Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Scientists develop world’s first light-activated antimicrobial surface that also works in the dark

Samples of silicone with the various dyes infused
Samples of silicone with the various dyes infused

Abstract:
Researchers at UCL have developed a new antibacterial material which has potential for cutting hospital acquired infections. The combination of two simple dyes with nanoscopic particles of gold is deadly to bacteria when activated by light - even under modest indoor lighting. And in a first for this type of substance, it also shows impressive antibacterial properties in total darkness.

Scientists develop world’s first light-activated antimicrobial surface that also works in the dark

London, UK | Posted on March 24th, 2014

The research, from by Sacha Noimark and Ivan Parkin (both UCL Chemistry) and Elaine Allan (UCL Eastman Dental Institute), is published today in the journal Chemical Science.

Hospital-acquired infections are a major issue for modern medicine, with pathogens like methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile (C. diff) getting extensive publicity. Although medical establishments have stringent cleaning policies, insist on frequent hand-washing by staff, and have powerful drugs at their disposal, it is difficult to eliminate these infections unless you can make the hospital environment more hostile to microbes. Surfaces, such as door handles, medical equipment, keyboards, pens and so on are an easy route for germs to spread, even onto freshly-cleaned hands.

One possible solution to this is to develop alternative strategies such as antibacterial coatings that make surfaces less accommodating to germs. These surfaces are not like antibacterial fluids that just wash away - the goal is to make a surface which is intrinsically deadly to harmful bacteria.

"There are certain dyes that are known to be harmful to bacteria when subjected to bright light," explains the study's corresponding author Ivan Parkin (Head of UCL Chemistry). "The light excites electrons in them, promoting the dye molecules to an excited triplet state and ultimately produces highly reactive oxygen radicals that damage bacteria cell walls. Our project tested new combinations of these dyes along with gold nanoparticles, and simplified ways of treating surfaces which could make the technology easier and cheaper to roll out."

The team, tested several different combinations of the dyes crystal violet (already used to treat staph infections), methylene blue and nanogold, deposited on the surface of silicone. This flexible rubbery substance is widely used as a sealant, a coating and to build medical apparatus such as tubes, catheters and gaskets, and can also be used as protective casings for things like keyboards and telephones.

While work to create antimicrobial surfaces in the past has often concentrated on complex ways of bonding dyes to the surface, this study took a simpler approach. The researchers used an organic solvent to swell the silicone, allowing the methylene blue and gold nanoparticles to diffuse through the polymer. They then dipped the silicone into a crystal violet solution to form a thin dye layer at the polymer surface.

In their tests, in which infected surfaces were subjected to light levels similar to those measured in hospital buildings, surfaces treated with a combination of crystal violet, methylene blue and nanogold showed the most potent bactericidal effect ever observed in such a surface. Moreover, the treatment did not significantly change the properties of the silicone (for instance, how water repellent it is), and the coating was not affected by rubbing with alcohol wipes, meaning it can stand up to the repeated cleaning that goes on in hospitals, without being worn off.

"Despite contaminating the surface with far more bacteria than you would ever see in a hospital setting, placed under a normal fluorescent light bulb, the entire sample was dead in three to six hours, depending on the type of bacteria," says the paper's lead author, Sacha Noimark. "That was an excellent result, but the bigger surprise was the sample which we left in the dark. That sample too showed significant reductions in bacterial load, albeit over longer timescales of about three to eighteen hours. The precise mechanism by which this dark-kill works is not yet clear, though."

This is the first time a light-activated antimicrobial surface has had any kind of effect in the dark. This, along with its unprecedented performance under hospital lighting conditions, and relatively simple and cost-effective manufacture, means that the technology is extremely promising for future applications.

The team have been granted a patent on the formulation. The work was sponsored through the UCL M3S engineering doctorate centre and co-funded by Ondine Biopharma.

