Au capped magnetic core/mesoporous silica shell nanoparticles for combined photothermo-/chemo-therapy and multimodal imaging

Uniform Au NRs-capped magnetic core/mesoporous silica shell nanoellipsoids (Au NRs-MMSNEs) were prepared by coating a uniform layer of Au NRs on the outer surface of a magnetic core/mesoporous silica shell nanostructure, based on a two-step chemical self-assembly process. This multifunctional nanocomposite integrate simultaneous chemotherapy, photo-thermotherapy, in vivo MR-, infrared thermal and optical imaging into one single system. The obtained multifunctional nanoellipsoids showed very low cytotoxicity, and the cancer cell uptake and intracellular location of the nanoellipsoids were observed by confocal laser scanning microscopy and bio-TEM. Importantly, the prepared multifunctional nanoellipsoids showed high doxorubicin loading capacity and pH value-responsive release mainly due to the electrostatic interaction between DOX molecules and mesoporous silica surface. Besides, a synergistic effect of combined chemo- and photo-thermo therapy was found at moderate power intensity of NIR irradiation based on the DOX release and the photothermal effect of Au NRs. (C) 2011 Elsevier Ltd. All rights reserved.