Fig. 6: Comprehensive evaluation of Au@MIL NPs: cellular uptake, electron transfer, oxidative stress, spectral analysis, and cytotoxicity under hypoxic conditions.

a The cellular uptake of Au@MIL NPs was assessed in two normal cell lines and three cancer cell lines treated with 100 nm Au@MIL NPs for 48 h. (n = 3 replicates). Data were presented as the mean ± SEM. Statistical analysis was conducted using a two-tailed Student’s t-test. b A schematic illustration depicting the transfer of electrons to Au NPs through the MIL. The redox potentials of Au NPs and MIL versus NHE are also indicated. c To assess the role of oxidative stress in cell death, fluorescence microscopy was used to evaluate live and dead staining in two normal and three cancer cell lines following antioxidant (Vitamin E, Vit E) treatment. Cells were treated with 100 nm Au@MIL NPs (300 ppm Au) for 48 h, with 2.5 μM Vit E added every 24 h in the Vit E and Au@MIL + Vit E groups. d The UV-visible spectra of Au NPs, Au@MIL NPs, and Au@MIL NPs after 72 h of incubation with cells were analyzed. The corresponding SPR and full width at half maximum (FWHM) bandwidth values are provided in the table below. e The XANES spectra at the Au L3-edge were obtained for Au NPs, Au@MIL NPs, Au@MIL NPs after 72 h of cell incubation, and Au foil. f TEM images of 100 nm Au@SiO₂ NPs and Au@SiO₂@MIL NPs. Dark spheres indicate Au NPs, the gray layer represents SiO₂, and the outer transparent layer is MIL. Fluorescence images show live/dead cell distribution in Hep G2 cells after 48 h treatment with 70 nm and 100 nm Au@SiO₂@MIL (300 ppm Au). g Cytotoxicity of 100 nm Au@MIL NPs under hypoxic conditions (1% O₂). Fluorescence images of Hep G2 cells after 48 h of incubation with 100 nm Au@MIL NPs show the distribution of live and dead cells. (n = 3 replicates). c, f The images are representative of three independent experiments. c, f, g Scale bars: 100 μm. Source data are provided as a Source Data file.