Intracellular localization of natural and modified oligonucleotides in primary human endothelial cells

Intracellular localization of natural and fluorescent-labeled oligonucleotides in primary human endothelial cells was studied by means of fluorescence microscopy and radioisotope analysis. Transport and distribution of oligonucleotides in endotheliocytes depended on their structure and resistance to hydrolysis under the effect of cell nucleases. Modification of 5'-terminal phosphate and 3'-terminal oligonucleotide increased the stability and ensures nuclear localization of oligonucleotides in cells.