A Noble AuPtAg-GOx Nanozyme for Synergistic Tumor Immunotherapy Induced by Starvation Therapy-Augmented Mild Photothermal Therapy

FeS embedded bioreactor collaborate with artesunate for cascade-catalytic tumor ferroptosis

Ferroptosis, a non-apoptotic programmed cell death modality, has been recognized as an emerging therapeutic target for cancer treatment, particularly with the rapid advancements in bionanotechnology. However, the insufficient intracellular Fe2+ ions and low reactive oxygen species (ROS) production severely restrict the efficacy of ferroptosis at tumor sites. Herein, a pH-responsive multifunctional nanoplatform (p-COF@GOx-FeS@HA/ART) was constructed to achieve efficient tumor ferroptosis through self-supplied Fe2+ ions and amplified ROS. In this system, the large specific surface area and mesoporous structure enabled the porphyrin-based covalent organic frameworks (p-COFs) to act as scaffolds and drug carriers for enhancing the catalytic activity of glucose oxidase-stabilized ferrous sulfide nanodots (GOx@FeS) and encapsulation of artesunate (ART). By oxidizing glucose (Glu) in tumor cells, GOx not only consumed Glu for starvation therapy but also promoted intracellular acidity and supplied hydrogen peroxide (H2O2) in the tumor microenvironment (TME), which facilitated the FeS-mediated chemodynamic therapy (CDT) as well as the release of hydrogen sulfide (H2S) for accelerating the ROS generation. Moreover, the lowered acidic TME could simultaneously trigger the release of ART and Fe2+ ions, thus exacerbating ART-mediated ferroptosis. Due to its photothermal and photodynamic behavior, the nanoplatform under laser irradiation could generate ROS storms in tumor cells for high-performance ferroptosis therapy, which was demonstrated both in cancer cells and tumor-bearing mice. This work provides a promising strategy for the simple construction of a multifunctional nanoplatform with TME-responsive and self-triggered ferroptosis, showing great potential in cascade amplification of ferroptosis 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.

Recent progress of noble metal-based nanozymes: structural engineering and biomedical applications

Due to their tunable catalytic activity, high chemical stability, and favorable electronic structure, noble metal-based nanozymes that can mimic important biocatalytic processes have attracted great attention. Rational structural design of noble metal-based nanozymes can endow them with excellent enzyme-like activities, enhanced sensitivity and stability, as well as unique physicochemical functionalities towards various biomedical applications such as sensing, diagnostics, and disease treatment. This review summarizes the recent progress in structural engineering of noble metal-based nanozymes and emphasizes the relationship between key structural factors of nanozymes and their enzyme-like properties in various enzyme-mimicking reactions. The diverse applications of noble metal-based nanozymes in biosensors, antibiosis, and disease treatment are further introduced. Finally, current challenges and future research directions in noble metal-based nanozymes are discussed. This review could offer scientific guidance to design and fabricate advanced nanozymes with enhanced functionality and performance towards clinical, environmental and biomedical applications.

Dual-drug loaded hyaluronic acid conjugates coated polydopamine nanodrugs for synergistic chemo-photothermal therapy in triple negative breast cancer

Although combination of chemotherapy and photothermal therapy (PTT) holds significant promise for treating triple-negative breast cancer, the existing delivery systems for achieving synergistic antitumor activity remains unsatisfactory. Herein, we developed of dual-drug loaded hyaluronic acid (HA) nanodrugs, which exhibited pH, glutathione (GSH), and thermal triple-responsiveness and CD44-targeting capabilities for chemo-PTT synergistic therapy in breast cancer. Gemcitabine (GCB) and metformin (MET) were conjugated to HA via amide and disulfide bonds to form dual-drug loaded prodrugs (HSGM), which were then coated onto the surface of polydopamine nanoparticles (PDA NPs) to self-assemble into HSGM/PDA NPs. These NPs selectively accumulated at the tumor site through HA receptors and released GCB and MET in response to low pH and high GSH concentrations. The NPs demonstrated excellent photothermal performance, with heat generated from near-infrared (NIR)-laser irradiation accelerating drug release within tumor. Additionally, MET inhibited the production of heat shock protein 70 (HSP 70), mitigating thermotolerance induced by PTT, thereby enhancing the PTT effect. The combination of chemotherapy and PTT synergistically improved anti-tumor efficacy (tumor inhibition ratio: 99.11 %) while showing negligible systemic toxicity, effectively preventing tumor metastasis and recurrence. This integrated approach offers valuable insights for the clinical treatment of breast cancer and other malignant tumors.

Removing Barriers to Tumor 'Oxygenation': Depleting Glutathione Nanozymes in Cancer Therapy

Nanozymes are nanomaterials capable of mimicking natural enzyme catalysis in the complex biological environment of the human body. Due to their good stability and strong catalytic properties, nanozymes are widely used in various fields of biomedicine. Among them, nanozymes that trigger intracellular reactive oxygen species (ROS) levels for cancer therapy have gained significant attention. However, the 'explosion' of ROS in tumor cells was prevented by the high levels of glutathione (GSH) in the tumor microenvironment (TME). GSH, a prominent endogenous antioxidant, increases the resistance of tumor cells to oxidative stress by scavenging ROS. Certain nanozymes can deplete intracellular GSH levels by mimicking GSH oxidase (GSHOx), GSH peroxidase (GPx) or by interfering with the reduction of oxidized glutathione (GSSG). On the one hand, elevated the level of intracellular ROS and induced lipid peroxidation reaction leading to ferroptosis. On the other hand, it creates favorable conditions for the treatment of tumors with photodynamic therapy (PDT), sonodynamic therapy (SDT), chemodynamical therapy (CDT) and targeted therapy. In this paper, we present a comprehensive analysis of GSH-depleting nanozymes reported in recent years, including classification, mechanism, responsiveness to TME and their roles in cancer therapy, and look forward to future applications and developments.

Tumor Antigen-Coated Two-Dimensional Black Phosphorus as a Nanovaccine for Synergistic Cancer Photothermal Therapy and Immunotherapy

Vaccine immunotherapy is paving the way for an effective long-term immune response and targeted destruction of tumor cells and shows promise as a leading strategy in tumor treatment. Nanoparticles are crucial in combining vaccine immunotherapy and photothermal therapy (PTT), generating local tumor thermal ablation, and triggering a powerful antitumor immune response that inhibits tumor recurrence. In this study, we designed a nanovaccine that combined PTT and immunotherapy for tumors using two-dimensional black phosphorus (BP) as a nanoplatform that was modified with maleimide poly(ethylene glycol) (PEG-MAL) and coated with tumor antigen proteins (BP-PEG-MAL@antigen). The BP-PEG-MAL@antigen nanovaccines displayed outstanding stability and biocompatibility due to the comodification of PEG and antigen proteins. The nanovaccines induced strong immune responses in vitro and in vivo that effectively inhibited orthotopic and bilateral tumor growth, prolonged survival time, and improved the survival rate of mice. In addition, the nanovaccines generated a long-term immune response and effectively inhibited tumor recurrence.

Inorganic Nanobiomaterials Boost Tumor Immunotherapy: Strategies and Applications

ConspectusTumor immunotherapy, as a new antitumor method to fight cancer by activating or enhancing the body's own immune system, has been extensively studied and applied in clinical practice. However, as an extremely complex system, tumor heterogeneity and complex immunosuppressive tumor microenvironment (TME) lead to poor immune response rate or secondary drug resistance. The advent of nanotechnology has ushered in a new era for immunotherapy. In particular, inorganic nanomaterials, with their unique physicochemical properties and excellent biocompatibility, are becoming an important tool for enhancing immunotherapy. Inorganic nanomaterials can be used as carriers for immune agents, improving drug delivery efficiency and thereby reducing systemic immunotoxicity and enhancing immune responses. Inorganic nanomaterials also trigger tumor immunogenic cell death (ICD), stimulate antitumor immune responses, and alleviate immunosuppressive TME by increasing oxygen levels, modulating metabolic pathways, and altering the secretion of immunosuppressive cytokines. The synergistic integration of inorganic nanomaterials with immunotherapy adeptly navigates around the constraints of conventional treatments, reducing side effects while concurrently augmenting therapeutic efficacy. In this review, we summarize our recent efforts in the design and synthesis of inorganic nanobiomaterials to enhance the efficacy of tumor immunotherapy. These nanomaterials achieve the desired immune efficacy mainly through four strategies, including inducing ICD, developing tumor nanovaccines, activating pyroptosis, and regulating tumor metabolism, providing beneficial implications for tumor immunotherapy. For one thing, due to the deficiency of ICD effect in single therapy, we mainly developed nanocatalysts that integrate multiple therapeutic functions to play a catalytic role in TME, converting tumor substances or metabolites into therapeutic products in situ, and further enhancing ICD. For another, in order to solve the problems of low antigen loading and therapeutic efficiency of existing adjuvants, several novel multifunctional nanoadjuvants were prepared, which combine high antigen loading and multimode therapeutic function in one, and achieve efficient immune activation. Moreover, to attain strong inflammatory responses and immunogenicity, we engineer pyroptosis adjuvants that selectively induce tumor cell pyroptosis by enhancing intracellular oxidative stress or ion overload. Finally, to reverse the immunosuppressive microenvironment, we developed nanoplatforms that target tumor metabolism, altering the levels of nutrients and metabolites in tumor such as glucose, lactic acid, citric acid, and tryptophan to effectively alter the TME, thereby activating and enhancing the body's immune response. The implementation of these strategies not only improves the therapeutic effect but also reduces the side effects and provides valuable insights and references for the development of novel nanomaterials to assist immunotherapy.

