Manganese dioxide nanosheets-based redox/pH-responsive drug delivery system for cancer theranostic application

Figures & data

Figure 1 Schematic illustration of nanosheets and their biofunctions.

Notes: (A) Schematic illustration of preparation of MnO₂/HA/CDDP nanosheets; (B) the drug release in response to the pH decrease and the GSH increase in the tumor microenvironment; (C) the biofunctions of MnO₂/HA/CDDP nanosheets.

Abbreviations: CDDP, cis-diamminedichloroplatinum; GSH, glutathione; HA, hyaluronic acid; MnO₂, manganese dioxide; MRI, magnetic resonance imaging.

Figure 2 Characterization of MnO₂ nanosheets.

Notes: (A) TEM images of synthesized MnO₂ nanosheets; (B) HRTEM images of synthesized MnO₂ nanosheets; (C) EDS pattern of synthesized MnO₂ nanosheets; (D) zeta potential; (E) XPS spectra for the O 1s region; (F) XPS spectra for the Mn 2p region.

Abbreviations: EDS, energy-dispersive X-ray spectroscopy; HRTEM, high-resolution transmission electron microscopy; MnO₂, manganese dioxide; TEM, transmission electron microscopy; XPS, X-ray photoelectron spectroscopy.

Figure 3 Characterization of MnO₂/HA and MnO₂/HA/CDDP.

Notes: (A) FTIR spectra of HA, MnO₂, and MnO₂/HA; (B) TGA curves of MnO₂ and MnO₂/HA; (C) loading efficiency of CDDP at different feed ratios.

Abbreviations: CDDP, cis-diamminedichloroplatinum; FTIR, Fourier-transform infrared; HA, hyaluronic acid; MnO₂, manganese dioxide; TGA, thermogravimetric analysis.

Figure 4 Characterization of MnO₂/HA/CDDP.

Notes: (A) TEM images of MnO₂/HA/CDDP; (B) EDS pattern of MnO₂/HA/CDDP; (C) size distribution; (D) zeta potential; (E) appearance of MnO₂ and MnO₂/HA/CDDP dispersed in pure water and saline, respectively, at day 0; (F) appearance of MnO₂ and MnO₂/HA/CDDP dispersed in pure water and saline, respectively, at day 3. (a) MnO₂ dispersed in pure water; (b) MnO₂ dispersed in saline; (c) MnO₂/HA/CDDP dispersed in pure water; (d) MnO₂/HA/CDDP dispersed in saline. (G) in vitro release profiles of CDDP from MnO₂/HA/CDDP nanosheets at different release media.

Abbreviations: CDDP, cis-diamminedichloroplatinum; EDS, energy-dispersive X-ray spectroscopy; GSH, glutathione; HA, hyaluronic acid; MnO₂, manganese dioxide; TEM, transmission electron microscopy.

Figure 5 In vitro MRI.

Notes: (A) T1-weighted images; (B) mean MRI signal intensity; (C) relaxation rate r₁ (1/T1) versus molar concentrations of an aqueous suspension of MnO₂/HA/CDDP at pH 7.4 and pH 5.0 containing 2 mM GSH, respectively.

Abbreviations: CDDP, cis-diamminedichloroplatinum; GSH, glutathione; HA, hyaluronic acid; MnCl₂, manganese chloride; MnO₂, manganese dioxide; MRI, magnetic resonance imaging.

Figure 6 Flow cytometry analysis of A549 cells exposed to free Cy 5.5, MnO₂/HA/Cy 5.5 for different times.

Notes: (A) Cy 5.5 group; (B) MnO₂/HA/Cy 5.5 group.

Abbreviations: HA, hyaluronic acid; MnO₂, manganese dioxide; Cy, Cyanine dye.

Figure 7 CLSM images of A549 cancer cells after the uptake of MnO₂/HA/Cy 5.5 (A), free Cy 5.5 (B) at the equivalent Cy 5.5 concentration of 5 μg/mL at 4 hours.

Abbreviations: CLSM, confocal laser scanning microscopy; DAPI, 4′,6-diamidino-2-phenylindole; HA, hyaluronic acid; MnO₂, manganese dioxide; Cy, Cyanine dye.

Figure 8 Cell cytotoxicity.

Notes: (A) A549 cell viabilities after incubation with MnO₂/HA for 24 hours and 48 hours; (B) A549 cell viabilities after incubation with CDDP and MnO₂/HA/CDDP for 24 hours; (C) A549 cell viabilities after incubation with CDDP and MnO₂/HA/CDDP for 48 hours. *P<0.05; **P<0.01.

Abbreviations: CDDP, cis-diamminedichloroplatinum; HA, hyaluronic acid; MnO₂, manganese dioxide.

Figure 9 Cell cycle and cell apoptosis analysis.

Notes: (A) Cell cycle analysis; (B) cell apoptosis determined by DAPI staining: (a) control group; (b) MnO₂/HA group; (c) CDDP group; (d) MnO₂/HA/CDDP group.

Abbreviations: CDDP, cis-diamminedichloroplatinum; DAPI, 4′,6-diamidino-2-phenylindole; HA, hyaluronic acid; MnO₂, manganese dioxide.

Figure 10 In vivo NIR fluorescence imaging.

Notes: (A) Cy 5.5-labeled MnO₂/HA/CDDP group; (B) free Cy 5.5 group. The red semi-circles refer to the tumor site.

Abbreviations: CDDP, cis-diamminedichloroplatinum; HA, hyaluronic acid; MnO₂, manganese dioxide; NIR, near infrared; Cy, Cyanine dye.

Figure 11 In vivo T1-weighted MRI and pharmacokinetic properties.

Notes: (A) In vivo T1-weighted MRI of tumor-bearing mice under different treatments; (B) average MRI signal intensity of each group; (C) plasma concentration–time curves of CDDP after intravenous injection of free CDDP solution and MnO₂/HA/CDDP nanosheets, respectively. (a) Control mice; (b) 4 hours after intratumoral injection with MnO₂/HA/CDDP; (c) 4 hours after intravenous injection with MnO₂/HA/CDDP. *P<0.05; **P<0.01. The red semi-circles refer to the tumor site.

Abbreviations: CDDP, cis-diamminedichloroplatinum; HA, hyaluronic acid; MnO₂, manganese dioxide; MRI, magnetic resonance imaging.

Table 1 Pharmacokinetic parameters

Parameter	Unit	CDDP	MnO2/HA/CDDP
t1/2	Hours	1.44	2.38
AUC0–t	μg/mL·h	4.32	9.46
AUC0–inf_obs	μg/mL·h	4.53	9.80
AUMC0–inf_obs	μg/mL·h^Citation2	7.23	27.64
MRT0–inf_obs	Hours	1.59	2.81
Vzobs	(mg/kg)/(μg/mL)	1.40	1.05
Clobs	(mg/kg)/(μg/mL)/h	0.66	0.86

Abbreviations: AUC, area under the curve; CDDP, cis-diamminedichloroplatinum; HA, hyaluronic acid; MnO₂, manganese dioxide; AUMC, area under moment curve; MRT, mean residence time; Vz_obs, apparent volume of distribution; Cl_obs, Clearance.

Figure 12 In vivo antitumor effect.

Notes: (A) Body weight of tumor-bearing mice as a function of time; (B) relative tumor volumes of tumor-bearing mice at different times; (C) H&E-stained tumor tissues harvested from the mice under different treatments; (D) H&E-stained kidney tissues harvested from the mice under different treatments; (a) control group; (b) MnO₂/HA group; (c) CDDP group; (d) MnO₂/HA/CDDP group. The scale bar is 100 μm. *P<0.05.

Abbreviations: CDDP, cis-diamminedichloroplatinum; HA, hyaluronic acid; H&E, hematoxylin and eosin; MnO₂, manganese dioxide; V, tumor volume at a certain day; V₀, initial tumor volume.

Figure S1 XRD spectrum of MnO₂ nanosheets.

Abbreviations: MnO₂, manganese dioxide; XRD, X-ray diffraction.

Figure S2 The interaction between CDDP and HA.

Notes: (A) The interaction of CDDP with carboxyl groups in HA from adjacent nanosheets. (B) The weakening of the metal–carboxylate bond via protonation of the carboxylic groups of the HA units.

Abbreviations: CDDP, cis-diamminedichloroplatinum; HA, hyaluronic acid.

Figure S3 The color change of different formulations under various conditions.

Notes: The images of MnO₂/HA/CDDP in pH 5.0 (A), reductive pH 7.4 PBS containing 2 mM GSH (B) and pH 5.0 containing 2 mM GSH (C). (D) The appearance of the dialysis tubing after 12-hour dialysis for the in vitro release experiment.

Abbreviations: CDDP, cis-diamminedichloroplatinum; GSH, reduced glutathione; HA, hyaluronic acid; MnO₂, manganese dioxide; PBS, phosphate-buffered saline.

Figure S4 H&E staining of major organs from different groups (200×).

Abbreviations: CDDP, cis-diamminedichloroplatinum; HA, hyaluronic acid; H&E, hematoxylin and eosin; MnO₂, manganese dioxide.

ColeJTHollandNBMultifunctional nanoparticles for use in theranostic applicationsDrug Deliv Transl Res20155329530925787729

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