Alleviation Of Hypoxia Research Articles

Ultrathin-FeOOH-Coated MnO2 Sonosensitizers with Boosted Reactive Oxygen Species Yield and Remodeled Tumor Microenvironment for Efficient Cancer Therapy.

Sonodynamic therapy (SDT) typically suffers from compromised anticancer efficacy owing to the low reactive oxygen species (ROS) yield and complicated tumor microenvironment (TME) which can consume ROS and support the occurrence and development of tumors. Herein, ultrathin‐FeOOH‐coated MnO2 nanospheres (denoted as MO@FHO) as sonosensitizers which can not only facilitate ultrasound (US)‐triggered ROS but also tune the TME by hypoxia alleviation, H2O2 consumption as well as glutathione (GSH) depletion are designed. The FeOOH coating will boost the production yield of singlet oxygen (1O2) and hydroxyl radicals (•OH) by inhibiting the recombination of US‐initiated electron–hole pairs and Fenton‐like reaction, respectively. Additionally, the catalase‐like and GSH peroxidase‐like activities of MO@FHO nanospheres enable them to break the TME equilibrium via hypoxia alleviation and GSH depletion. The combination of high ROS yield and fundamental destruction of TME equilibrium results in satisfactory antitumor outcomes, as demonstrated by the high tumor suppression efficacy of MO@FHO on MDA‐MB‐231‐tumor‐bearing mice. No obvious toxicity is detected to normal tissues at therapeutic doses in vivo. The capability to modulate the ROS production and TME simultaneously can afford new probability for the development of advanced sonosensitizers for synergistic comprehensive cancer therapy.

Nanococktail Based on Supramolecular Glyco-Assembly for Eradicating Tumors In Vivo.

The development of robust phototherapeutic strategies for eradicating tumors remains a significant challenge in the transfer of cancer phototherapy to clinical practice. Here, a phototherapeutic nanococktail atovaquone/17-dimethylaminoethylamino-17-demethoxygeldanamycin/glyco-BODIPY (ADB) was developed to enhance photodynamic therapy (PDT) and photothermal therapy (PTT) via alleviation of hypoxia and thermal resistance that was constructed using supramolecular self-assembly of glyco-BODIPY (BODIPY-SS-LAC, BSL-1), hypoxia reliever atovaquone (ATO), and heat shock protein inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG). Benefiting from a glyco-targeting and glutathione (GSH) responsive units BSL-1, ADB can be rapidly taken up by hepatoma cells, furthermore the loaded ATO and 17-DMAG can be released in original form into the cytoplasm. Using in vitro and in vivo results, it was confirmed that ADB enhanced the synergetic PDT and PTT upon irradiation using 685 nm near-infrared light (NIR) under a hypoxic tumor microenvironment where ATO can reduce O2 consumption and 17-DMAG can down-regulate HSP90. Moreover, ADB exhibited good biosafety, and tumor eradication in vivo. Hence, this as-developed phototherapeutic nanococktail overcomes the substantial obstacles encountered by phototherapy in tumor treatment and offers a promising approach for the eradication of tumors.

Engineering defected 2D Pd/H-TiO2 nanosonosensitizers for hypoxia alleviation and enhanced sono-chemodynamic cancer nanotherapy

