Ultrasound-Amplified Enzyodynamic Tumor Therapy by Perovskite Nanoenzyme-Enabled Cell Pyroptosis and Cascade Catalysis

Self-synergy-powered Ni/Fe nanocube-based cholesterol detection with dual modes

Nanoenzyme-leveraged multimode detection would benefit enhancing sensitivity and mitigating detection error. Moreover, multienzyme-like nanozymes hold tremendous potential in sensing by offering synergistic effects and cascaded catalysis. Herein, cost-effective multienzymic Ni/Fe nanocubes (Ni/FeNCs) were synthesized via a facile co-precipitation, and verified to catalyze H2O2 decomposition as peroxidase (POD) and catalase (CAT) mimics. Thereby, a dual-mode sensing platform based on Ni/FeNC and cholesterol oxidase (ChOx) was developed for cholesterol detection. Utilizing the H2O2 produced via the oxidation of cholesterol catalyzed by ChOx, OH•/O2•- radicals and O2 were formed efficiently via Ni/FeNCs-based H2O2 decomposition, facilitating the generation of chemiluminescence (CL) and fluorescence signals. For CL assay, an Ni/FeNC-luminol-H2O2 CL system was fabricated, where both POD-mimic-mediated radical decomposition of H2O2 and ferricyanide ions in Ni/FeNCs could induce CL reaction with respective mechanism. Notably, these two CL processes were both deduced to be enhanced by in-situ generated O2. This dual-catalyzed luminol CL system, involving self-cascade catalysis of ferricyanogen and CAT mimic as well as the self-synergy between POD-like and CAT-like activities of Ni/FeNCs, was proposed for the first time, and able to boost CL signal. To generate fluorescent signal, o-phenylenediamine was introduced, and oxidized by both OH•/O2•- and O2 produced via POD/CAT-mimic-mediated H2O2 decomposition to 2,3-diaminophenazinc, which could quench the fluorescence of WS2 quantum dots via internal filtration effect. The Ni/FeNC-based dual-mode assay is applicable and flexible for cholesterol detection. Particularly, the low-cost Ni/FeNC is a promising candidate of luminol-H2O2 CL system due to its dual-CL-mechanism involving self-cascade and synergistic catalysis.

Inert-remodeling strategy to build bimetal-confined nitrogen-doped carbon nanozyme for colorimetric-chemiluminescent imaging dual-mode cascade enzyme sensing

The metal-organic frameworks (MOFs)-derived nanozymes in air atmosphere have gained great attention in biosensing fields. Nevertheless, this derivative pattern may result in the destabilization of the MOF framework and the aggregation of active sites, consequently diminishing its catalytic activity. Herein, we reported an inert-remodeling strategy to build bimetal-confined nitrogen-doped carbon nanozyme for dual-mode cascade enzyme biosensing. The strategy was easily achieved by pyrolysis of MOFs (CoNi-ZIF-67 as model) precursor in argon atmosphere, leading to the formation of CoNi bimetallic nanoparticles uniformly confined nitrogen-doped carbon (CoNi-CN) nanozyme. This derivative nanozyme exhibits significantly enhanced peroxidase (POD)-like activity, which is 4 times higher than that of NiCo2O4 nanozyme (CoNi-ZIF-67 derivative in air atmosphere) and 54 times higher than that of CoNi-ZIF-67 precursor. The excellent POD-like activity of CoNi-CN nanozyme is ascribed to the following facts: i) integrate structure with uniformly dispersed CoNi bimetal active sites; ii) confinement effect of CoNi bimetal encapsulated in CN architecture. Integrating with glucose oxidase (GOx) to prepare cascade enzyme of CoNi-CN@GOx, colorimetric-chemiluminescent imaging sensor based on CoNi-CN@GOx cascade system was developed for glucose detection. Glucose was assayed in wide linear ranges of 0.08-15 mM (colorimetric) and 0.1-30 mM (CL imaging). This research provides a promising inert-remodeling strategy to construct high-performance nanozyme for dual mode biosensing applications.

Spatial-Constraint Modulation of Intra/Extracellular Reactive Oxygen Species by Adaptive Hybrid Materials for Boosting Pyroptosis and Combined Immunotherapy of Breast Tumor

