Recent Advances in Glucose-Oxidase-Based Nanocomposites for Tumor Therapy

Nanozyme as tumor energy homeostasis disruptor mediated ferroptosis for high-efficiency radiotherapy

Radioresistance in tumors, driven by the insufficiency and rapid depletion of reactive oxygen species (ROS), limits the efficacy of radiotherapy (RT). This study introduces an Ir@Au nanozyme that enhances tumor radiosensitivity by disrupting energy homeostasis and inducing ferroptosis in tumor cells. The Ir@Au nanozyme mimics glucose oxidase to block the tumor's energy supply, continuously produces hydrogen peroxide (H2O2), and lowers the pH to optimize Fenton reactions. Acting as a peroxidase (POD), it generates additional ROS for chemodynamic therapy (CDT), depletes glutathione (GSH), and perturbs the tumor's antioxidant defenses. Upon exposure to ionizing radiation, the nanozyme absorbs photons and emits electrons, interacting with water to amplify ROS production. This ROS accumulation, combined with radiation, enhances DNA damage and lipid peroxidation, reversing radioresistance and promoting ferroptosis. Additionally, Ir@Au serves as a contrast agent for computed tomography, enabling precise RT through the delineation of tumor boundaries. In summary, the Ir@Au nanozyme effectively disrupts tumor energy homeostasis, initiating ROS-based cascades that inhibit tumor growth. It thus offers a promising strategy for overcoming radioresistance during cancer therapy.

Emerging glucose oxidase-delivering nanomedicines for enhanced tumor therapy

Abnormalities in glucose metabolism have been shown to characterize malignant tumors. Glucose depletion by glucose oxidase (GOD) has shown great potential in tumor therapy by causing tumor starvation. Since 2017, nanomedicines have been designed and utilized to deliver GOD for more precise and effective glucose modulation, which can overcome intrinsic limitations of different cancer therapeutic modalities by remodeling the tumor microenvironment to enhance antitumor therapy. To date, the topic of GOD-delivering nanomedicines for enhancing tumor therapy has not been comprehensively summarized. Herein, this review aims to provide an overview and discuss in detail recent advances in GOD delivery and directly involved starvation therapy strategies, GOD-sensitized various tumor therapy strategies, and GOD-mediated multimodal antitumor strategies. Finally, the challenges and outlooks for the future progress of the emerging tumor therapeutic nanomedicines are discussed. This review provides intuitive and specific insights to a broad audience in the fields of nanomedicines, biomaterials, and cancer therapy.

Diversified nanocarrier design to optimize glucose oxidase-mediated anti-tumor therapy: Strategy and progress

Given the inherent complexity and heterogeneity of tumors, current therapeutic approaches often fall short in meeting prognostic requirements. Starvation therapy (ST) utilizing glucose oxidase (GOx) has emerged as a promising strategy, specifically targeting tumor glucose consumption to disrupt nutrient supply. However, the therapeutic potential of GOx is significantly hampered by its inherent limitations as a protein, particularly its poor stability and short in vivo half-life. In recent years, the development of nanocarriors has provided an effective platform for intravenous and local tumor delivery of GOx. This review systematically examines three key strategies in GOx delivery: stimulus-response, biofilm modification, and local delivery. The progress in various carrier systems for GOx-mediated tumor therapy is comprehensively summarized, providing valuable insights for nanocarrier design. Furthermore, the existing challenges and future directions to advance the development of GOx-based tumor therapies are critically analyzed.

An injectable multimodal thiolated carboxymethyl cellulose hydrogel for advanced gastric cancer treatment

Chemotherapy is a standard preoperative treatment for locally advanced resectable gastric cancer (GC). However, its efficacy is often limited by the high intracellular glutathione (GSH) levels in tumor cells, which diminish the effectiveness of chemotherapeutic agents. In this study, we developed a GSH-sensitive injectable hydrogel, T-CMC@Fe3+(5-FU + GOx), incorporating ferric ions (Fe3+), glucose oxidase (GOx), and 5-fluorouracil (5-FU) for advanced GC multimodal treatment. The hydrogel synergistically enhances anti-tumor activity through multiple mechanisms, including chemodynamic therapy, starvation therapy, and chemotherapy. Thiolated carboxymethyl cellulose (T-CMC) was synthesized by grafting L-cysteine onto carboxymethyl cellulose, with successful preparation confirmed by XPS, FTIR, and 13C NMR characterizations. The T-CMC@Fe3+ hydrogel demonstrated responsive degradation of GSH and exhibited favorable biocompatibility in co-culture experiments with GES-1 cells. In vitro analyses revealed that the T-CMC@Fe3+(5-FU + GOx) hydrogel significantly enhanced anti-tumor efficacy compared to chemotherapy alone, reducing cell viability to 12.28 ± 2.88 % after 48 h. In vivo studies using cell-derived and patient-derived xenograft models further confirmed its potent anti-tumor effects, with a marked reduction in tumor volume by 14 days (8.12 ± 4.89 mm3). These findings highlight the potential of the T-CMC@Fe3+(5-FU + GOx) hydrogel as a novel and effective strategy for enhancing GC treatment through its multimodal therapeutic approach.

Tumor-microenvironment-mediated second near-infrared light activation multifunctional cascade nanoenzyme for self-replenishing O2/H2O2 multimodal tumor therapy

Developing a catalytic nanoenzyme activated by the tumor microenvironment (TME) shows excellent potential for in situ cancer treatment. However, the rational design of a cascade procedure to achieve high therapeutic efficiency remains challenging. In this study, the colorectal TME-responsive multifunctional cascade nanoenzyme Cu2-xO@MnO2@glucose oxidase (GOx)@hyaluronic acid (HA) was developed to target in situ cancer starvation/chemodynamic therapy (CDT)/photothermal therapy (PTT). First, the MnO2 nanolayer specifically decomposes within the acidic TME to generate Mn2+ and oxygen (O2), thereby alleviating the hypoxic TME. Subsequently, Cu2-xO can be vulcanized into Cu2-xS by overexpressing sulfuretted hydrogen (H2S) gas in the colorectal tumor for a second near-infrared (NIR-II) light-triggered deep tissue PTT. Cu2-xS nanoparticles can react with hydrogen peroxide (H2O2) to generate hydroxyl radical (OH) for the CDT. In addition, GOx catalyzes the conversion of glucose into H2O2 for starvation therapy and enhances the CDT efficiency by self-supplying H2O2. Interestingly, the generated reactive oxygen species (ROS) induce immunogenic cell death (ICD), which further activates adaptive cancer immunity for anti-tumor immunotherapy. Finally, therapeutic efficiency was greatly improved after coating with tumor-targeted HA. Collectively, these TME-responsive cascade nanoenzymes can realize PTT, CDT starvation therapy, and immunotherapy, paving the way for the design of TME-responsive cascade nanoenzymes for synergistically enhanced tumor-specific therapy.

Responsive plasmonic hybrid nanorods enables metabolism reprogramming via cuproptosis-photothermal combined cancer therapy

Abnormal tumor metabolism leads to tumor growth, metastasis, and recurrence, reprogramming tumor metabolism and activating potent anti-tumor immune response have been demonstrated to have good therapeutic effects on tumor elimination. Copper-based nanomaterials involved in cuproptosis show great prospects in these two aspects, but their efficiency is restricted by Cu homeostasis and the toxicity of the chelator. Here, the pH-responsive AuNRs@Cu2O core-shell plasmonic hybrid nanorods (ACNRs) have been successfully fabricated to realize microenvironment-controlled release at the tumor site for the combined therapy of cuproptosis and photothermal treatment. The AuNRs core exhibited excellent NIR-II photothermal property, which boost the intracellular concentration of copper to trigger severe cuproptosis and induce immunogenic cell death of tumor cells. In vivo studies demonstrated the ACNR exhibited efficient tumor therapy for primary, metastatic, and recurrent tumors. ACNRs-induced cuproptosis and PTT were capable of reprogramming energy metabolism, leading to a decreased production of lactic acid. This potential of metabolic reprogramming assisted in reshaping the immunosuppressive tumor microenvironment to facilitate the infiltration of immune cells and boost the immune responses triggered by PTT. The therapeutic mechanism was further verified by metabolomics analysis, which indicated that ACNRs + PTT treatment led to the inhibition of the Pentose Phosphate Pathway and Glycolysis pathways in tumor cells. The suppression of glycolytic reduced ATP synthesis, thereby hindering energy-dependent copper efflux, which in turn promoted cuproptosis. Taken together, this study offers promising insights for cuproptosis-based cancer treatment and sheds new light on nanomedicine-mediated metabolic modulation for future tumor therapy.

A multifunctional hyaluronic acid-engineered mesoporous nanoreactor with H2O2/O2 self-sufficiency for pH-triggered endo-lysosomal escape and synergetic cancer therapy

Monotherapy has poor accuracy and is easily restricted by tumor microenvironment (TME). Remodeling components of the TME to activate multimodal cancer therapy with high precision and efficiency is worth exploring. A multifunctional nanoreactor was fabricated by decorating chlorin e6-modified and PEGylated hyaluronic acid bearing diethylenetriamine-conjugated dihydrolipoic acid on the surface of glucose oxidase (GOx)-loaded hollow mesoporous CuS nanoparticles (labeled as GOx@HCuS@HA). This nanoreactor efficiently targets tumor sites, enhances cellular internalization, and swiftly escapes from endo-lysosomes after intravenous injection. Subsequently, GOx@HCuS@HA was activated in hyaluronidase and H + -rich TME to produce H2O2 and gluconic acid through the oxidation of glucose, which not only blocks the energy supply of cancer cells, executing starvation treatment (ST), but also bolsters hydroxyl radicals (•OH)-based chemodynamic therapy (CDT) by Fenton-like reaction between HCuS and H2O2. Furthermore, reductive Cu ions could catalyze H2O2 to produce O2 to alleviate the limitation of photodynamic therapy (PDT) for tumor hypoxia. Additionally, the photothermal effect of HCuS under NIR irradiation could increase the temperature of tumor tissues to perform photothermal therapy (PTT). This synergistic antitumor strategy could ultimately achieve precise tumor cell destruction and maintain excellent biosafety. Hence, this nanoreactor offer promising prospects for efficient tumor treatment.

Self-propelling intelligent nanomotor: A dual-action photothermal and starvation strategy for targeted deep tumor destruction

Delivering nanoparticles to deep tumor tissues while maintaining high therapeutic efficacy and minimizing damage to surrounding tissues has long posed a significant challenge. To address this, we have developed innovative self-propelling bowl-shaped nanomotors MSLA@GOx-PDA composed of mesoporous silica loaded with l-arginine and polydopamine, along with glucose oxidase (GOx). These nanomotors facilitate the generation of hydrogen peroxide through GOx-catalyzed glucose oxidation, thereby initiating nitric oxide production from l-arginine. This dual mechanism equips MSLA@GOx-PDA with the robust motility required for deep tumor tissue penetration while depleting essential nutrients necessary for tumor growth, consequently impeding tumor progression. In addition, near-infrared lasers have the significant advantage of being depth-penetrating and non-invasive, allowing real-time fluorescence imaging and guiding dopamine-mediated mild photothermal therapy. Notably, starvation therapy depletes intracellular adenosine triphosphate and inhibits the synthesis of heat shock proteins, thus overcoming the Achilles' heel of mild photothermal therapy and significantly enhancing the efficacy of this therapy with encouraging synergistic anti-tumour effects. Overall, the integration of biochemical and optics strategies in this nanomotor platform represents a significant advancement in deep-tissue tumor therapy. It has substantial clinical translational value and is expected to have a transformative impact on future cancer treatments.

Achievements and challenges in glucose oxidase-instructed multimodal synergistic antibacterial applications

Glucose oxidase (GOx) with unique catalytic properties and inherent biocompatibility can effectively oxidize both endogenous and exogenous glucose with oxygen (O2) into gluconic acid and hydrogen peroxide (H2O2). Accordingly, the GOx-based catalytic chemistry offers new possibilities for designing and constructing multimodal synergistic antibacterial systems. The consumption of glucose permanently downregulates bacterial cell metabolism by blocking essential energy supplies, inhibiting their growth and survival. Additionally, the production of gluconic acid could downregulates the pH within the bacterial infection microenvironment, enhancing the production of hydroxyl radicals (∙OH) from H2O2 via enhanced Fenton or Fendon-like reactions and triggering the pH-responsive release of drugs. Furthermore, the generated H2O2 in situ avoids the addition of exogenous hydrogen peroxide. Therefore, it is possible to design GOx-based multimodal antibacterial synergistic therapies by combining GOx-instructed cascade reactions with other therapeutic approaches such as chemodynamic therapies (CDT), hypoxia-activated prodrugs, photosensitizers, and stimuli-responsive drug release. Such multimodal strategies are expected to exhibit better therapeutic effects than single therapeutic modes. This tutorial review highlights recent advancements in GOx-instructed multimodal synergistic antibacterial systems, focusing on design philosophy and construction strategies. Current challenges and future prospects for advancing GOx-based multimodal antibacterial synergistic therapies are discussed.

Rational Design of Single‐Atom Nanozymes for Combination Cancer Immunotherapy

Remodeling of the tumor immune microenvironment and enhancement of antitumor immune responses are necessary to overcome immunotherapy resistance in tumors. However, tumor heterogeneity and complexity of immune evasion mechanisms pose significant therapeutic challenges. Nanozymes exhibit enzyme‐like characteristics and unique nanomaterial properties, showing potential for tumor therapy. However, design of effective nanozymes remains complex, inefficient, and functionally limited. Therefore, in this study, a novel strategy combining rationally designed single‐atom nanozymes (SAzymes) with immune checkpoint blockade (ICB) therapy is established. Molybdenum SAzymes supported on graphitic carbon nitride (Mo SAs) are constructed using 25 transition metal candidates from the 4th to 6th periods based on high‐throughput calculations and optimal piezoelectric‐enhanced multienzyme‐like activities. Upon activation by ultrasound, Mo SAs exerted potent therapeutic effects against ICB‐resistant tumors and remodeled the tumor immune microenvironment by inducing tumor immunogenic cell death, alleviating tumor hypoxia, and modulating chemokine expression in tumors. Combination of Mo SAs with anti‐programmed death protein‐1 antibodies further enhanced their antitumor efficacy, highlighting their potential to treat ICB‐resistant tumors.

Anti-Tumor Strategies Targeting Nutritional Deprivation: Challenges and Opportunities

Higher and richer nutrient requirements are typical features that distinguish tumor cells from AU: cells, ensuring adequate substrates and energy sources for tumor cell proliferation and migration. Therefore, nutrient deprivation strategies based on targeted technologies can induce impaired cell viability in tumor cells, which are more sensitive than normal cells. In this review, nutrients that are required by tumor cells and related metabolic pathways are introduced, and anti-tumor strategies developed to target nutrient deprivation are described. In addition to tumor cells, the nutritional and metabolic characteristics of other cells in the tumor microenvironment (including macrophages, neutrophils, natural killer cells, T cells, and cancer-associated fibroblasts) and related new anti-tumor strategies are also summarized. In conclusion, recent advances in anti-tumor strategies targeting nutrient blockade are reviewed, and the challenges and prospects of these anti-tumor strategies are discussed, which are of theoretical significance for optimizing the clinical application of tumor nutrition deprivation strategies.

Emerging Roles of Nanozyme in Tumor Metabolism Regulation: Mechanisms, Applications, and Future Directions

Nanozymes, nanomaterials with intrinsic enzyme activity, have garnered significant attention in recent years due to their catalytic abilities comparable to natural enzymes, cost-effectiveness, high catalytic activities, and stability against environmental fluctuations. As functional analogs of natural enzymes, nanozymes participate in various critical metabolic processes, including glucose metabolism, lactate metabolism, and the maintenance of redox homeostasis, all of which are essential for normal cellular functions. However, disruptions in these metabolic pathways frequently promote tumorigenesis and progression, making them potential therapeutic targets. While several therapies targeting tumor metabolism are currently in clinical or preclinical stages, their efficacy requires further enhancement. Consequently, nanozymes that target tumor metabolism are regarded as a promising therapeutic strategy. Despite extensive studies investigating the application of nanozymes in tumor metabolism, relevant reviews are relatively scarce. This article first introduces the physicochemical properties and biological behaviors of nanozymes. Subsequently, we analyze the role of nanozymes in tumor metabolism and explore their potential applications in tumor therapy. In conclusion, this review aims to foster innovative research in related fields and advance the development of nanozyme-based strategies for cancer diagnostics and therapeutics.

Iron-glucose oxidase nanogel assembly for amplified starvation-ferroptosis anti-tumor therapy

Developing advanced and effective enzyme-drug systems for cancer treatment is of significant interest. Herein, a novel approach is reported to create a highly active and robust enzyme-drug system. Glucose oxidase nanogels (nGOx) are first synthesized by polymerization on the surface of GOx using vinylimidazole as comonomers. Fe3+ are utilized to induce self-assembly of nGOx through the imidazole-metal coordination interaction to form GOx nanogel clusters (Fe@nGOx), enhancing the permeability and retention of nGOx into tumor cells by EPR effect. nGOx can deplete glucose in the presence of oxygen and generate H2O2, which is converted to highly cytotoxic hydroxyl radical (·OH) by Fe3+ and GSH, and the proximity between Fe3+ and GOx act in tandem for enhanced tumor therapy. The FeIII/FeII redox cycle reacts with GSH and H2O2, enabling continuous generation of ·OH within tumor cells, thus facilitating the anticancer effect. Moreover, the generation of H2O2 and ·OH can further promote the repolarization of tumor-associated macrophages from an M2 phenotype towards an M1 phenotype polarization, thus enhancing immune response. The cascade reaction between GOx and Fe3+/Fe2+ endows Fe@nGOx with excellent anti-tumor efficacy in mice models, highlighting its potential as a promising anticancer drug for clinical applications. This work establishes a new platform for utilizing enzyme/protein and metal ion complexes in versatile applications, advancing the field of enzyme-based cancer therapies.

Recent advances in zeolitic imidazolate frameworks as drug delivery systems for cancer therapy

Biological nanotechnologies based on functional nanoplatforms have synergistically catalyzed the emergence of cancer therapies. As a subtype of metal-organic frameworks (MOFs), zeolitic imidazolate frameworks (ZIFs) have exploded in popularity in the field of biomaterials as excellent protective materials with the advantages of conformational flexibility, thermal and chemical stability, and functional controllability. With these superior properties, the applications of ZIF-based materials in combination with various therapies for cancer treatment have grown rapidly in recent years, showing remarkable achievements and great potential. This review elucidates the recent advancements in the use of ZIFs as drug delivery agents for cancer therapy. The structures, synthesis methods, properties, and various modifiers of ZIFs used in oncotherapy are presented. Recent advances in the application of ZIF-based nanoparticles as single or combination tumor treatments are reviewed. Furthermore, the future prospects, potential limitations, and challenges of the application of ZIF-based nanomaterials in cancer treatment are discussed. We except to fully explore the potential of ZIF-based materials to present a clear outline for their application as an effective cancer treatment to help them achieve early clinical application.

Glucose oxidase: An emerging multidimensional treatment option for diabetic wound healing

The healing of diabetic skin wounds is a complex process significantly affected by the hyperglycemic environment. In this context, glucose oxidase (GOx), by catalyzing glucose to produce gluconic acid and hydrogen peroxide, not only modulates the hyperglycemic microenvironment but also possesses antibacterial and oxygen-supplying functions, thereby demonstrating immense potential in the treatment of diabetic wounds. Despite the growing interest in GOx-based therapeutic strategies in recent years, a systematic summary and review of these efforts have been lacking. To address this gap, this review article outlines the advancements in the application of GOx and GOx-like nanozymes in the treatment of diabetic wounds, including reaction mechanisms, the selection of carrier materials, and synergistic therapeutic strategies such as multi-enzyme combinations, microneedle structures, and gas therapy. Finally, the article looks forward to the application prospects of GOx in aiding the healing of diabetic wounds and the challenges faced in translating these innovations to clinical practice. We sincerely hope that this review can provide readers with a comprehensive understanding of GOx-based diabetic treatment strategies, facilitate the rigorous construction of more robust multifunctional therapeutic systems, and ultimately benefit patients with diabetic wounds.

Tumor-Targeted Catalytic Immunotherapy

Cancer immunotherapy holds significant promise for improving cancer treatment efficacy; however, the low response rate remains a considerable challenge. To overcome this limitation, advanced catalytic materials offer potential in augmenting catalytic immunotherapy by modulating the immunosuppressive tumor microenvironment (TME) through precise biochemical reactions. Achieving optimal targeting precision and therapeutic efficacy necessitates a thorough understanding of the properties and underlying mechanisms of tumor-targeted catalytic materials. This review provides a comprehensive and systematic overview of recent advancements in tumor-targeted catalytic materials and their critical role in enhancing catalytic immunotherapy. It highlights the types of catalytic reactions, the construction strategies of catalytic materials, and their fundamental mechanisms for tumor targeting, including passive, bioactive, stimuli-responsive, and biomimetic targeting approaches. Furthermore, this review outlines various tumor-specific targeting strategies, encompassing tumor tissue, tumor cell, exogenous stimuli-responsive, TME-responsive, and cellular TME targeting strategies. Finally, the discussion addresses the challenges and future perspectives for transitioning catalytic materials into clinical applications, offering insights that pave the way for next-generation cancer therapies and provide substantial benefits to patients in clinical settings.

Tumor microenvironment-regulated nanoplatform for enhanced chemotherapy, cuproptosis and nonferrous ferroptosis combined cancer therapy

Therapeutic approaches combining various treatments have attracted intensive interests for tumor therapy. Nevertheless, these strategies still face many obstacles, such as overexpressed GSH and hypoxia, owing to the intricate tumor microenvironment (TME). Herein, a versatile nanoplatform, CeO2@CuO2@DOX-RSL3@HA (CCDRH), was initially constructed for promoting the antitumor efficiency via regulation of the TME. The CCDRH was prepared taking mixed valence CeO2 as the nanocarrier, followed by the attachment of CuO2 nanodots, DOX and RSL3 and the camouflaging of hyaluronic acid. The CuO2 could disassemble in the acidic TME to release Cu2+ and H2O2. The POD- and CAT-mimicking activities of CeO2 could convert H2O2 to ˙OH and O2, leading to the enhancement of chemo-chemodynamic therapy. Meanwhile, RSL3 could effectively suppress GPX4 expression, and the overloaded Cu2+ and Ce4+ could deplete excess GSH, resulting in an intensive accumulation of LPO and significant nonferrous ferroptosis. Additionally, Cu+ induces the oligomerization of lipoylated DLAT and downregulates iron-sulfur cluster proteins, resulting in potent cellular cuproptosis. The experimental results revealed that CCDRH exhibited high performance in tumor inhibition, which is attributed to the combined effect of enhanced chemotherapy, ferroptosis and cuproptosis. The study provides a new approach for improving anticancer efficiency via regulation of the TME.

Recent Advances in Metal-Organic Frameworks as Oxidase Mimics: A Comprehensive Review on Rational Design and Modification for Enhanced Sensing Applications

Metal-organic frameworks (MOFs) have emerged as innovative nanozyme mimics, particularly in the area of oxidase catalysis, outperforming traditional MOF-based peroxidase and other nanomaterial-based oxidase systems. This review explores the various advantages that MOFs offer in terms of catalytic activity, low-cost, stability, and structural versatility. With a primary focus on their application in biochemical sensing, MOF-based oxidases have demonstrated remarkable utility, prompting a thorough exploration of their design and modification strategies. Moreover, the review aims to provide a comprehensive analysis of the strategies employed in the rational design and modification of MOF structures to optimize key parameters such as sensitivity, selectivity, and stability in the context of biochemical sensors. Through an exhaustive examination of recent research and developments, this article seeks to offer insights into the nuanced interplay between MOF structures and their catalytic performance, shedding light on the mechanisms that underpin their effectiveness as nanozyme mimics. Finally, this review addresses challenges and opportunities associated with MOF-based oxidase mimics, aiming to drive further advancements in MOF structure design and the development of highly effective biochemical sensors for diverse applications.

Iron-based theranostic nanoenzyme for combined tumor magneto-photo thermotherapy and starvation therapy

To address the issue of high-dose treatment agents in magnetic hyperthermia-mediated multi-model tumor therapy, a unique iron-based theranostic nanoenzyme with excellent magnetothermal and catalytic properties was constructed. By using a high-temperature arc method, the iron carbon nanoparticles (MF1-3) with a particle size between 13.7 and 27.6 nm and shell thickness between 1 and 5 nm were prepared. After screening, we selected MF3 as the magnetic core due to its high Ms. value and excellent thermal properties. Under the magneto-photo dual thermal conditions, MF3 exhibited a remarkable specific absorption rate (SAR) of 4917 W/g, which was 20 times more than that of iron oxide. Notably, MF3 also exhibited best peroxidase (POD)-like catalytic in pH 5.0 and maintained stable catalytic performance at 45 °C. Considering the "starvation" strategy of cutting off the energy supply to tumor cells and killing them, the glucose oxidase (GOX) and chitosan oligosaccharide (COS) was further grafted onto MF3, forming the MF3/GOX/COS. This multifunctional therapeutic nanoenzyme not only exhibited significant peroxidase-like activity, but also had glucose decomposition and glutathione (GSH) consumption capabilities. The thermal effect significantly promoted the uptake of MF3/GOX/COS by 4T1 cells, and the IC50 value of MF3/GOX/COS reached low to 3.75 μg/mL. In vivo anti-tumor experiment, compared with single treatment methods, the combined therapy of MF3/GOX/COS mediated magneto-photo thermotherapy (M-PTT) and starvation therapy (ST) exhibited higher tumor inhibition rate of 82.1 % by increased cell apoptosis through the mitochondrial pathway. Overall, MF3/GOX/COS therapeutic nanoenzyme combined the advantages of nano-catalysis, M-PTT and ST, providing a solution for achieving sustained, stable, and effective tumor inhibition rates at lower dose levels.

Nano-medicine therapy reprogramming metabolic network of tumour microenvironment: new opportunity for cancer therapies

Metabolic heterogeneity is one of the characteristics of tumour cells. In order to adapt to the tumour microenvironment of hypoxia, acidity and nutritional deficiency, tumour cells have undergone extensive metabolic reprogramming. Metabolites involved in tumour cell metabolism are also very different from normal cells, such as a large number of lactate and adenosine. Metabolites play an important role in regulating the whole tumour microenvironment. Taking metabolites as the target, it aims to change the metabolic pattern of tumour cells again, destroy the energy balance it maintains, activate the immune system, and finally kill tumour cells. In this paper, the regulatory effects of metabolites such as lactate, glutamine, arginine, tryptophan, fatty acids and adenosine were reviewed, and the related targeting strategies of nano-medicines were summarised, and the future therapeutic strategies of nano-drugs were discussed. The abnormality of tumour metabolites caused by tumour metabolic remodelling not only changes the energy and material supply of tumour, but also participates in the regulation of tumour-related signal pathways, which plays an important role in the survival, proliferation, invasion and metastasis of tumour cells. Regulating the availability of local metabolites is a new aspect that affects tumour progress. (The graphical abstract is by Figdraw).

