Features of doxorubicin adsorption on Fe3O4 magnetic nanoparticles coated with SiO2 or SiO2/aminopropylsilane

New nanocomposites based on Fe3O4 magnetic nanoparticles coated with SiO2 or SiO2/aminopropylsilane (APS), including those using N-(phosphonomethyl)iminodiacetic acid (PMIDA), were obtained, and the immobilization of the antitumor agent doxorubicin (Dox) on nanocomposites was examined. It has been shown that the binding of Dox to the negatively charged surface of SiO2 particles occurs more efficiently than that to the APS-modified surface with positively charged amino groups; the presence of PMIDA molecules on the surface significantly increased the loading content. Based on DFT calculations, a mechanism for Dox binding to the surface of the synthesized nanocomposites was proposed.