Enhanced Cytotoxicity of Silver Nanoparticles by the Use of Electrical Pulses

Abstract

Background: Electroporation is an electrical technique to deliver different molecules to target tissues. Application of potent electric pulses can increase permeability of the membrane for a number of molecules via creating transient pores in cell membrane. On the other hand, while significant antimicrobial properties of silver nanoparticles (SNP) has made them candidates for destroying cancer cells, because of their toxicity, reducing the side effects of toxicity for vital organs of the body requires administration of low doses of these nanoparticles. In this study, a low dose of silver nanoparticle was applied to MCF-7 cancer cells and reduced treatment efficacy was compensated using electroporation. Methods: We first evaluated the toxicity of silver nanoparticles in different concentrations. Four square electric pulses with different strengths and durations were applied to cells in 1 Hz frequency by ECM-830 electroporator instrument in presence and absence of 10-nm silver nanoparticles; the performance of the technique was evaluated using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The characteristics of electric pulses to generate effective synergism with a small dose of nanoparticle were determined. Findings: IC50 of silver nanoparticles was estimated to be 4.5 µg/ml. Application of silver nanoparticles and electric pulses, with the strength of 700 V/cm and the duration of 100, 500, and 300 μs, simultaneously provided an effective cell death. Maximum synergism between nanoparticles and electric pulses was recorded in the duration of 100 μs. Conclusion: The application of electric pulses in presence of silver nanoparticles enables compensation of the effect of administering lower doses of nanoparticles.

Keywords

• Silver nanoparticles
• Electroporation
• MCF-7 cell line