Emerging nitric oxide gas-assisted cancer photothermal treatment

Photothermal therapy (PTT) has garnered significant attention in recent years, but the standalone application of PTT still faces limitations that hinder its ability to achieve optimal therapeutic outcomes. Nitric oxide (NO), being one of the most extensively studied gaseous molecules, presents itself as a promising complementary candidate for PTT. In response, various nanosystems have been developed to enable the simultaneous utilization of PTT and NO-mediated gas therapy (GT), with the integration of photothermal agents (PTAs) and thermally-sensitive NO donors being the prevailing approach. This combination seeks to leverage the synergistic effects of PTT and GT while mitigating the potential risks associated with gas toxicity through the use of a single laser irradiation. Furthermore, additional internal or external stimuli have been employed to trigger NO release when combined with different types of PTAs, thereby further enhancing therapeutic efficacy. This comprehensive review aims to summarize recent advancements in NO gas-assisted cancer photothermal treatment. It commences by providing an overview of various types of NO donors and precursors, including those sensitive to photothermal, light, ultrasound, reactive oxygen species, and glutathione. These NO donors and precursors are discussed in the context of dual-modal PTT/GT. Subsequently, the incorporation of other treatment modalities such as chemotherapy (CHT), photodynamic therapy (PDT), alkyl radical therapy, radiation therapy, and immunotherapy (IT) in the creation of triple-modal therapeutic nanoplatforms is presented. The review further explores tetra-modal therapies, such as PTT/GT/CHT/PDT, PTT/GT/CHT/chemodynamic therapy (CDT), PTT/GT/PDT/IT, PTT/GT/starvation therapy (ST)/IT, PTT/GT/Ca2+ overload/IT, PTT/GT/ferroptosis (FT)/IT, and PTT/GT/CDT/IT. Finally, potential challenges and future perspectives concerning these novel paradigms are discussed. This comprehensive review is anticipated to serve as a valuable resource for future studies focused on the development of innovative photothermal/NO-based cancer nanotheranostics.

A pH-Sensitive Glucose Oxidase and Hemin Coordination Micelle for Multi-Enzyme Cascade and Amplified Cancer Chemodynamic Therapy

Chemodynamic therapy (CDT) is an emerging therapeutic paradigm for cancer treatment that utilizes reactive oxygen species (ROS) to induce apoptosis of cancer cells but few biomaterials have been developed to differentiate the cancer cells and normal cells to achieve precise and targeted CDT. Herein, a simple cascade enzyme system is developed, termed hemin-micelles-GOx, based on hemin and glucose oxidase (GOx)-encapsulated Pluronic F127 (F127) micelles with pH-sensitive enzymatic activities. Histidine-tagged GOx can be easily chelated to hemin-F127 micelles via the coordination of histidine and ferrous ions in the center of hemin by simple admixture in an aqueous solution. In tumor microenvironment (TME), hemin-micelles-GOx exhibits enhanced peroxidase (POD)-like activities to generate toxic hydroxyl radicals due to the acidic condition, whereas in normal cells the catalase (CAT)-like, but not POD-like activity is amplified, resulting in the elimination of hydrogen peroxide to generate oxygen. In a murine melanoma model, hemin-micelles-GOx significantly suppresses tumor growth, demonstrating its great potential as a pH-mediated enzymatic switch for tumor management by CDT.

A multifunctional cascade gas-nanoreactor with MnO2 as a gatekeeper to enhance starvation therapy and provoke antitumor immune response

Glucose oxidase (GOx)-mediated starvation therapy is an effective tumor treatment that blocks energy and activates the immune response. However, the insufficient tumor immunogenicity and immunosuppressive tumor microenvironment (TME) limited its therapeutic efficacy. To address this, we have designed a multifunctional cascade gas-nanoreactor with a MnO2 coating, which serves as an out gatekeeper to encapsulate both GOx and a carbon monoxide (CO) donor (denoted as GCM). Due to the protective effect of MnO2 coating, GCM maintains better stability in normal physiological environments, enhancing the catalytic activity of GOx and minimizing toxic side effects. Upon accumulation in the tumor, the degradation of MnO2 coating exposes the GOx enzyme, thereby initiating a cascade catalysis reaction to generate hydrogen peroxide (H2O2) and release CO in the hypoxic conditions. Additionally, the released Mn2+ reacts with H2O2 to generate toxic hydroxyl radical (•OH) as chemodynamic therapy (CDT). The synergistic treatments of starvation therapy, CO gas therapy and CDT effectively kill cancer cells and amplify immunogenic cell death (ICD), maturing DC cells and activating anti-tumor immune response. Furthermore, the released CO increases M1 macrophages infiltration and reduces myeloid-derived suppressor cells (MDSCs) infiltration, thus reversing the immunosuppressive TME. This multifunctional gas-nanoreactor provides a strategy for CO gas generation to trigger a robust anti-tumor immune response and has the potential for clinical application in cancer immunotherapy. STATEMENT OF SIGNIFICANCE: A multifunctional cascade gas-nanoreactor with a MnO2 gatekeeper was developed to perform synergistic treatments involving starvation therapy, CO gas therapy and chemodynamic therapy (CDT) for tumor elimination. The MnO2 gatekeeper enhanced the catalytic activity of GOx within the nanoreactor by generating oxygen, thereby minimizing toxic side effects after intravenous injection. The gas-nanoreactor amplified ICD through synergistic treatments to mature DC cells and activate anti-tumor immune response. Furthermore, the released CO could reverse the immunosuppression of the TME to enhance cancer immunotherapy. The combination strategy utilizing the gas-nanoreactor demonstrates clinical potential for facilitating cancer immunotherapy.

Nano- and Micro-Platforms in Therapeutic Proteins Delivery for Cancer Therapy: Materials and Strategies

Proteins have emerged as promising therapeutics in oncology due to their great specificity. Many treatment strategies are developed based on protein biologics, such as immunotherapy, starvation therapy, and pro-apoptosis therapy, while some protein biologics have entered the clinics. However, clinical translation is severely impeded by instability, short circulation time, poor transmembrane transportation, and immunogenicity. Micro- and nano-particles-based drug delivery platforms are designed to solve those problems and enhance protein therapeutic efficacy. This review first summarizes the different types of therapeutic proteins in clinical and research stages, highlighting their administration limitations. Next, various types of micro- and nano-particles are described to demonstrate how they can overcome those limitations. The potential of micro- and nano-particles are then explored to enhance the therapeutic efficacy of proteins by combinational therapies. Finally, the challenges and future directions of protein biologics carriers are discussed for optimized protein delivery.

A Nanoreactor Based on Metal-Organic Frameworks With Triple Synergistic Therapy for Hepatocellular Carcinoma

The transformation of monotherapy into multimodal combined targeted therapy to fully exploit synergistic efficacy is of increasing interest in tumor treatment. In this work, a novel nanodrug-carrying platform based on iron-based MOFs, which is loaded with doxorubicin hydrochloride (DOX), dihydroartemisinin (DHA), and glucose oxidase (GOx), and concurrently covalently linked to the photosensitizer 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) in polydopamine (PDA)-encapsulated MIL-101(Fe) (denoted as MIL-101(Fe)-DOX-DHA@TCPP/GOx@PDA, MDDTG@P), is successfully developed. Upon entering the tumor microenvironment, MDDTG@P catalyzes the hydrogen peroxide (H2O2) into hydroxyl radicals (·OH) and depletes glutathione (GSH); thus, exerting the role of chemodynamic therapy (CDT). The reduced Fe2+ can also activate DHA, further expanding CDT and promoting tumor cell apoptosis. The introduced GOx will rapidly consume glucose and oxygen (O2) in the tumor; while, replenishing H2O2 for Fenton reaction, starving the cancer cells; and thus, realizing starvation and chemodynamic therapy. In addition, the covalent linkage of TCPP endows MDDTG@P with good photodynamic therapeutic (PDT) properties. Therefore, this study develops a nanocarrier platform for triple synergistic chemodynamic/photodynamic/starvation therapy, which has promising applications in the efficient treatment of tumors.

Eutectogels: The Multifaceted Soft Ionic Materials of Tomorrow

Eutectogels, a rising category of soft materials, have recently garnered significant attention owing to their remarkable potential in various domains. This innovative class of materials consists of a eutectic solvent immobilized in a three-dimensional network structure. The use of eco-friendly and cost-effective eutectic solvents further emphasizes the appeal of these materials in multiple applications. Eutectogels exhibit key characteristics of most eutectic solvents, including environmental friendliness, facile preparation, low vapor pressure, and good ionic conductivity. Moreover, they can be tailored to display functionalities such as self-healing capability, adhesiveness, and antibacterial properties, which are facilitated by incorporating specific combinations of the eutectic mixture constituents. This perspective article delves into the current landscape and challenges associated with eutectogels, particularly focusing on their potential applications in CO2 separation, drug delivery systems, battery technologies, biocatalysis, and food packaging. By exploring these diverse realms, we aim to shed light on the transformative capabilities of eutectogels and the opportunities they present to address pressing industrial, academic, and environmental challenges.

Multifunctional Nanocomposite Hydrogel with Enhanced Chemodynamic Therapy and Starvation Therapy for Inhibiting Postoperative Tumor Recurrence

Surgical resection is the primary treatment for melanoma; however, preventing tumor recurrence after resection remains a significant clinical challenge. To address this, we developed a multifunctional nanocomposite hydrogel (H-CPG) composed of glucose oxidase (GOx)-coated CuS@PDA@GOx (CPG) nanoparticles, aminated hyaluronic acid (HA-ADH), and oxidized rhizomatous polysaccharides (OBSP), which are interconnected through hydrogen bonds and dynamic Schiff base linkages. In the acidic tumor micro-environment, the hydrogel releases GOx, catalyzing the production of hydrogen peroxide (H2O2), which enhances chemokinetic activity through a Cu2+-mediated Fenton-like reaction. This process generates hydroxyl radicals that intensify oxidative stress and promote macrophage polarization from the M2 to M1 phenotype. This polarization triggers the release of pro-inflammatory cytokines, thereby inhibiting tumor recurrence. Additionally, the hydrogel induces photothermal effects that help eradicate residual bacteria at the wound site. Overall, the H-CPG hydrogel offers a dual mechanism to prevent melanoma recurrence and reduce resistance to monotherapy, presenting a promising strategy for postoperative tumor management.

Emerging trends on the uptake of fluorescent probes based on glucose analogs by cancer cells: From basic studies to therapeutics

The cancer cell metabolism, notably characterized by the Warburg effect, has been the focus of intense investigation regarding the mechanisms of the uptake of glucose analogs, opening up perspectives for diagnosis and treatment of cancer disease. In this review, we delve into the ever-evolving landscape of cancer research, centering on fluorescent probes based on glucose analogs. These analogs, resulting from modifications in the carbohydrate structure with functional groups, have stood out as versatile molecules in applications ranging from disease comprehension to therapeutic innovation, especially when combined with fluorescent compounds. Fluorescence-based assays have provided valuable contributions to the revelation of complex biological mechanisms in life sciences. This review presents selected studies from about the past six years up to 2024 related to the use of glucose-based fluorescent probes, for the investigation of their uptake profile as well as for therapeutic purposes. We believe that these investigations offer insights into the intricate interaction between glucose analogs and cancer cell metabolism, guiding future research and clinical applications in this field.

Cholesterol Depletion-Enhanced Ferroptosis and Immunotherapy via Engineered Nanozyme

Ferroptosis, an iron- and reactive oxygen species (ROS)-dependent cell death, holds significant promise for tumor therapy due to its ability to induce lipid peroxidation (LPO) and trigger antitumor immune responses. However, elevated cholesterol levels in cancer cells impede ferroptosis and compromise immune function. Here, a novel nanozyme, Fe-MOF/CP, composed of iron metal-organic framework (Fe-MOF) nanoparticles loaded with cholesterol oxidase and PEGylation for integrated ferroptosis and immunotherapy is introduced. Fe-MOF/CP depletes cholesterol and generates hydrogen peroxide, enhancing ROS levels and inducing LPO, thereby promoting ferroptosis. This process disrupts lipid raft integrity and downregulates glutathione peroxidase 4 and ferroptosis suppressor protein 1, further facilitating ferroptosis. Concurrently, Fe-MOF/CP augments immunogenic cell death, reduces programmed death-ligand 1 expression, and revitalizes exhausted CD8+ T cells. In vivo studies demonstrate significant therapeutic efficacy in abscopal, metastasis, and recurrent tumor models, highlighting the robust antitumor immune responses elicited by Fe-MOF/CP. This study underscores the potential of Fe-MOF/CP as a multifunctional therapeutic agent that combines ferroptosis and immunotherapy, offering a promising strategy for effective and durable cancer treatment.

Nanozymes in cancer immunotherapy: metabolic disruption and therapeutic synergy

Over the past decade, there has been a growing emphasis on investigating the role of immunotherapy in cancer treatment. However, it faces challenges such as limited efficacy, a diminished response rate, and serious adverse effects. Nanozymes, a subset of nanomaterials, demonstrate boundless potential in cancer catalytic therapy for their tunable activity, enhanced stability, and cost-effectiveness. By selectively targeting the metabolic vulnerabilities of tumors, they can effectively intensify the destruction of tumor cells and promote the release of antigenic substances, thereby eliciting immune clearance responses and impeding tumor progression. Combined with other therapies, they synergistically enhance the efficacy of immunotherapy. Hence, a large number of metabolism-regulating nanozymes with synergistic immunotherapeutic effects have been developed. This review summarizes recent advancements in cancer immunotherapy facilitated by nanozymes, focusing on engineering nanozymes to potentiate antitumor immune responses by disturbing tumor metabolism and performing synergistic treatment. The challenges and prospects in this field are outlined. We aim to provide guidance for nanozyme-mediated immunotherapy and pave the way for achieving durable tumor eradication.

Current status and prospects of MOFs loaded with H2O2-related substances for ferroptosis therapy

Ferroptosis is a programmed cell death mechanism characterized by the accumulation of iron (Fe)-dependent lipid peroxides within cells. Ferroptosis holds excellent promise in tumor therapy. Metal-organic frameworks (MOFs) offer unique advantages in tumor ferroptosis treatment due to their high porosity, excellent stability, high biocompatibility, and targeting capabilities. Inducing ferroptosis in tumor cells primarily involves the production of reactive oxygen species (ROS), like hydroxyl radicals (˙OH), through iron-mediated Fenton reactions. However, the intrinsic H2O2 levels in tumor cells are often insufficient to sustain prolonged consumption, limiting therapeutic efficacy if ˙OH production is inadequate. Therefore, catalyzing or supplementing the intracellular H2O2 levels in tumor cells is essential for inducing ferroptosis by nanoscale metal-organic frameworks. This article reviews the biological characteristics and molecular mechanisms of ferroptosis, introduces H2O2-related substances, and reviews MOF-based nanoscale strategies for enhancing intracellular H2O2 levels in tumor cells. Finally, the challenges and prospects of this approach are discussed, aiming to provide insights into improving the effectiveness of ferroptosis induced by MOFs.

Hyaluronic Acid-Modified Spherical MgO2/Pd Nanocomposites Exhibit Superior Antitumor Effect through Tumor Microenvironment-Responsive Ferroptosis Induction and Photothermal Therapy

Metal peroxide nanomaterials as efficient hydrogen peroxide (H2O2) self-supplying agents have attracted the attention of researchers for antitumor treatment. However, relying solely on metal peroxides to provide H2O2 is undoubtedly insufficient to achieve optimal antitumor effects. Herein, we construct novel hyaluronic acid (HA)-modified nanocomposites (MgO2/Pd@HA NCs) formed by decorating palladium nanoparticles (Pd NPs) onto the surfaces of a magnesium peroxide (MgO2) nanoflower as a highly effective nanoplatform for the tumor microenvironment (TME)-responsive induction of ferroptosis in tumor cells and tumor photothermal therapy (PTT). MgO2/Pd@HA NC could be well endocytosed into tumor cells with CD44 expression depending on the specific recognition of HA with CD44, and then, the nanocomposites can be rapidly decomposed in mild acid and hyaluronidase overexpressed TME, and plenty of H2O2 was released. Simultaneously, Pd NPs catalyze self-supplied H2O2 to generate abundant hydroxyl radicals (•OH) and catalyze glutathione (GSH) into glutathione disulfide owing to its peroxidase and glutathione oxidase mimic enzyme activities, while the abundant •OH could also consume GSH in tumor cells and disturb the defense pathways of ferroptosis leading to the accumulation of lipid peroxidation and resulting in the occurrence of ferroptosis. Additionally, the superior photothermal conversion performance of Pd NPs in near-infrared II could also be used for PTT, synergistically cooperating with nanocomposite-induced ferroptosis for tumor inhibition. Consequently, the successfully prepared TME-responsive MgO2/Pd@HA NCs exhibited marked antitumor effect without obvious biotoxicity, contributing to thoroughly explore the nanocomposites as a novel and promising treatment for tumor therapy.

Custom-Design of Multi-Stimuli-Responsive Degradable Silica Nanoparticles for Advanced Cancer-Specific Chemotherapy

Chemotherapy is crucial in oncology for combating malignant tumors but often encounters obatacles such as severe adverse effects, drug resistance, and biocompatibility issues. The advantages of degradable silica nanoparticles in tumor diagnosis and treatment lie in their ability to target drug delivery, minimizing toxicity to normal tissues while enhancing therapeutic efficacy. Moreover, their responsiveness to both endogenous and exogenous stimuli opens up new possibilities for integrating multiple treatment modalities. This review scrutinizes the burgeoning utility of degradable silica nanoparticles in combination with chemotherapy and other treatment modalities. Commencing the elucidation of degradable silica synthesis and degradation mechanisms, emphasis is placed on the responsiveness of these materials to endogenous (e.g., pH, redox reactions, hypoxia, and enzymes) and exogenous stimuli (e.g., light and high-intensity focused ultrasound). Moreover, this exploration delves into strategies harnessing degradable silica nanoparticles in chemotherapy alone, coupled with radiotherapy, photothermal therapy, photodynamic therapy, gas therapy, immunotherapy, starvation therapy, and chemodynamic therapy, elucidating multimodal synergies. Concluding with an assessment of advances, challenges, and constraints in oncology, despite hurdles, future investigations are anticipated to augment the role of degradable silica in cancer therapy. These insights can serve as a compass for devising more efficacious combined tumor treatment strategies.

A Glucose Oxidase-Curcumin Composite Nanoreactor for Multimodal Synergistic Cancer Therapy

Glucose oxidase (GOx) selectively oxidizes β-d-glucose into gluconic acid and hydrogen peroxide; thus, it has emerged as a promising anticancer agent by tumor starvation and oxidative therapy. Here, we developed a nanoscale platform or "nanoreactor" that incorporates GOx and the bioactive natural product curcumin (CUR) to achieve a multimodal anticancer nanocomposite. The composite nanoreactor was formed by loading CUR in biodegradable polymeric nanoparticles (NPs) of poly(ethylene glycol)-b-poly(ε-caprolactone) (PEG-PCL). Prime-coating of the NPs with an iron(III)-tannic acid complex enabled facile immobilization of GOx on the NP surface. The NPs were monodisperse with a hydrodynamic diameter of 122 nm and a partially negative surface charge. The NPs were also associated with an excellent CUR loading efficiency and sustained release up to 96 h, which was accelerated by surface-immobilized GOx and followed supercase II transport. Viability assays were conducted on two model cancer cell lines, MCF-7 and MDA-MB-231 cells, as well as human dermal fibroblasts as a representative normal cell line. The assays revealed significantly improved potency of CUR in the composite nanoreactor, with up to 6000- and 1280-fold increase in MCF-7 and MDA-MB-231 cells, respectively, and lower toxicity toward normal cells. The NPs were also able to promote intracellular reactive oxygen species (ROS) generation and dissipation of the mitochondrial membrane potential, providing important clues on the mechanism of action of the nanoreactor. Further investigation of caspase-3 activity revealed that the nanoreactor had no effect or inhibited caspase-3 levels, signifying a caspase-independent mechanism of inducing apoptosis. Our findings present a promising nanocarrier platform that combines therapeutic agents with distinct mechanisms of action acting in synergy for more effective cancer therapy.

A mesoporous theranostic platform for ultrasound and photoacoustic dual imaging-guided photothermal and enhanced starvation therapy for cancer

Tumor starvation therapy utilizing glucose oxidase (GOx), has gained traction due to its non-invasive and bio-safe attributes. However, its effectiveness is often hampered by severe hypoxia in the tumor microenvironment (TME), limiting GOx's catalytic activity. To address this issue, a multifunctional nanosystem based on mesoporous polydopamine nanoparticles (MPDA NPs) was developled to alleviate TME hypoxia. This nanosystem integrated GOx modification and oxygenated perfluoropentane (PFP) encapsulation to address hypoxia-related challenges in the TME. Under NIR laser irradiation, the MPDA NPs exhibit significant photothermal conversion efficacy, activating targeted tumor photothermal therapy (PTT), while also serving as proficient photoacoustic (PA) imaging agents. The ensuing temperature rise facilitates oxygen (O2) release and induces liquid-gas conversion of PFP, generating microbubbles for enhanced ultrasound (US) imaging signals. The supplied oxygen alleviates local hypoxia, thereby enhancing GOx-mediated endogenous glucose consumption for tumor starvation. Overall, the integration of ultrasound/photoacoustic dual imaging-guided PTT and starvation therapy within MPDA-GOx@PFP@O2 nanoparticles (MGPO NPs) presents a promising platform for enhancing the efficacay of tumor treatment by overcoming the complexities of the TME. STATEMENT OF SIGNIFICANCE: A multifunctional MPDA-based theranostic nanoagent was developed for US/PAI imaging-guided PTT and starvation therapy against tumor hypoxia by direct O2 delivery. The incorporation of oxygenated perfluoropentane (PFP) within the mesoporous structure of MGPO not only enables efficient US imaging but also helps in alleviating tumor hypoxia. Moreover, the strong near-infrared (NIR) absorption of MGPO NPs promote the generation of PFP microbubbles and release of oxygen, thereby enhancing US imaging and GOx-mediated starvation therapy. Such a multifunctional nanosystem leverages synergistic effects to enhance therapeutic efficacy while incorporating US/PA imaging for precise visualization of the tumor.

A multifunctional cascade enzyme system for enhanced starvation/chemodynamic combination therapy against hypoxic tumors

Starvation therapy has shown promise as a cancer treatment, but its efficacy is often limited when used alone. In this work, a multifunctional nanoscale cascade enzyme system, named CaCO3@MnO2-NH2@GOx@PVP (CMGP), was fabricated for enhanced starvation/chemodynamic combination cancer therapy. CMGP is composed of CaCO3 nanoparticles wrapped in a MnO2 shell, with glucose oxidase (GOx) adsorbed and modified with polyvinylpyrrolidone (PVP). MnO2 decomposes H2O2 in cancer cells into O2, which enhances the efficiency of GOx-mediated starvation therapy. CaCO3 can be decomposed in the acidic cancer cell environment, causing Ca2+ overload in cancer cells and inhibiting mitochondrial metabolism. This synergizes with GOx to achieve more efficient starvation therapy. Additionally, the H2O2 and gluconic acid produced during glucose consumption by GOx are utilized by MnO2 with catalase-like activity to enhance O2 production and Mn2+ release. This process accelerates glucose consumption, reactive oxygen species (ROS) generation, and CaCO3 decomposition, promoting the Ca2+ release. CMGP can alleviate tumor hypoxia by cycling the enzymatic cascade reaction, which increases enzyme activity and combines with Ca2+ overload to achieve enhanced combined starvation/chemodynamic therapy. In vitro and in vivo studies demonstrate that CMGP has effective anticancer abilities and good biosafety. It represents a new strategy with great potential for combined cancer therapy.

Glycooligomer-Functionalized Catalytic Nanocompartments Co-Loaded with Enzymes Support Parallel Reactions and Promote Cell Internalization

A major shortcoming associated with the application of enzymes in drug synergism originates from the lack of site-specific, multifunctional nanomedicine. This study introduces catalytic nanocompartments (CNCs) made of a mixture of PDMS-b-PMOXA diblock copolymers, decorated with glycooligomer tethers comprising eight mannose-containing repeating units and coencapsulating two enzymes, providing multifunctionality by their in situ parallel reactions. Beta-glucuronidase (GUS) serves for local reactivation of the drug hymecromone, while glucose oxidase (GOx) induces cell starvation through glucose depletion and generation of the cytotoxic H2O2. The insertion of the pore-forming peptide, melittin, facilitates diffusion of substrates and products through the membranes. Increased cell-specific internalization of the CNCs results in a substantial decrease in HepG2 cell viability after 24 h, attributed to simultaneous production of hymecromone and H2O2. Such parallel enzymatic reactions taking place in nanocompartments pave the way to achieve efficient combinatorial cancer therapy by enabling localized drug production along with reactive oxygen species (ROS) elevation.

Real time imaging of cell-permeable nanoreactor with SERS for insight into cellular processes

Intracellular glucose detection is crucial due to its pivotal role in metabolism and various physiological processes. Precise glucose monitoring holds significance in diabetes management, metabolic studies, and biotechnological applications. In this study, we developed an innovative and expedient cell-permeable nanoreactor for intracellular glucose based on surface-enhanced Raman scattering (SERS). The nanoreactor was designed with gold nanoparticles (AuNPs), which were engineered with glucose oxide (GOx) and a H2O2-responsive Raman reporter 2-mercaptohydroquinone (2-MHQ). The interaction between 2-MHQ and H2O2 generated by glucose and GOx could simultaneously induce the appearance in the peak at 985 cm-1. Our results showed excellent performance in detecting glucose within the concentration range from 0.1 μM to 10 mM, with a low detection limitation of 14.72 nM. In addition, the glucose distribution in single HeLa cells was evaluated by real time SERS mapping. By combining noble metal particles and natural oxidases, the nanoreactor possesses both Raman activity and enzymatic functionality, thus enables sensitive glucose detection and facilitates imaging at a single cell level, which offers an insightful monitoring of cellular processes.

