Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Implant Bacteria, Beware: Researchers Create Nano-sized Assassins

Bacterial assassins
 Iron-oxide nanoparticles developed at Brown University target an infected prosthesis, penetrate a bacterial film on the implantís surface and thwart the colony by killing the bacteria. The nanoparticles also are believed to help natural bone cell growth. 
Credit: Erik Taylor/Brown University
Bacterial assassins Iron-oxide nanoparticles developed at Brown University target an infected prosthesis, penetrate a bacterial film on the implantís surface and thwart the colony by killing the bacteria. The nanoparticles also are believed to help natural bone cell growth. Credit: Erik Taylor/Brown University

Abstract:
Infected implants now have a foe. Brown University researchers have created a nanoparticle that can penetrate a bacterial-produced film on prosthetics and kill the bacteria. The finding, published in the International Journal of Nanomedicine, is the first time that iron-oxide nanoparticles have been shown to eliminate a bacterial infection on an implanted prosthetic device.

Implant Bacteria, Beware: Researchers Create Nano-sized Assassins

Providence, RI | Posted on June 26th, 2009

Staphylococcus epidermidis is quite an opportunist. Commonly found on human skin, the bacteria pose little danger. But s. epidermidis is a leading cause of infections in hospitals. From catheters to prosthetics, the bacteria are known to hitch a ride on a range of medical devices implanted into patients.

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.

To carry out the study, the researchers created iron-oxide particles (they call them "superparamagnetic") with an average diameter of eight nanometers. They chose iron oxide because the metallic properties mean the particles can be guided by a magnetic field to the implant, while its journey can be tracked using a simple magnetic technique, such as magnetic resonance imaging (MRI). Moreover, previous experiments showed that iron seemed to cause s. epidermidis to die, although researchers are unsure why. (Webster said it may be due to iron overload in the bacteria's cell.)

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.

####

About Brown University
Approximately 5,900 students are enrolled in the Undergraduate College, 1,500 in the Graduate School and 340 in the Medical School. These students represent all 50 states and many foreign countries. For 2010, more than 18,000 applicants applied for 1,450 places in the freshman class. All undergraduates were admitted under a need-blind admission policy.

Brownís three schools offer nearly 100 programs of study. The University adheres to a collaborative university-college model in which faculty are as committed to teaching as they are to research, embracing a curriculum that requires students to be architects of their education.

For more information, please click here

Contacts:
Brown University
Box R
71 George St, Providence, RI 02912 401.863.2476

Copyright © Brown University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Nano Ruffles in Brain Matter: Freiburg researchers decipher the role of nanostructures around brain cells in central nervous system function October 31st, 2014

Gold nanoparticle chains confine light to the nanoscale October 31st, 2014

'Nanomotor lithography' answers call for affordable, simpler device manufacturing October 31st, 2014

Device invented at Johns Hopkins provides up-close look at cancer on the move: Microscopic view of metastasis could give insight about how to keep cancer in check October 31st, 2014

Possible Futures

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Superconducting circuits, simplified: New circuit design could unlock the power of experimental superconducting computer chips October 18th, 2014

Nanocoatings Market By Product Is Expected To Reach USD 8.17 Billion By 2020: Grand View Research, Inc. October 15th, 2014

Perpetuus Carbon Group Receives Independent Verification of its Production Capacity for Graphenes at 140 Tonnes per Annum: Perpetuus Becomes the First Manufacturer in the Sector to Allow Third Party Audit October 7th, 2014

Nanomedicine

Nano Ruffles in Brain Matter: Freiburg researchers decipher the role of nanostructures around brain cells in central nervous system function October 31st, 2014

Production of Biocompatible Polymers in Iran October 30th, 2014

Amorphous Coordination Polymer Particles as alternative to classical nanoplatforms for nanomedicine October 30th, 2014

'Electronic skin' could improve early breast cancer detection October 29th, 2014

Announcements

Nano Ruffles in Brain Matter: Freiburg researchers decipher the role of nanostructures around brain cells in central nervous system function October 31st, 2014

Gold nanoparticle chains confine light to the nanoscale October 31st, 2014

'Nanomotor lithography' answers call for affordable, simpler device manufacturing October 31st, 2014

Device invented at Johns Hopkins provides up-close look at cancer on the move: Microscopic view of metastasis could give insight about how to keep cancer in check October 31st, 2014

Nanobiotechnology

Tiny carbon nanotube pores make big impact October 29th, 2014

Molecular beacons shine light on how cells 'crawl' October 27th, 2014

Breakthrough in molecular electronics paves the way for DNA-based computer circuits in the future: DNA-based programmable circuits could be more sophisticated, cheaper and simpler to make October 27th, 2014

NYU Researchers Break Nano Barrier to Engineer the First Protein Microfiber October 23rd, 2014

NanoNews-Digest
The latest news from around the world, FREE





  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE