Optimization of synthesis parameters for mesoporous shell formation on magnetic nanocores and their application as nanocarriers for docetaxel cancer drug.

In this work, Fe3O4@SiO2 nanoparticles were coated with mesoporous silica shell by S-N+I- pathway by using anionic surfactant (S-) and co-structure directing agent (N+). The role of co-structure directing agent (CSDA) is to assist the electrostatic interaction between negatively charged silica layers and the negatively charged surfactant molecules. Prior to the mesoporous shell formation step, magnetic cores were coated with a dense silica layer to prevent iron oxide cores from leaching into the mother system under any acidic circumstances. However, it was found that both dense and mesoporous coating parameters affect the textural properties of the produced mesoporous silica shell (i.e., surface area, pore volume and shell thickness). The synthesized Fe3O4@SiO2@m-SiO2 (MCMSS) nanoparticles have been characterized by low-angle X-ray diffraction, transmission electron microscopy (TEM), and N2 adsorption-desorption analysis, and magnetic properties. The synthesized particles had dense and mesoporous silica shells of 8-37 nm and 26-50 nm, respectively. Furthermore, MCMSS possessed surface area of ca. 259-621 m2·g-1, and pore volume of ca. 0.216-0.443 cc·g-1. MCMSS showed docetaxcel cancer drug storage capacity of 25-33 w/w% and possessed control release from their mesochannels which suggest them as proper nanocarriers for docetaxcel molecules.