Inside the body, the bacteria multiply on the implant's surface and then build a slimy, protective film to shield the colony from antibiotics. According to a study in the journal Clinical Infectious Diseases, up to 2.5 percent of hip and knee implants alone in the United States become infected, affecting thousands of patients, sometimes fatally.
More ominously, there is no effective antidote for infected implants. The only way to get rid of the bacteria is to remove the implant. "There is no [easy] solution," said Thomas Webster, a biomedical engineer at Brown University.
Now, Webster and Brown graduate student Erik Taylor have created a nano-sized headhunter that zeroes in on the implant, penetrates S. epidermidis's defensive wall and kills the bacteria. The finding, published in the International Journal of Nanomedicine, is the first time iron-oxide nanoparticles have been shown to eliminate a bacterial infection on an implanted prosthetic device.
In lab tests, Taylor, the lead author, and Webster, associate professor of engineering and orthopaedics, noted that up to 28 percent of the bacteria on an implant had been eliminated after 48 hours by injecting 10 micrograms of the nanoparticle agents. The same dosage repeated three times over six days destroyed essentially all the bacteria, the experiments showed.
The tests show "there will be a continual killing of the bacteria until the film is gone," said Webster, who is editor-in-chief of the peer-reviewed journal in which the paper appears.A surprising added benefit, the scientists learned, is the nanoparticles' magnetic properties appear to promote natural bone cell growth on the implant's surface, although this observation needs to be tested further.
Once the nanoparticles arrive at the implant, they begin to penetrate the bacterial shield. The researchers are studying why this happens, but they believe it's due to magnetic horsepower. In the tests, the researchers positioned a magnet below the implant, producing a strong enough field to force the nanoparticles above to filter through the film and proceed to the implant, Webster explained.
The particles then penetrate the bacterial cells because of their super-small size. A micron-sized particle, a thousand times larger than a nanoparticle, would be too large to penetrate the bacterial cell wall.
The researchers plan to test the iron-oxide nanoparticles on other bacteria and then move on to evaluating the results on implants in animals. The research was funded by the private Hermann Foundation Inc. In addition, Taylor's tuition and stipend are funded through the National Science Foundation GK-12 program.
Richard Lewis | EurekAlert!
Team discovers how bacteria exploit a chink in the body's armor
20.01.2017 | University of Illinois at Urbana-Champaign
Rabies viruses reveal wiring in transparent brains
19.01.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Process Engineering
23.01.2017 | Physics and Astronomy
23.01.2017 | Life Sciences