Importance of radiolytic reactions during high-LET irradiation modalities: LET effect, role of O2 and radiosensitization by nanoparticles

Abstract

Background It is striking how chemists and biologists showed an interest for ionizing radiations very soon after their discovery by Roentgen and Becquerel, and initiated parallel developments of these new fields of research: radiation chemistry and radiobiology. Radiation chemistry deals with the chemical effects produced when materials are exposed to ionizing radiations and begun long before 1942 when it was formally named by Burton (Magee 1988). Early pioneering works were achieved by Curie and Debierne in 1901 by observing gas bubbling out of radium salt solutions, Giesel in 1902 (Giesel 1902), Ramsay in 1903, and the progress and enthusiasm persisted throughout the beginning of 20th century (Debierne 1914; Kernbaum 1909

Heavy-ion beam-induced reactive oxygen species and redox reactions

“…The detection efficiency was therefore greater than 64%. When the primary G-value of OH of 2.7, which is the yield of OH at the chemical stage (!10 À7 s) [48] was used, the expected yield of OH was 0.280 lmol/L/Gy, less than our experimental DMPO-OH yield. The EPR spin-trapping method can scavenge OH, probably the initial yield, during its markedly short lifetime, enabling the collection of information about momentary OH generation.…”

“…The yield of H 2 O 2 expected from the primary G-value of H 2 O 2 of 0.7 [48] was 0.073 lmol/L/Gy. However, a larger yield of H 2 O 2 was experimentally observed as 0.26 ± 0.01 lmol/L/Gy in an X-ray-irradiated water sample [43].…”

X-ray and UV Radiation Damage of dsDNA/Protein Complexes

“…More and more people are diagnosed with cancer each year. To prevent cancer deaths, many research groups are searching for "cancer drugs", both theoretically and experimentally [10,13,18]. Many new branches and directions of research have been created, including the study of the sensitization of DNA to radiation, because the majority of patients with localized cancers undergo radiation therapy and, less frequently, dynamic phototherapy [13].…”

“…In oxygenated cells, hydroxyl radicals are produced in higher concentrations compared to solvated electrons. However, in hypoxic conditions, solvated electrons appear at the same concentration as hydroxyl radicals [ 9 , 10 ]. This observation is similar to the hypoxic conditions observed in solid tumor cells with insufficient angiogenesis [ 11 ].…”

The role of shock waves on the biodamage induced by ion beam radiation

“…This is due to the rich radiationinduced chemistry, which strongly depends on LET. A comprehensive review on the experimental evidence available on the yields and reactions of chemically reactive species in ion tracks can be found in the current series (Baldacchino et al 2019). The prevalence of indirect DNA damage by chemically reactive species is especially true for low-LET radiation (e.g.…”