title: DNA Damage in Bone Marrow Cells Induced by Femtosecond and Nanosecond Ultraviolet Laser Pulses.
abstract: OBJECTIVE
  The purpose of this study was to investigate the possible genotoxic impact of new generation 205 nm femtosecond solid-state laser irradiation on the DNA of murine bone marrow cells in vitro, and to compare the DNA damage caused by both femtosecond and nanosecond UV laser pulses.
  
  
  BACKGROUND
  Recent experiments of corneal stromal ablation in vitro and in vivo applying femtosecond UV pulses showed results comparable with or superior to those obtained using nanosecond UV lasers. However, the possible genotoxic effect of ultrashort laser pulses was not investigated.
  
  
  METHODS
  Mouse bone marrow cells were exposed to different doses of 205 nm femtosecond, 213 and 266 nm nanosecond lasers, and 254 nm UV lamp irradiation. The comet assay was used for the evaluation of DNA damage.
  
  
  RESULTS
  All types of irradiation demonstrated intensity-dependent genotoxic impact. The DNA damage induced depended mainly upon wavelength rather than on other parameters such as pulse duration, repetition rate, or beam delivery to a target.
  
  
  CONCLUSIONS
  Both 205 nm femtosecond and clinically applied 213 nm nanosecond lasers' pulses induced a comparable amount of DNA breakage in cells exposed to the same irradiation dose. To further evaluate the suitability of femtosecond UV laser sources for microsurgery, a separate investigation of the genotoxic and mutagenic effects on corneal cells in vitro and, particularly, in vivo is needed.
authors.affiliation: 1 Department of Botany and Genetics, Faculty of Natural Sciences, Vilnius University , Vilnius, Lithuania .
authors.forename: Vaidotas
authors.initials: V
authors.lastname: Morkunas
authors.affiliation: 2 Light Conversion Ltd. , Vilnius, Lithuania .|3 Department of Quantum Electronics, Faculty of Physics, Vilnius University , Vilnius, Lithuania .
authors.forename: Egle
authors.initials: E
authors.lastname: Gabryte
authors.affiliation: 3 Department of Quantum Electronics, Faculty of Physics, Vilnius University , Vilnius, Lithuania .
authors.forename: Mikas
authors.initials: M
authors.lastname: Vengris
authors.affiliation: 2 Light Conversion Ltd. , Vilnius, Lithuania .
authors.forename: Romualdas
authors.initials: R
authors.lastname: Danielius
authors.affiliation: 4 Joint Stock Company Akiu Gydytoju Praktika , Vilnius, Lithuania .
authors.forename: Egle
authors.initials: E
authors.lastname: Danieliene
authors.affiliation: 5 Department of Neurobiology and Biophysics, Faculty of Natural Sciences, Vilnius University , Vilnius, Lithuania .
authors.forename: Osvaldas
authors.initials: O
authors.lastname: Ruksenas
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000528:radiation effects*; D004249:DNA Damage; D007834:Lasers; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D014466:Ultraviolet Rays