Confining Prepared Ultrasmall Nanozymes Loading ATO for Lung Cancer Catalytic Therapy/Immunotherapy

NIR-II-Responsive Chainmail Nanocatalysts for Spatiotemporally Controlled Enzymatic Tumor Therapy

The clinical translation of metal-based peroxidase-like nanozymes for antitumor therapy faces two critical challenges: off-target catalytic activation and suboptimal hydroxyl radical (•OH) generation efficiency. To address these limitations, an innovative chainmail nanocatalyst featuring nitrogen-doped carbon-encapsulated nanoceria is developed, which combines spatial confinement effects with photo-trigger catalytic enhancement. The graphitic carbon shell serves as a physical barrier that effectively isolates metallic cerium from the biological environment, reducing nonspecific catalytic activation by 100% compared to bare nanoceria. Remarkably, under 1064 nm laser irradiation, electrons of cerium species can penetrate the carbon confinement through quantum tunneling effects, activating multiple enzymatic pathways. Vacancy engineering further optimizes the Ce3+/Ce4+ redox pair ratio (1.75 vs 0.44 in pristine nanoceria), establishing an electron reservoir that facilitates catalytic amplification of H2O2-to-•OH conversion and glutathione oxidase-mimicking activity for tumor microenvironment remodeling. This dual mechanism synergistically elevates intracellular oxidative stress while preserving normal tissue viability. In vivo evaluations demonstrate that the photoactivated nanocatalyst exhibits remarkable tumor suppression efficacy, prolonging the survival duration of tumor-bearing mice from 33 days to 70 days. The light-gated chainmail architecture provides a paradigm for spatiotemporally controlled catalytic therapy, resolving the critical dilemma between catalytic potency and biological specificity in nanozyme design.

Construction of In Situ Personalized Cancer Vaccines by Bioorthogonal Catalytic Microneedles for Augmented Melanoma Immunotherapy

In situ personalized tumor vaccines are produced directly at the primary tumor site by killing cancer cells and stimulating immune cells, they are effective against individuals and bypass the complexity and high cost of in vitro vaccine production. However, their clinical application is hindered by insufficient efficiency in inducing immunogenic cancer cell death (ICD) and systemic inflammation caused by immune adjuvants. Here, personalized cancer vaccines are constructed in situ for melanoma immunotherapy based on bioorthogonal catalytic microneedles, which enable the catalytic release of prodrugs at tumor sites and mediate strong ICD and an enhanced tumor immune response while avoiding systemic immune storms and toxic side effects. By incorporating TiO2 nanosheets supported Pd into swellable microneedles, the bioorthogonal microneedles are constructed to catalyze the depropargylation reaction of doxorubicin (DOX) prodrug and imiquimod (IMQ) prodrug in situ. The activated DOX at subcutaneous tumor sites induced strong ICD and released tumor-associated antigens. Concurrently, the activated IMQ acts as a Toll-like receptor (TLR7) agonist, enhancing the anti-tumor immune response. In vivo experiments demonstrate that this immunotherapy achieves ≈97% inhibition of primary tumors and effectively inhibits untreated distant tumors (≈94% inhibition) and lung metastasis (≈92% inhibition).

Self-promoted tumor-targeting nanomedicine activates STING-driven antitumor immunity via photodynamic DNA damage and PARP inhibition

The activation of antitumor immunity through strategically designed nanomedicine presents a promising approach to overcome the limitations of conventional cancer therapies. In this work, bioinformatic analysis found an abnormal poly(ADP-ribose) polymerase-1 (PARP-1) expression in breast cancer, linked to the cyclic GMP-AMP synthase (cGAS)-stimulator of the interferon gene (STING) pathway and immune suppression. PARP-1 inhibitor screening revealed olaparib (Ola) as a promising candidate, enhancing DNA damage and potentiating the immunotherapeutic response. Consequently, a self-promoted tumor-targeting nanomedicine (designated as PN-Ola) was proposed to activate STING-driven antitumor immunity through photodynamic DNA damage and PARP inhibition. PN-Ola was composed of a programmed death-ligand 1 (PD-L1) targeting amphiphilic peptide-photosensitizer conjugate (C16-K(PpIX)-WHRSYYTWNLNT), which effectively encapsulates Ola. Notably, PN-Ola demonstrated selective accumulation in tumor cells that overexpress PD-L1, while concurrently enhancing PD-L1 expression, thereby establishing a self-promoting mechanism for improved drug accumulation within tumor cells. Meanwhile, the photodynamic therapy (PDT) effects of PN-Ola would result in oxidative DNA damage and subsequent accumulation of DNA fragments. Additionally, the PARP inhibition provided by PN-Ola disrupted the DNA repair pathways in tumor cells, leading to a boosted release of DNA fragments that further stimulated STING-driven antitumor immunity. The synergistic mechanism of PN-Ola effectively activates the immunotherapeutic response by enhancing T cell activation and infiltration, leading to the eradication of metastatic tumors without inducing side effects. This study presents a promising strategy to overcome targeting ligand heterogeneity while activating systemic antitumor immunity for the effective eradication of metastatic tumors.

Overcoming tumor hypoxic bismuth-based ternary heterojunctions enable defect modulation-augmented tumor sonocatalytic immunotherapy

Inducing reactive oxygen species (ROS) via sonocatalysis to initiate inflammatory programmed cell death (PANoptosis) and immunogenic cell death (ICD) presents a promising strategy for activatable cancer immunotherapy. However, the limited ROS generation by sonosensitizers under ultrasound and the immunosuppressive tumor microenvironment hinder the efficiency of sono-immunotherapy. To overcome these challenges, a bismuth-based ternary heterojunction, Bi@Bi2O3-Pt-PEG (BBOP), was developed for sonocatalytic therapy aimed at activating immune responses. This system enhances ROS production during sonocatalysis and leverages dual therapeutic mechanisms by inducing PANoptosis and ICD to achieve improved anti-tumor efficacy. BBOP forms a Z-scheme heterojunction and Schottky contact through the formation of an intermediate Bi2O3 layer and the introduction of Pt. These structures significantly enhance sonocatalytic activity, while the Pt nanozyme exhibits catalase-like behavior, supplying oxygen for sonocatalysis, boosting ROS generation, and effectively relieving tumor hypoxia to reduce immune suppression. Further in vitro and in vivo experiments confirmed BBOP's ability to activate immune responses under ultrasound, inhibiting tumor growth and metastasis. RNA sequencing revealed the therapeutic biological mechanisms. The construction of this catalytic system not only provides insights for optimizing sonosensitizers but also offers a safer and more effective sono-immunotherapy activation strategy and theoretical basis for clinical cancer treatment.

Bimetallic peroxide-based nanotherapeutics for immunometabolic intervention and induction of immunogenic cell death to augment cancer immunotherapy

Immunotherapy has transformed cancer treatment, but its efficacy is often limited by the immunosuppressive characteristics of the tumor microenvironment (TME), which are predominantly influenced by the metabolism of cancer cells. Among these metabolic pathways, the indoleamine 2,3-dioxygenase (IDO) pathway is particularly crucial, as it significantly contributes to TME suppression and influences immune cell activity. Additionally, inducing immunogenic cell death (ICD) in tumor cells can reverse the immunosuppressive TME, thereby enhancing the efficacy of immunotherapy. Herein, we develop CGDMRR, a novel bimetallic peroxide-based nanodrug based on copper-cerium peroxide nanoparticles. These nanotherapeutics are engineered to mitigate tumor hypoxia and deliver therapeutics such as 1-methyltryptophan (1MT), glucose oxidase (GOx), and doxorubicin (Dox) in a targeted manner. The design aims to alleviate tumor hypoxia, reduce the immunosuppressive effects of the IDO pathway, and promote ICD. CGDMRR effectively inhibits the growth of 4T1 tumors and elicits antitumor immune responses by leveraging immunometabolic interventions and therapies that induce ICD. Furthermore, when CGDMRR is combined with a clinically certified anti-PD-L1 antibody, its efficacy in inhibiting tumor growth is enhanced. This improved efficacy extends beyond unilateral tumor models, also affecting bilateral tumors and lung metastases, due to the activation of systemic antitumor immunity. This study underscores CGDMRR's potential to augment the efficacy of PD-L1 blockade in breast cancer immunotherapy.

