The problem of creation of magnetically targeted nanosystems for a smart delivery of drugs to target cells has been solved with the application of a fundamentally novel method that obtaining from stable protein coatings. The method is based on the ability of proteins to form interchain covalent bonds under the action of free radicals which are generated locally on nanoparticles surface. By the set of physical and biochemical methods it has been proved that the free radical cross-linking of proteins allows obtaining stable single layer protein coatings of several nanometers in thickness. The cross-linked coatings were formed on the surface of individual magnetic nanoparticles (MNPs) (d ~ 17 nm) by free radical processes taking place strictly in the adsorption layer. Spin labels technique has been applied for studying of macromolecules adsorption on nanoparticles. The free radical cross-linking of proteins on the surface of nanoparticles has been shown to keep native properties of the protein molecules (was demonstrated on thrombin coating). The method may be used to reach various biomedical goals concerning a smart delivery of drugs and biologically active substances revealing new possibilities of design of single layer multiprotein polyfunctional coatings on all the surfaces containing metals of variable valence (for example, Fe, Cu, Cr).