Non-Agglomerated Oligonucleotide-Containing Nanocomposites Based on Titanium Dioxide Nanoparticles

Objective: Stability and monodispersity are important properties of nanoparticles and nanocomposites, that ensure the reliability of their application in biological systems and the reproducibility of results. The preparation of non-agglomerated oligonucleotide-containing nanocomposites based on anatase titanium dioxide nanoparticles (Ans~ODN) is the aim of this study. Methods: The immobilization of oligodeoxynucleotides on TiO₂ nanoparticles was studied by dynamic light scattering and transmission electron microscopy. The antiviral activity of the synthesized samples was evaluated against VERO cells infected with herpes simplex virus type 1. Results and Discussion: The effect of NaCl on the agglomeration of the nanoparticles and the nanocomposites in aqueous solutions was studied. The presence of NaCl leads to agglomeration of the nanoparticles and the nanocomposites. It was shown that the nanocomposites are formed in an aqueous solution in the absence of NaCl. A comparison of the biological activities of the nanocomposites prepared in water and in saline solution was carried out on the example of inhibition of replication of the herpes simplex virus type 1 in the cell culture. The studied nanocomposite, regardless of the preparation method (in water or in 0.9% NaCl), inhibited virus replication by 4.5 orders of magnitude when used 1 day after preparation. After 10 days of storage, the activity of the sample prepared in saline solution was two orders of magnitude lower than that of the active sample prepared in water. Conclusions: We have developed a method for the preparation of non-agglomerated oligonucleotide-containing nanocomposites based on anatase nanoparticles and demonstrated their potential use for the study of their biological activity. Unlike nanocomposites prepared in the presence of the salt, which lose their efficacy during storage, nanocomposites that are not prone to agglomeration can be obtained in water for future use.