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 SiO(2) nanoparticles was proposed. A simple and versatile method was developed for the preparation of SiO(2)-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 SiO(2)-dNTP were tested using Klenow fragment and HIV reverse transcriptase. Nucleoside triphosphates being a part of the SiO(2)-dNTP nanocomposites were shown to be incorporated into the growing DNA chain. The rate of polymerization with the use of SiO(2)-dNTP or common dNTP in case of HIV reverse transcriptase differed insignificantly. It was shown by confocal microscopy that the proposed SiO(2)-dNTP nanocomposites bearing the fluorescent label penetrate into cells and even into cellular nuclei.