Pyroptosis-immunotherapy has potential for triple-negative breast cancer treatment, but its efficacy is limited by insufficient pyroptosis activation and the need for phased, balanced, and spatially controlled activation of active species during long-term treatment. To reconcile intracellular/extracellular demands in tumor ablation, a nanoparticle-hydrogel hybrid enabling spatiotemporal reactive oxygen species (ROS) modulation is engineered. An open-shell sonosensitizer with unpaired electrons in its molecular orbitals is prepared by chelating Cu2⁺ with TCPP. These sonosensitizers are undergoing bovine serum albumin mediated biomineralization to form calcium phosphate particles and are incorporated into an injectable hydrogel through Schiff base crosslinking between dopamine-functionalized oxidized hyaluronic acid and gallic acid-modified chitosan. After intratumoral injection, nanoparticles endocytosed into tumor cells undergo acidic degradation, releasing calcium ions and GSH-activatable sonosensitizers. Calcium overload synergizes with ultrasound-mediated oxidative stress to induce mitochondrial damage and pyroptosis, while adhesive hydrogels retained in the extracellular matrix control excessive secondary ROS levels to protect oxidation-sensitive entities. This dual-action mechanism enhances the overall therapeutic effect by combining immediate tumor killing with long-term immune activation. This study provides a new route to hybrid material design, addressing the conflicting demands of short-term tumor ablation and long-term immune activation, overcoming the limitations of current pyroptosis-based immunotherapies.

In Situ Generation of Pyroptosis Inducer Mediated by Intracellular Labile Copper Pool for Safe and Robust Antitumor Immunotherapy

Pyroptosis has garnered increasing interest in the realm of cancer immunotherapy. Utilizing reactive oxygen species (ROS) to trigger oxidative stress is considered an effective strategy for promoting pyroptosis. However, existing catalytic nanoparticles used as pyroptosis inducers contain heavy metals, which inevitably cause potential side effects on normal tissues due to their high toxicity and off-target effects. Herein, a labile copper pool-mediated in situ pyroptosis inducer was designed and developed using a hydrogen-bonded organic framework (HOF)-based nanoplatform to achieve safe and robust antitumor immunotherapy. The nanoplatform could target mitochondria and elevate labile Cu2+ levels in cells, implementing the in situ synthesis of a pyroptosis inducer through the formation of catalytic nanoparticles with peroxidase (POD) and superoxide dismutase (SOD)-mimicking activities. Our results confirmed that the nanoplatform could generate high levels of ROS, resulting in pyroptotic cell death. When combined with antiprogrammed death receptor 1 therapy (αPD-1), the pyroptosis inducer exhibited excellent antitumor capacity in tumor models. Meanwhile, it exhibited minimal toxicity to healthy tissues due to the low intracellular copper concentration in normal cells. Overall, our work provides potential for the development of efficient and safe antitumor immunotherapy.

Green-Reduced Biodegradable Core-Shell Smart-Responsive MOFs for Photothermal-Enhanced Chemo-Chemodynamic in Tumor Catalysis Therapy

Metal-organic frameworks (MOFs) have been widely developed for the treatment of malignant tumors due to their high porosity, ease of functionalization, and smart-responsive degradation. Herein, a core-shell nanocomposite PAZDH (HA@DOX-PDA@Bio-Ag/ZIF-8) based on polydopamine (PDA)-coated green-reduced silver nanoparticles (Bio-Ag NPs) loaded on zeolite imidazolium framework-8 (ZIF-8) is designed, which can trigger near-infrared light (NIR)-enhanced chemodynamic reaction and chemotherapy for effective tumor treatment. Due to the targeting of the shell to the CD44 receptor, which is overexpressed in tumor cells, PAZDH NPs can actively aggregate at the tumor site. Subsequently, based on the pH-sensitive degradation of the core, this nanocomposite can release Bio-Ag NPs and doxorubicin (DOX) in a smart-responsive manner. Moreover, Bio-Ag NPs prepared by the green-reduced method using plant extract have a particle size of 40 nm, which can easily enter the tumor cells by endocytosis and induce apoptosis by catalyzing the production of cytotoxic ·OH from H2O2 enriched in the TME. Importantly, the high temperature generated by PTT can promote the release of DOX and accelerate the generation rate of ·OH, enabling photothermal-enhanced chemo-chemodynamic therapy. The PAZDH NPs can efficiently induce tumor ablation and inhibit solid tumors by up to 91.72%. In conclusion, this study provides a promising strategy for the development of smart-responsive MOFs in the field of tumor treatment.

Microwave-Responsive AlEu-MOFs Potentiate NLRP3-Mediated Pyroptosis via a "Triple Initiating" Tactic for Breast Cancer Microwave-Immunotherapy

Microwave thermotherapy is favored in clinical practice for breast cancer conservation strategies due to its minimally invasive characteristic. Nevertheless, the immunosuppressive tumor microenvironment (TME) significantly attenuates the therapeutic efficacy of anti-tumor immune response, posing challenges in effectively preventing tumor recurrence and metastasis. Pyroptosis, a recently identified form of programmed cell death triggered by inflammasomes, presents unique inflammatory and immunogenic properties that hold promise for cancer immunotherapy. Herein, microwave-responsive AlEu-MOFs are designed and synthesized to boost NLRP3-mediated pyroptosis via a "Triple Initiating" tactic for breast cancer microwave-immunotherapy. The potent microwave thermal effect of AEM facilitates the up-regulation of HSP90, thereby initiating NLRP3 expression. Concurrently, it induces mitochondrial dysfunction to generate substantial quantities of ROS, further enhancing NLRP3 expression to achieve a targeted amplification of microwave thermotherapy-induced pyroptosis. Simultaneously, the microwave-responsive directed anchoring release of highly active metal ions promotes the activation of the NLRP3 inflammasome jointly, ultimately inducing high-efficiency pyroptosis. This innovative "2M" (materials and methods) dual-pronged strategy not only significantly inhibits primary tumor proliferation, but also further impedes distant tumor progression and lung metastasis. This work provides a novel strategy to accurately and effectively achieve pyroptosis and offers a new approach to overcome the obstacles of clinical microwave thermotherapy.