Nano drug delivery systems for advanced immune checkpoint blockade therapy

Immune checkpoint inhibitors (ICIs) have been widely utilized in the first-line therapy of various types of cancer. However, immune-related adverse events (irAEs) and resistance to ICIs remain intractable challenges for immune checkpoint blockade (ICB) therapy during clinic treatment. Nano drug delivery systems (NDDSs) have shown promising potential to improve anticancer efficacy and reduce side effects of small molecular drugs. The combination of nanotechnology and ICB provides new opportunities to overcome the challenges of immunotherapy. Nanoplatforms have been employed for direct delivery of ICIs, and they are preferred vehicles for combination therapy of ICIs and other therapeutic agents. In this review, the strategies of using NDDSs for advancing ICB therapy in recent years are surveyed, emphasizing the employment of NDDSs for combination treatment by ICIs and other agents to manipulate antitumor immunity. Analysis of current strategies for applying NDDSs for ICB leads to future research directions and development trends.

Injectable, self-healing and phase change nanocomposite gels loaded with two nanotherapeutic agents for mild-temperature, precise and synergistic photothermal-thermodynamic tumor therapy

Hyperthermia has emerged as a popular treatment option due to its high efficacy and seamless integration with other therapeutic approaches. To enhance treatment outcomes, hydrogels loaded with photothermal agents and activated by near-infrared (NIR) light for localized tumor therapy have attracted considerable attention. This approach minimizes drug dosage and mitigates the adverse effects of systemic drug delivery on healthy tissues. However, a challenge arises when NIR light sources inadvertently expose hydrogels loaded with high concentrations of photothermal agents, potentially causing localized overheating. Such overheating may trigger issues like inflammation, severe burns, and tissue crusting. To address this issue, the water in traditional hydrogels was substituted with the phase change material poly(ethylene glycol) (PEG), creating a phase change composite gel. This gel utilized PEG 2 M (PEG with a molecular weight of approximately 2,000,000 g/mol) as the gel scaffold and PEG 1.5 K (PEG with a molecular weight of approximately 1,500 g/mol) as the gel medium. Polydopamine modified with folic acid (PDA-FA) and MOF-199 loaded with 2, 2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIPH@MOF-199) were uniformly dispersed throughout the gel. Experimental results have demonstratedthat this system can extend the duration of photothermal therapy while effectively avoiding localized overheating. Additionally, it synergizes well with thermodynamic therapy.

Logic-gated approach for targeted delivery and site-selective activation of photothermal agents in precision cancer treatment

Logic-gated strategies represent a promising approach to achieving highly selective cancer therapies. In this work, we present LG-AB (Logic-Gated Aza-BODIPY), an OFF-ON photothermal therapy (PTT) agent designed to selectively target cancer cells. LG-AB undergoes a red-shift in its maximum absorbance wavelength when activated in the tumor microenvironment, enabling the molecule to precisely generate heat in the cancerous tissue upon light irradiation. Unlike conventional activatable agents that rely on a single biomarker, LG-AB employs an AND logic-gated design, where glucose transporter 1 (GLUT1) overexpression facilitates targeted cellular uptake in cancer cells, followed by activation through elevated glutathione (GSH) levels. Beyond demonstrating photothermal efficacy in human lung cancer and murine breast cancer cells, we show that LG-AB effectively attenuates cancer progression through heat-induced apoptosis, with minimal off-target effects to surrounding tissues. The versatility of this strategy is further demonstrated through the development and application of LG-CPT (Logic-Gated Camptothecin), which utilizes the same logic-gated design. Our results show that enhancing specificity and limiting collateral damage can be broadly applied across different therapeutic agents.

Graphdiyne biomaterials: from characterization to properties and applications

Graphdiyne (GDY), the sole synthetic carbon allotrope with sp-hybridized carbon atoms, has been extensively researched that benefit from its pore structure, fully conjugated surfaces, wide band gaps, and more reactive C≡C bonds. In addition to the intrinsic features of GDY, engineering at the nanoscale, including metal/transition metal ion modification, chemical elemental doping, and other biomolecular modifications, endowed GDY with a broader functionality. This has led to its involvement in biomedical applications, including enzyme catalysis, molecular assays, targeted drug delivery, antitumor, and sensors. These promising research developments have been made possible by the rational design and critical characterization of GDY biomaterials. In contrast to other research areas, GDY biomaterials research has led to the development of characterization techniques and methods with specific patterns and some innovations based on the integration of materials science and biology, which are crucial for the biomedical applications of GDY. The objective of this review is to provide a comprehensive overview of the biomedical applications of GDY and the characterization techniques and methods that are essential in this process. Additionally, a general strategy for the biomedical research of GDY will be proposed, which will be of limited help to researchers in the field of GDY or nanomedicine.

Nanozymes in Biomedical Applications: Innovations Originated From Metal-Organic Frameworks

Nanozymes exhibit significant potential in medical theranostics, environmental protection, energy development, and biopharmaceuticals due to their exceptional catalytic performance. Compared with natural enzymes, nanozymes have the advantages of simple preparation and purification, convenient production and low cost. Therefore, it is very important to prepare nanozymes quickly and efficiently, which not only helps to expand their application scope, but also can further exert their great potential in various fields. Metal-organic frameworks (MOF) materials serve as versatile substrates for constructing nanozymes, offering unique advantages like adjustable structure, high specific surface area, and porous channels. MOF coordination nodes constructed from metal ions or metal clusters have unique properties that can be leveraged to tailor nanozyme characteristics for different applications. This review describes and analyzes recent methods for constructing nanozymes using MOF materials, and explores their application prospects in biomedicine. By expounding the preparation techniques and biomedical applications of nanozymes, this review aims to inspire researchers to develop innovative nanozyme materials and explore new application directions.

Hollow gold-platinum nanoshells as a delivery platform for Ce6: cascading catalysis for enhanced multimodal therapy in tumor ablation and antitumor immunity

Precious metal nanozymes are renowned for their enzyme-mimicking properties, which can modulate the tumor microenvironment (TME) and enhance treatment. However, their small size often leads to aggregation and their single and limited catalytic potential impedes antitumor and immune-activating capabilities. To address these limitations, we developed a nanocomposite with multiple enzyme activities that synergistically enhances photodynamic and photothermal therapy (PDT and PTT), significantly boosting antitumor efficacy and immune response. Our approach involved using UiO-66-NH2 to facilitate the growth of gold-platinum bimetallic nanozymes, resulting in a core-shell structure of UiO-66-NH2@AuPt (UAuPt). The UiO-66-NH2 was then etched to create hollow gold-platinum bimetallic (HAuPt) nanoshells and further encapsulated with PEG-SH and the photosensitizer Ce6 to form the HAuPt@Ce6-PEG-SH (HCP) nanocomposite. Regarding the HCP nanocomposite, its absorption capability in the near-infrared second (NIR-II) region makes it a suitable photothermal agent for PTT, while Ce6 serves as the active agent for PDT. Furthermore, the gold nanoparticles (Au NPs) and platinum nanoparticles (Pt NPs) exhibit glucose oxidase (GOD)-, catalase (CAT)-, and peroxidase (POD)-like activities. This triple-enzyme activity forms an efficient cascade catalytic system, leading to refined remodeling of the TME and efficient enhancement of PTT and PDT. Moreover, the combination therapy triggers tumor-associated macrophage (TAM) polarization and immunogenic cell death (ICD), which not only promotes dendritic cell (DC) maturation but also stimulates T cell activation and the release of tumor-specific immune factors. This cascade ultimately results in a robust antitumor immune response. The in vitro and in vivo results demonstrated a significant antitumor efficacy and immune response, promising efficient nanozymes for therapeutic advancement.

New horizons for the therapeutic application of nanozymes in cancer treatment

The advent of nanozymes has revolutionized approaches to cancer diagnosis and therapy, introducing innovative strategies that address the limitations of conventional treatments. Nanozyme nanostructures with enzyme-mimicking catalytic abilities exhibit exceptional stability, biocompatibility, and customizable functions, positioning them as promising tools for cancer theranostics. By emulating natural enzyme reactions, nanozymes can selectively target and eradicate cancer cells, minimizing harm to adjacent healthy tissues. Nanozymes can also be functionalized with specific targeting ligands, allowing for the precise delivery and regulated release of therapeutic agents, improving treatment effectiveness and reducing adverse effects. However, issues such as biocompatibility, selectivity, and regulatory compliance remain critical challenges for the clinical application of nanozymes. This review provides an overview of nanozymes, highlighting their unique properties, various classifications, catalytic activities, and diverse applications in cancer treatments. The strategic oncological deployment of nanozymes could profoundly impact future advancements in personalized medicine, highlighting recent progress and prospective directions in enzyme-mimetic approaches for cancer treatment. This review summarizes an overview of nanozymes, highlighting their unique properties, various classifications, catalytic activities, and diverse applications in cancer treatments.

Tumor Microenvironment-Responsive Multinucleated Nanocomplexes Loaded with Carbon Dots for Combined Photothermal/Chemodynamic Therapy of Breast Cancer

Low cure rate and high death rate of cancers have seriously threatened human health. The combining multiple therapies is a promising strategy for cancer treatment. In this study, we construct a novel multinucleated nanocomplex loaded with carbon dots (CDs-SA@TAMn) that responds to tumor microenvironment for combined photothermal/chemodynamic cancer therapy. Fluorescence imaging results show that CDs-SA@TAMn can effectively accumulated in tumor sites. In acidic tumor microenvironment, CDs-SA@TAMn will release Mn2+, activating chemodynamic therapy and producing substantial reactive oxygen species (ROS) to kill tumor. Additionally, when irradiated by an 808 nm laser, CDs-SA@TAMn will exert the photothermal effect to realize high performance of cancer hyperthermia treatment. The nanocomplexes feather simple preparation, low toxicity, controlled release and imaging-guided therapy, showcasing the potential of precise and high-performance anti-tumor combination therapy in biomedical applications.

Supramolecular Nanozymes Based on Self-Assembly of Biomolecule for Cancer Therapy

Natural enzyme systems possess extraordinary functions and characteristics, making them highly appealing for use in eco-friendly technologies and innovative cancer treatments. However, their inherent instability and structural complexity often limit their practical applications, leading to the exploration of biomolecular nanozyme alternatives. Supramolecular nanozymes, constructed using self-assembly techniques and various non-covalent interactions, have emerged as a promising solution. Amino acids, peptides, and protein motifs offer flexible building blocks for constructing these nanozymes. Importantly, the well-defined structural regulation mechanisms of biomolecular nanozymes, along with their unique properties as fundamental biological modules in living systems-such as selectivity, permeability, retention, and biocompatibility-present new opportunities for cancer therapy. This review highlights recent advances in supramolecular self-assembled nanozymes, including peroxidases, oxidases, catalases, superoxide dismutases, and other nanozyme systems, as building blocks for tumor therapy. Additionally, it discusses precise functional modulation through supramolecular non-covalent interactions and their therapeutic applications in targeting the tumor microenvironment. These studies provide valuable insights that may inspire the design of novel supramolecular nanozymes with enhanced catalytic selectivity, biocompatibility, and tumor-killing efficacy.

Exploring the application of metal-based photothermal agents in photothermal therapy combined with immune checkpoint therapy

Photothermal therapy (PTT), a popular local treatment that uses heat to ablate tumors, has limited efficacy in addressing metastatic and deeply located tumors when used alone. Integrating PTT with immunotherapy not only yields a synergistic effect but also promotes cancer regression and confers the benefit of immune memory, which can surmount the challenges faced by PTT when used in isolation. Metal-based nanomaterials, renowned for their superior photothermal conversion efficiency and distinctive photochemical properties, have been extensively researched and applied in the field of PTT. This review summarizes the latest developments in combination therapies, with a specific focus on the combination of PTT and immune checkpoint therapy (ICT) for cancer treatment, including a comprehensive overview of the recent advancements in noble metal-based and 2D transition metal chalcogenides (TMDCs)-based photothermal agents, and their anticancer effect when combining PTT with immune checkpoint blockades (anti-CTLA-4 and anti-PD-L1) therapy. The goal of this review is to present an overview of the application, current challenges and future prospects of metal-based photothermal agents in PTT combined with ICT for cancer treatment.

Traditional Chinese Medicine-Based Nanoformulations for Enhanced Photothermal Therapy of Cancer

Photothermal therapy (PTT) has shown promise in the ablation of small, unresectable tumors by boosting the tumor's temperature above 50 °C. However, the high local temperature-induced cancer cell necrosis could create severe local inflammation, which may deteriorate normal tissues and increase tumor spreading. Although mild photothermal therapy (MPTT) at 42-45 °C could avoid the undesired side effect to some extent with minimal nonspecific heat diffusion, the self-protective behavior of tumors during MPTT results in an unsatisfactory therapeutic effect. Inspired by the widespread applications of traditional Chinese medicine (TCM) in various ailments, we also extensively explored the use of TCM in PTT and MPTT. In this Review, we summarize the application and function of TCM in PTT and MPTT, including the following: (1) TCM improves the performance of PTT and MPTT by elevating the photothermal conversion ability of photothermal agents (PTAs) and overcoming the self-protective effect of tumors, (2) PTT enhances TCM-based chemotherapy by improving the sensitivity and cellular uptake of TCM in tumors, and (3) natural TCM and metal-chelated TCM-based nanoparticles could directly act as PTAs for carrier-free combination therapy. We expect this Review will further illuminate TCM's utility and applicability in cancer treatment and create new combination strategies for theragnostic use.

Orchestrating cancer therapy: Recent advances in nanoplatforms harmonize immunotherapy with multifaceted treatments

Advancements in cancer therapy have increasingly focused on leveraging the synergistic effects of combining immunotherapy with other treatment modalities, facilitated by the use of innovative nanoplatforms. These strategies aim to augment the efficacy of standalone treatments while addressing their inherent limitations. Nanoplatforms enable precise delivery and controlled release of therapeutic agents, which enhances treatment specificity and reduces systemic toxicity. This review highlights the critical role of nanomaterials in enhancing immunotherapy when combined with chemotherapy, radiotherapy, photodynamic therapy, photothermal therapy, and sonodynamic therapy. Additionally, it addresses current challenges, including limited in vivo studies, difficulties in standardizing and scaling production, complexities of combination therapies, lack of comparative analyses, and the need for personalized treatments. Future directions involve refining nanoplatform engineering for improved targeting and minimizing adverse effects, alongside large animal studies to establish the long-term efficacy and safety of these combined therapeutic strategies. These efforts aim to translate laboratory successes into clinically viable treatments, significantly improving therapeutic outcomes and advancing the field of oncology.

Synchronous Interference of Dual Metabolic Pathways Mediated by H2S Gas/GOx for Augmenting Tumor Microwave Thermal Therapy

Sublethal tumor cells have an urgent need for energy, making it common for them to switch metabolic phenotypes between glycolysis and oxidative phosphorylation (OXPHOS) for compensatory energy supply; thus, the synchronous interference of dual metabolic pathways for limiting energy level is essential in inhibiting sublethal tumor growth. Herein, a multifunctional nanoplatform of Co-MOF-loaded anethole trithione (ADT) and myristyl alcohol (MA), modified with GOx and hyaluronic acid (HA) was developed, namely, CAMGH. It could synchronously interfere with dual metabolic pathways including glycolysis and OXPHOS to restrict the adenosine triphosphate (ATP) supply, achieving the inhibition to sublethal tumors after microwave (MW) thermal therapy. Under low-power MW irradiation, CAMGH induced certain tumor thermal damage while ensuring the safety of the surrounding normal tissues. The loaded GOx consumed glucose in tumors, undoubtedly blocking the main energy supply pathway, the glycolytic pathway. Then, H2O2 generated from GOx reacted with Co2+ to produce cytotoxic ·OH, combining with the released H2S from ADT to co-obstruct OXPHOS and then synergy with the above glycolysis blocking for a more effective ATP inhibition. The powerful depletion of ATP caused significant suppression of damage resistance protein upregulated after thermal stimulation, i.e., HSP90, and then the activation of caspase-3, achieving the simultaneous reversal of heat resistance and apoptosis resistance. Altogether, the CAMGH-based synchronous interference of dual metabolic pathways shows the potential to break down tumor self-repair, presenting an alternative strategy to enhance the therapeutic effect of tumor MW thermal therapy.

