Magnetic core-shell structures have a high potential for promising application in biomedicine as drug carriers. In this paper, magnetic core-shell structure obtained by the sol-gel method was presented. In order to provide the protective coating of magnetic MnFe2O4 nanoparticles, amorphous silica was used. It has been shown that magnetic core was successfully encapsulated in SiO2 matrix and that the received core-shell material had magnetic properties.