Mesoporous MnO2 Research Articles

Mesoporous manganese dioxide prepared by nano-casting: An efficient catalyst for of methyl orange and oxalic acid degradation in aqueous solution

In the present study, mesoporous manganese dioxide catalysts with large high specific surface area, pore volume and large pore size structure were synthesised using the nano-casting method with a mesoporous structure of silica SBA-15 as a hard template. Therefore, the physical and chemical properties of mesoporous MnO2 were characterised by XRD, FT-IR, Raman, UV–Vis, N2 adsorption-desorption, SEM, EDS, TEM, TG and XPS. In this study, the oxidative reactivity of MnO2 corresponding to methyl orange (MO) and oxalic acid (OA) was assessed. MnO2 was found to contain the most abundant oxygen vacancies and easily reducible surface adsorbed oxygen (Olatt), which facilitates the catalytic utilisation of ozone. As a result, the highest catalytic performance was achieved for methyl orange and oxalic acid, with degradation efficiencies of 98.37% and 92.96%. This present study deepens our understanding of manganese dioxide catalyzed ozone and provides a reference for improving process efficiency.

Synthesis and energy storage characteristics of MnO microchains induced by high magnetic field

A magnetic field induced hydrothermal method is applied to synthesize precursors, followed by annealing to prepare mesoporous MnO microchains. Different morphologies of the ultimate products can be dominated by changing the magnetic field strength to acquire good electrochemical performances. The initial high reversible capacity of MnO microchains is 948 mA h g−1. After 250 cycles, the reversible capacity retains about 769 mA h g−1 at 2 C, even after 2000 cycles, the reversible capacity maintains around 198 mA h g−1 at 8 C. The superb electrochemical properties could originate from the mesoporosity of aggregated nanoparticles of the MnO 1D-microchain structure induced by applied magnetic field of 8 T, which is beneficial for the fast transport of Li+ and electron, and can adapt to the dramatic volume change during the Li+ deintercalation.

Biodegradable MnO-Based Nanoparticles with Engineering Surface for Tumor Therapy: Simultaneous Fenton-Like Ion Delivery and Immune Activation.

Immune checkpoint inhibitors have achieved significant clinical success but are still suffering from inadequate immune activation. It is worth noting that manganese as a nutritional inorganic trace element is closely associated with immune activation to fight against tumor growth and metastasis via the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway. Herein, we designed hollow mesoporous silica-coated MnO nanoparticles (NPs), followed by conjugation of tumor homing peptide iRGD (CRGDKGPD). The obtained NPs (MnO@mSiO2-iRGD NPs) were applied to magnetic resonance imaging (MRI)-guided tumor immune-chemodynamic combination therapy, in which MnO NPs can be harnessed for cGAS-STING pathway-activated immunotherapy, Fenton-like reaction-induced reactive oxygen species upregulation, and T1-weighted MRI. The rough surface and large cavities of the mSiO2 shell promote cellular uptake and MnO NPs delivery. Meanwhile, it was found that MnO@mSiO2-iRGD NPs would dissociate under an acid environment, resulting in tumor specificity of MRI and exogenous Mn2+ release. Our results revealed that these pH-responsive biodegradable MnO@mSiO2-iRGD NPs synergized with α-PD-1 (PD-1 = programmed cell death-1) blocking antibody to highly elicit cytotoxic T lymphocyte infiltration and restrict melanoma progression and metastasis, which were envisioned as a promising candidate for tumor theranostics.

Synthesis of Dual-Response MnO2 Nanospheres as Multifunctional Drug Carriers

Recently, hollow structures have attracted much attention due to their high specific surface area, clear interior space, low density and good permeability. Among them, manganese dioxide (MnO2) hollow structure has also been widely studied for catalysis, drug delivery and energy storage. Based on the characteristics of low pH and high GSH concentration in tumor microenvironment, it is possible to develop an intelligent drug delivery system with pH/GSH response based on hollow mesoporous MnO2 nanospheres. In addition, the excellent physical and chemical properties of MnO2 nanomaterials provide conditions for its synergistic photothermal therapy. For example, Mn2+ released after manganese dioxide reacts with GSH can enhance T1-MAGNETIC resonance (MR) imaging. Meanwhile, manganese dioxide can also react with H2O2 in tumor microenvironment to release oxygen and alleviate tumor hypoxia. In order to prevent drug loss during delivery, a GSH-responsive hollow mesoporous manganese dioxide microsphere was selected as the drug carrier in this paper, and a series of studies were carried out on the performance of the carrier. Hollow mesoporous MnO2 nanospheres with particle size below 100 nm were prepared by hydrothermal method, and their response to tumor microenvironment was simulated in vitro. It has been proved that hollow mesoporous MnO2 nanospheres can be desorbed at low pH and GSH response, and can be used to deliver drugs or photothermal agents, as well as for collaborative cancer imaging and treatment.

Tumor microenvironment–responsive versatile “Trojan horse” theranostic nanoplatform for magnetic resonance imaging–guided multimodal synergistic antitumor treatment

A natural killer (NK)-92 cell membrane-camouflaged mesoporous MnO2-enveloped Au@Pd (Au@Pd@MnO2) nanoparticles (denoted as APMN NPs)-based versatile biomimetic theranostic nanoplatform was developed for magnetic resonance (MR) imaging-guided multimodal synergistic antitumor treatments. In this core-shell nanostructure, an Au@Pd core induced near-infrared (NIR)-activatable hyperthermal effects and nanozyme catalytic activity, while a mesoporous MnO2 shell not only afforded a high drug-loading capability, tumor microenvironment (TME)-triggered MR imaging and drug release, but also endowed catalase-, glutathione peroxidase-, and Fenton-like activities. Furthermore, the NK-92 cell membrane camouflaging endowed the NPs with enhanced tumor-targeting capability, immune escape function, and membrane protein-mediated tumoral uptake property. The doxorubicin-loaded APMN (D-APMN) NPs exhibited TME-responsive drug release properties. Furthermore, the cellular uptake, in vivo MR imaging, and NIR thermal imaging confirmed the active tumor-targeting capability and TME-responsive MR imaging property of these biomimetic NPs. An antitumor efficacy test, histological analyses, and blood biochemical profiles suggested that the developed D-APMN NPs possessed a high antitumor activity and biosafety in tumor-bearing nude mice. Therefore, the developed APMN NPs held great potential as an intelligent and comprehensive theranostic nanoplatform for tumor-specific bioimaging and TME-responsive multimodality treatment based on photothermal therapy, chemodynamic therapy, and chemotherapy. Statement of significanceExploring intelligent and comprehensive theranostic nanoplatforms to integrate tumor-specific bioimaging and TME-responsive multimodal therapy effectively is a challenge. Herein, we successfully developed a new kind of NK-92 cell membrane-camouflaged mesoporous MnO2-enveloped Au@Pd nanoparticles (APMN NPs)-based versatile biomimetic theranostic nanoplatform for the potential MR imaging-guided multimodal synergistic antitumor treatments. These NPs could integrate unique structural, optical, multiple-catalytic, paramagnetic, and biological merits of NK-92 cell membrane, Au@Pd cores and mesoporous MnO2 shell in a single nanoplatform. The NK-92 cell membrane camouflaging endowed the NPs with enhanced tumor-targeting capability, immune escape function, and membrane protein–mediated tumoral uptake property. The new information obtained from this study may be beneficial to promote the development of novel TME-responsive versatile “Trojan horse” theranostic nanoplatforms for efficient MR imaging-guided multimodal synergistic treatment.

Hybrid Mesoporous MnO2-Upconversion Nanoparticles for Image-Guided Lung Cancer Spinal Metastasis Therapy.

Upconversion nanoparticles (UCNPs) and MnO2 composite materials have broad prospects in biological applications due to their near-infrared (NIR) imaging capability and tumor microenvironment-responsive features. Nevertheless, the synthesis of such composite nanoplatforms still faces many hurdles such as redundant processing and uneven coatings. Here, we explored a simple, rapid, and universal method for precisely controlled coating of mesoporous MnO2 (mMnO2) using poly(ethylene imine) as a reducing agent and potassium permanganate as a manganese source. Using this strategy, a mMnO2 shell was successfully coated on UCNPs. We further modified the mMnO2-coated UCNPs (UCNP@mMnO2) with a photosensitizer (Ce6), cisplatin drug (DSP), and tumor targeting pentapeptide (TFA) to obtain a nanoplatform UCNP/Ce6@mMnO2/DSP-TFA for treating spinal metastasis of nonsmall cell lung cancer (NSCLC-SM). The utilization of both upconversion and downconversion luminescence of UCNPs with different NIR wavelengths can avoid the simultaneous initiation of NIR-II in vivo imaging and tumor photodynamic therapy, thus reducing damage to normal tissues. This platform achieved a high synergistic effect of photodynamic therapy and chemotherapy. This leads to beneficial antitumor effects on the therapy of NSCLC-SM.

Mesoporous nitrogen-doped carbon MnO2 multichannel nanotubes with high performance for Li-ion batteries

Lack of suitable ion channels and low electronic conductivity hinder MnO2 as an anode material for lithium-ion batteries. Multiple ion channels rapidly and selectively gate ion transport to maintain superior energy storage. We report a mesoporous N-doped C modified MnO2 hollow nanotube with multiple Li-ion transport channels. When used as Li-ion batteries anode, due to multichannel ion transport of mesoporous N-doped C modified MnO2, the diffusion coefficient of Li+ reaches ~ 10−8 cm2 s−1. And the batteries show excellent specific capacity (as high as 468.4 mA h g−1 at 5 A g−1), superior rate capability (the current density from 100 A g−1 to 5 A g−1), good cycling ability (preserving ~92.5% capacity after 10000 cycles). Our multiple ion channels design contributes a novel idea for preparing outstanding comprehensive performance anode materials for lithium-ion batteries.

Employing manufactured Mn3O4–ZnO nanocomposite for ameliorated photocatalytic performance under visible light

Pluronic P-65 was appropriated as a structure-directing agent in this study to create mesoporous Mn3O4–ZnO nanostructured materials with 1, 2, 3, and 4 wt% Mn3O4 NPs. ZnO NPs (nanoparticles) were extremely disseminated and they were completely consistent in size or shape, with mean particle diameter close to 20 nm. The resulting mesoporous structure revealed by the produced Mn3O4–ZnO nanostructured materials had a large surface area as well as a large pore volume. Upon visible illumination, photocatalytic effectiveness of the manufactured Mn3O4–ZnO nanostructured materials was examined for tetracycline (TC) degradation and was furtherly correlated with those of pure ZnO NPs and commercial P-25. After 120 min of illumination by visible light, Mn3O4–ZnO heterojunction with 3.0 wt% Mn3O4 NPs was capable of accomplishing almost complete decomposition of TC however, only 3.7 and 8.9% of TC were decomposed by the application of ZnO NPs and commercial P-25 (commercial titanium dioxide), correspondingly. In other words, the removal effectiveness of such heterojunctions was 27 and 11-fold stronger than those of pure ZnO NPs and P-25, accordingly. In addition, the decomposition performance of 3 wt% Mn3O4–ZnO nanostructured material is eminent in comparison to other manufactured nanostructured heterojunctions. To investigate the mechanism of TC photocatalytic degradation, transient photocurrent intensity as well as photoluminescence characteristics were addressed. It is envisioned that this research may give some ideas for comprehending more heterojunctions with distinguished behaviorism.

Graphene anchored mesoporous MnO2 nanostructures as stable and high-performance anode materials for Li-ion batteries

Among various transition metal oxides, MnO2 is a promising anode material for Li-ion battery applications due to its lower discharge potential, good capacity and high abundance. However, poor electronic conductivity hampers its practical applications. Herein we report two unique mesoporous MnO2–graphene composites, M1-MnO2-G and M8-MnO2-G, where M1 and M8 represent the use of specific silica template, MCM-41 and MCM-48 respectively in deriving these phases. Our results show that as anode materials for Li-ion battery application, both the composites exhibit good cycling stability, high discharge capacity, and superior rate performance. For instance, M1-MnO2-G and M8-MnO2-G deliver stable discharge capacity of 1112 mA h g−1 and 1494 mA h g−1 at C/5 rate. The high specific capacities and superior rate performance of the composites are due to the synergistic effects of graphene integrated mesoporous MnO2. The mesoporous architecture with nano-size wall thickness provides shorter diffusion paths for Li+ ion conduction in addition to facilitating uniform electrolyte infiltration throughout the electrode, while the graphene enhances the electronic conductivity and mechanical strength of the composite electrode. Full cell studies using mesoporous MnO2-Graphene composites anode against LiNi0.8Mn0.1Co0.1O2 cathode (M8-MnO2-G║LiNMC811) indicate very stable capacity (200 cycles at 0.1C) and high rate (5C) performance.

Mesoporous MnO2 polymorphs as sorbent materials for removal of cationic dyes from water

ABSTRACT Scientists have become interested in treating dye-contaminated water due to the health issues and ecological imbalances caused by the presence of these injurious compounds in water. Herein, two MnO2 polymorphs i.e. ε- and γ-MnO2 were prepared by the comproportionation reaction between KMnO4 and MnCl2. In comparison to γ-MnO2, ε-MnO2 has greater surface area, pore width, and pore volume. According to the thermal study, ε-MnO2 contains more surplus mass in the form of negatively charged surface hydroxyl groups than γ- phase. The adsorption capability of both polymorphs was examined for the removal of both cationic (methylene blue, malachite green and crystal violet) and anionic dyes (eosin yellow). The efficient adsorption for the cationic dyes using ε-MnO2 was occurred in the neutral medium, where it had a highly negative surface as determined by zeta potential measurements. It only took few minutes to complete the removal. The electrostatic interactions of the cationic dye molecules with the OH- groups account for this result. While, complete dye removal (40 min) was occurred in the acidic medium using γ-MnO2. On the other hand, in the neutral medium the adsorption of the anionic dye molecules on the surface of both MnO2 phases was hampered by the repulsion forces. As a result, despite extending the contact time to 180 min and the adsorbent dose to 50 mg, no anionic dye removal was seen. On the contrary, in the acidic medium very fast removal occurs for Eosin Y as the surface of both MnO2 phases acquired a positive charge. The influence of the ionic strength on MB elimination was investigated. The results showed that as the content of NaCl was increased, the removal effectiveness decreased from 100% to 35%. The kinetics of cationic dye adsorption on the ε-MnO2 surface was studied, and it was discovered that the mechanism follows a pseudo-second order model.

Self-oxygenation mesoporous MnO2 nanoparticles with ultra-high drug loading capacity for targeted arteriosclerosis therapy

Atherosclerosis (AS) is a leading cause of vascular diseases that severely threats the human health due to the lack of efficient therapeutic methods. During the development and progress of AS, macrophages play critical roles, which are polarized into pro-inflammatory M1 phenotype to excrete abundant cytokines and overproduce reactive oxygen species (ROS), and take up excess amount of lipid to form foam cells. In this work, we developed a MnO2-based nanomedicine to re-educate macrophages for targeting AS therapy. The MnO2 was one-pot synthesized under mild condition, showing intrinsic catalase-mimic activity for self-oxygenation by using endogenous H2O2 as substrate. Moreover, the mesoporous structure as well as the abundant metal coordination sites in MnO2 structure facilitated the loading of an anti-AS drug of curcumin (Cur), achieving extraordinarily high drug loading capacity of 54%. Cur displayed a broad spectrum of anti-oxidant and anti-inflammatory capabilities to repolarize M1 macrophages into M2 phenotype, and the catalytic MnO2 recovered the function of lipid efflux transporter to remove lipid from cells by suppressing HIF-1α. Collectively, the nanocarrier and the payload drug functioned as an all-active nanoplatform to synergistically alleviate the syndromes of AS. In ApoE−/− mice model, the nanosystem could significantly prolong the circulation half-life of Cur by sixfold, and enhance drug accumulation in atherosclerotic lesion by 3.5-fold after intravenous injection by virtue of surface hyaluronic acid (HA) modification. As a result, a robust anti-AS efficacy was achieved as evidenced by the decrease of atherosclerotic lesion, plaque area, lipid level.Graphical

In Situ Synthesis of Mesoporous Silica-Based Mno2 Nanozymes for the Regulation of Macrophage Polarization and its Catalytic Mechanism

In Situ Synthesis of Mesoporous Silica-Based Mno2 Nanozymes for the Regulation of Macrophage Polarization and its Catalytic Mechanism

Mg ion pre-intercalated MnO2 nanospheres as high-performance cathode materials for aqueous Zn-ion batteries.

Rechargeable Zn-MnO2 batteries with mild and nearly neutral aqueous electrolytes have shown great potential for large-scale energy storage because of their high safety, low cost, environmental friendliness and high energy density. However, MnO2 cathode materials usually have disadvantages such as low capacity and poor cycling stability, which limit the development of Zn-MnO2 batteries. In this study, mesoporous MnO2 nanospheres were prepared by in situ Mg ion pre-intercalation via a simple chemical method. The prepared MnO2 shows a high reversible capacity (247 mA h g-1 at 0.3 A g-1), excellent cycling stability (a capacity retention of 93% over 800 cycles at 0.8 A g-1) and good rate performance. The GITT, in situ EIS, ex situ XRD, ex situ XPS and ex situ SEM show that the zinc storage mechanism of MnO2 should be H+/Zn2+ co-intercalation/de-intercalation. This research could provide specific inspiration and promotion for the development and mechanism research of high-performance rechargeable Zn-MnO2 batteries.

Inkjet-printed transparent micro-supercapacitors with morphology tailored co-continuous mesoporous Mn3O4

The inkjet-printed transparent/ flexible MSCs based on mesoporous Mn3O4 show gravimetric and volumetric specific capacitances of 679.5 F g−1 and 2411 F cm−3, respectively, with wide potential window of 2.6 V, and cycling stability up to 10000 cycles.

Selective Mild Oxidation of Anilines into Nitroarenes by Catalytic Activation of Mesoporous Frameworks Linked with Gold-Loaded Mn3 O4 Nanoparticles.

This work reports the synthesis and catalytic application of mesoporous Au-loaded Mn3 O4 nanoparticle assemblies (MNAs) with different Au contents, i. e., 0.2, 0.5 and 1 wt %, towards the selective oxidation of anilines into the corresponding nitroarenes. Among common oxidants, as well as several supported gold nanoparticle platforms, Au/Mn3 O4 MNAs containing 0.5 wt % Au with an average particle size of 3-4 nm show the best catalytic performance in the presence of tert-butyl hydroperoxide (TBHP) as a mild oxidant. In all cases, the corresponding nitroarenes were isolated in high to excellent yields (85-97 %) and selectivity (>98 %) from acetonitrile or greener solvents, such as ethyl acetate, after simple flash chromatography purification. The 0.5 % Au/Mn3 O4 catalyst can be isolated and reused four times without a significant loss of its activity and can be applied successfully to a lab-scale reaction of p-toluidine (1 mmol) leading to the p-nitrotulene in 83 % yield. The presence of AuNPs on the Mn3 O4 surface enhances the catalytic activity for the formation of the desired nitroarene. A reasonable mechanism was proposed including the plausible formation of two intermediates, the corresponding N-aryl hydroxylamine and the nitrosoarene.

Preparation of Mesoporous MnO2 Catalysts with Different Morphologies for Catalytic Ozonation of Organic Compounds

Preparation of Mesoporous MnO2 Catalysts with Different Morphologies for Catalytic Ozonation of Organic Compounds

Black Phosphorus Quantum Dots Encapsulated Biodegradable Hollow Mesoporous MnO2: Dual‐Modality Cancer Imaging and Synergistic Chemo‐Phototherapy

AbstractTo achieve an accurate diagnosis and efficient tumor treatment, developing a facile and powerful strategy to build multifunctional nanotheranostics is highly desirable. Benefiting from the distinct characteristics of black phosphorus quantum dots (BPQDs), herein, a versatile nanoprobe (H‐MnO2/DOX/BPQDs) is constructed for dual‐modality cancer imaging and synergistic chemo‐phototherapy. The hollow mesoporous MnO2 (H‐MnO2) nanoparticles are sequentially decorated with a cationic polymer poly (allylamine hydrochloride) (PAH) and an anionic polymer poly (acrylic acid) (PAA). The obtained H‐MnO2‐PAH‐PAA is covalently grafted with BPQDs‐PEG‐NH2 via a carbodiimide cross‐linking reaction and then loaded with anti‐cancer drug DOX to form final nanoprobe H‐MnO2/DOX/BPQDs. Under the tumor microenvironment, H‐MnO2/DOX/BPQDs is degraded to release encapsulated functional molecules DOX and BPQDs. DOX acts as the chemotherapy and fluorescence imaging agent, and BPQDs endows the nanoprobe with photodynamic therapy (PDT) and photothermal therapy (PTT) abilities under dual laser irradiation of 630 and 808 nm. H‐MnO2 offers contrasts for magnetic resonance imaging (MRI) and facilitates conversion of endogenous H2O2 to oxygen, thereby relieving tumor hypoxia and enhancing PDT efficacy. All in vitro and in vivo results demonstrate that the designed nanoprobe displays dual‐modality MRI/FL imaging and synergistic chemotherapy/PDT/PTT, which ultimately enhances the accuracy of cancer diagnosis and therapeutic performance.

A Cellulose-Derived Nanofibrous MnO2-TiO2-Carbon Composite as Anodic Material for Lithium-Ion Batteries.

A bio-inspired nanofibrous MnO2-TiO2-carbon composite was prepared by utilizing natural cellulosic substances (e.g., ordinary quantitative ashless filter paper) as both the carbon source and structural matrix. Mesoporous MnO2 nanosheets were densely immobilized on an ultrathin titania film precoated with cellulose-derived carbon nanofibers, which gave a hierarchical MnO2-TiO2-carbon nanoarchitecture and exhibited excellent electrochemical performances when used as an anodic material for lithium-ion batteries. The MnO2-TiO2-carbon composite with a MnO2 content of 47.28 wt % exhibited a specific discharge capacity of 677 mAh g−1 after 130 repeated charge/discharge cycles at a current rate of 100 mA g−1. The contribution percentage of MnO2 in the composite material is equivalent to 95.1% of the theoretical capacity of MnO2 (1230 mAh g−1). The ultrathin TiO2 precoating layer with a thickness ca. 2 nm acts as a crucial interlayer that facilitates the growth of well-organized MnO2 nanosheets onto the surface of the titania-carbon nanofibers. Due to the interweaved network structures of the carbon nanofibers and the increased content of the immobilized MnO2, the exfoliation and aggregation, as well as the large volume change of the MnO2 nanosheets, are significantly inhibited; thus, the MnO2-TiO2-carbon electrodes displayed outstanding cycling performance and a reversible rate capability during the Li+ insertion/extraction processes.