Gas Empowered Dual-Cascade Strategy for Augmented Single-Atom Nanotherapies

Single-atom nanotherapies have received numerous attention in malignant oncotherapy. However, the insufficient enzyme substrate and the upregulation of heat shock proteins during therapeutic interventions are seldom concurrently noticed. Herein, a novel gas empowered dual-cascade synergistic treatment strategy is demonstrated with domino effect, which can sequentially reinforce single-atom nanozyme (SAzyme)-based enzymatic therapeutics and mild photothermal therapy (PTT) (< 45 °C). In the proof-of-concept study, Fe single atom nanozyme (Fe/SAzyme) loaded with hydrogen sulfide (H2S) donor NaHS is developed for HSPs-silencing mediated mild PTT. The generated H2S suppresses the catalase activity to achieve "intracellular H2O2 conservation", thereby furnishing the enzyme substrate to Fe/SAzyme to produce abundant cytotoxic hydroxyl radicals (·OH) for augmented enzymatic therapeutics. Then, excess ·OH induced mitochondrial dysfunction blocks adenosine triphosphate (ATP) energy supply to realize cellular energy remodeling, which hinders overexpression of HSPs and enhances mild PTT of Fe/SAzyme both in vitro and vivo. Consequently, the gas-triggered dual-cascade strategy achieves domino H2S/·OH/mitochondrial dysfunction synergistic effect, endowing SAzymes with maximum antitumor efficacy via enzymatic therapeutics combined with mild PTT. This dual-cascaded gas/enzymatic/mild PTT synergistic oncotherapy not only exhibits a new pathway for gas-facilitated mild PTT, but also offers a valuable paradigm for the application of "1 + 1 + 1 > 3" multimodal synergistic tumor therapy.

Applications of nanotheranostics in the second near-infrared window in bioimaging and cancer treatment

Achieving accurate and efficient tumor imaging is crucial in the field of tumor treatment, as it facilitates early detection and precise localization of tumor tissues, thereby informing therapeutic strategies and surgical interventions. The optical imaging technology within the second near-infrared (NIR-II) window has garnered significant interest for its remarkable benefits, such as enhanced tissue penetration depth, superior signal-to-background ratio (SBR), minimal tissue autofluorescence, reduced photon attenuation, and lower tissue scattering. This review explained the design and optimization strategies of nano-agents responsive to the NIR-II window, such as single-walled carbon nanotubes, quantum dots, lanthanum-based nanomaterials, and noble metal nanomaterials. These nano-agents enable non-invasive, deep-tissue imaging with high spatial resolution in the NIR-II window, and their superior optical properties significantly improve the accuracy, efficiency, and versatility of imaging-guided tumor treatments. And we discussed the characteristics and advantages of fluorescence imaging (FL)/photoacoustic imaging (PA) in NIR-II window, providing a comprehensive overview of the latest research progress of different nano-agents in FL/PA imaging-guided tumor therapy. Furthermore, we exhaustively reviewed the latest applications of multifunctional nano-phototherapy technologies carried out by NIR-II light including photothermal therapy (PTT), photodynamic therapy (PDT), and combined modalities like photothermal-chemodynamic therapy (PTT-CDT), photothermal-chemotherapy (PTT-CT), and photothermal- immunotherapy (PTT-IO). These imaging-guided integrated tumor therapy approaches within the NIR-II window have gradually matured over the past decade and are expected to become a safe and effective non-invasive tumor treatment. Finally, we outlined the prospects and challenges of development and innovation of the NIR-II integrated diagnosis and therapy nanoplatform. This review aims to provide insightful perspectives for future advancements in NIR-II optical tumor diagnosis and integrated treatment platforms.

Mitochondria-targeting nanozyme for catalytical therapy and radiotherapy with activation of cGAS-STING

BACKGROUND

Overcoming radio-resistance and enhance radio-sensitivity to obtain desired therapeutic outcome plays an important role in treating cancer.

METHODS

Here we constructed a versatile enzyme-like nano-radiosensitizer MDP. MDP is composed of MnCO decorated and Ru-based nanozyme with triphenylphosphine (TPP) group coordinated on the surface.

RESULTS

Due to the mitochondria-targeting ability of TPP and enhanced permeability and retention effect (EPR) effect of MDP, MDP accumulated in the mitochondria of tumor cells. Therefore, quantities of reactive oxygen species were produced via multiple enzyme-like properties including peroxidase (POD) and catalase (CAT) in a tumor microenvironment mimicking status. In additional, more energy of radiation ionizing was deposed in tumor site via Compton effect and secondary electron scattering by Ru element. Impressively, it was disclosed that the nanozyme can act as a cGAS-STING agonist to provoke immune response of the system, which hereby further elevated this combined therapy.

CONCLUSIONS

Collectively, we fabricated a novel nanozyme with POD and CAT mimicking properties for the combination therapy of catalytical therapy, radiotherapy as well as immune therapy to eliminate cancer.

pH-Responsive injectable self-healing hydrogels loading Au nanoparticles-decorated bimetallic organic frameworks for synergistic sonodynamic-chemodynamic-starvation-chemo therapy of cancer

A novel and efficient cancer therapy was developed using a smart hydrogel containing multifunctional bimetallic organic frameworks and anticancer drugs. The injectable self-healing hydrogel with pH-responsiveness was constructed through borate ester and imine bonds among dopamine-grafted sodium alginate (SADA), hydroxypropyl chitosan (HPCS) and 2-formylphenylboronic acid (2-FPBA). The Au nanoparticles-decorated Ti/Fe bimetallic organic framework tetragonal nanosheets (Au/TF-MOF TNS) were synthesized and incorporated into the hydrogel with the anticancer drugs doxorubicin (DOX). Upon intratumoral injection of nanocomposite hydrogel, the acidic tumor microenvironment triggered the cleavage of borate ester and imine bonds, causing the hydrogel to break down and accelerating the release of both Au/TF-MOF TNS and DOX. These Au/TF-MOF TNS functioned as nanozymes, producing hydroxyl radicals (·OH) for chemodynamic therapy (CDT), generating oxygen (O2) to support sonodynamic therapy (SDT), and depleting glucose for starvation therapy (ST). Additionally, the Au/TF-MOF TNS served as sonosensitizers, capable of converting O2 into singlet oxygen (1O2) upon ultrasound irradiation to achieve SDT. Therefore, this nanocomposite hydrogel system enabled synergistic sonodynamic-chemodynamic-starvation-chemo therapy (SDT-CDT-ST-CT) of cancer, presenting a promising platform for advanced cancer therapy strategies.

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.

Stable triangle: nanomedicine-based synergistic application of phototherapy and immunotherapy for tumor treatment

In recent decades, cancer has posed a challenging obstacle that humans strive to overcome. While phototherapy and immunotherapy are two emerging therapies compared to traditional methods, they each have their advantages and limitations. These limitations include easy metastasis and recurrence, low response rates, and strong side effects. To address these issues, researchers have increasingly focused on combining these two therapies by utilizing a nano-drug delivery system due to its superior targeting effect and high drug loading rate, yielding remarkable results. The combination therapy demonstrates enhanced response efficiency and effectiveness, leading to a preparation that is highly targeted, responsive, and with low recurrence rates. This paper reviews several main mechanisms of anti-tumor effects observed in combination therapy based on the nano-drug delivery system over the last five years. Furthermore, the challenges and future prospects of this combination therapy are also discussed.

Nanozymes-Mediated Cascade Reaction System for Tumor-Specific Diagnosis and Targeted Therapy

Cascade reactions are described as efficient and versatile tools, and organized catalytic cascades can significantly improve the efficiency of chemical interworking between nanozymes. They have attracted great interest in many fields such as chromogenic detection, biosensing, tumor diagnosis, and therapy. However, how to selectively kill tumor cells by enzymatic reactions without harming normal cells, as well as exploring two or more enzyme-engineered nanoreactors for cascading catalytic reactions, remain great challenges in the field of targeted and specific cancer diagnostics and therapy. The latest research advances in nanozyme-catalyzed cascade processes for cancer diagnosis and therapy are described in this article. Here, various sensing strategies are summarized, for tumor-specific diagnostics. Targeting mechanisms for tumor treatment using cascade nanozymes are classified and analyzed, "elements" and "dimensions" of cascade nanozymes, types, designs of structure, and assembly modes of highly active and specific cascade nanozymes, as well as a variety of new strategies of tumor targeting based on the cascade reaction of nanozymes. Finally, the integrated application of the cascade nanozymes systems in tumor-targeted and specific diagnostic therapy is summarized, which will lay the foundation for the design of more rational, efficient, and specific tumor diagnostic and therapeutic modalities in the future.