####

For more information, please click here

Contacts:
Oli Usher

020-767-97964

Copyright © University College London

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 Links

UCL Chemistry:

UCL Eastman Dental Institute:

Full paper available in Chemical Science (£):

Related News Press

News and information

Sunblock poses potential hazard to sea life August 20th, 2014

Rice physicist emerges as leader in quantum materials research: Nevidomskyy wins both NSF CAREER Award and Cottrell Scholar Award August 20th, 2014

Graphene may be key to leap in supercapacitor performance August 20th, 2014

Newly-Developed Nanobiosensor Quickly Diagnoses Cancer August 20th, 2014

Nanomedicine

Newly-Developed Nanobiosensor Quickly Diagnoses Cancer August 20th, 2014

Graphene rubber bands could stretch limits of current healthcare, new research finds August 19th, 2014

Interaction between Drug, DNA for Designing Anticancer Drugs Studied in Iran August 17th, 2014

Iranian Scientists Stabilize Protein on Highly Stable Electrode Surface August 14th, 2014

Discoveries

Sunblock poses potential hazard to sea life August 20th, 2014

Rice physicist emerges as leader in quantum materials research: Nevidomskyy wins both NSF CAREER Award and Cottrell Scholar Award August 20th, 2014

Newly-Developed Nanobiosensor Quickly Diagnoses Cancer August 20th, 2014

Ultrasonic Waves Applied in Production of Graphene Nanosheets August 20th, 2014

Announcements

Rice physicist emerges as leader in quantum materials research: Nevidomskyy wins both NSF CAREER Award and Cottrell Scholar Award August 20th, 2014

Graphene may be key to leap in supercapacitor performance August 20th, 2014

Newly-Developed Nanobiosensor Quickly Diagnoses Cancer August 20th, 2014

Ultrasonic Waves Applied in Production of Graphene Nanosheets August 20th, 2014

Food/Agriculture/Supplements

Success in Intracellular Imaging of Cesium Distribution in Plants Used for Cesium Absorption August 19th, 2014

AQUANOVA receives Technology Leadership Award 2014 FROST & SULLIVAN honors NovaSOL® Technology again August 12th, 2014

Silver Nanocoatings Better Choice for Packaging of Foodstuff August 12th, 2014

PerkinElmer to Display Innovative Detection and Informatics Offerings at ACS National Meeting & Exposition Detection, Data Visualization and Analytics for Chemistry Professionals August 8th, 2014

Grants/Awards/Scholarships/Gifts/Contests/Honors/Records

Rice physicist emerges as leader in quantum materials research: Nevidomskyy wins both NSF CAREER Award and Cottrell Scholar Award August 20th, 2014

Oxford Instruments Asylum Research Receives the 2014 Microscopy Today Innovation Award for blueDrive Photothermal Excitation August 18th, 2014

AQUANOVA receives Technology Leadership Award 2014 FROST & SULLIVAN honors NovaSOL® Technology again August 12th, 2014

Focal blood-brain-barrier disruption with high-frequency pulsed electric fields August 12th, 2014

Research partnerships

Сalculations with Nanoscale Smart Particles August 19th, 2014

Promising Ferroelectric Materials Suffer From Unexpected Electric Polarizations: Brookhaven Lab scientists find surprising locked charge polarizations that impede performance in next-gen materials that could otherwise revolutionize data-driven devices August 18th, 2014

Nano Bonds Increase Raw Strength of Fireproof Concretes August 18th, 2014

Production of Toxic Ion Nanosorbents with High Sorption Capacity in Iran August 17th, 2014

Dental

New Powder Nanocomposite Miracle in Bone Recovery May 10th, 2014

Newly-Produced Bone Cement Able to Carry Medicine April 21st, 2014

Plasma tool for destroying cancer cells: Inducing biological tissue damage with an atmospheric pressure plasma source could open the door to many applications in medicine March 26th, 2014

Inhibition of oral biofilm and cell-cell communication using natural-products derivatives March 20th, 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