Multienzyme-like polyoxometalate for oxygen-independent sonocatalytic enhanced cancer therapy

Artificially synthesized nanozymes exhibit enzymatic activity similar to that of natural enzymes. However, in the complex tumor microenvironment, their diversity and catalytic activity show significant variations, limiting their effectiveness in catalytic therapy. Developing artificial enzymes with multiple enzymatic activities and spatiotemporal controllable catalytic abilities is of great clinical significance. Herein, we propose a novel strategy for synergistic enzyme catalysis and sonocatalytic therapy of tumors using polyoxometalates-based nanozymes. Copper-doped molybdenum-based polyoxometalates (denoted as CP) were rapidly synthesized at room temperature through a one-step method. CP contains mixed-valence states of Cu+/Cu2+ and Mo5+/Mo6+ ions, endowing it with enzyme-like activities of peroxidase, catalase, and glutathione peroxidase. Additionally, the incorporation of copper ions introduces oxygen vacancies into the nano-polyoxometalate, which not only reduces the bandgap but also enhances carrier separation efficiency, thereby improving the sonocatalytic performance of CP as a semiconductor. The combined effects of enzyme-like catalysis and sonocatalysis generate multiple reactive oxygen species (ROS), synergistically depleting glutathione (GSH) and disrupting the redox homeostasis of the tumor, inducing ferroptosis in tumor cells and thereby inhibiting tumor proliferation. This study provides new insights into the design of artificial nanozymes with multiple enzymatic activities and ultrasound activation functions for combined tumor therapy.

Engineered IL-21-Expressing Nanovesicles for Co-Delivery of GOX and Ferrocene to Induce Synergistic Anti-Tumor Effects

Glucose oxidase (GOX)-induced starvation is a safe treatment for tumor. However, the non-specific targeting of GOX and the plasticity of tumor metabolism lead to toxic side effects and low tumor mortality. Thus, it is necessary to develop a synergistic strategy with high tumor targeting specificity to enhance the mortality of GOX. In this study, a genetically engineered CD44 targeting peptide (CP) and IL-21 fusion protein-displaying nanovesicles platform (mCP@IL21-Fc-GOX) are designed to efficiently encapsulate GOX and ferrocene (Fc). After reaching the tumor site, IL-21 can be precisely released and targeted to NK cells through the cleavage of MMP-2, thus achieving precise anti-tumor immunotherapy of IL-21. Second, the exposed CP enable mCP-Fc-GOX to be further targeted to tumor cells, completing the synergistic anti-cancer effects of starvation and chemodynamic therapy (CDT) triggered by GOX and Fc. In situ breast cancer models, the results show that mCP@IL21-Fc-GOX not only enhances NK and T cells aggregation in tumor tissue but also achieves precise nutrition deprivation and abundant reactive oxygen species production, thus significantly inhibits tumor growth based on the synergistic function of the immunotherapy, starvation and CDT. Therefore, this work provides a smart nanovesicle platform for achieving precise and safe synergistic anti-tumor therapy.

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.

