Fig 1.
Schematic procedure of SF-loaded FITC/FA@[Fe3O4@Au] NPs synthesis (A), and TEM and SEM of NPs (B,C).
A: Schematic procedure for synthesizing SF-loaded FITC/FA@[Fe3O4@Au] NPs. Abbreviations: PEG, poly(ethylene glycol); FA, folate; FITC, fluorescence isothiocyanate; SF, sulforaphane; NPs, nanoparticles. B: TEM of FITC/FA@[Fe3O4@Au] NPs. C: SEM of FITC/FA@[Fe3O4@Au] NPs.
Fig 2.
The energy dispersive X-ray spectrum of [Fe3O4@Au] NPs. Inset: The FT-IR spectra of free SF, FITC/FA@[Fe3O4@Au] NPs, and SF-loaded FITC/FA@[Fe3O4@Au] NPs.
Fig 3.
Magnetization hysteresis loop of NPs.
The room-temperature magnetization (M) hysteresis loop curves of the same mass of [Fe3O4@Au] NPs and FITC/FA@[Fe3O4@Au] NPs as a function of applied magnetic field (H).
Fig 4.
Release of FITC from NPs (A) and average hydrodynamic (B) of NPs.
A: Release of FITC from FITC/FA@[Fe3O4@Au] NPs. B: The average hydrodynamic diameter of [Fe3O4@Au] and FITC/FA@[Fe3O4@Au] NPs at pH = 7.4.
Fig 5.
SF loading (A) and releasing (B).
A: The profile of SF loading in FITC/FA@[Fe3O4@Au] NPs. B: The profile of SF releasing from SF-loaded FITC/FA@[Fe3O4@Au] NPs at two different pHs (PBS buffer: pH = 7.4 and citrate buffer: pH = 5.4).
Fig 6.
Viability of cells at different conditions.
Viability of MCF-7 cells which were assessed A: after 24 h, 48 h, and 72 h of incubation with different concentrations of SF-loaded FITC/FA@[Fe3O4@Au] NPs. B: at different concentrations of incubation with free SF, FITC/FA@[Fe3O4@Au] NPs, SF-loaded FITC@[Fe3O4@Au] NPs, and SF-loaded FITC/FA@[Fe3O4@Au] NPs. Data are presented as the mean ± standard deviation of replicates.
Fig 7.
Optical microscopy images of cells after 24 h.
A: Bright-field image, B: Fluorescence image of DAPI detection, and C: Combined of A and B, after 24 h incubation of MCF-7 cells (control). D: Bright-field image, E: Fluorescence image of DAPI detection, and F: Combined of D and E, after 24 h incubation of MCF-7 cells with free SF. G: bright-field image, H: fluorescence image of DAPI detection, and I: fluorescence image of FITC detection of the same area after 24 h incubation of MCF-7 cells with FITC@[Fe3O4@Au] NPs.
Fig 8.
Optical microscopy images of incubated cells by SF-loaded FITC@[Fe3O4@Au] NPs and SF-loaded FITC/FA@[Fe3O4@Au] NPs after 24 h.
A: Bright-field image, B: Fluorescence image of FITC detection, and C: Combined of A and B, after 24 h incubation of MCF-7 cells with SF-loaded FITC@/FA[Fe3O4@Au] NPs. D: Bright-field image, E: Fluorescence image of FITC detection, and F: Combined of D and E, after 24 h incubation of MCF-7 cells with SF-loaded FITC@[Fe3O4@Au] NPs.
Fig 9.
Optical microscopy images of incubated cells by SF-loaded FITC/FA@[Fe3O4@Au] NPs after 24 and 72 h.
A: bright-field image, B: fluorescence image of FITC detection, and C: fluorescence image of DAPI detection of the same area after 24 h incubation of MCF-7 cells with SF-loaded FITC/FA@[Fe3O4@Au] NPs. D: The corresponding fluorescence intensity maps (colorbar shown) of FITC (in SF-loaded FITC/FA@[Fe3O4@Au] NPs) distribution of Fig 9B. E: Combined of A and B. F: Combined of A and C. G: bright-field image, H: fluorescence image of FITC detection, and I: fluorescence image of DAPI detection of the same area after 72 h incubation of MCF-7 cells with SF-loaded FITC/FA@[Fe3O4@Au] NPs. J: The corresponding fluorescence intensity maps (colorbar shown) of FITC (in SF-loaded FITC/FA@[Fe3O4@Au] NPs) distribution of Fig 9B. K: Combined of G and H. L: Combined of G and I.
Fig 10.
Flow cytometric analysis (A and B) and the rate of gene expression in MCF-7 cells (C).
A: Flow cytometric analysis of MCF-7 cells were treated with free SF, FITC/FA@[Fe3O4@Au] NPs, SF-loaded FITC@[Fe3O4@Au] NPs, and SF-loaded FITC/FA@[Fe3O4@Au] NPs at equivalent SF concentration after 48 h. B: SF-loaded FITC/FA@[Fe3O4@Au] NPs induces significantly apoptosis versus free SF. Data are presented as the mean ± standard deviation of replicates. C: The rate of gene expression in MCF-7 cells after 72 h treatment with free SF, FITC/FA@[Fe3O4@Au] NPs, SF-loaded FITC@[Fe3O4@Au] NPs, and SF-loaded FITC/FA@[Fe3O4@Au] NPs.