Plasmid DNA damage by heavy ions at spread-out Bragg peak energies

H. M. Dang*, M. J. van Goethem, E. R. van der Graaf, S. Brandenburg, R. Hoekstra, T. Schlatholter

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

8 Citations (Scopus)

Abstract

Interaction of ionizing radiation with plasmid DNA can lead to formation of single strand breaks, double strand breaks and clustered lesions. We have investigated the response of the synthetic plasmid pBR322 in aqueous solution upon irradiation with (12)C ions under spread-out Bragg peak conditions (densely ionizing) and with (137)Cs gamma-photons (sparsely ionizing) as a function of dose. To evaluate the relevance of indirect effects, i.e. influences of diffusion limited radical induced DNA damage triggered by water radiolysis, the experiments were performed at various concentrations of the radical scavenger mannitol. Agarose gel electrophoresis was employed to quantify the DNA damage. At low scavenger concentration for a given dose DNA damage is higher for gamma-photons than for (12)C. For the latter, the microscopic dose distribution is inhomogeneous, with very high dose deposited along the few tracks through the solution. This is in agreement with the concept that scavengers efficiently reduce damage for gamma-photons, implying that the underlying damage mechanism is single strand break induction by OH radicals. For (12)C induced damage, the fraction of SSB and DSB that is unaffected by radical scavengers and thus due to direct effect is quantified.

Original languageEnglish
Pages (from-to)51-58
Number of pages8
JournalEuropean Physical Journal D
Volume60
Issue number1
DOIs
Publication statusPublished - Oct-2010

Keywords

  • ATOMIC-FORCE MICROSCOPY
  • DOUBLE-STRAND BREAK
  • LOCAL EFFECT MODEL
  • SCAVENGER CONCENTRATION
  • SINGLE-STRAND
  • IONIZING-RADIATION
  • AQUEOUS-SOLUTION
  • MAMMALIAN-CELLS
  • IN-VITRO
  • YIELD

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