Anchoring Ru single-atoms on MXene achieves dual-enzyme activities for mild photothermal augmented nanocatalytic therapy

Single-atom catalysts with abnormally high catalytic activity have garnered extensive attention and interest for their application in tumor therapy. Despite the advancements made with current nanotherapeutic agents, developing efficient systems for cancer treatment remains challenging due to low activity, uncontrollable behavior, and nonselective interactions. Herein, we have constructed Ru single-atom-anchored MXene nanozymes (Ru-Ti3C2Tx-PEG) with a mild photothermal effect and multi-enzyme catalytic activity for synergistic tumor therapy. Ru single atoms anchored on the surface of MXene nanosheets not only facilitate multi-enzyme catalytic activity but also amplify the photothermal performance owing to the localized surface plasmon resonance effect. The Ru single atoms could decompose H2O2 into toxic hydroxyl radicals (•OH) in response to the tumor microenvironment (TME) for enzyme catalytic therapy, and the heat produced by the nanozyme under near-infrared laser excitation enhanced the •OH generation yield. Moreover, the nanozyme exhibited oxygen formation and glutathione depletion capability in cancer cells, thereby regulating the TME and accelerating the •OH levels. The in vitro and in vivo studies in this work confirm that the two-dimensional Ru single-atom-anchored MXene nanozyme has an extraordinary tumor growth inhibition effect, thus presenting a rational therapeutic strategy for tumor ablation through the synergistic effect of photothermal activity and heat-promoted enzymatic catalysis.

Chemical Design of Magnetic Nanomaterials for Imaging and Ferroptosis-Based Cancer Therapy

Ferroptosis, an iron-dependent form of regulatory cell death, has garnered significant interest as a therapeutic target in cancer treatment due to its distinct characteristics, including lipid peroxide generation and redox imbalance. However, its clinical application in oncology is currently limited by issues such as suboptimal efficacy and potential off-target effects. The advent of nanotechnology has provided a new way for overcoming these challenges through the development of activatable magnetic nanoparticles (MNPs). These innovative MNPs are designed to improve the specificity and efficacy of ferroptosis induction. This Review delves into the chemical and biological principles guiding the design of MNPs for ferroptosis-based cancer therapies and imaging-guided therapies. It discusses the regulatory mechanisms and biological attributes of ferroptosis, the chemical composition of MNPs, their mechanism of action as ferroptosis inducers, and their integration with advanced imaging techniques for therapeutic monitoring. Additionally, we examine the convergence of ferroptosis with other therapeutic strategies, including chemodynamic therapy, photothermal therapy, photodynamic therapy, sonodynamic therapy, and immunotherapy, within the context of nanomedicine strategies utilizing MNPs. This Review highlights the potential of these multifunctional MNPs to surpass the limitations of conventional treatments, envisioning a future of drug-resistance-free, precision diagnostics and ferroptosis-based therapies for treating recalcitrant cancers.

Pt/Pd dual-modified porphyrin metal-organic frameworks for NIR-II photothermal-enhanced photodynamic/catalytic therapy

Photodynamic therapy (PDT) and catalytic therapy were promising treatment modes, but tumor hypoxia and poor catalytic activity severely limited their efficacies. Herein, using a porphyrin metal-organic framework (PCN-224) as nanocarrier, a platinum/palladium (Pt/Pd) dual-modified PCN-224 nanoprobe (PCN-224-Pt@Pd) with strong peroxidase (POD)/catalase (CAT)-like activities was developed, achieving photothermal-promoted PDT/catalytic therapy. Compared with single ultrasmall Pt modifying, CAT-like activity of Pt/Pd dual-modifying increased oxygen concentration from 6.24 to 9.35 mg/L, which improved singlet oxygen (1O2) yield from 63.8 % to 82.9 %. Moreover, POD-like activity of Pt/Pd dual-modifying significantly accelerated hydroxyl radicals (·OH) generation. Importantly, PCN-224-Pt@Pd possessed near-infrared II (NIR-II) photothermal effect with a high efficiency (55.6 %), which further promoted ·OH production. Under combined therapy of PCN-224-Pt@Pd, the cell survival rate greatly reduced to 5.8 %, and the tumors were cured, suggesting NIR-II photothermal-enhanced PDT/catalytic therapy.