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.

A novel acceptor-donor-acceptor structured molecule-based nanosystem for tumor mild photothermal therapy

Although photothermal therapy (PTT) is effective at killing tumor cells, it can inadvertently damage healthy tissues surrounding the tumor. Nevertheless, lowering the treatment temperature will reduce the therapeutic effectiveness. In this study, we employed 2,2'-((2Z,2'Z)-((4,4,9,9-Tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b']dithiophene-2,7-diyl)bis(methanylylidene))bis(3-oxo-2,3-dihydro-1H-indene-2,1-diylidene)) dimalononitrile (IDIC), a molecule possessing a conventional acceptor-donor-acceptor (A-D-A) structure, as a photothermal agent (PTA) to facilitate effective mild photothermal therapy (mPTT). IDIC promotes intramolecular charge transfer under laser irradiation, making it a promising candidate for mPTT. To enhance the therapeutic potential of IDIC, we incorporated quercetin (Qu) into IDIC to form IDIC-Qu nanoparticles (NPs), which can inhibit heat shock protein (HSP) activity during the process of mPTT. Moreover, IDIC-Qu NPs exhibited exceptional water dispersibility and passive targeting abilities towards tumor tissues, attributed to its enhanced permeation and retention (EPR) effect. These advantageous properties position IDIC-Qu NPs as a promising candidate for targeted tumor treatment. Importantly, the IDIC-Qu NPs demonstrated controllable photothermal effects, leading to outstanding in vitro cytotoxicity against cancer cells and effective in vivo tumor ablation through mPTT. IDIC-Qu NPs nano-system enriches the family of organic PTAs and holds significant promise for future clinical applications of mPTT.

Hierarchically Micro-, Meso-, and Macro-Porous MOF Nanosystems for Localized Cross-Scale Dual-Biomolecule Loading and Guest-Carrier Cooperative Anticancer Therapy

Mass transfer of bulky molecules, e.g., bioenzymes, particularly for cross-scale multibiomolecules, imposes serious challenges for microporous metal-organic frameworks (MOFs). Here, we create a hierarchically porous MOF heterostructure featuring highly region-ordered micro-, meso-, and macro-pores by growing a microporous ZIF-8 shell onto a hollow Prussian blue core through an epitaxial growth strategy. This allows for localized loading of large bioenzyme glucose oxidase (GOx) and small drug 5-fluorouracil (5-FU) within specific pores simultaneously and triggers unique guest-carrier cooperative anticancer capabilities. The stable ZIF-8 outer layer effectively blocks the core pores, preventing the undesired leakage of GOx into normal tissues. The acidity-induced ZIF-8 degradation gradually releases Zn2+ and loaded 5-FU for chemotherapy under acidic tumor microenvironments. With the loss of the shielding effect of the ZIF-8 coating, the released GOx depletes intratumoral glucose (Glu) for starvation therapy. Notably, an accelerated cascade reaction occurs between ZIF-8 decomposition and GOx release, facilitated by the modulator factor of Glu. This culminates in the realization of synergistic cancer therapy, as comprehensively demonstrated by in vitro and in vivo experiments, as well as transcriptome sequencing analyses. Our work not only introduces a hierarchically porous MOF heterostructure with highly region-ordered pores but also provides a perspective for guest-carrier cooperative anticancer therapy.

Theranostic Nanoplatform Based on Polydopamine-Coated Magnetic Mesoporous Silicon for Precise Cancer Triplex Nanotherapy and Multimodal Imaging

Although targeted therapy has revolutionized oncotherapy, engineering a versatile oncotherapy nanoplatform integrating both diagnostics and therapeutics has always been an intractable challenge to overcome the limitations of monotherapy. Herein, a theranostics platform based on DI/MP-MB has successfully realized the fluorescence detection of disease marker miR-21 and the gene/photothermal/chemo triple synergetic cancer therapy, which can trace the tumor through photothermal and fluorescence dual-mode imaging and overcome the limitations of monotherapy to improve the treatment efficiency of tumors. DI/MP-MB was prepared by magnetic mesoporous silicon nanoparticles (M-MSNs) loaded with doxorubicin (Dox) and new indocyanine green (IR820), and subsequently coating polydopamine as a "gatekeeper", followed by the surface adsorbed with molecular beacons capable of targeting miR-21 for responsive imaging. Under the action of enhanced permeability retention and external magnetic field, DI/MP-MB were targeted and selectively accumulated in the tumor. MiR-21 MB hybridized with miR-21 to form a double strand, which led to the desorption of miR-21 MB from the polydopamine surface and the fluorescence recovery to realize gene silencing and fluorescence imaging for tracking the treatment process. Meanwhile, with the response to the near-infrared irradiation and the tumor's microacid environment, the outer layer polydopamine will decompose, releasing Dox and IR820 to realize chemotherapy and photothermal therapy. Finally, the ability of DI/MP-MB to efficiently suppress tumor growth was comprehensively assessed and validated both in vitro and in vivo. Noteworthily, the excellent anticancer efficiency by the synergistic effect of gene/photothermal/chemo triple therapy of DI/MP-MB makes it an ideal nanoplatform for tumor therapy and imaging.

Multiple Treatment of Triple-Negative Breast Cancer Through Gambogic Acid-Loaded Mesoporous Polydopamine

Triple-negative breast cancer (TNBC) is a highly heterogeneous subtype of breast cancer, characterized by aggressiveness and high recurrence rate. As monotherapy provides limited benefit to TNBC patients, combination therapy emerges as a promising treatment approach. Gambogic acid (GA) is an exceedingly promising anticancer agent. Nonetheless, its application potential is hampered by low drug loading efficiency and associated toxic side effects. To overcome these limitations, using mesoporous polydopamine (MPDA) endowed with photothermal conversion capabilities is considered as a delivery vehicle for GA. Meanwhile, GA can inhibit the activity of heat shock protein 90 (HSP90) to enhance the photothermal effect. Herein, GA-loaded MPDA nanoparticles (GA@MPDA NPs) are developed with a high drug loading rate of 75.96% and remarkable photothermal conversion performance. GA@MPDA NPs combined with photothermal treatment (PTT) significantly inhibit the tumor growth, and effectively trigger the immunogenic cell death (ICD), which thereby increase the number of activated effector T cells (CD8+ T cells and CD4+ T cells) in the tumor, and hoist the level of immune-inflammatory cytokines (IFN-γ, IL-6, and TNF-α). The above results suggest that the combination of GA@MPDA NPs with PTT expected to activate the antitumor immune response, thus potentially enhancing the clinical therapeutic effect on TNBC.

Microfluidic-Enabled Assembly of Multicomponent Artificial Organelle for Synergistic Tumor Starvation Therapy

Artificial organelles (AOs) encapsulating enzymes are engineered to facilitate biocatalytic reactions for exerting therapeutic effects in various diseases. Exploiting the confinement effect, these catalytic properties exhibit significant enhancements without being influenced by the surrounding medium, enabling more efficient cascade reactions. In this study, we present a novel approach for synergistic tumor starvation therapy by developing multicomponent artificial organelles that combine enzymatic oncotherapy with chemotherapy. The construction process involves a microfluidic-based approach that enables the encapsulation of cationic cores containing doxorubicin (DOX), electrostatic adsorption of cascade enzymes, and surface assembly of the protective lipid membrane. Additionally, these multicomponent AOs possess multicompartment structures that enable the separation and sequential release of each component. By coencapsulating enzymes and chemotherapeutic agent DOX within AOs, we achieve enhanced enzymatic cascade reactions (ECR) and improved intrinsic permeability of DOX due to spatial confinement. Furthermore, exceptional therapeutic effects on 4T1 xenograft tumors are observed, demonstrating the feasibility of utilizing AOs as biomimetic implants in living organisms. This innovative approach that combines starvation therapy with chemotherapy using multicompartment AOs represents a promising paradigm in the field of precise cancer therapy.

Designing Mesoporous Prussian Blue@zinc Phosphate Nanoparticles with Hierarchical Pores for Varisized Guest Delivery and Photothermally-Augmented Chemo-Starvation Therapy

Background

With the rapid development of nanotechnology, constructing a multifunctional nanoplatform that can deliver various therapeutic agents in different departments and respond to endogenous/exogenous stimuli for multimodal synergistic cancer therapy remains a major challenge to address the inherent limitations of chemotherapy.

