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Today, cancer still poses a serious threat to human, but there is no exact cure. Therefore, exploring to accomplish high therapeutic performance is a challenging and urgent task. Since the nanoparticles unique properties were discovered, they have displayed promising potential for more effective therapies and have been widely used in photodynamic therapy (PDT) and radiation therapy (RT). However, some special properties of the tumour microenvironment (TME) have seriously affected the therapeutic outcomes, so the modulation of the TME becomes critical. Manganese dioxide (MnO2), as a transition metal oxide, has been widely used in biomedical fields with special physical and chemical properties, especially in regulating the TME. Furthermore, MnO2 has widely applications in various cancer treatments, such as PDT, chemodynamic therapy (CDT), immunotherapy, and some specific collaborative treatment. Herein, we reviewed the recent applications of MnO2 modified nanomaterials in tumour therapies and theranostics, including TME regulation, controlled drug loading/delivery/release, and imaging.

In recent years, the antitumor application of photodynamic therapy (PDT) has gained widespread interest in treating solid tumors. Due to the hypoxic environment in tumors, the major limit of PDT seems to be the source of oxygen. In this work, we attempted to relieve hypoxia and enhance photodynamic therapy, and therefore, designed and assembled a catalytic cascade-enhanced PDT multifunctional nanoplatform. The mentioned platform termed UIO@Ca-Pt is based on porphyrinic metal-organic framework (UIO) combination, which is simultaneously loaded by CaO2 NPs with polydopamine (PDA) and then the Pt raw material to further improve biocompatibility and efficiency. In a tumor microenvironment, CaO2 could react with water to generate calcium hydroxide and hydrogen peroxide, which was further decomposed by Pt nanoparticles to form oxygen, thereby facilitating the generation of cytotoxic singlet oxygen by photosensitizer TCPP under laser irradiation. Both in vitro and in vivo experiment results confirmed the excellent oxygen production capacity and enhanced PDT effect of UIO@Ca-Pt. With guaranteed safety in PDT, the oxygen-supplying strategy might stimulate considerable interest in the development of various metal-organic materials with multifunctionality for tumor diagnosis and therapy.

Photodynamic therapy (PDT) under hypoxic conditions and drug resistance in chemotherapy are perplexing problems in anti-tumor treatment. In addition, central nervous system neoplasm-targeted nanoplatforms are urgently required. To address these issues, a new multi-functional protein hybrid nanoplatform is designed, consisting of transferrin (TFR) as the multicategory solid tumor recognizer and hemoglobin for oxygen supply (ODP-TH). This protein hybrid framework encapsulates the photosensitizer protoporphyrin IX (PpIX) and chemotherapeutic agent doxorubicin (Dox), which are attached by a glutathione-responsive disulfide bond. Mechanistically, ODP-TH crosses the blood-brain barrier (BBB) and specifically aggregated in hypoxic tumors via protein homology recognition. Oxygen and encapsulated drugs ultimately promote a therapeutic effect by down-regulating the abundance of multidrug resistance gene 1 (MDR1) and hypoxia-inducible factor-1-α (HIF-1α). The results reveal that ODP-TH achieves oxygen transport and protein homology recognition in the hypoxic tumor occupation. Indeed, compared with traditional photodynamic chemotherapy, ODP-TH achieves a more efficient tumor-inhibiting effect. This study not only overcomes the hypoxia-related inhibition in combination therapy by targeted oxygen transport but also achieves an effective treatment of multiple tumors, such as breast cancer and glioma, providing a new concept for the construction of a promising multi-functional targeted and intensive anti-tumor nanoplatform.