Current advances in nanozyme-based nanodynamic therapies for cancer

Nanozymes are nano-catalysis materials with enzyme-like activities, which can repair the defects of natural enzyme such as harsh catalytic conditions, and harness their strengths to treat tumor. The emerging nanodynamic therapies improved drug selectivity and decreased drug tolerance, while causing efficient cell apoptosis through the generated reactive oxygen species (ROS). Nanodynamic therapies based on nanozymes can improve the complicated tumor microenvironment (TME) to reduce the defect rate of nanodynamic therapies, and provide more options for tumor treatment. This review summarized the characteristics and applications of nanozymes with different activities and the factors influencing the activity of nanozymes. We also focused on the application of nanozymes in nanodynamic therapies, including photodynamic therapy (PDT), chemodynamic therapy (CDT), and sonodynamic therapy (SDT). Moreover, we discussed the strategies for optimizing nanodynamic therapies based on nanozymes for tumor treatment in detail, and provided a systematic review of tactics for synergies with other tumor therapies. Ultimately, we analyzed the shortcomings of nanodynamic therapies based on nanozymes and the relevant research prospect, which would provide sufficient evidence and lay a foundation for further research. STATEMENT OF SIGNIFICANCE: 1. The novelty and significance of the work with respect to the existing literatures. (1) Recent advances in nanozyme-based nanodynamic therapies are comprehensively and systematically reviewed, and strategies to address the limitations and challenges of current therapies based on nanozymes are discussed firstly. (2) The mechanism of nanozymes in nanodynamic therapies is described for the first time. The synergistic therapies, prospects, and challenges of nanozyme-based nanodynamic therapies are innovatively discussed. 2. The scientific impact and interest to our readership. This review focuses on the recent progress of nanozyme-based nanodynamic therapies. This review indicates the way forward for the combined treatment of nanozymes and nanodynamic therapies, and lays a foundation for facilitating theoretical development in clinic.

Modulation of the Atomic Spacing of Electrocatalytic for Boosting Reactive Oxygen Species Production to Precise Hepatocellular Carcinoma Cell Apoptosis

Promoting tumor cell apoptosis through the catalytic regulation of reactive oxygen species (ROS) is an ideal therapeutic option for cancer. However, a stable and controllable exogenous source of ROS is still lacking. Efficient and controllable electrocatalysis has shown tremendous potential for cancer treatment, but its key challenge lies in achieving precise, efficient, and controllable electrocatalytic ROS production at the tumor site. This study describes an electrocatalytic treatment technique for hepatocellular carcinoma (HCC) based on traditional Chinese acupuncture. By attaching a biocompatible electrocatalyst NiO-P700 with optimal atomic spacing to the surface of silver acupuncture needles, a high-concentration ROS microenvironment was generated around tumor cells via ORRs when the needles were electrified. This induction led to the accumulation of inflammatory factors (IL-1β, IL-6, and TNF-α) and macrophage infiltration, accelerating tumor cell apoptosis and necrosis. Both in vitro and in vivo experiments demonstrated that the rate of ROS production can be rapidly controlled by adjusting voltage and current. Importantly, the high concentration of ROS can be safely and effectively confined to the lesion site without affecting the entire body. Our study attempted to integrate electrocatalysis and acupuncture in HCC treatment, successfully regulating NiO-P atomic spacing and enhancing ORR performance, thereby presenting a safe and reliable perspective for HCC therapy.

