In a recent development, scientists at the Tata Institute of Fundamental Research report that damage to DNA can be induced by ultrashort pulses of high intensity laser light. Published in Scientific Reports, these findings have important implications in clinical conditions, especially in reducing collateral damage to tissues surrounding the real target of conventional radiotherapy.
High intensity femtosecond laser pulses were used to probe damage to aqueous DNA . In propagating through the water medium, the intense light pulses cause H2O molecules to ionize and break-up, giving rise to low-energy electrons and OH-radicals. Both are responsible for producing breaks in DNA strands. Infact, earlier work carried out by the same team [2, 3] showed that OH radicals were four times more likely than electrons to produce double strand breaks in DNA.
A collaborative project between TIFR Mumbai, the Centre for Excellence in Basic Sciences, Mumbai, and Manipal University, the experiments described in this new publication utilized different incident laser energies and various external focusing conditions to establish that DNA damage occurs in two distinct regimes. Interestingly, the numerical aperture of the focusing lens (the light-gathering ability of the lens) delineates the two regimes. This permits optical control to be exercised over the extent of DNA damage by simply varying the focal length of the focusing lens.
"The experimental technique of generating, in situ, slow electrons and radicals within aqueous media has important implications in different scenarios where the effects of non-ionizing radiation need to be probed under physiologically relevant conditions," says Professor Deepak Mathur, senior scientist at TIFR Mumbai, and the lead scientist of this study.
It has been suggested that detrimental dose distributions within tissues that are irradiated by gamma radiation - one of the major difficulties in radiotherapy -- might be avoided by use of femtosecond laser induced filamentation. This is due to ultrashort laser pulses, particularly in the infrared region, being spatially confined to volumes (~125 μm3) that are much smaller than what is possible to attain using contemporary clinical radiation sources. This is important for minimising damage to non-target tissues in the vicinity.
1. J. A. Dharmadhikari, A. K. Dharamdhikari, K. C. Kasuba, H. Bharambe, J. S. D'Souza, K. D. Rathod, and D. Mathur, Sci. Reports -- in press
2. J. S. D'Souza et al., Phys. Rev. Letters 106 (2011) 118101,/p>
3. A. K. Dharmadhikari et al., Phys. Rev. Letters 112 (2014) 138105
Professor Deepak Mathur | EurekAlert!
More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn
How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy