Monodisperse Rattle-Structured Gold Nanorod-Mesoporous Silica Nanoparticles Core-Shell as Sulforaphane Carrier and its Sustained-Release Property

Sulforaphane (SF) was loaded into the multi-functioned rattlestructured gold nanorod mesoporous silica nanoparticles core-shell to improve its stability and efficacy through its efficient delivery to tumors. The rattle-structured gold nanorod mesoporous silica nanoparticles (rattle-structured AuNR@mSiO(2) core-shell NPs) were obtained by covering the surface of Au NPs with Ag and mSiO(2) shell and subsequently selective Ag shell etching strategy. Then the surface of rattle-structured AuNR@mSiO(2) NPs was decorated with thiolated polyethylene glycol-FITC and thiolated polyethylene glycol-folic acid to the designed form. The obtained FITC/FA@ [rattle-structured AuNR@mSiO(2)] NPs was characterized by different techniques including energy dispersive X-ray spectroscopy (EDX), scanning and transmission electron microscopy (SEM & TEM), UV-visible spectrophotometer and dynamic light scattering (DLS). The FITC/FA@ [rattle-structured AuNR@mSiO(2)] NPs has an average diameter around similar to 33 nm, which increases to similar to 38 nm after the loading of sulforaphane. The amount of the loaded drug was similar to 2.8 x 10-4 mol of SF per gram of FITC/FA@ [rattle-structured AuNR@mSiO(2)] NPs. The rattle-structured AuNR@mSiO(2) and FITC/FA@ [rattle-structured AuNR@mSiO(2)] NPs showed little inherent cytotoxicity, whereas the SF loaded FITC/FA@ [rattlestructured AuNR@ mSiO(2)] NPs was highly cytotoxic in the case of MCF-7 cell line. Finally, Fluorescence microscopy and flow cytometry were used to demonstrate that the nanoparticles could be accumulated in specific regions and SF loaded FITC/FA@ [Fe3O4@Au] NPs efficiently induce apoptosis in MCF-7 cell line.