Table 1

Experimental reagents and materials

Table 2

Experimental instruments

Fig. 1

The characterization of MH NPs. (a) TEM and TEM mapping image of MH NPs; (b) Size distribution of MH NPs; (c) Zeta potential of MH NPs; (d) XPS spectra of Fe element in MH NPs; (e) XPS spectra of Mn element in MH NPs; (f) UV-vis absorption spectra of hemin and MH NPs; (g) FT-IR spectra of hemin and MH NPs

Fig. 2

The enzyme-like catalytic performance of MH NPs. (a) Schematic illustration of catalytic process of MH NPs; (b) UV-vis absorption spectra and photographs of DTNB after reaction of GSH with MH NPs solution at different concentrations (12.5, 25, 50, 100, and 200 μg·mL-1) ; (c) The generation of O2 over time after the reaction of H2O2 with MH NPs of different concentrations (0, 10, 20, 30, 40 and 50 μg·mL-1) ; (d) ESR spectra of H2O2 reacting with MH NPs (90 μL, 25 μg·mL-1), Fe2+ and H2O, respectively; (e) UV-vis absorption spectra of different reaction systems [TMB, TMB + H2O2, TMB + H2O2 + MH NPs (10 μL, 0.1 mg·mL-1)]; (f) UV-vis absorption spectra of reaction system [TMB + H2O2 + MH NPs (10 μL, 0.1 mg·mL-1)] at different times

Fig. 3

The photothermal and photoacoustic performance of MH NPs. (a) The heating curve and infrared thermographs of MH NPs solution (500 μg·mL-1) and H2O under NIR laser irradiation (808 nm laser, 500 mW·cm-2); (b) Temperature change curves of MH NPs solutions with various concentrations irradiated by 808 nm laser (500 mW·cm-2); (c) Temperature change curves of MH NPs solution (500 μg·mL-1) irradiated by 808 nm laser of different power densities; (d) Calculation of the photothermal conversion efficiency of MH NPs; (e) Temperature change curves of MH NPs solutions under the cyclic irradiation of 808 nm laser (500 mW·cm-2); (f) Correlation of the photoacoustic signal intensity with the concentrations of MH NPs solutions and photoacoustic images of MH NPs solutions at different concentrations

Fig. 4

The T2-weighted MR imaging capability of MH NPs. (a) T2 MRI images of MH NPs at various pH conditions; (b) The linear relationship for the transverse relaxation rate of MH NPs as a function of Mn concentration under different pH conditions; (c) In vitro release curve of Mn2+ from MH NPs at various pH conditions (pH = 7.4, 6.5, and 5.5); (d) T2 MRI images of MH NPs after reaction with various concentrations of GSH; (e) The linear relationship for the transverse relaxation rate of MH NPs as a function of Mn concentration under different GSH conditions; (f) In vitro release curve of Mn2+ from MH NPs after reaction with various concentrations of GSH

Fig. 5

In vitro assessments of photothermal-enhanced anti-tumor catalytic therapy mediated by MH NPs. (a) Confocal fluorescence images of the cellular ROS level in 4T1 cells after different treatments (scale bar: 100 μm); (b) Semi-quantitative analysis of ROS level in 4T1 cells after different treatments; (c) Confocal fluorescence images of the cellular LPO level in 4T1 cells after different treatments (scale bar: 100 μm); (d) Semi-quantitative analysis of LPO level in 4T1 cells after different treatments; (e) Western blot assay of the STING signaling pathway-related protein expressed in 4T1 cells after different treatments; (f) Semi-quantitative analysis of the STING pathway-related protein expressed in 4T1 cells after different treatments; (g) The scheme of transwell system utilized to explore the maturation of dendritic cells induced by different treatments for 4T1 cells; (h) The expression level of IFN-β in the cell supernatant; (i) The expression level of TNF-α in the cell supernatant; (j) The level of mature dendritic cells measured by flow cytometry

Fig. 6

In vivo biodistribution and MRI & PAI performance of MH NPs. (a) In vivo fluorescence images of 4T1 tumor-bearing mice at different time points after intravenous injection with MH@ICG NPs; (b) The fluorescence variation curves of tumor sites in 4T1 tumor-bearing mice at different time points after intravenous injection with MH@ICG NPs; (c) Fluorescence images of major organs of 4T1 tumor-bearing mice after intravenous injection with MH@ICG NPs for 72 h; (d) Semi-quantitive analysis of MH@ICG NPs in major organs of 4T1 tumor-bearing mice after intravenous injection with MH@ICG NPs for 72 h; (e) T2 MRI images of 4T1 tumor-bearing mice after intravenous injection with MH NPs at different time points; (f) Photoacoustic images of tumor sites in 4T1 tumor-bearing mice after intravenous injection with MH NPs at different time points; (g) The T2 MRI signal variation curves of tumor sites in 4T1 tumor-bearing mice at different time points after intravenous injection with MH NPs; (h) The photoacoustic signal variation curves of tumor sites in 4T1 tumor-bearing mice at different time points after intravenous injection with MH NPs

Fig. 7

Photothermal-enhanced MH NPs-mediated anti-tumor catalytic immunotherapy synergized with αPD-L1 against 4T1 tumor xenografts. (a) Schematic illustration of the photothermal-enhanced MH NPs-meidated anti-tumor catalytic immunotherapy synergized with αPD-L1; (b, e) Primary and distant tumor growth curves of the 4T1 tumor-bearing mice with different treatments; (c, f) The weight of primary and distant tumors in 4T1 tumor-bearing mice with different treatments; (d, g) Photographs of primary and distant tumors in 4T1 tumor-bearing mice with different treatments; (h) H&E and TUNEL staining histological analysis of primary tumor sections from 4T1 tumor-bearing mice with different treatments