BackgroundSonodynamic therapy (SDT) is a burgeoning modality for cancer therapy owing to its high tissue-penetrating capability, controllability and safety. Whereas, the undesirable reactive oxygen species (ROS) yield of sonosensitizers and tumor hypoxia are two vulnerable spots of SDT. Therefore, it is an advisable strategy to augment ROS level and simultaneously relieve hypoxia for SDT to arrive its full potential in cancer treatment.ResultsIn this work, the defected two-dimensional (2D) Pd/H-TiO2 nanosheets (NSs) with triple antineoplastic properties were dexterously elaborated and engineered using a facile one-pot Pd-catalyzed hydrogenation tactic by loading a tiny amount of Pd and then inletting hydrogen flow at atmospheric pressure and temperature. The 2D black Pd/H-TiO2 NSs with oxygen defects exerted eximious SDT effect based on the decreased bandgap that made it easier for the separation of electrons and holes when triggered by ultrasound as theoretically guided by density functional theory calculations. Additionally, Pd/H-TiO2 NSs could serve as Fenton-like agents because of the presence of oxygen defects, facilitating the conversion of hydrogen peroxide into hydroxyl radicals for exerting the chemodynamic therapy (CDT). Simultaneously, the introduced tiny Pd component possessed catalase-like activity responsible for oxygen production to ameliorate hypoxic condition and thus contributed to improving SDT and CDT efficacies. Both in vitro and in vivo results provided compelling evidences of high ROS yield and aggrandized sono-chemodynamic effect of Pd/H-TiO2 nanosonosensitizers with the detailed underlying mechanism investigation by RNA sequencing.ConclusionThis work delves the profound potential of Pd-catalyzed hydrogenated TiO2 on oncotherapy, and the effective antineoplastic performance and ignorable therapeutic toxicity make it a powerful competitor among a cornucopia of nanosonosensitizers.Graphical

Glutathione responsive nitric oxide release for enhanced photodynamic therapy by a porphyrinic MOF nanosystem

In photodynamic therapy (PDT), the concentration of reactive oxygen species (ROS) generated in cells directly determines the therapeutic effect. However, excessive glutathione (GSH) concentration at the tumor site and hypoxic environment strongly reduce the production of ROS. Nitric oxide (NO) has a variety of anti-tumor activities, including the induction of cell apoptosis and sensitization to PDT, so it is in the spotlight in the area of cancer intervention. Therefore, it is very innovative to combine NO therapy with PDT and simultaneously reduce GSH content and relieve hypoxia. Metal-organic framework (MOF) is an emerging drug delivery vehicle that can exert photodynamic effects when a photosensitizer is used as its organic ligand. In this study, we constructed a GSH-responsive NO producing nanosystem to enhance ROS production through GSH depletion and hypoxia alleviation. Briefly, nicorandil (Nic) is encapsulated into porous porphyrinic MOF nanoparticles, and hyaluronic acid (HA) is electrostatically adsorbed on the surface of the MOF nanoparticles for CD44 receptor-targeting and prevention of Nic leakage. Notably, the Nic reacts with GSH to produce NO gas with vasodilation and GSH reduction, thus improving oxygen supply for efficient ROS generation. Moreover, the generated NO can further react with superoxide radical anion to produce highly reactive peroxynitrite (ONOO−) molecules with higher cytotoxicity. Overall, the Nic-MOF@HA nanosystem combines NO gas therapy with PDT, resulting in a significant increase in ROS production and greatly enhancing the efficacy of PDT.

In situ injectable nano-complexed hydrogel based on chitosan/dextran for combining tumor therapy via hypoxia alleviation and TAMs polarity regulation

The tumor microenvironment (TME) is characterized by low pH, hypoxia, and infiltrated tumor-associated macrophages (TAMs). Therefore, regulation of TAMs polarization into anti-tumor M1 phenotype and meanwhile alleviation of the hypoxia in TME are expected to improve anti-tumor therapeutic efficacy. To this end, a novel in situ injectable nano-complexed hydrogel was developed in this study for combining tumor therapy. Thereunto, hyaluronic acid modified transfersomes loaded with chlorogenic acid functioned to reverse M2 type into M1 type via CD44 mediated internalization, the nanomedicine was entrapped in Schiff-based crosslinked injectable hydrogel (fabricated with carboxymethyl chitosan and oxidized dextran) whose linkage was labile to the acidic TME for controlled drug release. Moreover, catalase was integrated in the hydrogel enabling to convert hydrogen peroxide in TME into dissolved oxygen and alleviate tumor hypoxia. The multifunctional nano-complexed injectable hydrogel was verified to efficiently inhibit tumor growth through synergetic effects of hypoxia alleviation and TAMs polarity regulation.