Defective mesoporous carbon/MnO2 nanocomposite as an advanced electrode material for supercapacitor application

Herein, the supercapacitive characteristics of a novel nanocomposite based on defective mesoporous carbon (DMC) and MnO2 is presented. DMC was obtained via a facile and low-cost synthesis route and its interconnected pore network was served as host matrix for the growth of MnO2 nanoparticles to form the DMC/MnO2 nanocomposite. The deposition of MnO2 nanoparticles at the surface of DMC support was investigated using different structural analyses including FT-IR, Nitrogen adsorption/desorption, XRD, XPS, SEM and TEM. Compared to DMC and MnO2 electrodes, the DMC/MnO2 nanocomposite exhibited the highest specific capacitance reaching to 292 F g−1 at current density of 0.5 A g−1. Also, DMC/MnO2 possessed good rate performance (61% capacity retention over 0.5–10 A g−1) and cycling stability (21% capacity loss after 2000 charge/discharges cycles). Furthermore, a two-electrode symmetric supercapacitor device delivered a high specific energy of 34 W h kg−1 at specific power of 100 W kg−1.

Overcoming chemotherapy resistance using pH-sensitive hollow MnO2 nanoshells that target the hypoxic tumor microenvironment of metastasized oral squamous cell carcinoma

BackgroundSmart nanoscale drug delivery systems that target acidic tumor microenvironments (TME) could offer controlled release of drugs and modulate the hypoxic TME to enhance cancer therapy. The majority of previously reported MnO2 nanostructures are nanoparticles, nanosheets, or nanocomposites incorporated with other types of nanoparticles, which may not offer the most effective method for drug loading or for the controlled release of therapeutic payloads. Previous studies have designed MnO2 nanoshells that achieve tumor-specific and enhanced combination therapy for localized advanced cancer. However, the therapeutic effect of MnO2 nanoshells on metastatic cancer is still uncertain.ResultHere, intelligent “theranostic” platforms were synthesized based on hollow mesoporous MnO2 (H-MnO2) nanoshells that were loaded with chemotherapy agents docetaxel and cisplatin (TP) to form H-MnO2-PEG/TP nanoshells, which were designed to alleviate tumor hypoxia, attenuate angiogenesis, trigger the dissolution of Mn2+, and synergize the efficacy of first-class anticancer chemotherapy. The obtained H-MnO2-PEG/TP nanoshells decomposed in the acidic TME, releasing the loaded drugs (TP) and simultaneously attenuated tumor hypoxia and hypoxia-inducible factor-1α (HIF-1α) expression by inducing endogenous tumor hydrogen peroxide (H2O2) decomposition. In vitro experiments showed that compared with the control group, the proliferation, colony formation and migration ability of CAL27 and SCC7 cells were significantly reduced in H-MnO2-PEG/TP group, while cell apoptosis was enhanced, and the expression of hypoxia-inducible factor-1α(HIF-1α) was down-regulated. In vivo experiments showed that tumor to normal organ uptake ratio (T/N ratio) of mice in H-MnO2-PEG/TP group was significantly higher than that in TP group alone (without the nanoparticle), and tumor growth was partially delayed. In the H-MnO2-PEG/TP treatment group, HE staining showed that most of the tumor cells were severely damaged, and TUNEL assay showed cell apoptosis was up-regulated. He staining of renal and liver sections showed no obvious fibrosis, necrosis or hypertrophy, indicating good biosafety. Fluorescence staining showed that HIF-1α expression was decreased, suggesting that the accumulation of MnO2 in the tumor caused the decomposition of H2O2 into O2 and alleviated the hypoxia of the tumor.ConclusionIn conclusion, a remarkable in vivo and in vitro synergistic therapeutic effect is achieved through the combination of TP chemotherapy, which simultaneously triggered a series of antiangiogenic and oxidative antitumor reactions.Graphic abstract