Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Death by Light

Nanoparticles as agents for the photodynamic killing of antibiotic-resistant bacteria

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.

Author: Luisa De Cola, Westfälische Wilhelms-Universität Münster (Germany),

Title: 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

Luisa De Cola | Angewandte Chemie
Further information:

Further reports about: Angewandte Chemie Cola Germany bacterial cells death oxygen molecule

More articles from Life Sciences:

nachricht Make way for the mini flying machines
21.03.2018 | American Chemical Society

nachricht New 4-D printer could reshape the world we live in
21.03.2018 | American Chemical Society

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

TRAPPIST-1 planets provide clues to the nature of habitable worlds

21.03.2018 | Physics and Astronomy

The search for dark matter widens

21.03.2018 | Materials Sciences

Natural enemies reduce pesticide use

21.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>