Associate Professor of Engineering Thomas Webster and Erik Taylor GS have created nanoparticles to fight implant infections.
According to the American Academy of Orthopaedic Surgeons, about a million people receive implants to replace a hip, shoulder or knee each year.
Over 11 percent of these implants become infected with bacteria, Webster said. The bacteria that cause these infections can be found on most surfaces, including human skin. But if they enter the body and colonize, the bacteria can cause severe damage to tissue, especially in people with compromised immune systems, he said.
In the case of infected bone implants, the bacteria gradually multiply and form a layer of biofilm on the implant, Webster said. The biofilm subsequently discourages attachment of the implant to the patient's bone, causing pain and discomfort, he said. Doctors usually prescribe antibiotics to treat the infection, but in the case of antiobiotic-resistant bacteria, the treatments prove ineffective and the patients end up having the implants removed, Webster added.
But the nanoparticles that Webster and Taylor have created "penetrate the biofilm, start manipulating bacteria, decreasing bacteria function," Webster said in a March 15 interview with KFSN-TV. In lab tests, these nanoparticles killed 74 percent of bacteria in 48 hours, Webster said. Their studies have shown that the nanoparticles promote growth of new bone cells, which could be an effect of the iron in the particles, he added.
Webster said he envisions future treatments that will involve a simple injection of iron oxide particles. Doctors could then use a magnet to direct the particles to the source of the infection, he said. Unlike traditional antiobiotic treatments, humans can withstand "repeat exposures of iron" until the infection is completely gone, as long as the recommended daily intake of iron is not exceeded, he said.
Though several years of research and clinical studies are still required before the nanoparticle treatment becomes approved for implant infections, iron oxide nanoparticles are already approved by the Food and Drug Administration, which will substantially reduce the time for the treatment to be approved, Webster said.