Methods

Herein, we synthesized hollow mesoporous Prussian Blue@zinc phosphate nanoparticles to load glucose oxidase (GOx) and DOX (designed as HMPB-GOx@ZnP-DOX NPs) in the non-identical pore structures of their HMPB core and ZnP shell, respectively, for photothermally augmented chemo-starvation therapy.

Results

The ZnP shell coated on the HMPB core, in addition to providing space to load DOX for chemotherapy, could also serve as a gatekeeper to protect GOx from premature leakage and inactivation before reaching the tumor site because of its degradation characteristics under mild acidic conditions. Moreover, the loaded GOx can initiate starvation therapy by catalyzing glucose oxidation while causing an upgradation of acidity and H2O2 levels, which can also be used as forceful endogenous stimuli to trigger smart delivery systems for therapeutic applications. The decrease in pH can improve the pH-sensitivity of drug release, and O2 can be supplied by decomposing H2O2 through the catalase-like activity of HMPBs, which is beneficial for relieving the adverse conditions of anti-tumor activity. In addition, the inner HMPB also acts as a photothermal agent for photothermal therapy and the generated hyperthermia upon laser irradiation can serve as an external stimulus to further promote drug release and enzymatic activities of GOx, thereby enabling a synergetic photothermally enhanced chemo-starvation therapy effect. Importantly, these results indicate that HMPB-GOx@ZnP-DOX NPs can effectively inhibit tumor growth by 80.31% and exhibit no obvious systemic toxicity in mice.

Conclusion

HMPB-GOx@ZnP-DOX NPs can be employed as potential theranostic agents that incorporate multiple therapeutic modes to efficiently inhibit tumors.

"Golgi-customized Trojan horse" nanodiamonds impair GLUT1 plasma membrane localization and inhibit tumor glycolysis

Nutrient or energy deprivation, especially glucose restriction, is a promising anticancer therapeutic approach. However, establishing a precise and potent deprivation strategy remains a formidable task. The Golgi morphology is crucial in maintaining the function of transport proteins (such as GLUT1) driving glycolysis. Thus, in this study, we present a "Golgi-customized Trojan horse" based on tellurium loaded with apigenin (4',5,7-trihydroxyflavone) and human serum albumin, which was able to induce GLUT1 plasma membrane localization disturbance via Golgi dispersal leading to the inhibition of tumor glycolysis. Diamond-shaped delivery system can efficiently penetrate into cells as a gift like Trojan horse, which decomposes into tellurite induced by intrinsically high H2O2 and GSH levels. Consequently, tellurite acts as released warriors causing up to 3.8-fold increase in Golgi apparatus area due to the down-regulation of GOLPH3. Further, this affects GLUT1 membrane localization and glucose transport disturbance. Simultaneously, apigenin hinders ongoing glycolysis and causes significant decrease in ATP level. Collectively, our "Golgi-customized Trojan horse" demonstrates a potent antitumor activity because of its capability to deprive energy resources of cancer cells. This study not only expands the applications of tellurium-based nanomaterials in the biomedicine but also provides insights into glycolysis restriction for anticancer therapy.

Zeolitic imidazole framework-derived rich-Zn-Co3O4/N-doped porous carbon with multiple enzyme-like activities for synergistic cancer therapy

Reactive oxygen species (ROS)-centered chemodynamic therapy (CDT) holds significant potential for tumor-specific treatment. However, insufficient endogenous H2O2 and extra glutathione within tumor microenvironment (TME) severely deteriorate the CDT's effectiveness. Herein, rich-Zn-Co3O4/N-doped porous carbon (Zn-Co3O4/NC) was fabricated by two-step pyrolysis, and applied to build high-efficiency nano-platform for synergistic cancer therapy upon combination with glucose oxidase (GOx), labeled Zn-Co3O4/NC-GOx for clarity. Specifically, the multiple enzyme-like activities of the Zn-Co3O4/NC were scrutinously investigated, including peroxidase-like activity to convert H2O2 to O2∙-, catalase-like activity to decompose H2O2 into O2, and oxidase-like activity to transform O2 to O2∙-, which achieved the CDT through the catalytic cascade reaction. Simultaneously, GOx reacted with intracellular glucose to produce gluconic acid and H2O2, realizing starvation therapy. In the acidic TME, the Zn-Co3O4/NC-GOx rapidly caused intracellular Zn2+ pool overload and disrupted cellular homeostasis for ion-intervention therapy. Additionally, the Zn-Co3O4/NC exhibited glutathione peroxidase-like activity, which consumed glutathione in tumor cells and reduced the ROS consumption for ferroptosis. The tumor treatments offer some constructive insights into the nanozyme-mediated catalytic medicine, coupled by avoiding the TME limitations.

Metallic Copper-Based Dual-Enzyme Biomimetic Nanoplatform for Mild Photothermal Enhancement of Anticancer Catalytic Activity

Background: Chemodynamic therapy (CDT) is recognized as a promising cancer treatment. Recently, copper sulfide nanostructures have been extensively employed as Fenton-like reagents that catalyze the formation of acutely toxic hydroxyl radicals (·OH) from hydrogen peroxide (H2O2). However, CDT therapeutic potency is restricted by the tumor microenvironment (TME), such as insufficient amounts of hydrogen peroxide, excessive glutathione levels, etc. To address these disadvantages, glucose oxidase (GOx) or catalase (CAT) can be utilized to enhance CDT, while low therapeutic efficacy still inhibits their future applications. Our previous study revealed that mild photothermal effect could boost the CDT catalytic effectiveness as well as GOx enzyme activity over a range. Results: We engineered and constructed a hollow CuS nanoplatform loaded with GOx and CAT, coating with macrophage membranes (M@GOx-CAT@CuS NPs). The nanoplatforms allowed enhancement of the reactive oxygen species creation rate and GOx catalytic activeness of CDT through mild phototherapy directed by photoacoustic imaging. After actively targeting vascular cell adhesion molecule-1 (VCAM-1) in cancer cells mediated by macrophage membrane coating, M@GOx-CAT@CuS NPs released GOx and CAT under near-infrared irradiation. GOx catalyzed the formation of H2O2 and gluconic acid with glucose, creating a better catalytic environment for CDT. Meanwhile, CAT-catalyzed H2O2 decomposition to generate sufficient oxygen, appropriately alleviating the oxygen shortage in the TME. In addition, starvation effects decreased adenosine triphosphate levels and further underregulated heat shock protein expression to reduce the heat resistance of tumor cells, resulting in a better mild phototherapy outcome. Both in vitro and in vivo experiments demonstrated that the newly developed M@GOx-CAT@CuS nanoplatform has remarkable synergistic anticancer therapeutic effects. Conclusion: The cascade reaction-enhanced biomimetic nanoplatform opens up a new avenue for precision tumor diagnostic and therapeutic research.

Chemodynamic PtMn Nanocubes for Effective Photothermal ROS Storm a Key Anti-Tumor Therapy in-vivo

Background

Chemodynamic therapy (CDT) is a new treatment approach that is triggered by endogenous stimuli in specific intracellular conditions for generating hydroxyl radicals. However, the efficiency of CDT is severely limited by Fenton reaction agents and harsh reaction conditions.

Methods

Bimetallic PtMn nanocubes were rationally designed and simply synthesized through a one-step high-temperature pyrolysis process by controlling both the nucleation process and the subsequent crystal growth stage. The polyethylene glycol was modified to enhance biocompatibility.

Results

Benefiting from the alloying of Pt nanocubes with Mn doping, the structure of the electron cloud has changed, resulting in different degrees of the shift in electron binding energy, resulting in the increasing of Fenton reaction activity. The PtMn nanocubes could catalyze endogenous hydrogen peroxide to toxic hydroxyl radicals in mild acid. Meanwhile, the intrinsic glutathione (GSH) depletion activity of PtMn nanocubes consumed GSH with the assistance of Mn3+/Mn2+. Upon 808 nm laser irradiation, mild temperature due to the surface plasmon resonance effect of Pt metal can also enhance the Fenton reaction.

Conclusion

PtMn nanocubes can not only destroy the antioxidant system via efficient reactive oxygen species generation and continuous GSH consumption but also propose the photothermal effect of noble metal for enhanced Fenton reaction activity.

