Spatially confined fabrication of core-shell gold nanocages@Mesoporous silica for near-infrared controlled photothermal drug release

In this work, we have successfully developed a novel multifunctional near-infrared (NIR)-stimulus controlled drug release system based on gold nanocages as photothermal cores, mesoporous silica shells as supporters to increase the anticancer drug loading and thermally responsive poly(N-isopropylacrylamide) (PNIPAM) as NIR-stimuli gatekeepers (Au-nanocage@mSiO2@ PNIPAM). The unique Au-nanocage@mSiO2 nanocarrier was elaborately fabricated by utilizing yolk-shell Ag-nanocube@mSiO2 nanostructure as a template by means of spatially confined galvanic replacement. The Au nanocage cores can effectively absorb and convert light to heat upon irradiation with a NIR laser, resulting in the collapse of the PNIPAM shell covering the exterior of mesoporous silica, and exposes the pores of mesoporous silica shell, realizing the triggered release of entrapped DOX drugs. The in vitro studies have clearly demonstrated the feasibility and advantage of the novel nanocarriers for remote-controlled drug release systems. © 2013 American Chemical Society.