Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Successful laboratory test of photoswitchable anti-tumor agent

25.04.2016

KIT researchers develop oxygen-independent, photoswitchable molecule and test it successfully in the lab for its effect against tumors

Photoswitchable agents might reduce side effects of a chemotherapy. So far, photodynamic therapies have been dependent on oxygen in the tissue. But hardly any oxygen exists in malignant, rapidly growing tumors.


The GS-DProSw molecule in its inactive form (blue) can be activated by visible light (red) and "switched off" again by UV light.

Figure: KIT

A group of researchers of KIT and the University of Kiev has now developed a photo-switchable molecule as a basis of an oxygen-independent method. Their successful laboratory tests on tumors are reported in the journal Angewandte Chemie (Applied Chemistry). DOI: 10.1002/ange.201600506.

Photodynamic therapy (PDT) in medicine usually uses a substance that reacts to light and converts the oxygen in the tissue into aggressive radicals. These reactive substances are toxic and damage the neighboring cells, such that e.g. tumors are decomposed. As a result of their quicker growth, however, many tumors have a high oxygen consumption. This reduces the concentration of oxygen available in the tissue, which may aggravate conventional PDT.

Researchers of KIT and the University of Kiev have now developed a new photo-switchable molecule for oxygen-independent PDT. The effect of the GS-DProSw molecule can be "switched off" by ultraviolet light prior to therapy. Only upon application is it "switched on" in the tumor tissue by visible light and damages the tumor tissue there.

"The surrounding organs remain in the dark and are not affected by the active substance," Anne S. Ulrich, Professor for Biochemistry and Director of the KIT Institute for Biological Interfaces, explains. "As a result, side effects are reduced significantly."

For the first time, this new concept has now been tested on animal models. Once per day, the photoswitchable GS-DProSw molecule was administered. Then, the tumors were irradiated locally with visible light for a period of 20 minutes. After ten days of PDT treatment, the tumors were found to be far smaller than comparative groups not treated with light.

To initiate an oxygen-independent reaction in a PDT, the molecule applied has to be of cytotoxic nature. This means that it has to directly attack the tumor tissue irrespective of other reaction partners. A suitable molecule with cytotoxic properties against tumors is the biomolecule gramicidin S (GS), a natural antibiotic. To prevent it from damaging healthy tissue, the research team inserted a photo-switchable diaryl ethene segment into the ring structure.

As a result, the GS-DProSw molecule can be switched between two states with the help of light: The agent can be administered in the inactive state and is activated at the desired location by specific irradiation with light. There, it attacks the surrounding tumor tissue and contrary to conventional PDT, it does not require any oxygen for this purpose.

"This first proof of functioning represents an important step in fundamental research for the development of anti-tumor agents," Ulrich explains. "But we still have a far way to go: To reliably use this type of photoswitchable molecules for a photodynamic therapy of patients, numerous other studies have to be carried out in cooperation with our partners in Kiev."

###

Oleg Babii, Sergii Afonin, Liudmyla V. Garmanchuk, Viktoria V. Nikulina, Tetiana V. Nikolaienko, Olha V. Storozhuk, Dmytro V. Shelest, Olga I. Dasyukevich, Liudmyla I. Ostapchenko, Volodymyr Iurchenko, Sergey Zozulya, Anne S. Ulrich, and Igor V. Komarov: Direct photocontrol of peptidomimetics: an alternative to oxygen dependent photodynamic cancer therapy. Angewandte Chemie (2016). DOI: 10.1002/ange.201600506

Media Contact

Monika Landgraf
presse@kit.edu
49-721-608-47414

 @KITKarlsruhe

http://www.kit.edu/index.php 

Monika Landgraf | EurekAlert!

More articles from Health and Medicine:

nachricht Potential seen for tailoring treatment for acute myeloid leukemia
10.12.2018 | University of Washington Health Sciences/UW Medicine

nachricht UC San Diego researchers develop sensors to detect and measure cancer's ability to spread
06.12.2018 | University of California - San Diego

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Researchers develop method to transfer entire 2D circuits to any smooth surface

What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.

Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...

Im Focus: Three components on one chip

Scientists at the University of Stuttgart and the Karlsruhe Institute of Technology (KIT) succeed in important further development on the way to quantum Computers.

Quantum computers one day should be able to solve certain computing problems much faster than a classical computer. One of the most promising approaches is...

Im Focus: Substitute for rare earth metal oxides

New Project SNAPSTER: Novel luminescent materials by encapsulating phosphorescent metal clusters with organic liquid crystals

Nowadays energy conversion in lighting and optoelectronic devices requires the use of rare earth oxides.

Im Focus: A bit of a stretch... material that thickens as it's pulled

Scientists have discovered the first synthetic material that becomes thicker - at the molecular level - as it is stretched.

Researchers led by Dr Devesh Mistry from the University of Leeds discovered a new non-porous material that has unique and inherent "auxetic" stretching...

Im Focus: The force of the vacuum

Scientists from the Theory Department of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science (CFEL) in Hamburg have shown through theoretical calculations and computer simulations that the force between electrons and lattice distortions in an atomically thin two-dimensional superconductor can be controlled with virtual photons. This could aid the development of new superconductors for energy-saving devices and many other technical applications.

The vacuum is not empty. It may sound like magic to laypeople but it has occupied physicists since the birth of quantum mechanics.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

Expert Panel on the Future of HPC in Engineering

03.12.2018 | Event News

 
Latest News

Small but ver­sat­ile; key play­ers in the mar­ine ni­tro­gen cycle can util­ize cy­anate and urea

10.12.2018 | Life Sciences

New method gives microscope a boost in resolution

10.12.2018 | Physics and Astronomy

Carnegie Mellon researchers probe hydrogen bonds using new technique

10.12.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>