In this paper, 41 hybrid compounds containing diaryl-1,5-diazole and morpholine structures acting as dual COX-2/5-LOX inhibitors have been designed, synthesized and biologically evaluated. Most of them showed potent antiproliferative activities and COX-2/5-LOX inhibitory in vitro. Among them, compound A33 displayed the most potency against cancer cell lines (IC50 = 6.43–10.97 μM for F10, HeLa, A549 and MCF-7 cells), lower toxicity to non-cancer cells than celecoxib (A33: IC50 = 194.01 μM vs. celecoxib: IC50 = 97.87 μM for 293T cells), and excellent inhibitory activities on COX-2 (IC50 = 0.17 μM) and 5-LOX (IC50 = 0.68 μM). Meanwhile, the molecular modeling study was performed to position compound A33 into COX-2 and 5-LOX active sites to determine the probable binding models. Mechanistic studies demonstrated that compound A33 could block cell cycle in G2 phase and subsequently induced apoptosis of F10 cells. Furthermore, compound A33 could significantly inhibit tumor growth in F10-xenograft mouse model, and pharmacokinetic study of compound A33 indicated that it showed better stability in vivo. In general, compound A33 could be a promising candidate for cancer therapy.

Cancer is a major disease burden worldwide. In recent years, in addition to surgical resection, radiotherapy and chemotherapy are recognized as the most effective methods for treating solid tumors. These methods have been introduced to treat tumors of different origins and stages clinically. However, due to insufficient blood flow and oxygen (O2) supply in solid tumors, hypoxia is caused, leading to decreased sensitivity of tumor cells and poor therapeutic effects. In addition, hypoxia will also lead to resistance to most anticancer drugs, accelerate malignant progress, and increase metastasis. In solid tumors, adequate O2 supply and adequate delivery of anticancer drugs are essential to improve radiotherapy and chemotherapy sensitivity. In recent decades, the researches on relieving tumor hypoxia have attracted researchers’ extensive attention and achieved good results. However, as far as we know, there is no detailed review of the researches on alleviating tumor hypoxia. Therefore, in this contribution, we hope to give an overview of the researches on methods to improve tumor hypoxia environment and summarize their effect and application in tumor therapy, to provide a methodological reference for the research and development of new antitumor agents.

Lately, chemotherapy and photodynamic therapy (PDT) synergistic therapy has become a promising anti-cancer treatment mean. However, the hypoxia in tumor leads to huge impediments to the oxygen-dependent PDT effects. In this work, a multifunctional nanoplatform (TUDMP) based on a multivariable porphyrin-nMOFs core and a manganese dioxide (MnO

The abnormal angiogenesis and insufficient oxygen supply in solid tumors lead to intratumoral hypoxia, which severely limits the efficacy of traditional photodynamic therapy (PDT). Here, a multifunctional nanoplatform (ZDZP@PP) based on a zeolitic imidazolate framework-67 (ZIF-67) core as a hydrogen peroxide catalyst, a zeolitic imidazolate framework-8 (ZIF-8) shell with a pH-responsive property, and a polydopamine-poly(ethylene glycol) (PDA-PEG) layer for improving the biocompatibility is fabricated for not only relieving tumor hypoxia but also enhancing the efficacy of combination chemo-photodynamic therapy. The chemotherapy drug doxorubicin (DOX) and photosensitizer protoporphyrin IX (PpIX) are encapsulated in different layers independently; thus, a unique two-stage stepwise release becomes possible. Moreover, the nanoplatform can effectively decompose hydrogen peroxide to produce oxygen and thus relieve tumor hypoxia, which further facilitates the production of cytotoxic reactive oxygen species (ROS) by PpIX under laser irradiation. Both in vitro and in vivo experimental results confirm that the combination chemo-photodynamic therapy with the ZDZP@PP nanoplatform can provide more effective cancer treatment than chemotherapy or PDT alone. Consequently, the oxygen self-sufficient multifunctional nanoplatform holds promising potential to overcome hypoxia and treat solid tumors in the future.

