A method was proposed for preparing a core-shell nanocomposite material based on Fe3O4 magnetic nanoparticles (MNPs) modified with pharmacologically active iron and silicon glycerolates. The material was characterized by modern physicochemical methods including Mössbauer spectroscopy, atomic emission spectroscopy, transmission electron microscopy, and X-ray phase analysis. The shell : core distribution of Fe (32 : 68), the shell : core weight ratio for Fe (66 : 34), and the total amount of glycerol residues С3Н5О3 (4.38 mmol per gram of MNPs) in the synthesized nanomaterial were determined.