"Three Musketeers" Enhances Photodynamic Effects by Reducing Tumor Reactive Oxygen Species Resistance

Photodynamic therapy (PDT) based on upconversion nanoparticles (UCNPs) has been widely used in the treatment of a variety of tumors. Compared with other therapeutic methods, this treatment has the advantages of high efficiency, strong penetration, and controllable treatment range. PDT kills tumors by generating a large amount of reactive oxygen species (ROS), which causes oxidative stress in the tumor. However, this killing effect is significantly inhibited by the tumor's own resistance to ROS. This is because tumors can either deplete ROS by high concentration of glutathione (GSH) or stimulate autophagy to eliminate ROS-generated damage. Furthermore, the tumor can also consume ROS through the lactic acid metabolic pathway, ultimately hindering therapeutic progress. To address this conundrum, we developed a UCNP-based nanocomposite for enhanced PDT by reducing tumor ROS resistance. First, Ce6-doped SiO2 encapsulated UCNPs to ensure the efficient energy transfer between UCNPs and Ce6. Then, the biodegradable tetrasulfide bond-bridged mesoporous organosilicon (MON) was coated on the outer layer to load chloroquine (CQ) and α-cyano4-hydroxycinnamic acid (CHCA). Finally, hyaluronic acid was utilized to modify the nanomaterials to realize an active-targeting ability. The obtained final product was abbreviated as UCNPs@MON@CQ/CHCA@HA. Under 980 nm laser irradiation, upconverted red light from UCNPs excited Ce6 to produce a large amount of singlet oxygen (1O2), thus achieving efficient PDT. The loaded CQ and CHCA in MON achieved multichannel enhancement of PDT. Specifically, CQ blocked the autophagy process of tumor cells, and CHCA inhibited the uptake of lactic acid by tumor cells. In addition, the coated MON consumed a high level of intracellular GSH. In this way, these three functions complemented each other, just as the "three musketeers" punctured ROS resistance in tumors from multiple angles, and both in vitro and in vivo experiments had demonstrated the elevated PDT efficacy of nanomaterials.

Noble Metal Nanoparticle-Based Photothermal Therapy: Development and Application in Effective Cancer Therapy

Photothermal therapy (PTT) is a promising cancer therapy modality with significant advantages such as precise targeting, convenient drug delivery, better efficacy, and minimal adverse effects. Photothermal therapy effectively absorbs the photothermal transducers in the near-infrared region (NIR), which induces the photothermal effect to work. Although PTT has a better role in tumor therapy, it also suffers from low photothermal conversion efficiency, biosafety, and incomplete tumor elimination. Therefore, the use of nanomaterials themselves as photosensitizers, the targeted modification of nanomaterials to improve targeting efficiency, or the combined use of nanomaterials with other therapies can improve the therapeutic effects and reduce side effects. Notably, noble metal nanomaterials have attracted much attention in PTT because they have strong surface plasmon resonance and an effective absorbance light at specific near-infrared wavelengths. Therefore, they can be used as excellent photosensitizers to mediate photothermal conversion and improve its efficiency. This paper provides a comprehensive review of the key role played by noble metal nanomaterials in tumor photothermal therapy. It also describes the major challenges encountered during the implementation of photothermal therapy.

Dual-enzyme decorated semiconducting polymer nanoagents for second near-infrared photoactivatable ferroptosis-immunotherapy

Enzymes provide a class of potential options to treat cancer, while the precise regulation of enzyme activities for effective and safe therapeutic actions has been poorly reported. Dual-enzyme decorated semiconducting polymer nanoagents for second near-infrared (NIR-II) photoactivatable ferroptosis-immunotherapy are reported in this study. Such nanoagents (termed SPHGA) consist of hemoglobin (Hb)-based semiconducting polymer (SP@Hb), adenosine deaminase (ADA) and glucose oxidase (GOx) with loadings in a thermal-responsive nanoparticle shell. NIR-II photoactivation of SPHGA results in the generation of heat to trigger on-demand releases of two enzymes (ADA and GOx) via destroying the thermal-responsive nanoparticle shells. In the tumor microenvironment, GOx oxidizes glucose to form hydrogen peroxide (H2O2), which promotes the Fenton reaction of iron in SP@Hb, resulting in an enhanced ferroptosis effect and immunogenic cell death (ICD). In addition, ADA degrades high-level adenosine to reverse the immunosuppressive microenvironment, thus amplifying antitumor immune responses. Via NIR-II photoactivatable ferroptosis-immunotherapy, SPHGA shows an improved effect to absolutely remove bilateral tumors and effectively suppress tumor metastases in subcutaneous 4T1 breast cancer models. This study presents a dual-enzyme-based nanoagent with controllable therapeutic actions for effective and precise cancer therapy.

Cascade-Catalyzed Nanogel for Amplifying Starvation Therapy by Nitric Oxide-Mediated Hypoxia Alleviation

Glucose oxidase (Gox)-mediated starvation therapy offers a prospective advantage for malignancy treatment by interrupting the glucose supply to neoplastic cells. However, the negative charge of the Gox surface hinders its enrichment in tumor tissues. Furthermore, Gox-mediated starvation therapy infiltrates large amounts of hydrogen peroxide (H2O2) to surround normal tissues and exacerbate intracellular hypoxia. In this study, a cascade-catalyzed nanogel (A-NE) was developed to boost the antitumor effects of starvation therapy by glucose consumption and cascade reactive release of nitric oxide (NO) to relieve hypoxia. First, the surface cross-linking structure of A-NE can serve as a bioimmobilization for Gox, ensuring Gox stability while improving the encapsulation efficiency. Then, Gox-mediated starvation therapy efficiently inhibited the proliferation of tumor cells while generating large amounts of H2O2. In addition, covalent l-arginine (l-Arg) in A-NE consumed H2O2 derived from glucose decomposition to generate NO, which augmented starvation therapy on metastatic tumors by alleviating tumor hypoxia. Eventually, both in vivo and in vitro studies indicated that nanogels remarkably inhibited in situ tumor growth and hindered metastatic tumor recurrence, offering an alternative possibility for clinical intervention.

Recent advances in nanotechnology for programmed death ligand 1-targeted cancer theranostics

Programmed cell death ligand 1 (PD-L1)/programmed cell death protein 1 (PD-1) checkpoint inhibitor-based immunotherapy has provided a unique and potent weapon against cancer in clinical practice. The likelihood of achieving beneficial effects from PD-L1/PD-1 immune checkpoint blockade (ICB) therapy is clinically assessed by detecting PD-L1 expression through invasive tissue biopsies. However, PD-L1 expression is susceptible to tumor heterogeneity and dynamic response to ICB therapy. Moreover, currently, anti-PD-L1 immunotherapy still faces challenges of the low targeting efficiency of antibody drugs and the risk of immune-associated adverse events. To overcome these issues, advanced nanotechnology has been developed for the purpose of quantitative, non-invasive, and dynamic analyses of PD-L1, and to enhance the efficiency of ICB therapy. In this review, we first introduce the nanoprobe-assisted in vitro/in vivo modalities for the selective and sensitive analysis of PD-L1 during the diagnostic and therapeutic process. On the other hand, the feasibility of fabricating diverse functional nanocarriers as smart delivery systems for precisely targeted delivery of PD-L1 immune checkpoint inhibitors and combined therapies is highlighted. Finally, the current challenges are discussed and future perspectives for PD-L1-targeted cancer theranostics in preclinical research and clinical settings are proposed.

Dumbbell-shaped bimetallic AuPd nanoenzymes for NIR-II cascade catalysis-photothermal synergistic therapy

The noble metal NPs that are currently applied to photothermal therapy (PTT) have their photoexcitation location mainly in the NIR-I range, and the low tissue penetration limits their therapeutic effect. The complexity of the tumor microenvironment (TME) makes it difficult to inhibit tumor growth completely with a single therapy. Although TME has a high level of H2O2, the intratumor H2O2 content is still insufficient to catalyze the generation of sufficient hydroxide radicals (‧OH) to achieve satisfactory therapeutic effects. The AuPd-GOx-HA (APGH) was obtained from AuPd bimetallic nanodumbbells modified by glucose oxidase (GOx) and hyaluronic acid (HA) for photothermal enhancement of tumor starvation and cascade catalytic therapy in the NIR-II region. The CAT-like activity of AuPd alleviates tumor hypoxia by catalyzing the decomposition of H2O2 into O2. The GOx-mediated intratumoral glucose oxidation on the one hand can block the supply of energy and nutrients essential for tumor growth, leading to tumor starvation. On the other hand, the generated H2O2 can continuously supply local O2, which also exacerbates glucose depletion. The peroxidase-like activity of bimetallic AuPd can catalyze the production of toxic ‧OH radicals from H2O2, enabling cascade catalytic therapy. In addition, the high photothermal conversion efficiency (η = 50.7 %) of APGH nanosystems offers the possibility of photothermal imaging-guided photothermal therapy. The results of cell and animal experiments verified that APGH has good biosafety, tumor targeting, and anticancer effects, and is a precious metal nanotherapeutic system integrating glucose starvation therapy, nano enzyme cascade catalytic therapy, and PTT therapy. This study provides a strategy for photothermal-cascade catalytic synergistic therapy combining both exogenous and endogenous processes. STATEMENT OF SIGNIFICANCE: AuPd-GOx-HA cascade nanoenzymes were prepared as a potent cascade catalytic therapeutic agent, which enhanced glucose depletion, exacerbated tumor starvation and promoted cancer cell apoptosis by increasing ROS production through APGH-like POD activity. The designed system has promising photothermal conversion ability in the NIR-II region, simultaneously realizing photothermal-enhanced catalysis, PTT, and catalysis/PTT synergistic therapy both in vitro and in vivo. The present work provides an approach for designing and developing catalytic-photothermal therapies based on bimetallic nanoenzymatic cascades.

