Synthesis and Characterization of Magnetic FexOy@SBA-15 Composites with Different Morphologies for Controlled Drug Release and Targeting

Magnetic functionalization of the ordered mesoporous SBA-15 (SiO 2 ) aggregate blocks and rice grain-like particles were realized by using a sol−gel method, resulting in the formation of Fe x O y @SBA-15 composite materials. The X-ray diffraction (XRD), N 2 adsorption/desorption, and transmission electron microscopy (TEM) results show that these composites conserved ordered mesoporous structure after the formation of Fe x O y nanoparticles in the pores and on the outer surface of SBA-15. It was confirmed by the XRD and X-ray photoelectron spectroscopy (XPS) analysis that the Fe x O y generated in these mesoporous silica hosts is mainly composed of γ-Fe 2 O 3 . Magnetic measurements reveal that these composites possess superparamagnetic properties at 300 K. The saturation magnetization of these composites increased with the increasing loading amount of γ-Fe 2 O 3 . These composites, which possess high surface area and high pore volume, show magnetic response sufficient for drug targeting in the presence of an external magnetic field. These magnetic composites show sustained release profiles with ibuprofen as the model drug. The rice grain-like Fe x O y @SBA-15 particles show higher release rate with respect to the Fe x O y @SBA-15 aggregate blocks.