanometers wide.
In a recent study published in Scientific Reports-Nature, Nam and ARS postdoctoral research chemist Krystal Fontenot showed that even after 50 home laundering cycles, their silver-cotton nanocomposite fiber retained about 93 percent of its antimicrobial silver nanoparticles and continued to kill harmful bacteria. The new technology also strengthened the cotton fibers.
The technology has many possible applications. For example, fabrics or bandages made with these new nanoparticle-containing fibers may be effective in wound or burn treatments, says Brian Condon, the unit’s research leader. “The nanoparticles may be used in durable or nonwash fabrics—disposable undergarments, shoe liners, upholstery, and bedding—to protect the users from infection,” he adds.
For now, the researchers plan to produce a nonwoven fabric cloth for wiping floors to evaluate its antimicrobial activities.
Nam says: “We want to find out how many bacteria are killed on the floor initially and how many are killed after repeated washing.”
Reporting: Sandra Avant