图1 Nb、MN和MN@FS样品的形貌表征

Fig. 1 Morphologies of Nb, MN and MN@FS (a) Photographs of Nb, MN and MN@FS; (b-g) SEM images of Nb (b, e), MN (c, f) and MN@FS (d, g); (h) EDS mappings of MN@FS; (i) Particle size distribution of Fe2S3 on the surface of MN@FS (MN: Nb2O5 coatings on pure niobium surfaces prepared by microarc oxidation treatment; FS: Fe2S3)

图2 MN和MN@FS的XRD (a)和XPS (b~f)图谱

Fig. 2 XRD patterns (a) and XPS spectra (b-f) of MN and MN@FS (a) XRD patterns of MN and MN@FS; (b) Total XPS spectra of MN@FS; (c, d) High-resolution XPS spectrra of Nb3d (c) and O1s (d) of MN@FS; (e, f) High-resolution XPS spectra of Fe2p (e) and S2p (f) of MN@FS and Fe2S3

图3 不同样品的类酶活性

Fig. 3 Enzyme-like activity of the samples (a) MB degradation by different samples (pH 5.5); (b) ESR of ·OH production by MN@FS; (c) MB degradation by MN@FS versus pH; (d) Ti2(SO4)3 degradation by different samples (pH 7.4); (e) Oxygen production curves of different samples (pH 7.4, 10 mmol/L H2O2); (f) Mechanism of enzymatic catalytic activity; (g) MB degradation by MN@FS versus US power (pH 5.5, 10 mmol/L H2O2); (h) ESR of·OH production by MN@FS at different conditions (pH 5.5, 10 mmol/L H2O2, 0.5 W/cm2 US); (i) Oxygen production curves of MN@FS versus US power (pH 7.4, 10 mmol/L H2O2)

图4 不同样品的声动力性能

Fig. 4 Sonodynamic performance of the samples (a, c, d) Degradation of RhB (a), MB (c) and DPBF (d) by MN and MN@FS; (b) Degradation of RhB by MN@FS versus time; (e, f) ESR of ·OH (e) and ·O2- (f) production by MN and MN@FS with US; (g, h) Degradation of RhB (g) and ESR of ·OH production (h) by MN@FS under different conditions. The conditions for all ultrasound stimuli were 1.5 W/cm2, 1 MHz and 5 min, under pH 5.5 and 10 mmol/L H2O2 environment

图5 MN@FS异质结机理及电化学分析

Fig. 5 Mechanism and electrochemical analysis of the MN@FS heterojunction (a, b) Valence band XPS spectra of Nb2O5 (a) and Fe2S3 (b); (c, d) Tauc plots of Nb2O5 (c) and Fe2S3 (d); (e, f) EIS spectra (e) and transient acoustic-current responses (f) of Fe2S3, MN, and MN@FS; (g) PL spectra of MN and MN@FS; (h) Diagram of the ultrasonic dynamic mechanism of the heterogeneous junction

图6 MN@FS异质结的抗菌性能

Fig. 6 Antimicrobial properties of the MN@FS heterojunction (a) Photographs of crystal violet staining; (b) Photographs of colonies; (c) Biofilm residual rate; (d) Antimicrobial rate of S. aureus (****: p < 0.0001, n=3)

图7 MN@FS杀菌和清除生物膜机理分析

Fig. 7 Analysis of the mechanism of sterilization and biofilm clearance by MN@FS (a, b) SEM (a) and ROS fluorescence staining (b) images of S. aureus; (c, d) Protein leakage without US (c) and with US (d) (****: p < 0.0001, n=3)

图8 在氧化应激(200 μmol/L H2O2)条件下MN@FS促进rBMSCs增殖

Fig. 8 Promotion effect of MN@FS on rBMSCs proliferation under oxidative stress conditions (200 μmol/L H2O2) (a, b) SEM (a) and CLSM (b) images of rBMSCs after incubation for different days; (c) Cell proliferation; (d) Cell viability; (e) CLSM images of ROS in cells (*: p < 0.05; ***: p < 0.001; ****: p < 0.0001, n=3)

图9 在氧化应激(200 μmol/L H2O2)条件下MN@FS促进rBMSCs成骨分化

Fig. 9 Promotion effect of MN@FS on rBMSCs osteogenic differentiation under oxidative stress conditions (200 μmol/L H2O2) (a, b) ALP (a) and alizarin red (b) staining images; (c, d) ALP activity (c) and calcium module formation (d) of rBMSCs at different days after culturing for different days (*: p < 0.05; **: p < 0.01; ***: p < 0.001, n=3)