Fe3O4-Nanoparticle-Embedded Multifunctional Hollow Mesoporous Silica Capsules

Magnetic nanoparticle‐embedded hollow mesoporous silica capsules (Mag‐HMSCs) with a large surface hole are prepared by a cholesterol‐assisted emulsion method. The resulting Mag‐HMSC materials have a hollow capsular geometry with a mesostructured silica wall. They exhibit a very high intracellular delivery efficiency of the representative large protein, antibody immunoglobulin G (IgG). As a result of the embedded Fe3O4 nanoparticles, Mag‐HMSC materials also serve as magnetic resonance imaging (MRI) contrast agents. Good T2‐weighted MR image contrasts were observed. We report a facile preparation method of cell‐permeable multifunctional hollow mesoporous silica capsule (denoted as Mag‐HMSC) materials with embedded magnetic Fe3O4 nanoparticles. Mag‐HMSCs can deliver IgG into HeLa cells very efficiently and they can be applicable to magnetic resonance imaging.