Ultrasmall Manganese Ferrites for In Vivo Catalase Mimicking Activity and Multimodal Bioimaging.

Manganese ferrite nanoparticles display interesting features in bioimaging and catalytic therapies. They have been recently used in theranostics as contrast agents in magnetic resonance imaging (MRI), and as catalase-mimicking nanozymes for hypoxia alleviation. These promising applications encourage the development of novel synthetic procedures to enhance the bioimaging and catalytic properties of these nanomaterials simultaneously. Herein, a cost-efficient synthetic microwave method is developed to manufacture ultrasmall manganese ferrite nanoparticles as advanced multimodal contrast agents in MRI and positron emission tomography (PET), and improved nanozymes. Such a synthetic method allows doping ferrites with Mn in a wide stoichiometric range (Mnx Fe3-x O4 , 0.1 ≤ x≤ 2.4), affording a library of nanoparticles with different magnetic relaxivities and catalytic properties. These tuned magnetic properties give rise to either positive or dual-mode MRI contrast agents. On the other hand, higher levels of Mn doping enhance the catalytic efficiency of the resulting nanozymes. Finally, through their intracellular catalase-mimicking activity, these ultrasmall manganese ferrite nanoparticles induce an unprecedented tumor growth inhibition in a breast cancer murine model. All of these results show the robust characteristics of these nanoparticles for nanobiotechnological applications.

Bimetallic PdPt-based nanocatalysts for Photothermal-Augmented tumor starvation and sonodynamic therapy in NIR-II biowindow assisted by an oxygen Self-Supply strategy

Tumor starvation by depleting intratumoral glucose has been validated as a promising therapeutic strategy to combat cancer. However, inadequate oxygenation in hypoxic tumorous tissue significantly compromises the treatment efficacy. Herein, PdPt bimetallic nanocatalyst conjugated with glucose oxidase (GOx) and sonosensitizer IR780 is developed for photothermal-augmented tumor starvation and sonodynamic therapy (SDT) in near-infrared (NIR)-II biowindow, assisted by an oxygen self-supply strategy. As a catalase-mimicking nanozyme, PdPt@GOx/IR780 (PGI) can facilitate the alleviation of tumor hypoxia through catalyzing H2O2 decomposition into O2. Furthermore, GOx-mediated intratumoral glucose consumption may block the essential energy and nutrient supply to achieve tumor starvation. The resultant H2O2 production enables a continuous supply of local O2, which subsequently aggravates glucose depletion. Meanwhile, the hypoxia alleviation also promotes the production of 1O2 for a more efficacious SDT with the aid of sonosensitizer IR780. In another aspect, hyperthermia generation by PGI under NIR-II laser irradiation leads to the thermal ablation of tumor cells, which effectively incorporates with tumor starvation and SDT for a complete tumor eradication. More importantly, the combination therapy can trigger strong immunogenic cell death (ICD), which favors the overcoming of immune suppression and the enhancement of antitumor immunity. The admirable tumor suppression effect by PGI is demonstrated on tumor-bearing mice with minimal adverse effect. Taken together, this paradigm provides a useful strategy for PdPt functionalization in the pursuit of effective tumor therapy with high clinical relevance.

Promotion of diabetic wound healing using novel Cu2O/Pt nanocubes through bacterial killing and enhanced angiogenesis in rats

Chronic bacterial infection, local inflammation, and insufficient angiogenesis contribute to poor healing of diabetic wounds. Here, Cu2O/Pt nanocubes (CPN) are successfully developed with good biocompatibility for treatment of diabetic wounds in rats. The synthesized CPN are characterized using SEM, XPS, and XRD. CPN exhibit triple-enzyme mimetic activity: oxidase-like, peroxidase-like, and catalase-like activities. Moreover, CPN show significant antibacterial activity against Gram-negative and Gram-positive bacteria when combined with low concentration of H2O2, via generation of highly reactive ROS. CPN also exhibit significantly accelerated wound healing in a full-layer deprivation rat model infected by Staphylococcus aureus, which is ascribed to the constant release of copper ions, subsequently activating the VEGF/AKT/ERK1/2 signaling pathway and promoting angiogenesis. CPN are able to catalyze H2O2 to generate O2 for local hypoxia alleviation. Furthermore, in vivo results indicate that treatment with CPN promotes the expression of transforming growth factor and matrix metalloproteinases, causing enhanced cell proliferation and collagen deposition, as well as extracellular matrix remodeling. In contrast, CPN decrease the expression of proinflammatory cytokines, such as TNF-ɑ and IL-1β, which are induced by bacterial infection and hyperglycemia. These results suggest a novel strategy for the treatment of diabetic wound healing.

A pH-sensitive nanomedicine incorporating catalase gene and photosensitizer augments photodynamic therapy and activates antitumor immunity

Immunological "cold" tumors including most triple-negative breast cancers (TNBCs) hardly respond to immunotherapy due to their extreme immunosuppressive microenvironment. Among various immunosuppressive factors, hypoxia provides a vital target for boosting antitumor immunotherapy as it plays a key role in mediating adaptive immune resistance of tumors. Here, a multifunctional nanomedicine incorporating a plasmid DNA encoding catalase gene (pDNA-cat) and photosensitizer Ce6 was developed to elicit robust immunity via photodynamic therapy (PDT) and hypoxia alleviation. The pH-sensitive sheddable coating of nanomedicine facilitated the codelivery of Ce6 and pDNA-cat into tumor cells. Under near-infrared laser irradiation, Ce6 generated cytotoxic reactive oxygen species (ROS) to induce immunogenic cell death (ICD), which promoted the maturation of dendric cells (DCs) and tumor infiltration of antitumor T cells. Meanwhile, tumor cells transfected with pDNA-cat expressed catalase to catalyze the O2 production from tumor-enriched H2O2in situ. Tumor hypoxia relief not only augmented photodynamic therapy (PDT) known as an oxygen-consuming process but also induced strong antitumor immunity. Consequently, the multifunctional nanomedicine demonstrated strong efficacy to inhibit the tumor growth and recurrence.

Targeting Tumor Microenvironment by Metal Peroxide Nanoparticles in Cancer Therapy.

Solid tumors have a unique tumor microenvironment (TME), which includes hypoxia, low acidity, and high hydrogen peroxide and glutathione (GSH) levels, among others. These unique factors, which offer favourable microenvironments and nourishment for tumor development and spread, also serve as a gateway for specific and successful cancer therapies. A good example is metal peroxide structures which have been synthesized and utilized to enhance oxygen supply and they have shown great promise in the alleviation of hypoxia. In a hypoxic environment, certain oxygen-dependent treatments such as photodynamic therapy and radiotherapy fail to respond and therefore modulating the hypoxic tumor microenvironment has been found to enhance the antitumor impact of certain drugs. Under acidic environments, the hydrogen peroxide produced by the reaction of metal peroxides with water not only induces oxidative stress but also produces additional oxygen. This is achieved since hydrogen peroxide acts as a reactive substrate for molecules such as catalyse enzymes, alleviating tumor hypoxia observed in the tumor microenvironment. Metal ions released in the process can also offer distinct bioactivity in their own right. Metal peroxides used in anticancer therapy are a rapidly evolving field, and there is good evidence that they are a good option for regulating the tumor microenvironment in cancer therapy. In this regard, the synthesis and mechanisms behind the successful application of metal peroxides to specifically target the tumor microenvironment are highlighted in this review. Various characteristics of TME such as angiogenesis, inflammation, hypoxia, acidity levels, and metal ion homeostasis are addressed in this regard, together with certain forms of synergistic combination treatments.

Redox dyshomeostasis modulation of the tumor intracellular environment through a metabolic intervention strategy for enhanced photodynamic therapy.

Rationale: Photodynamic therapy (PDT) is a clinically approved anticancer treatment with a promising therapeutic prospect, however, usually suffers from the unfavorable intracellular environment including cellular hypoxia and excessive glutathione (GSH). Comprehensive and long-term modulation of tumor intracellular environment is crucial for optimizing therapeutic outcomes. However, current strategies do not enable such requirements, mainly limited by flexible networks of intracellular metabolic avenues.Methods: A metabolic pre-intervention (MPI) strategy that targets critical pathways of cellular metabolism, ensuring long-term modulation of the intracellular environment. A versatile lipid-coating photosensitive metal-organic framework (MOF) nano-vehicle encapsulating aerobic respiration inhibitor metformin (Met) and GSH biosynthesis inhibitor buthionine sulfoximine (BSO) (termed PBMLR) was developed for comprehensive sustainable hypoxia alleviation and GSH downregulating.Results: Since MPI could effectively circumvent the compensatory accessory pathway, PBMLR, therefore functioned as an efficient singlet oxygen (1O2) radical generator during the subsequent laser irradiation process and enhanced PDT anti-tumor efficiency. We emphasized the concordance of long-term hypoxia alleviation, persistent GSH depletion, and tumor enrichment of photosensitizers, which is very meaningful for a broad therapeutic time window and the successful enhancement of PDT.Conclusion: Our findings indicate that maintaining the sensitivity of tumor cells via MPI could enhance anti-tumor PDT, and may be applied to other dynamic therapies such as radiodynamic therapy and sonodynamic therapy.

Combined phototherapy with metabolic reprogramming-targeted albumin nanoparticles for treating breast cancer.

Triple-negative breast cancer (TNBC) is characterized by rapid tumor growth and resistance to cancer therapy, and has a poor prognosis. Accumulating data have revealed that cancer metabolism relies on both the Warburg effect and oxidative phosphorylation (OXPHOS), which are strongly related to the high proliferation and chemoresistance of cancer cells. Phototherapy is considered as a non-invasive method to precisely control drug activity with reduced side effects. Herein, our group introduced an Abraxane-like nanoplatform, named LCIR NPs, which significantly eradicates cancer cells via synergism between metabolic reprogramming and phototherapy effects. Endowed with mitochondria-targeting residues, the nanoparticles efficiently inhibited mitochondrial complexes I and IV as well as hexokinase II, leading to the depletion of intracellular ATP. Consequently, the photodynamic and photothermal effect triggered by NIR irradiation was enhanced due to the alleviation of hypoxia and the thermoresistance mechanism that rely on mitochondrial metabolism. In vivo experiments showed that the tumor size of mice that received the combination treatment was only 50.7 mm3, which was 21 times smaller than that of the untreated group and was much lower than those of other single treatments after 21 days. Additionally, almost no systemic undesired toxicity was detected during the observation period. We believe that the concept of LCIR as presented here offers a potential platform to overcome the resistance to conventional therapies by the incorporation with the energy metabolism inhibition approach.

Erythrocyte Membrane Camouflaged Metal–Organic Framework Nanodrugs for Remodeled Tumor Microenvironment and Enhanced Tumor Chemotherapy

