A scientific article by Chinese scientists “Damaging Intermolecular Relaxation Processes Initiated by Heavy-Ion Irradiation of Hydrated Biomolecules”, co-authored by Anna Skitnevskaya, Senior Researcher at the Laboratory of Quantum-Chemical Modeling of Molecular Systems (LQMMS) of ISU, Candidate of Chemical Sciences, and Alexander Trofimov, Leading Researcher at ISU LQMMS, Doctor of Chemical Sciences, Professor of the Russian Academy of Sciences, has been published in the prestigious international scientific journal Physical Review X. This journal, which publishes selected research in the field of physics, is listed among the most prestigious journals by Nature Publishing Group (impact factor 11.6).
The year-long study, using model systems, reveals the mechanisms of intermolecular processes that occur when tissues are irradiated with beams of heavy ions and are likely responsible for DNA strand breaks in tumor cells. This occurs as a result of Intermolecular Coulombic Decay (ICD) – a universal fundamental process. Modern research into ICD sheds light on previously poorly understood aspects of molecular behavior under radiation. Heavy-ion irradiation is a promising method for radiation cancer therapy. Studying the mechanisms of the processes described in the work may be useful for further optimizing treatment protocols.
The theoretical modeling of the processes described in the article was carried out at ISU, while the Institute of Modern Physics of the Chinese Academy of Sciences in Lanzhou (China), home to a heavy ion accelerator, served as the base for the experiments.
Anna Skitnevskaya:
This device is designed to search for new elements but is also used for cancer therapy. It is the only installation of its kind in China. The processes of energy and charge transfer, which we are studying, were previously investigated using photons (laser) and electron beams to irradiate molecular complexes. However, there were no real experimental results with irradiation by heavier particles as an energy carrier, except for results obtained on very small complexes. In our work, the studies were conducted for a relatively large system – a pyrimidine molecule with several water molecules in the immediate vicinity. Together with our Chinese colleagues, we were able to prove that the processes occurring during bombardment with heavy nuclei (iron and carbon) are similar to the changes under the influence of photons and electrons. Our work found that the effectiveness of the studied processes changes significantly depending on the number of neighboring molecules – water molecules in this case. This important conclusion was only possible thanks to a comparison of theoretical and experimental data.
ISU LQMMS scientists have been working on this topic since 2017. Experimental results in this area cannot be interpreted without theoretical confirmation, that is why close collaboration between theorists and experimentalists is necessary. Experiments of this kind are not currently conducted in Russia. The LQMMS research group collaborates not only with the group in Lanzhou but also has joint projects with a group of physicists at Xi’an University (China) led by Professor Ren Xueguang and with German experimentalists and theorists.
Anna Skitnevskaya:
Today, China gives a lot of attention and invests heavily in the development of science. I see that the instruments that my colleagues from China are assembling in their universities, in terms of performance, quality, resolution and other characteristics, surpass those used by the more renowned German experimentalists, from whom most of today’s Chinese professors once learned. It must be said that the scientific groups that we interacted with show a high interest in collaborating with Russian scientists.
