In Ukrainian

Abstract

The aim of the work is investigation of cytotoxic influence of the magnetocarried polyfunctional nanocomposites based on single-domain magnetite (Fe 3 O 4 ) and anthracycline antibiotic doxorubicin (DOX) on yeast cells Saccharomyces cerevisiae. Magnetite was synthesized according to the Elmor reaction. For investigations we used a fraction of particles with sizes of 6-23 nm. Specific surface area of the samples studied was S = 105–180 m 2 /g. Magnetosensitive nanocomposites Fe 3 O 4 /DOX, Fe 3 O 4 /SiO 2 /DOX, Fe 3 O 4 /TiO 2 /DOX, Fe 3 O 4 / hydroxyapatite (HA)/DOX were synthesized. To obtain Fe 3 O 4 /SiO 2 nanocomposites, we used tetraethoxysilane (TEOS) as a modifying agent. The technique for synthesis of nanocomposites consisting of magnetite modified with silica dioxide involves hydrolysis of TEOS. The coating was 0.2 g of SiO 2 on 1 g of magnetite. Specific surface area of the nanocomposite increases from 105 m 2 /g (for unmodified magnetite) to 130 m 2 /g. To obtain Fe 3 O 4 /TiO 2 nanocomposites, we used n-butylorthotitanate as a modifying agent. The technique based on the reaction of conversion of n-butylorthotitanate on the magnetite surface into ТіО 2 . This conversion consists in hydrolysis of n-butylorthotitanate followed by condensation of hydrolysis products with formation of amorphous ТіО 2 . Modification of the surface of nanosized magnetite with hydroxyapatite (obtaining of Fe 3 O 4 /H А composites) was carried out by the reaction: 10 Са (NO 3 ) 2 + 6 (NH 4 )2HPO 4 + 8 NH 4 ОН → Са 10 (PO 4 ) 6 ( ОН ) 2 + 20 NH 4 NO 3 . We realized immobilization of DOX on the surfaces of magnetite Fe 3 O 4 and nanostructures Fe 3 O 4 /SiO 2 , Fe 3 O 4 /TiO 2 , Fe 3 O 4 /HA by adsorption method from saline environment. Bioactivity of the nanocomposites was determined in the study of viability of cells by a cytochemical method using optical microscopy and Goryaev chamber with registration of concentration change for cells in suspensions containing nanocomposites, yeast cells, minimal synthetic nutrient medium and saline. Fe3O4/DOX, Fe 3 O 4 /SiO 2 /DOX, Fe 3 O 4 /TiO 2 /DOX, Fe 3 O 4 /HA/DOX nanocomposites had cytotoxic and antiproliferative activity with respect to Saccharomyces cerevisiae cells, which were characteristic for a free form of doxorubicin. Using the chosen objects, we worked out rather effective, reliable, safe and relatively inexpensive technique for control of cytotoxic activity of nanocomposites, which could be actual for use in development of new medical magnetocarried remedies of targeted delivery, in particular, for oncology.