Safety Landscape of Therapeutic Nanozymes and Future Research Directions

Oxidative stress and inflammation are at the root of a multitude of diseases. Treatment of these conditions is often necessary but current standard therapies to fight excessive reactive oxygen species (ROS) and inflammation are often ineffective or complicated by substantial safety concerns. Nanozymes are emerging nanomaterials with intrinsic enzyme-like properties that hold great promise for effective cancer treatment, bacterial elimination, and anti-inflammatory/anti-oxidant therapy. While there is rapid progress in tailoring their catalytic activities as evidenced by the recent integration of single-atom catalysts (SACs) to create next-generation nanozymes with superior activity, selectivity, and stability, a better understanding and tuning of their safety profile is imperative for successful clinical translation. This review outlines the current applied safety assessment approaches and provides a comprehensive summary of the safety knowledge of therapeutic nanozymes. Overall, nanozymes so far show good in vitro and in vivo biocompatibility despite considerable differences in their composition and enzymatic activities. However, current safety investigations mostly cover a limited set of basic toxicological endpoints, which do not allow for a thorough and deep assessment. Ultimately, remaining research gaps that should be carefully addressed in future studies are highlighted, to optimize the safety profile of therapeutic nanozymes early in their pre-clinical development.

Photo-Activated Oxidative Stress Amplifier: A Strategy for Targeting Glutathione Metabolism and Enhancing ROS-Mediated Therapy in Triple-Negative Breast Cancer Treatment

Amplifying oxidative stress within tumor cells can effectively inhibit the growth and metastasis of triple-negative breast cancer (TNBC). Therefore, the development of innovative nanomedicines that can effectively disrupt the redox balance represents a promising yet challenging therapeutic strategy for TNBC. In this study, an oxidative stress amplifier, denoted as PBCH, comprising PdAg mesoporous nanozyme and a CaP mineralized layer, loaded with GSH inhibitor L-buthionine sulfoximine (BSO), and further surface-modified with hyaluronic acid that can target CD44, is introduced. In the acidic tumor microenvironment, Ca2+ is initially released, thereby leading to mitochondrial dysfunction and eventually triggering apoptosis. Additionally, BSO suppresses the synthesis of intracellular reduced GSH and further amplifies the level of oxidative stress in cancer cells. Furthermore, PdAg nanozyme can be activated by near-infrared light to induce photothermal and photodynamic effects, causing a burst of ROS and simultaneously promoting cell apoptosis via provoking immunogenic cell death. The high-performance therapeutic effects of PBCH, based on the synergistic effect of aforementioned multiple oxidative damage and photothermal ablation, are validated in TNBC cells and animal models, declaring its potential as a safe and effective anti-tumor agent. The proposed approach offers new perspectives for precise and efficient treatment of TNBC.

Hollow Magnetic Nanocarrier-Based Microrobot Swarms for NIR-Responsive Targeted Drug Delivery and Synergistic Therapy

Nanocarriers are frequently used for drug delivery due to their large surface area, biocompatibility, and photothermal effects. However, they face the problem of premature drug leakage during drug transport. To address this challenge, we developed near-infrared light (NIR)-responsive hollow magnetic nanocarriers (HMC) by incorporating a chitosan-based molecular valve onto hollow magnetic nanocarriers (CHMC) to enable NIR-triggered drug release. Despite this advancement, this material still encounters the challenge of inadequate targeting. Recognizing the efficacy of magnetically driven micro/nanorobot swarms in remote wireless control, targeted motion, and efficient transport, we merged CHMC with magnetically controlled micro/nanorobot swarms. We evaluated their performance under programmable magnetic fields, which can be precisely controlled in biological fluid and directed toward targeting cells. Additionally, they demonstrated the ability to execute a responsive drug release under NIR irradiation. Ultimately, we confirmed their capacity for targeted delivery, responsive drug release, and photothermal therapy for liver cancer treatment in vivo. This approach heralds new possibilities for responsive drug therapy facilitated by micro/nanorobot swarms, offering promising advancements in medical treatment.

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 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.

