Gold-based nanocomposites have attracted intensive attention due to their unique optical properties and great potential in biomedical applications. Herein, we report a simple route for the synthesis of multiple gold nanorods encapsulated, hierarchically porous silica nanospheres (MGNRs@HPSNs) based on the cooperative self-assembly of amphiphilic block copolymer polystyrene-b-poly (acrylic acid) (PS-b-PAA), cetyl trimethyl ammonium bromide (CTAB), gold nanorods and the organosilane of tetraethyl orthosilicate (TEOS) in an oil/water system. Multiple gold nanorods have been loaded successfully into the interior of the hierarchically porous silica nanospheres, which consist of large, interconnected pores of 13.2 nm throughout the whole sphere and small pores of 2.7 nm in the silica framework. Moreover, the loading amount (or number) of gold nanorods in the silica matrix can be tuned by simply changing the initial concentration of preformed gold nanorods. Due to the presence of the hierarchically porous structure, the PEGylated MGNRs@HPSNs display high loading capability for both small anti-tumor drugs (i.e., doxorubicin hydrochloride, 69.2 ± 7.2 mg g−1) and bio-macromolecules (i.e., bovine serum albumin, 248.1 ± 12.3 mg g−1). More importantly, MGNRs@HPSNs present better photothermal effect than that of hierarchically porous silica nanoparticles containing less (one or two) gold nanorods at the same Au concentration. It is thus demonstrated that MGNRs@HPSNs can not only act as promising drug/protein nanocarriers, but also can be used as photoabsorbers for photothermal tumor therapy under NIR laser irradiation.

The combination of mesoporous silica nanoparticles and superparamagnetic nanocrystals to fabricate multifunctional platforms presents great potentials for simultaneous imaging and drug delivery. In this work, we have successfully developed a simple one-step approach to synthesize magnetite-loaded dual-mesoporous silica spheres consisting of large pores in the core and small pores in the shell (Fe3O4@DMSSs) by embedding oil-soluble Fe3O4 into the large pores of DMSSs, which were prepared by employing polystyrene-b-poly(acrylic acid) (PS-b-PAA) and cetyl trimethyl ammonium bromide (CTAB) as dual-templates. The loading amounts of magnetite can be easily adjusted by varying the initial concentrations of Fe3O4 nanoparticles in the oil phase. The in vitro test indicates that Fe3O4@DMSSs possesses excellent T2-weighted magnetic resonance (MR) imaging performance with a maximum T2 relaxivity (r2) of 421.5 mMFe−1 S−1. Furthermore, a high doxorubicin (DOX) loading capacity (65 wt%) was achieved and the obtained DOX-loaded Fe3O4@DMSSs (DOX/Fe3O4@DMSSs) exhibits pH-sensitive behaviour with accelerated release of DOX in acidic environment. Confocal laser scanning microscopy observation shows that DOX/Fe3O4@DMSSs was able to locate in the cytoplasm of MCF-7 cells and release DOX into the nucleus to kill cancer cells. Therefore, it is anticipated that Fe3O4@DMSSs can be promising candidates as both T2-weighted MR contrast agents and drug delivery carriers in further biomedical applications.

Gold-based nanocomposites have attracted intensive attention due to their unique optical properties and great potential in biomedical applications. Herein, we report a simple route for the synthesis of multiple gold nanorods encapsulated, hierarchically porous silica nanospheres (MGNRs@HPSNs) based on the cooperative self-assembly of amphiphilic block copolymer polystyrene-b-poly (acrylic acid) (PS-b-PAA), cetyl trimethyl ammonium bromide (CTAB), gold nanorods and the organosilane of tetraethyl orthosilicate (TEOS) in an oil/water system. Multiple gold nanorods have been loaded successfully into the interior of the hierarchically porous silica nanospheres, which consist of large, interconnected pores of 13.2 nm throughout the whole sphere and small pores of 2.7 nm in the silica framework. Moreover, the loading amount (or number) of gold nanorods in the silica matrix can be tuned by simply changing the initial concentration of preformed gold nanorods. Due to the presence of the hierarchically porous structure, the PEGylated MGNRs@HPSNs display high loading capability for both small anti-tumor drugs (i.e., doxorubicin hydrochloride, 69.2 ± 7.2 mg g−1) and bio-macromolecules (i.e., bovine serum albumin, 248.1 ± 12.3 mg g−1). More importantly, MGNRs@HPSNs present better photothermal effect than that of hierarchically porous silica nanoparticles containing less (one or two) gold nanorods at the same Au concentration. It is thus demonstrated that MGNRs@HPSNs can not only act as promising drug/protein nanocarriers, but also can be used as photoabsorbers for photothermal tumor therapy under NIR laser irradiation.