On possible role of hydrogen peroxide molecules in ion beam therapy of cancer cells

Abstract

The possible role of molecular products of cell radiolysis, in particular, hydrogen peroxide molecules, in blocking DNA activity in cancer cells during irradiation with heavy ions is investigated. It is supposed that hydrogen peroxide molecules can form long-lived molecular complexes with DNA atomic groups and, thus, prevent the realization of genetic information in the biological cells. Using the quantum-mechanical approach based on density functional method and implicitly taking into account the aqueous medium, the competitive interactions of water and hydrogen peroxide molecules with DNA nucleic bases have been analyzed. Estimates of the characteristic lifetimes of complexes of water molecules and hydrogen peroxide with atomic groups of DNA allow showing the possibility to block the genetic activity of DNA by hydrogen peroxide in biological cells after their irradiation with ion beams. The effect of DNA blocking in cancer cells could be enhanced by a decrease in the cell temperature.

Radiosensitizing Effect of Dextran-Coated Iron Oxide Nanoparticles on Malignant Glioma Cells

“…The current research considers two mechanisms for the manifestation of the radiosensitizing properties of iron oxide nanoparticles: (i) an increase in the local absorbed dose due to the generation of secondary electrons by the dense core of nanoparticles; (ii) an increase in the formation of ROS, which cause oxidative stress, catalyzed by the core material when the organic shell of the nanoparticle is destroyed inside the cell [26,[32][33][34]. Organically coated nanoparticles by themselves do not cause significant toxicity when absorbed by cells by means of endocytosis.…”