AbstractThe abundant extracellular matrix (ECM) in solid tumors causes limited drug penetration and hypoxia‐mediated chemoresistance, which lead to poor chemotherapy outcomes. To solve this problem, a biomimetic metal–organic framework nanodrug (ZIF‐8‐DOX‐LY‐RM) is developed with red blood cell membrane (RM) camouflage and encapsulation of type 1 transforming growth factor β receptor (TGFBR1) inhibitor and doxorubicin (DOX) for efficient chemotherapy. Based on the biomimetic properties of the erythrocyte membrane, ZIF‐8‐DOX‐LY‐RM can effectively accumulate in tumor tissues with immune escape and prolonged blood circulation. Then, the enriched nanodrug ZIF‐8‐DOX‐LY‐RM releases the TGFBR1 to remove collagen, subsequently leading to enhanced nanodrug penetration and increased oxygen supply. The abundant oxygen supply then relieves hypoxia‐mediated chemoresistance of DOX through increased cellular uptake and elevated reactive oxygen species production. The in vivo studies demonstrate the outstanding performance of ZIF‐8‐DOX‐LY‐RM nanoparticles in chemotherapy of cancer. This work presents an ECM normalization strategy for the synergistic collagen depletion and hypoxia alleviation and opens a promising avenue for effective chemotherapy of solid tumors.

Engineering Endogenous Tumor‐Associated Macrophage‐Targeted Biomimetic Nano‐RBC to Reprogram Tumor Immunosuppressive Microenvironment for Enhanced Chemo‐Immunotherapy (Adv. Mater. 39/2021)

Cancer Chemo-Immunotherapy In article number 2103497, Yubin Huang, Dongfang Zhou, and co-workers demonstrate an engineered endogenous tumor-associated macrophages (TAMs)-targeting biomimetic nano-red-blood-cell (RBC) system to deliver chemotherapeutic doxorubicin and oxygen for enhanced cancer chemo-immunotherapy. TAMs-targeting depletion and hypoxia alleviation synergistically reprogram the tumor immunosuppressive microenvironment. The ensuing TAMs-targeted chemo-immunotherapeutic effects markedly inhibit tumor metastasis and recurrence.

Co-delivery of gefitinib and hematoporphyrin by aptamer-modified fluorinated dendrimer for hypoxia alleviation and enhanced synergistic chemo-photodynamic therapy of NSCLC

Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs)-based molecular targeted therapy are proved to be effective in the treatment of non-small cell lung cancer (NSCLC) with EGFR mutation, its efficacy is limited by the acquired drug resistance. The combination of EGFR-TKIs with photodynamic therapy (PDT) has been explored to combat NSCLC with promising synergistic results. However, hypoxic tumor microenvironment is associated with the development of EGFR-TKIs resistance and severely limits the efficacy of PDT. Here, we synthesized an aptamer modified fluorinated dendrimer (APF) as a drug carrier and prepared nanocomplexes APFHG by encapsulation of gefitinib (Gef) and hematoporphyrin (Hp). APF has good oxygen-carrying capacity, high drug entrapment efficiency, and could release Gef and Hp in response to intracellular pH. APF can specifically recognize EGFR-positive NSCLC cells and effectively improve the tumor hypoxic microenvironment due to the targeting effect of aptamer and the good oxygen-carrying capacity of the fluorinated dendrimer. Under the laser irradiation, APFHG can significantly increase the production of the intracellular reactive oxygen species and produce a synergistic therapeutic effect in inhibition of cellular growth and induction of cell cycle arrest and apoptosis on both Gef-sensitive and Gef-resistant EGFR-mutant NSCLC cells through PDT/molecular targeted therapy. This work indicates that fluorinated dendrimer could be a potent drug delivery platform to overcome hypoxia-related resistance and the co-delivery of EGFR-TKI and photosensitizer by the fluorinated dendrimer could be a promising therapeutic approach for reversal of EGFR-TKIs resistance in EGFR mutation-positive NSCLC.

Engineering Endogenous Tumor-Associated Macrophage-Targeted Biomimetic Nano-RBC to Reprogram Tumor Immunosuppressive Microenvironment for Enhanced Chemo-Immunotherapy.