Cetyltrimethylammonium-chloride assisted in situ metabolic incorporation of nano-sized ROS-generating cascade-reaction containers in Gram-positive and Gram-negative peptidoglycan layers for the control of bacterially-induced sepsis

Cascade-reaction containers generating reactive oxygen species (ROS) as an alternative for antibiotic-based strategies for bacterial infection control, require endogenous oxygen-sources and ROS-generation close to or preferably inside target bacteria. Here, this is achieved by cetyltrimethylammonium-chloride (CTAC) assisted in situ metabolic labeling and incorporation of mesoporous SiO2-nanoparticles, dual-loaded with glucose-oxidase and Fe3O4-nanoparticles as cascade-reaction containers, inside bacterial cell walls. First, azide-functionalized d-alanine (D-Ala-N3) was inserted in cell wall peptidoglycan layers of growing Gram-positive pathogens. In Gram-negatives, this could only be achieved after outer lipid-membrane permeabilization, using a low concentration of CTAC. Low concentrations of CTAC had no adverse effect on in vitro blood clotting or hemolysis nor on the health of mice when blood-injected. Next, dibenzocyclooctyne-polyethylene-glycol modified, SiO2-nanoparticles were in situ click-reacted with d-Ala-N3 in bacterial cell wall peptidoglycan layers. Herewith, a two-step cascade-reaction is facilitated inside bacteria, in which glucose-oxidase generates H2O2 at endogenously-available glucose concentrations, while subsequently Fe3O4-nanoparticles catalyze generation of •OH from the H2O2 generated. Generation of •OH inside bacterial cell walls by dual-loaded mesoporous SiO2-nanoparticles yielded more effective in vitro killing of both planktonic Gram-positive and Gram-negative bacteria suspended in 10 % plasma than SiO2-nanoparticles solely loaded with glucose-oxidase. Gram-positive or Gram-negative bacterially induced sepsis in mice could be effectively treated by in situ pre-treatment with tail-vein injected CTAC and d-Ala-N3, followed by injection of dual-loaded cascade-reaction containers without using antibiotics. This makes in situ metabolic incorporation of cascade-reaction containers as described attractive for further investigation with respect to the control of other types of infections comprising planktonic bacteria. STATEMENT OF SIGNIFICANCE: In situ metabolic-incorporation of cascade-reaction-containers loaded with glucose-oxidase and Fe3O4 nanoparticles into bacterial cell-wall peptidoglycan is described, yielding ROS-generation from endogenous glucose, non-antibiotically killing bacteria before ROS inactivates. Hitherto, only Gram-positives could be metabolically-labeled, because Gram-negatives possess two lipid-membranes. The outer membrane impedes direct access to the peptidoglycan. This problem was solved by outer-membrane permeabilization using a quaternary-ammonium compound. Several studies on metabolic-labeling perform crucial labeling steps during bacterial-culturing that in real-life should be part of a treatment. In situ metabolic-incorporation as described, can be applied in well-plates during in vitro experiments or in the body as during in vivo animal experiments. Surprisingly, metabolic-incorporation proceeded unhampered in blood and a murine, bacterially-induced sepsis could be well treated.

2D Catalytic Nanozyme Enables Cascade Enzyodynamic Effect-Boosted and Ca2+ Overload-Induced Synergistic Ferroptosis/Apoptosis in Tumor

The introduction of glucose oxidase, exhibiting characteristics of glucose consumption and H2O2 production, represents an emerging antineoplastic therapeutic approach that disrupts nutrient supply and promotes efficient generation of reactive oxygen species (ROS). However, the instability of natural enzymes and their low therapeutic efficacy significantly impede their broader application. In this context, 2D Ca2Mn8O16 nanosheets (CMO NSs) designed and engineered to serve as a high-performance nanozyme, enhancing the enzyodynamic effect for a ferroptosis-apoptosis synergistic tumor therapy, are presented. In addition to mimicking activities of glutathione peroxidase, catalase, oxidase, and peroxidase, the engineered CMO NSs exhibit glucose oxidase-mimicking activities. This feature contributes to their antitumor performance through cascade catalytic reactions, involving the disruption of glucose supply, self-supply of H2O2, and subsequent efficient ROS generation. The exogenous Ca2+ released from CMO NSs, along with the endogenous Ca2+ enrichment induced by ROS from the peroxidase- and oxidase-mimicking activities of CMO NSs, collectively mediate Ca2+ overload, leading to apoptosis. Importantly, the ferroptosis process is triggered synchronously through ROS output and glutathione consumption. The application of exogenous ultrasound stimulation further enhances the efficiency of ferroptosis-apoptosis synergistic tumor treatment. This work underscores the crucial role of enzyodynamic performance in ferroptosis-apoptosis synergistic therapy against tumors.

Lactic acid responsive sequential production of hydrogen peroxide and consumption of glutathione for enhanced ferroptosis tumor therapy

Ferroptosis is characterized by the lethal accumulation of lipid reactive oxygen species (ROS), which has great potential for tumor therapy. However, developing new ferroptosis-inducing strategies by combining nanomaterials with small molecule inducers is important. In this study, an enzyme-gated biodegradable natural-product delivery system based on lactate oxidase (LOD)-gated biodegradable iridium (Ir)-doped hollow mesoporous organosilica nanoparticles (HMONs) loaded with honokiol (HNK) (HNK@Ir-HMONs-LOD, HIHL) is designed to enhance ferroptosis in colon tumor therapy. After reaching the tumor microenvironment, the outer LOD dissociates and releases the HNK to induce ferroptosis. Moreover, the released dopant Ir4+ and disulfide-bridged organosilica frameworks deplete intracellular glutathione (GSH), which is followed by GSH-mediated Ir(IV)/Ir(III) conversion. This leads to the repression of glutathione peroxidase 4 (GPX4) activity and decomposition of intratumoral hydrogen peroxide (H2O2) into hydroxyl radicals (•OH) by Ir3+-mediated Fenton-like reactions. Moreover, LOD efficiently depletes lactic acid to facilitate the generation of H2O2 and boost the Fenton reaction, which in turn enhances ROS generation. With the synergistic effects of these cascade reactions and the release of HNK, notable ferroptosis efficacy was observed both in vitro and in vivo. This combination of natural product-induced and lactic acid-responsive sequential production of H2O2 as well as the consumption of glutathione may provide a new paradigm for achieving effective ferroptosis-based cancer therapy.

Enzyme-Empowered "Two Birds with One Stone" Strategy for Amplifying Tumor Apoptosis and Metabolic Clearance

Nanomedicine has reshaped the landscape of cancer treatment. However, its efficacy is still hampered by innate tumor defense systems that rely on adenosine triphosphate (ATP) for fuel, including damage repair, apoptosis resistance, and immune evasion. Inspired by the naturally enzymatic reaction of glucose oxidase (GOx) with glucose, here a novel "two birds with one stone" technique for amplifying enzyme-mediated tumor apoptosis and enzyme-promoted metabolic clearance is proposed and achieved using GOx-functionalized rhenium nanoclusters-doped polypyrrole (Re@ReP-G). Re@ReP-G reduces ATP production while increasing H2O2 concentrations in the tumor microenvironment through GOx-induced enzymatic oxidation, which in turn results in the downregulation of defense (HSP70 and HSP90) and anti-apoptotic Bcl-2 proteins, the upregulation of pro-apoptotic Bax, and the release of cytochrome c. These processes are further facilitated by laser-induced hyperthermia effect, ultimately leading to severe tumor apoptosis. As an enzymatic byproduct, H2O2 catalyzes the conversion of rhenium nanoclusters in Re@ReP-G nanostructures into rhenate from the outside in, which accelerates their metabolic clearance in vivo. This Re@ReP-G-based "two birds with one stone" therapeutic strategy provides an effective tool for amplifying tumor apoptosis and safe metabolic mechanisms.

NIR-promoted ferrous ion regeneration enhances ferroptosis for glioblastoma treatment

Ferroptosis, a unique iron-dependent mode of cell death characterized by lipid peroxide accumulation, holds significant potential for the treatment of glioblastoma (GBM). However, the effectiveness of ferroptosis is hindered by the limited intracellular ferrous ions (Fe2+) and hydrogen peroxide (H2O2). In this study, a novel near-infrared (NIR)-light-responsive nanoplatform (ApoE-UMSNs-GOx/SRF) based on upconversion nanoparticles (UCNPs) was developed. A layer of mesoporous silica and a lipid bilayer were coated on UCNPs sequentially and loaded with glucose oxidase (GOx) and sorafenib, respectively. Further attachment of the ApoE peptide endowed the nanoplatform with BBB penetration and GBM targeting capabilities. Our results revealed that ApoE-UMSNs-GOx/SRF could efficiently accumulated in the orthotopic GBM and induce amplified ferroptosis when combining with NIR irradiation. The UCNPs mediated the photoreduction of Fe3+ to Fe2+ by converting NIR to UV light, and excess H2O2 was produced by the reaction of glucose with the loaded GOx. These processes greatly promoted the production of ROS, which together with inhibition of system Xc- by the loaded sorafenib, leading to enhanced accumulation of lipid peroxides and significantly improved the antiglioma effect both in vitro and in vivo. Our strategy has the potential to enhance the effectiveness of ferroptosis as a therapeutic approach for GBM.

