Probabilistic two-stage model of cell inactivation by ionizing particles

Modelling the mechanism of cell inactivation by light ions at different energy values

For efficient application of protons and light ions in radiotherapy, detailed knowledge and realistic models of the corresponding radiobiological mechanism are necessary. Basic characteristics of this mechanism have been represented within a probabilistic two-stage model. The processes that occur immediately after the traversals of individual particles and the response of cell to the total damage formed by all the particles have been distinguished. The model involves a probabilistic description of DNA damage formation and repair processes, too.

Cell inactivation by diverse ions along their tracks

Irradiation of cell monolayers by monoenergetic ions has made it possible to establish survival curves at individual values of linear energy transfer. The two-step model of radiobiological mechanism proposed recently by Judas and Lokajicek (Judas L., Lokajicek M., 2001: Cell inactivation by ionizing particles and the shapes of survival curves. J. Theor. Biol. 210 (1), 15-21., doi:10.1006/jtbi.2001.2283) has then enabled to show that some significant deviations from the generally used linear-quadratic model should exist at higher values of linear energy transfer, which has been also demonstrate…

Mechanism of cell inactivation by different ions: Damage induction probabilities per single tracks

Biological effects of proton and light ion irradiations have been studied in detail by analyzing published cell survival data with the help of the probabilistic two-stage radiobiological model. Probabilities of single ion tracks to induce lesions of different severity have been assessed in dependence on their linear energy transfer (LET). The results are presented and their interpretation in terms of $Z_{eff}^2/β^2$ (the effective charge over velocity squared) is discussed.

Mathematical Model of DSB formation by Ionizing Radiation

The understanding of inactivation radiobiological mechanism in individual cells is important when from one side the application of ionizing radiation to tumour therapy and from the other side the protection against radiation are to be effectively improved. Important part of this mechanism is double-strand break (DSB) formation; these DSB may be formed directly by impacting ionizing particles or indirectly by different secondary radicals. The latter kind of formation is much more frequent when cells contain normal water content. Mathematical model of the corresponding chemical stage will be pre…

用于疫苗开发的SARS-CoV-2辐射诱导灭活的Monte Carlo模拟

Monte Carlo simulation of SARS-CoV-2 radiation-induced inactivation for vaccine development

本研究使用Monte Carlo工具包Geant4-DNA模拟电离辐射对SARS-CoV-2的灭活，发现加速带电粒子相比gamma射线能减少包膜蛋白损伤，为疫苗开发提供新方法。

Detailed analysis of the cell-inactivation mechanism by accelerated protons and light ions

Published survival data for V79 cells irradiated by monoenergetic protons, helium-3, carbon, and oxygen ions and for CHO cells irradiated by carbon ions have been analyzed using the probabilistic two-stage model of cell inactivation. Three different classes of DNA damages formed by traversing particles have been distinguished, namely severe single-track damages which might lead to cell inactivation directly, less severe damages where cell inactivation is caused by their combinations, and damages of negligible severity that can be repaired easily. Probabilities of single ions to form these dama…