Immunotherapy has shown encouraging results in various cancers, but the response rates are relatively low due to the complex tumor immunosuppressive microenvironment (TIME). The presence of tumor-associated macrophages (TAMs) and tumor hypoxia correlates significantly with potent immunosuppressive activity. Here, a hemoglobin-poly(ε-caprolactone) (Hb-PCL) conjugate self-assembled biomimetic nano red blood cell (nano-RBC) system (V(Hb)) is engineered to deliver chemotherapeutic doxorubicin (DOX) and oxygen for reprogramming TIME. The Hb moiety of V(Hb)@DOX can bind to endogenous plasma haptoglobin (Hp) and specifically target the M2-type TAMs via the CD163 surface receptor, and effectively kill the cells. In addition, the O2 released by the Hb alleviates tumor hypoxia, which further augments the antitumor immune response by recruiting fewer M2-type macrophages. TAM-targeting depletion and hypoxia alleviation synergistically reprogram the TIME, which concurrently downregulate PD-L1 expression of tumor cells, decrease the levels of immunosuppressive cytokines such as IL-10 and TGF-β, elevate the immunostimulatory IFN-γ, enhance cytotoxic T lymphocyte (CTL) response, and boost a strong memory response. The ensuing TAM-targeted chemo-immunotherapeutic effects markedly inhibit tumor metastasis and recurrence. Taken together, the engineered endogenous TAM-targeted biomimetic nano-RBC system is a highly promising tool to reprogram TIME for cancer chemo-immunotherapy.

Oxygen-generating glycol chitosan-manganese dioxide nanoparticles enhance the photodynamic effects of chlorin e6 on activated macrophages in hypoxic conditions

This study aimed to investigate the use of glycol chitosan (GC) for the synthesis of MnO2 nanoparticles (NPs) and to evaluate whether the prepared GC-MnO2 NPs enhance the light-triggered photodynamic effects of chlorin e6 (Ce6) via the generation of oxygen and alleviation of hypoxia in lipopolysaccharide (LPS)-activated macrophages (RAW 264.7), which produce excessive amounts of reactive oxygen species (ROS). GC-MnO2 NPs were synthesized by a simple reaction between GC and KMnO4 in water. The prepared GC-MnO2 NPs were spherical in shape, with a mean diameter of approximately 60 nm. The particles effectively generated oxygen via H2O2-induced degradation under hypoxic conditions, which led to an increase in the singlet oxygen levels upon laser irradiation. Furthermore, GC-MnO2 NPs significantly enhanced the light-triggered photodynamic effects of Ce6 on activated macrophages under hypoxic conditions, as shown by the increased levels of cell death and cell membrane damage in activated macrophages. Therefore, these results suggest that GC can be used as an alternative natural polymer for the synthesis of MnO2 NPs and that oxygen-generating GC-MnO2 NPs enhance the light-triggered photodynamic effects of Ce6 on activated macrophages by alleviating hypoxia.

A cyclic nano-reactor achieving enhanced photodynamic tumor therapy by reversing multiple resistances

BackgroundPhotodynamic therapy (PDT) is a clinically implemented modality to combat malignant tumor, while its efficacy is largely limited by several resistance factors from tumor microenvironment (TME), such as hypoxia, anti-oxidant systems, and ATP-dependent tumor adaptive resistances. The aim of this work is to construct a multifunctional nanoplatform to remodel multiple resistant TME for enhanced PDT.ResultsHere, a targeting nano-reactor was facilely constructed to reverse the multiple resistances of PDT by incorporating glucose oxidase (GOx) and chlorin e6 (Ce6) into poly (D, L-lactic-co-glycolic acid) (PLGA)/ metal–organic framework (MOF) core–shell nanoassembly, with surface deposition of hyaluronic acid (HA) stabilized MnO2. The nano-reactor could selectively target tumor cells by virtue of surface HA modification, and once internalization, a few reactions were initiated to modulate TME. Glucose was consumed by GOx to inhibit ATP generation, and the produced H2O2 was catalyzed by MnO2 to generate O2 for tumor hypoxia alleviation and photodynamic sensitization, and glutathione (GSH) was also effectively depleted by MnO2 to suppress the tumor antioxidant defense. Consequently, the nano-reactor achieved robust PDT with amplified tumor therapy via intravenous injection.ConclusionsThis nano-reactor offers a multifunctional nanoplatform to sensitize TME-limited tumor treatment means via reversing multiple resistances.Grpahic abstract