Copper(II)-based metal-organic framework delivery of calcium ascorbate for enhanced chemodynamic therapy via H2O2 self-supply and glutathione depletion

Chemodynamic therapy (CDT) is a promising cancer treatment strategy. However, mild acidic pH, insufficient H2O2 content, and overexpressed glutathione (GSH) in the tumor microenvironment (TME) severely impair CDT efficiency. In this study, a novel therapeutic nanosystem (Cu/ZIF-8/Vc-Ca/HA) was constructed for H2O2 self-supply and GSH depletion co-enhanced CDT. Typically, calcium ascorbate (Vc-Ca) loaded on the surface of Cu2+-doped ZIF-8 (Cu/ZIF-8) was designed as an original source for H2O2 generation, and a hyaluronic acid (HA) shell was subsequently coated to act as a tumor-targeted "guide" and protective layer. Along with the HA shell disintegrated in the TME, exposed Cu/ZIF-8/Vc-Ca dissociated in the tumor acidic microenvironment, thus triggering the release of Vc-Ca and Cu2+. Vc-Ca selectively produced H2O2 in tumor cells, which provided abundant H2O2 for boosting Fenton-like reactions. Meanwhile, the released Cu2+ could get converted into Cu+ by consuming excess intracellular GSH, which could reduce the tumor antioxidant capability of the nanosystem. Moreover, byproduct Cu+ reacted with abundant H2O2 by a highly efficient Fenton-like reaction to generate toxic ˙OH. Biological assays indicated that the Cu/ZIF-8/HA@Vc-Ca nanosystem showed significant anticancer activity by enhancing the CDT process. This study may provide a new strategy for improving the effectiveness of CDT.

Nanozyme-Based Regulation of Cellular Metabolism and Their Applications

Metabolism is the sum of the enzyme-dependent chemical reactions, which produces energy in catabolic process and synthesizes biomass in anabolic process, exhibiting high similarity in mammalian cell, microbial cell, and plant cell. Consequently, the loss or gain of metabolic enzyme activity greatly affects cellular metabolism. Nanozymes, as emerging enzyme mimics with diverse functions and adjustable catalytic activities, have shown attractive potential for metabolic regulation. Although the basic metabolic tasks are highly similar for the cells from different species, the concrete metabolic pathway varies with the intracellular structure of different species. Here, the basic metabolism in living organisms is described and the similarities and differences in the metabolic pathways among mammalian, microbial, and plant cells and the regulation mechanism are discussed. The recent progress on regulation of cellular metabolism mainly including nutrient uptake and utilization, energy production, and the accompanied redox reactions by different kinds of oxidoreductases and their applications in the field of disease therapy, antimicrobial therapy, and sustainable agriculture is systematically reviewed. Furthermore, the prospects and challenges of nanozymes in regulating cell metabolism are also discussed, which broaden their application scenarios.

A biomimetic nanocarrier facilitates glucose consumption and reactive oxide species accumulation in enzyme therapy for colorectal cancer

Glucose oxidase (GOx)-based enzyme therapeutics are potential alternatives for colorectal cancer (CRC) treatment via glucose consumption and accumulation of hydrogen peroxide (H2O2). Given that H2O2 can be eliminated by cytoprotective autophagy, autophagy inhibitors that can interrupt autolysosome-induced H2O2 elimination are promising combination drugs of GOx. Here, we developed a multifunctional biomimetic nanocarrier for effective co-delivery of an autophagy inhibitor-chloroquine phosphate (CQP) and GOx to exert their synergistic effect by irreversibly upregulating intracellular reactive oxygen species (ROS) levels. Poly (D, l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) were used to encapsulate both GOx and CQP using a W/O/W multi-emulsion method. Calcium phosphate (CaP) was used to "fix" CQP to GOx in the internal water phase, where it served as a pH-sensitive unit to facilitate intracellular drug release. Folic acid-modified red blood cell membranes (FR) were used to camouflage the GOx/CQP/CaP encapsulated PLGA NPs (referred to as PLGA/GCC@FR). In an AOM/DSS-induced CRC mouse model, PLGA/GCC@FR exhibited improved antitumor effects, in which the number of tumor nodes were only a quarter of that in the free drug combination group. The enhanced therapeutic effects of PLGA/GCC@FR were attributed to the prolonged tumor retention which was verified by both dynamic in vivo imaging and drug biodistribution. This multifunctional biomimetic nanocarrier facilitated combined enzyme therapeutics by depleting glucose and augmenting intracellular ROS levels in tumor cells, which exerted a synergistic inhibitory effect on tumor growth. Therefore, this study proposed a novel strategy for the enhancement of combined enzyme therapeutics, which provided a promising method for effective CRC treatment.

Bimetallic nanoplatform for synergistic sonodynamic-calcium overload therapy utilizing self-supplied hydrogen peroxide and relieved hypoxia

Sonodynamic therapy (SDT) has emerged as a potential alternative to traditional cancer treatments as it offers deep cellular penetration and reduced invasivity. Sonosensitizers generate reactive oxygen species (ROS) under ultrasound activation, focusing the ultrasound energy on malignant sites located deep in tissues and causing cell apoptosis and necrosis. However, due to tumor hypoxia and the limited levels of intracellular endogenous hydrogen peroxide (H2O2 is a fundamental species for supplying oxygen via catalase activity), SDT efficacy is still insufficient. In this study, a bimetallic and multifunctional system (Fe3O4-TAPP@PVP-CaO2) was prepared by using ferrosoferric oxide (Fe3O4) as a carrier loaded with 5,10,15,20-tetrakis(4-aminophenyl), porphyrin (TAPP), that was then coated with polyvinyl pyrrolidone (PVP) and calcium peroxide (CaO2). The CaO2 layer elevated the levels of H2O2 and Ca2+ in the tumor microenvironment when exposed to intracellular acidity, providing essential elements for oxygen generation. Intracellular hypoxia was alleviated via the catalase-like activity of Fe3O4 inducing calcium overload. Under ultrasonic irradiation, SDT generated toxic reactive oxygen species (ROS, singlet oxygen) and activated calcium influx through acoustic cavitation. Meanwhile, calcium overload therapy efficiently induced cell apoptosis at the moment of uncontrollable cellular accumulation of Ca2+. In addition, we modified the PVP on the surface to make it more stable. This study presents a bimetallic nanoplatform that can efficiently induce cancer cell death by synergistic sonodynamic-calcium overload therapy via modulation of O2/ROS/Ca2+ species, indicating its potential for multi-modality cancer therapy.

Advances in Nanodelivery Systems Based on Metabolism Reprogramming Strategies for Enhanced Tumor Therapy

Tumor development and metastasis are closely related to the complexity of the metabolism network. Recently, metabolism reprogramming strategies have attracted much attention in tumor metabolism therapy. Although there is preliminary success of metabolism therapy agents, their therapeutic effects have been restricted by the effective reaching of the tumor sites of drugs. Nanodelivery systems with unique physical properties and elaborate designs can specifically deliver to the tumors. In this review, we first summarize the research progress of nanodelivery systems based on tumor metabolism reprogramming strategies to enhance therapies by depleting glucose, inhibiting glycolysis, depleting lactic acid, inhibiting lipid metabolism, depleting glutamine and glutathione, and disrupting metal metabolisms combined with other therapies, including chemotherapy, radiotherapy, photodynamic therapy, etc. We further discuss in detail the advantages of nanodelivery systems based on tumor metabolism reprogramming strategies for tumor therapy. As well as the opportunities and challenges for integrating nanodelivery systems into tumor metabolism therapy, we analyze the outlook for these emerging areas. This review is expected to improve our understanding of modulating tumor metabolisms for enhanced therapy.

"Three-in-One" Nanozyme Composite for Augmented Cascade Catalytic Tumor Therapy

Cascade catalytic reaction exhibits simple procedure and high efficiency, such as that from the orderly assembly of different enzymes in biological systems. Mimicking of the natural cascade procedure becomes critical, but the orderly assembly of different enzymes is still challenging. Herein, single Au-Pt nanozyme is reported with "three-in-one" functions to initiate cascade conversions for O2 supply as mimic catalase, H2 O2 production with its glucose oxidase-like property, and • OH generation as mimic peroxidase for chemodynamic therapy (CDT). Thus, the complex assembly and cross-talk among the different enzymes are avoided. To this end, metastable Cu2 O NPs, as scaffolds, are used to anchor ultrasmall Au-Pt nanozyme, while metal-organic framework (MOF) is used to encapsulate the nanozyme for tumor microenvironment response and shielding protein adsorption. Pluronic F127 is then modified on the surface to improve hydrophilicity and biocompatibility of the composite. The endogenous acidity and glutathione in tumor degrade MOF to expose nanozyme for cascade catalytic CDT. The high photothermal conversion ability also enhances the CDT, while Cu2+ ions consume GSH to further improve CDT efficiency as augmented cascade catalytic tumor therapy. Thus, a new paradigm is provided with drug-free single nanozyme for improving tumor therapeutic efficacy and minimizing side effects.