The overexpress of COX-2 was clearly associated with carcinogenesis and COX-2 as a possible target has long been exploited for cancer therapy. In this work, we described the design and synthesis of a series of diarylpyrazole derivatives integrating with chrysin. Among them, compound e9 exhibited the most potent inhibitory activity against COX-2 and antiproliferative activity against Hela cells with IC50 value of 1.12 μM. Further investigation revealed that e9 could induce apoptosis of Hela cells by mitochondrial depolarization and block the G1 phase of cell cycle in a dose-dependent manner. Besides, molecular docking simulation results was further confirmed that e9 could bind well with COX-2. In summary, compound e9 may be promising candidates for cancer therapy.

A novel series of aniline-containing hydroxamic acids were designed, synthesized and evaluated as anti-virulence agents for the treatment of gastritis and gastric ulcer caused by Helicobacter pylori. In vitro enzyme-based screen together with in vivo assays and structure−activity relationship (SAR) studies led to the discovery of three potent urease inhibitors 3-(3,5-dichlorophenylamino) N-hydroxypropanamide (3a), 3-(2-chlorophenylamino) N-hydroxypropanamide (3d) and 3-(2,4-dichlorophenylamino) N-hydroxypropanamide (3n). Compounds 3a, 3d and 3n showed excellent urease inhibition with IC50 values 0.043 ± 0.005, 0.055 ± 0.008 and 0.018 ± 0.002 μM, and significantly depressed gastritis developing at the dose of 32 mg/kg b. i.d with eradication rates of H. pylori reaching 92.3, 84.6 and 100%, respectively. Preliminary safety studies (acute toxicity in mice) disclosed that 3a, 3d and 3n was well-tolerated in KM mice with LD50s of 2982.8, 3349.4 and 3126.9 mg/kg, respectively. Collectively, the data obtained in this study indicate that 3a, 3d and 3n, in particular 3n, could considered as promising candidates for the potential treatment of H. pylori caused gastritis and gastric ulcer, and hence merit further studies.

Lately, chemotherapy and photodynamic therapy (PDT) synergistic therapy has become a promising anti-cancer treatment mean. However, the hypoxia in tumor leads to huge impediments to the oxygen-dependent PDT effects. In this work, a multifunctional nanoplatform (TUDMP) based on a multivariable porphyrin-nMOFs core and a manganese dioxide (MnO2) shell was prepared for relieving tumor hypoxia and enhancing chemo-photodynamic synergistic therapy performance. The obtained TUDMP nanoplatform could effectively catalyze the hydrolysis of hydrogen peroxide to generate oxygen and also lead to consumption of antioxidant GSH, thereby facilitating the production of cytotoxic reactive oxygen species (ROS) by photosensitizer under laser irradiation. More importantly, the decomposition of the MnO2 shell would further promote the release of the loaded doxorubicin (DOX), and thus an efficient chemo-PDT synergistic therapy was realized. Both in vitro and in vivo experimental results demonstrated the oxygen self-sufficient multifunctional nanoplatform could exhibit significantly enhanced anticancer efficiencies compared with chemotherapy or PDT alone.

In our previous study, we designed a series of pyrazole derivatives as novel COX-2 inhibitors. In order to obtain novel dual inhibitors of COX-2 and 5-LOX, herein we designed and synthesized 20 compounds by hybridizing pyrazole with substituted coumarin who was reported to exhibit 5-LOX inhibition to select potent compounds using adequate biological trials sequentially including selective inhibition of COX-2 and 5-LOX, anti-proliferation in vitro, cells apoptosis and cell cycle. Among them, the most potent compound 11g (IC50=0.23±0.16μM for COX-2, IC50=0.87±0.07μM for 5-LOX, IC50=4.48±0.57μM against A549) showed preliminary superiority compared with the positive controls Celecoxib (IC50=0.41±0.28μM for COX-2, IC50=7.68±0.55μM against A549) and Zileuton (IC50=1.35±0.24μM for 5-LOX). Further investigation confirmed that 11g could induce human non-small cell lung cancer A549 cells apoptosis and arrest the cell cycle at G2 phase in a dose-dependent manner. Our study might contribute to COX-2, 5-LOX dual inhibitors thus exploit promising novel cancer prevention agents.

