Death by light: Nanoparticles as agents for the photodynamic killing of antibiotic-resistant bacteria
October 5, 2009(PhysOrg.com) -- The increasing antibiotic resistance of bacteria is a serious problem of our time. Hospital germs in particular have developed strains against which practically every current antibiotic is ineffective. In the battle against resistant microbes, a team at the University of Münster (Germany) is now pursuing a new approach involving photodynamic therapy, which is a technique that is already being used in the treatment of certain forms of cancer and macular degeneration.
Upon irradiation with light, an agent produces oxygen in a special activated form that is highly toxic to cells. As the researchers led by Cristian A. Strassert and Luisa De Cola report in the journal Angewandte Chemie, they would like to use specially developed nanomaterials that bind specifically to bacterial cells to mark them and kill them under irradiation.
The researchers use nanoparticles made of a special porous material (zeolite L). The particles are modified so they carry a coating of amino groups. These bind preferentially to the surfaces of bacterial cells by means of electrostatic attraction and hydrogen bonds. The researchers put a green fluorescent dye into the channels of the mineral, making the bacteria visible under a fluorescence microscope. The actual “weapons” are photosensitizers anchored on the surface of the nanoparticles.
When these molecules are irradiated with light of the right wavelength, they absorb the light energy and transfer it to oxygen molecules found in the surroundings, for example in infected tissue. The oxygen is excited and enters into what is known as the singlet state, in which it is highly reactive and attacks biomolecules - but only in the immediate area in which the singlet oxygen was generated. In this case, the location is right on the bacterial cell where the mineral particle is bound.
The scientists tested their new light-activated killer particles on antibiotic-resistant cultures of E. coli bacteria. After about two hours of irradiation, the bacteria were almost completely killed off. The team achieved comparable results with a strain of resistant gonococci. Furthermore, the researchers from Münster are also considering this material for the treatment of skin cancer. In this case, the tumor cells could be destroyed upon targeted irradiation with red light.
More information: Luisa De Cola, Photoactive Hybrid Nanomaterial for Targeting, Labeling, and Killing Antibiotic-Resistant Bacteria, Angewandte Chemie International Edition 2029, 68, No. 42, 7928-7931, doi: 10.1002/anie.200902837
-
DNA Taxi: Photosensitive gold nanoparticles bind and release DNA
Apr 27, 2006 |
not rated yet |
0
-
Sweet nothings: Artificial vesicles and bacterial cells communicate by way of sugar components
Jun 05, 2008 |
not rated yet |
0
-
Drug-resistant bacteria can be controlled
Apr 05, 2007 |
not rated yet |
0
-
A Good Eye for Oxygen
Mar 27, 2009 |
not rated yet |
0
-
New antibiotic beats superbugs at their own game
Jul 03, 2008 |
not rated yet |
0
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (31) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (3) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (1) |
0
-
Mitosis
5 hours ago
-
Stem cell question.
6 hours ago
-
Protease cleavage
12 hours ago
-
Pertubance in a model
19 hours ago
-
Cancer drugs and Alzheimer's, Oh my!
Feb 09, 2012
-
Squishing cells
Feb 09, 2012
- More from Physics Forums - Biology
More news stories
What lies beneath: Mapping hidden nanostructures
The ability to diagnose and predict the properties of materials is vital, particularly in the expanding field of nanotechnology. Electron and atom-probe microscopy can categorize atoms in thin sheets of material, ...
17 hours ago |
5 / 5 (3) |
1
New kind of solar cell could capture significantly more energy than current cells
New solar cells could increase the maximum efficiency of solar panels by over 25%, according to scientists from the University of Cambridge.
Feb 08, 2012 |
4.5 / 5 (12) |
14
|
Nanoshell whispering galleries improve thin solar panels
Visitors to Statuary Hall in the U.S. Capitol Building may have experienced a curious acoustic feature that allows a person to whisper softly at one side of the cavernous, half-domed room and for another on ...
Nanotechnology / Nanomaterials
Feb 07, 2012 |
4.3 / 5 (6) |
6
|
'Dark plasmons' transmit energy
Microscopic channels of gold nanoparticles have the ability to transmit electromagnetic energy that starts as light and propagates via "dark plasmons," according to researchers at Rice University.
Feb 09, 2012 |
4.8 / 5 (8) |
1
|
Revealing how a battery material works
Since its discovery 15 years ago, lithium iron phosphate (LiFePO4) has become one of the most promising materials for rechargeable batteries because of its stability, durability, safety and ability to deliver ...
Nanotechnology / Nanomaterials
Feb 08, 2012 |
5 / 5 (5) |
0
|
Anonymous knocks CIA website offline (Update)
The website of the Central Intelligence Agency was inaccessible on Friday after the hacker group Anonymous claimed to have knocked it offline.
New error-correcting codes guarantee the fastest possible rate of data transmission
Error-correcting codes are one of the triumphs of the digital age. Theyre a way of encoding information so that it can be transmitted across a communication channel such as an optical fiber o ...
Google users warned of threat to smartphone wallets
Users of Google smartphone wallets were being warned on Friday that there is a way to crack pass codes intended to thwart thieves from going on illicit shopping sprees.
Humans may have helped the decline of African rainforests 3000 years ago
(PhysOrg.com) -- Large areas of rainforests in Central Africa mysteriously disappeared over three thousand years ago, to be replaced by savannas. The prevailing theory has been that the cause was a change ...
New power source discovered
(PhysOrg.com) -- Researchers at the Massachusetts Institute of Technology (MIT) and RMIT University have made a breakthrough in energy storage and power generation.
The power of estrogen -- male snakes attract other males
A new study has shown that boosting the estrogen levels of male garter snakes causes them to secrete the same pheromones that females use to attract suitors, and turned the males into just about the sexiest ...