Posted: Mar 04, 2015 |
Nanotechnology enhanced orthopedic implants fight infection
|
(Nanowerk News) As the number of joint replacement surgeries in the U.S. grows, so are concerns about the complications of infection from antibiotic-resistant “superbugs.” Biomedical engineers at NC State University are fighting back by developing nanotechnology built directly into orthopedic implants using a battery-activated device to power an army of microscopic germ-killers. Even antibiotic-resistant bacteria such as MRSA are on the hit list.
|
At the NC State Department of Industrial and Systems Engineering (ISE), one of the nation’s leading engineering departments specializing in advanced systems and processes, researchers have been engineering ways to apply a low-intensity electrical charge to a silver-titanium implant, releasing low-toxicity silver ions that kill or neutralize bacteria. The power source, similar to a watch battery, can be integrated into the implant design. The body’s own fluids act as a conducting medium between battery and silver, enabling the low-level charge. Broad application of the system could result in a milestone achievement in the fight against infection.
|
Research and testing conducted by Dr. Rohan Shirwaiker (ISE Assistant Professor and Adjunct Assistant Professor of Biomedical Engineering) and PhD candidate George Tan has shown a 99% decrease in bacteria growth on and around implants after 24 hours and an infection-free environment after 48 hours. Shirwaiker and Tan are also exploring the possibility of a smartphone app to control the power source and the release of silver ions remotely, and track the biophysical activity around the implant area.
|
“Silver has long been known for its anti-bacterial properties, but first it must ionize to be effective,” said Shirwaiker, who has been engaged in research on the project since 2007. “The breakthrough was in demonstrating that a little electric current to the silver on the implant releases the ion particles, which attach to bacteria cells and either kill them or prevent them from replicating.”
|
At a recent conference of the American Academy of Orthopedic Surgeons, a presentation by Shirwaiker received top honors, naming him Best Young Investigator. Shirwaiker was the only engineer among the medical researchers invited to showcase their work. A study conducted in collaboration with University of North Carolina Department of Orthopaedics to investigate the performance of implant prototypes in rats is currently in review in a leading biomedical journal.
|
“What we are exploring now is how to precisely control the level of silver that is released so that no healthy cells are compromised,” said Tan. “This is a system that could potentially be incorporated into any type of surgical implant.”
|
There are over a million joint replacement surgeries performed each year in the U.S. alone, and treatments for post-surgical infections cost the healthcare system more than $1.6 billion annually. Innovations in silver microbial technology could eventually have a wide-ranging impact on the healthcare industry while improving outcomes and quality of life for patients.
|