Focal adhesion kinase (FAK) is an important drug target that plays a fundamental role in mediating signal transduction system. We report herein the discovery of a novel class of 1,3,4-oxadiazole-2(3H)-thione derivatives containing piperazine skeleton with improved potency toward FAK. All of the 17 new synthesized compounds were assayed for the anticancer activities against four cancer cells, HepG2, Hela, SW116 and BGC823. Because of the combination of 1,4-benzodioxan, 1,3,4-oxadiazole and piperazine ring, most of them exhibited remarkable antitumor activities. Notably, compound 5m showed the most potent biological activities (IC50=5.78μM for HepG2, and IC50=47.15μM for SW1116), and its anti-FAK inhibitory activity (IC50=0.78μM) was also the best. Computational docking studies also showed that compound 5m has interaction with FAK key residues in the active site.

Responsive nanocarriers with biocompatibility and precise drug releasing capability have emerged as a prospective candidate for anticancer treatment. However, the challenges imposed by the complicated preparation process and limited loading capacities have seriously impeded the development of novel multifunctional drug delivery systems. Here, we developed a novel and dual-responsive nanocarrier based on a nanoscale ZIF-8 core and an organosilica shell containing disulfide bridges in its frameworks through a facile and efficient strategy. The prepared ZIF-8@DOX@organosilica nanoparticles (ZDOS NPs) exhibited a well-defined structure and excellent doxorubicin (DOX) loading capability (41.2%) with pH and redox dual-sensitive release properties. The degradation of the organosilica shell was observed after 12 h incubation with a 10 mM reducing agent. Confocal imaging and flow cytometry analysis further proved that the nanocarriers can efficiently enter cells and complete intracellular DOX release under the low pH and high glutathione concentrations, which resulted in an enhanced cytotoxicity of DOX for cancer cells. Meanwhile, subcellular localization experiments revealed that the ZDOS NPs entered cells mainly by endocytosis and then escaped from lysosomes into the cytosol. Moreover, in vivo assays also demonstrated that the ZDOS NPs exhibited negligible systemic toxicity and significantly enhanced anticancer efficiencies compared with free DOX. In summary, our prepared pH and redox dual-responsive nanocarriers provide a potential platform for controlled release and cancer treatment.

Cyclooxygenase-2 is frequently overexpression in malignant tumors and the product PGE2 promotes cancer cell progression and metastasis. We designed novel series of coumarin sulfonamides derivatives to improve biological activities of COX-2 inhibition and anticancer. Among them, compound 7t showed most powerful selective inhibitory and antiproliferative activity (IC50=0.09μM for COX-2, IC50=48.20μM for COX-1, IC50=0.36μM against HeLa cells), comparable to the control positive compound Celecoxib (0.31μM, 43.37μM, 7.79μM). Cancer cell apoptosis assay were performed and results indicated that compound 7t effectively fuels HeLa cells apoptosis in a dose and time-dependent manner. Moreover, 7t could significantly suppress cancer cell adhesion, migration and invasion which were essential process of cancer metastasis. Docking simulations results was further indicated that compound 7t could bind well to the COX-2 active site and guided a reasonable design of selective COX-2 inhibitor with anticancer activities in future.

A series of novel ferrocene-pyrazole derivatives containing nitric oxide donors as COX-2 inhibitors for cancer therapy were designed, synthesized and biologically evaluated. Among them, compound 7l displayed the most potent inhibitory against COX-2 (IC50 = 0.82 μM) and antiproliferative activities against Hela cells (IC50 = 0.34 μM) compared with Celecoxib (IC50 = 0.38 and 7.91 μM). The further mechanistic studies revealed that 7l could induce apoptosis of Hela cells by mitochondrial depolarization and the antiproliferative activities of 7l were positively correlated with the levels of intracellular NO release in Hela cells. Most notably, 7l could dramatically suppress tumor growth in Hela cells xenografted mouse model. In summary, compound 7l may be promising candidates for cancer therapy.