Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bringing the bling to antibacterials

02.07.2014

Shanghai researchers develop new way to combat bacterial biofilm formation with titanium encrusted with gold nanoparticles

Bacteria love to colonize surfaces inside your body, but they have a hard time getting past your rugged, salty skin. Surgeries to implant medical devices often give such bacteria the opportunity needed to gain entry into the body cavity, allowing the implants themselves to act then as an ideal growing surface for biofilms.


This image depicts destructive electron extraction from bacterial membranes by plasmonic gold nanoparticles.

Credit: Jinhua Li/SICCAS

A group of researchers at the Shanghai Institute of Ceramics in the Chinese Academy of Sciences are looking to combat these dangerous sub-dermal infections by upgrading your new hip or kneecap in a fashion appreciated since ancient times – adding gold. They describe the results of tests with a new antibacterial material they developed based on gold nanoparticles in the journal Applied Physics Letters, from AIP Publishing.

"Implant-associated infections have become a stubborn issue that often causes surgery failure," said Xuanyong Liu, the team's primary investigator at the Shanghai Institute of Ceramics. Designing implants that can kill bacteria while supporting bone growth, Liu said, is an efficient way to enhance in vivo osteointegration.

Titanium dioxide is able to kill bacteria itself due to its properties as a photocatalyst. When the metal is exposed to light, it becomes energetically excited by absorbing photons. This generates electron-hole pairs, turning titania into a potent electron acceptor that can destabilize cellular membrane processes by usurping their electron transport chain's terminal acceptor. The membrane is gradually destabilized by this thievery, causing the cell to leak out until it dies.

The dark conditions inside the human body, however, limit the bacteria-killing efficacy of titanium dioxide. Gold nanoparticles, though, can continue to act as anti-bacterial terminal electron acceptors under darkness, due to a phenomenon called localized surface plasmon resonance.

Surface plasmons are collective oscillations of electrons that occur at the interface between conductors and dielectrics – such as between gold and titanium dioxide. The localized electron oscillations at the nanoscale cause the gold nanoparticles to become excited and pass electrons to the titanium dioxide surface, thus allowing the particles to become electron acceptors.

Liu and his team electrochemically anodized titanium to form titanium dioxide nanotube arrays, and then further deposited the arrays with gold nanoparticles in a process called magnetron sputtering. The researchers then allowed Staphylococcus aureus and Escherichia coli to grow separately on the arrays -- both organisms were highly unsuccessful, exhibiting profuse membrane damage and cell leakage.

While silver nanoparticles have been previously explored as an antibacterial agent for in vivo transplants, they cause significant side effects such as cytotoxicity and organ damage, whereas gold is far more chemically stable, and thus more biocompatible.

"The findings may open up new insights for the better designing of noble metal nanoparticles-based antibacterial applications," Liu said.

###

Further research for Liu and his colleagues includes expanding the scope of experimental bacteria used and evaluating the arrays' in vivo efficacy in bone growth and integration.

The article, "Plasmonic gold nanoparticles modified titania nanotubes for antibacterial application" is authored by Jinhua Li, Huaijuan Zhou, Shi Qian, Ziwei Liu, Jingwei Feng, Ping Jin and Xuanyong Liu. It will appear in the journal Applied Physics Letters on July 1, 2014. After that date, it can be accessed at: http://scitation.aip.org/content/aip/journal/apl/104/26/10.1063/1.4885401

ABOUT THE JOURNAL

Applied Physics Letters features concise, rapid reports on significant new findings in applied physics. The journal covers new experimental and theoretical research on applications of physics phenomena related to all branches of science, engineering, and modern technology. See: http://apl.aip.org

Jason Socrates Bardi | Eurek Alert!
Further information:
http://www.aip.org

Further reports about: Ceramics Physics antibacterial bacteria damage dioxide kill nanoparticles oscillations titanium

More articles from Physics and Astronomy:

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

nachricht Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication
16.07.2018 | Chinese Academy of Sciences Headquarters

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>