SiO2 nanoparticles as platform for delivery of nucleoside triphosphate analogues into cells

A system for delivery of analogues of 2′-deoxyribonucleoside triphosphate (dNTP) based on SiO2 nanoparticles was proposed. A simple and versatile method was developed for the preparation of SiO2–dNTP conjugates using the ‘click’-reaction between premodified nanoparticles containing the azido groups and dNTP containing the alkyne-modified γ-phosphate group. The substrate properties of SiO2–dNTP were tested using Klenow fragment and HIV reverse transcriptase. Nucleoside triphosphates being a part of the SiO2–dNTP nanocomposites were shown to be incorporated into the growing DNA chain. The rate of polymerization with the use of SiO2–dNTP or common dNTP in case of HIV reverse transcriptase differed insignificantly. It was shown by confocal microscopy that the proposed SiO2–dNTP nanocomposites bearing the fluorescent label penetrate into cells and even into cellular nuclei.