Abstract
Auger electrons are impression as a potential and prospective gene therapy becaused of its high energy transfer (LET 4-26 keV/μm). There were many studies on DNA breakage induced by Auger electrons, and most of them applied 125I to the experiment rarely with 99mTc. In this study, we developed a new application of 99mTc radionuclide as the Auger electron emitter to obtain more information about the correlation between the dose of 99mTc and DNA breakage with various conditions of time, dose of 99mTc, and proportion of Dimethyl sulfoxide (DMSO). Quantification of DNA damage was analyzed by electrophoresis and Image J. The results shown, in supercoiled form DNA model from 3 hr to 24 hr, the open form DNA and linear form DNA produced by Auger electrons respectively arose from 15% to 65% and 2% to 8% under exposed to 5□1011 decays/cm3 99mTc amount. But in linear form DNA model from 3 hr to 24 hr, the disappearance of linear form DNA percentage, decreased from 80 % to 24 % under exposed approximately to 1011 decays/cm3. DMSO is a scavenger for hydroxyl radical. In DMSO condition, the inhibition of open form and linear form formation from DNA damage were observed. Additionally, the ratio of DMSO/99mTc and inhibition of DNA damage are in direct proportion. DNA damage has been observed decreased extremely, when excess amount of DMSO was present in experiment procedure. Based on the results in this study, DNA damage fit in with decays of 99mTc and DMSO condition. Thereby, 99mTc with low energy and suitable half time could be an ideal radionuclide for Auger electron study.