Biomimetic Nanotheranostics Camouflaged with Cancer Cell Membranes Integrating Persistent Oxygen Supply and Homotypic Targeting for Hypoxic Tumor Elimination

Treatment resistance of the tumors to photodynamic therapy (PDT) owing to O2 deficiency largely compromised the therapeutic efficacy, which could be addressed via modulating oxygen levels by using O2 self-enriched nanosystems. Here, we report on augmenting the O2-evolving strategy based on a biomimetic, catalytic nanovehicle (named as N/P@MCC), constructed by the catalase-immobilized hollow mesoporous nanospheres by enveloping a cancer cell membrane (CCM), which acts as an efficient nanocontainer to accommodate nitrogen-doped graphene quantum dots (N-GQDs) and protoporphyrin IX (PpIX). Inheriting the virtues of biomimetic CCM cloaking, the CCM-derived shell conferred N/P@MCC nanovehicles with highly specific self-recognition and homotypic targeting toward cancerous cells, ensuring tumor-specific accumulation and superior circulation durations. N-GQDs, for the first time, have been evidenced as a new dual-functional nanoagents with PTT and PDT capacities, enabling the generation of 1O2 for PDT and inducing local low-temperature hyperthermia for thermally ablating cancer cells and infrared thermal imaging (IRT). Leveraging the intrinsic catalytic features of catalase, such N/P@MCC nanovehicles effectively scavenged the excessive H2O2 to sustainably evolve oxygen for a synchronous O2 self-supply and hypoxia alleviation, with an additional benefit because the resulting O2 bubbles could function as an echo amplifier, leading to the sufficient echogenic reflectivity for ultrasound imaging. Concurrently, the elevated O2 reacted with N-GQDs and PpIX to elicit a maximally increased 1O2 output for augmented PDT. Significantly, the ultrasound imaging coupled with fluorescence imaging, IRT, performs a tumor-modulated trimodal bioimaging effect. Overall, this offers a paradigm to rationally explore O2 self-supply strategies focused on versatile nanotheranostics for hypoxic tumor elimination.

Self-propelled nanomotor reconstructs tumor microenvironment through synergistic hypoxia alleviation and glycolysis inhibition for promoted anti-metastasis

Solid tumors always exhibit local hypoxia, resulting in the high metastasis and inertness to chemotherapy. Reconstruction of hypoxic tumor microenvironment (TME) is considered a potential therapy compared to directly killing tumor cells. However, the insufficient oxygen delivery to deep tumor and the confronting “Warburg effect” compromise the efficacy of hypoxia alleviation. Herein, we construct a cascade enzyme-powered nanomotor (NM-si), which can simultaneously provide sufficient oxygen in deep tumor and inhibit the aerobic glycolysis to potentiate anti-metastasis in chemotherapy. Catalase (Cat) and glucose oxidase (GOx) are co-adsorbed on our previously reported CAuNCs@HA to form self-propelled nanomotor (NM), with hexokinase-2 (HK-2) siRNA further condensed (NM-si). The persistent production of oxygen bubbles from the cascade enzymatic reaction propels NM-si to move forward autonomously and in a controllable direction along H2O2 gradient towards deep tumor, with hypoxia successfully alleviated in the meantime. The autonomous movement also facilitates NM-si with lysosome escaping for efficient HK-2 knockdown to inhibit glycolysis. In vivo results demonstrated a promising anti-metastasis effect of commercially available albumin-bound paclitaxel (PTX@HSA) after pre-treated with NM-si for TME reconstruction. This cascade enzyme-powered nanomotor provides a potential prospect in reversing the hypoxic TME and metabolic pathway for reinforced anti-metastasis of chemotherapy.