Electrochemical Studies of the Interaction of Phospholipid Nanoparticles with dsDNA

Abstract

The effect of phospholipid nanoparticles with different contents of phosphatidylcholine (PhNP80 and PhNP100) on dsDNA was studied by means of the electrochemical method. Changes in the electrochemical behavior of heterocyclic bases guanine, adenine and thymine in the range of potentials of 0.2–1.2 V in the presence of PhNPs were used for the assessment of the binding mechanism of the ligand–DNA interaction. Comparative analysis of the effect of PhNPs with different contents of phosphatidylcholine showed a more pronounced effect on the dsDNA of the PhNP100 nanosystem. From the obtained experimental data on the decrease in the amplitude of the nucleobases’ electrochemical oxidation currents, the electrochemical coefficient of the toxic effect was calculated as the ratio of the electrooxidation currents of dsDNA and dsDNA in the presence of phospholipid nanoparticles. PhNP80/100 (up to 11.4 mg/mL) does not influence dsDNA, PhNP80/100 (14.3–28.5 mg/mL) has a moderate toxic effect on dsDNA, PhNP80/100 at concentrations above 28.5 mg/mL already have a toxic effect, significantly reducing the maximum amplitude of the heterocyclic bases’ electrochemical oxidation current. Peak potentials of electrochemical oxidation of nucleobases did not shift in the presence of PhNP80 and PhNP100 (in the concentration range of 2.3–42.2 mg/mL), which could be possible through a groove-binding mode of phospholipid nanoparticle interaction with dsDNA.