Fig. 1
Characterization of the different NPs. TEM images of the different NPs: (A) SiO2, (B) MSN, and (C) MF@SOR (scale bar: 50 nm). (D) SEM image of the MF@SOR (scale bar: 50 nm). (E) TEM image of MF@SOR in response to an environment at pH = 5 with GSH (scale bar: 50 nm). (F) HAADF and elemental mapping of MF@SOR (scale bar: 50 nm). (G) Diameters and (H) zeta potentials of the different NPs (n = 3). (I) XRD patterns of the MSN. (J) XPS spectrum of Mn in the MF@SOR. (K) N2 adsorption-desorption isotherm and (L) pore size distribution of the MSN. (M) FTIR spectra of SOR, MSN and MF@SOR. (N) The release of SOR from MF@SOR in PBS at pH 5.0 with GSH, pH 6.5 with GSH, pH 7.4 with GSH and pH 7.4 (n = 3). (O) The contents of Fe and Mn in the MF@SOR measured by ICP‒OES. In panel (N), the data are presented as the mean ± SD, and the p values were calculated by ANOVA. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001, ns, not significant