Nanozymes: a new approach for leukemia therapy

Leukemia is a type of clonal disorder of hematopoietic stem and progenitor cells characterized by bone marrow failure, differentiation arrest, and lineage skewing. Despite leukemia being a complex disease and it being difficult to identify a single driving force, redox homeostasis, the balance between reactive oxygen species (ROS) producers and cellular antioxidant systems, is normally impaired during leukemogenesis. In this context, the modulation of ROS in leukemia cells can be harnessed for therapeutic purposes. Nanozymes are functional nanomaterials with enzyme-like characteristics, which address the intrinsic limitations of natural enzymes and exhibit great potential in synergistic antitumor therapy. Nanozymes possess catalytic activities (e.g., peroxidase-like activity, catalase-like activity, superoxide dismutase-like activity, and oxidase-like activity) to regulate ROS levels in vitro and in vivo, making them promising for leukemia therapy. On account of the rapid development of nanozymes recently, their application potentials in leukemia therapy are gradually being explored. To highlight the achievements of nanozymes in the leukemia field, this review summarizes the recent studies of nanozymes with anti-leukemia efficacy and the underlying mechanism. In addition, the challenges and prospects of nanozyme research in leukemia therapy are discussed.

Photothermal-Enhanced Dual Inhibition of Lactate/Kynurenine Metabolism for Promoting Tumor Immunotherapy

Traditionally referred to as "metabolic junk", lactate has now been recognized as essential "energy currency" and crucial "messenger" that contributes to tumor evolution, immunosuppression, etc., thus presenting a promising strategy for antitumor interventions. Similarly, kynurenine (Kyn) also exerts an immunosuppressive function, thereby significantly compromising the effectiveness of immunotherapy. This study proposes and validates a strategy for enhancing immunotherapy through photothermal-assisted depletion of lactate sustained by cycle-like O2 supply, with blocking the tryptophan (Trp)/Kyn metabolic pathway. In brief, a nanozyme therapeutic agent (PNDPL) is constructed, which mainly consists of PtBi nanozymes, lactate oxidase (LOX) and the indoleamine 2,3-dioxygenase (IDO) inhibitor NLG919. The PtBi nanozymes, which exhibit a catalase (CAT)-like activity, form a positive feedback loop with LOX to consume lactate while self-supplying O2 . Moreover, PtBi nanozymes retain enzyme-like performance even in a slightly acidic tumor microenvironment. Under 1064 nm irradiation, photothermal therapy (PTT) not only induces tumor cell death but also accelerates lactate exhaustion. Therefore, the combination of lactate depletion-induced starvation therapy and PTT, along with the blocking of IDO-mediated immune escape, effectively inhibits tumor growth and reverses immunosuppressive microenvironment, thus preventing tumor metastasis. This study represents the first investigation into the synergistic antitumor effects by lactate metabolism regulation and IDO-related immunotherapy.

CeO2 and Glucose Oxidase Co-Enriched Ti3C2Tx MXene for Hyperthermia-Augmented Nanocatalytic Cancer Therapy

Foreseen as foundational in forthcoming oncology interventions are multimodal therapeutic systems. Nevertheless, the tumor microenvironment (TME), marked by heightened glucose levels, hypoxia, and scant concentrations of endogenous hydrogen peroxide could potentially impair their effectiveness. In this research, two-dimensional (2D) Ti3C2 MXene nanosheets are engineered with CeO2 nanozymes and glucose oxidase (GOD), optimizing them for TME, specifically targeting cancer therapy. Following our therapeutic design, CeO2 nanozymes, embodying both peroxidase-like and catalase-like characteristics, enable transformation of H2O2 into hydroxyl radicals for catalytic therapy while also producing oxygen to mitigate hypoxia. Concurrently, GOD metabolizes glucose, thereby augmenting H2O2 levels and disrupting the intracellular energy supply. When subjected to a near-infrared laser, 2D Ti3C2 MXene accomplishes photothermal therapy (PTT) and photodynamic therapy (PDT), additionally amplifying cascade catalytic treatment via thermal enhancement. Empirical evidence demonstrates robust tumor suppression both in vitro and in vivo by the CeO2/Ti3C2-PEG-GOD nanocomposite. Consequently, this integrated approach, which combines PTT/PDT and enzymatic catalysis, could offer a valuable blueprint for the development of advanced oncology therapies.

Ultrathin 2D As2Se3 Nanosheets for Photothermal-Triggered Cancer Immunotherapy

Arsenic trioxide (As2O3) has achieved groundbreaking success in the treatment of acute promyelocytic leukemia (APL). However, its toxic side effects seriously limit its therapeutic application in the treatment of solid tumors. To detoxify the severe side effects of arsenic, herein we synthesized innovative 2D ultrathin As2Se3 nanosheets (As2Se3 NSs) with synergistic photothermal-triggered immunotherapy effects. As2Se3 NSs are biocompatible and biodegradable under physiological conditions and can release As(III) and Se(0). Furthermore, selenium increases the immunomodulatory efficacy of arsenic treatments, facilitating reprogramming of the tumor microenvironment by As2Se3 NSs by enhancing the infiltration of natural killer cells and effector tumor-specific CD8+ T cells. The synergistic combination of photothermal therapy and immunotherapy driven by As2Se3 NSs via a simple but effective all-in-one strategy achieved efficient anticancer effects, addressing the key limitations of As2O3 for solid tumor treatment. This work demonstrates not only the great potential of selenium for detoxifying arsenic but also the application of 2D As2Se3 nanosheets for cancer therapy.

Nanomaterial-Enabled Photothermal Heating and Its Use for Cancer Therapy via Localized Hyperthermia

Photothermal therapy (PTT), which employs nanoscale transducers delivered into a tumor to locally generate heat upon irradiation with near-infrared light, shows great potential in killing cancer cells through hyperthermia. The efficacy of such a treatment is determined by a number of factors, including the amount, distribution, and dissipation of the generated heat, as well as the type of cancer cell involved. The amount of heat generated is largely controlled by the number of transducers accumulated inside the tumor, the absorption coefficient and photothermal conversion efficiency of the transducer, and the irradiance of the light. The efficacy of treatment depends on the distribution of the transducers in the tumor and the penetration depth of the light. The vascularity and tissue thermal conduction both affect the dissipation of heat and thereby the distribution of temperature. The successful implementation of PTT in the clinic setting critically depends on techniques for real-time monitoring and management of temperature.

Glucose oxidase and ruthenium nanorods-embedded self-healing polyvinyl alcohol/polyethylene imine hydrogel for simultaneous photothermal/photodynamic/starvation therapy and skin reconstruction

Tumor recurrence and wound healing represent significant burdens for tumor patients after the surgical removal of melanomas. Wound dressings with wound healing and anticancer therapeutic abilities could help to solve these issues. Thus, a hybrid hydrogel made of polyvinyl alcohol (PVA) and polyethylene imine (PEI) was prepared by cross-linking imine bond and boronic acid bond. This hydrogel was loaded with ruthenium nanorods (Ru NRs) and glucose oxidase (GOx) and named as nanocomposite hydrogel (Ru/GOx@Hydrogel), exhibiting remarkable photothermal/photodynamic/starvation antitumor therapy and wound repair abilities. Ru NRs are bifunctional phototherapeutic agents that simultaneously exhibit intrinsic photothermal and photodynamic functions. Three-dimensional composite hydrogel loaded with GOx can also consume glucose in the presence of O2 during tumor starvation therapy. Near-infrared (NIR) light-triggered hyperthermia can not only promote the consumption of glucose, but also facilitate the ablation of residual cancer cells. The antitumor effect of the Ru/GOx@Hydrogel resulted in significant improvements, compared to those observed with either phototherapy or starvation therapy alone. Additionally, the postoperative wound was substantially healed after treatment with Ru/GOx@Hydrogel and NIR irradiation. Therefore, the Ru/GOx@Hydrogel can be used as a multi-stimulus-responsive nanoplatform that could facilitate on-demand controlled drug release, and be used as a promising postoperative adjuvant in combination therapy.