Oxygen-bridged W-Pd atomic pairs enable H2O2 activation for sensitive immunoassays

Regulating the performance of peroxidase (POD)-like nanozymes is a prerequisite for achieving highly sensitive and accurate immunoassays. Inspired by natural enzyme catalysis, we design a highly active and selective nanozyme by loading atomically dispersed tungsten (W) sites on Pd metallene (W-O-Pdene) to construct an artificial three-dimensional (3D) catalytic center. The 3D asymmetric W-O-Pd atomic pairs can effectively stretch the O-O bonds in H2O2 and further promote the desorption of H2O to enhance POD-like activity. Moreover, the W-O-Pd sites with unique spatial structures demonstrate satisfactory specificity for H2O2 activation, effectively preventing the interference of dissolved oxygen. Accordingly, the highly active and specific W-O-Pdene nanozymes are utilized for sensitive and accurate prostate-specific antigen (PSA) immunoassay with a low detection limit of 1.92 pg mL-1, superior to commercial enzyme-linked immunosorbent assay.

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.

Gold brocade coated CoFe PBA with enhanced peroxidase-like activity for a chemiluminescent imaging immunoassay

Traditional chemiluminescence (CL) imaging immunoassays usually rely on natural enzymes as catalytic probes, which has hampered their extensive application due to the susceptibility to inactivation of natural enzymes. In response, a gold brocade coated CoFe Prussian blue analogue (CoFe PBA@Au brocade) with enhanced peroxidase-like activity was synthesized and utilized as a powerful label probe for constructing a highly sensitive CL imaging immunosensor targeting disease biomarkers with excellent performance. This research offers a universal strategy for enhancing the sensitivity of CL imaging immunoassays and further expands the application of PBA nanozymes.

Transition-Metal-Oxide-Based Nanozymes for Antitumor Applications

Transition metal oxide (TMO)-based nanozymes have appeared as hopeful tools for antitumor applications due to their unique catalytic properties and ability to modulate the tumor microenvironment (TME). The purpose of this review is to provide an overview of the latest progress made in the field of TMO-based nanozymes, focusing on their enzymatic activities and participating metal ions. These nanozymes exhibit catalase (CAT)-, peroxidase (POD)-, superoxide dismutase (SOD)-, oxidase (OXD)-, and glutathione oxidase (GSH-OXD)-like activities, enabling them to regulate reactive oxygen species (ROS) levels and glutathione (GSH) concentrations within the TME. Widely studied transition metals in TMO-based nanozymes include Fe, Mn, Cu, Ce, and the hybrid multimetallic oxides, which are also summarized. The review highlights several innovative nanozyme designs and their multifunctional capabilities. Despite the significant progress in TMO-based nanozymes, challenges such as long-term biosafety, targeting precision, catalytic mechanisms, and theoretical supports remain to be addressed, and these are also discussed. This review contributes to the summary and understanding of the rapid development of TMO-based nanozymes, which holds great promise for advancing nanomedicine and improving cancer treatment.

UV-assisted synthesis of ultra-small GO-Austar for efficient PTT therapeutic architectonic construction

Conventional Au nanomaterial synthesis typically necessitates the involvement of extensive surfactants and reducing agents, leading to a certain amount of chemical waste and biological toxicity. In this study, we innovatively employed ultra-small graphene oxide as a reducing agent and surfactant for the in situ generation of small Au nanoparticles under ultraviolet irradiation (UV) at ambient conditions. After ultra-small GO-Au seeds were successfully synthesized, we fabricated small star-like Au nanoparticles on the surface of GO, in which GO effectively prevented Austar from aggregation. To further use GO-Austar for cancer PTT therapy, through the modification of reduced human serum albumin-folic acid conjugate (rHSA-FA) and loading IR780, the final probe GO-Austar@rHSA-FA@IR780 was prepared. The prepared probe showed excellent biocompatibility and superb phototoxicity towards MGC-803 cells in vitro. In vivo, the final probe dramatically increased tumor temperature up to 58.6 °C after 5 minutes of irradiation by an 808 nm laser, significantly inhibiting tumor growth and nearly eradicating subcutaneous tumors in mice. This research provides a novel and simple method for the synthesis of GO-Au nanocomposites, showcasing significant potential in biological applications.

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.