Harnessing Porous Coordination Cages for Sonodynamic Therapy: Enhanced Efficacy Through Atomic Precision and Immune Activation

Sonodynamic therapy (SDT) has emerged as a promising non-invasive approach for immunotherapy. However, its broad applicability is often limited by the inefficiency of sonosensitizers. Here, we introduce a novel series of porous coordination cages (PCCs) specifically engineered to enhance sonodynamic therapeutic performance for the first time. These PCCs incorporate energy harvesting and conversion components, with variations in bandgap, electrical conductivity, and redox activity. Characterized by atomically precise compositions and well-defined structures, the PCCs enable strategic manipulation of functionalized moieties and metal centers, allowing for precise control over their sonodynamic efficiency. Their small particle size enhances penetration through dense tumor extracellular matrices, significantly improving tumor permeability. Upon ultrasound stimulation, the PCCs exhibit robust sonodynamic effects, resulting in increased reactive oxygen species (ROS) levels in tumor cells, which triggers apoptosis and antigens release. Notably, PCC-1 demonstrates metal-mediated catalytic activity, converting endogenous hydrogen peroxide into additional ROS, synergistically enhancing SDT efficacy and activating the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway in dendritic cells. In tumor model, PCCs effectively inhibited tumor growth and activated immune responses both locally and systemically. Collectively, these findings underscore the exceptional sonodynamic-immunotherapeutic potential of PCCs, paving the way for innovative strategies in tumor treatment.

Lanthanide-specific doping in vacancy-engineered piezocatalysts induces lysosomal destruction and tumor cell pyroptosis

BACKGROUND

Reactive oxygen species (ROS)-mediated pyroptosis provides a robust strategy for overcoming apoptosis resistance in breast cancer therapy. Nevertheless, the low efficiency of pyroptosis remains an undeniable challenge. Overcoming this obstacle necessitates the creation of innovative approaches and nanocatalysts to boost ROS generation. Herein, the distinct lanthanum-doped BiFeO3 (La-BFO) piezoelectric nanozymes are rationally designed and engineered for the specific cell pyroptosis of breast cancer through inducing the amplified production of ROS and releasing La ions.

RESULTS

The introduction of La reduces the recombination rate of electron-hole pairs through narrowing the bandgap and creating the oxygen vacancy of BFO, improving the harmful ROS generation efficiency. Importantly, the released La ions robustly disrupt the lysosomal membrane, ultimately inducing cell pyroptosis, in combination with ROS-induced biological effect.

CONCLUSION

In vitro and in vivo antineoplastic results confirm the desirable therapeutic effect on combating tumor. Especially, the iron and bismuth elemental components endow the nanocomposites with dual-mode computed tomography/magnetic resonance imaging ability, guaranteeing the potential therapeutic guidance and monitoring.

Self-Assembly of Short Peptides Activates Specific ER-Phagy and Induces Pyroptosis for Enhanced Tumor Immunotherapy

Developing specific endoplasmic reticulum-autophagy (ER-phagy) inducers is highly desirable for discovering new ER-phagy receptors and elucidating the detailed ER-phagy mechanism and potential cancer immunotherapy. However, most of the current ER-phagy-inducing methods cause nonselective autophagy of other organelles. In this work, we report the design and synthesis of simple and stable short peptides (D-FFxFFs) that could specifically trigger ER-phagy, which further induces pyroptosis and activates the immune response against tumor cells. D-FFxFFs locate preferentially in ER and readily self-assemble to form nanosized misfolded protein mimics, which lead to distinct upregulation of dedicated ER-phagy receptors with no obvious autophagy of other organelles. Significant unfolded protein response (UPR) is activated via IRE1-JNK and PERK-ATF4 pathways. Interestingly, the persistent ER-phagy triggers ER Ca2+ release and a surge in mitochondrial Ca2+ levels, resulting in GSDMD-mediated pyroptosis other than apoptosis. The ER-phagy induces pyroptosis and activates a distinct antitumor immune response without evolving the acquired drug resistance. This work not only provides a powerful tool for investigating the mechanism and function of ER-phagy but also offers an appealing strategy for anticancer immunotherapy.

Gallium-Magnesium Layered Double Hydroxide for Elevated Tumor Immunotherapy Through Multi-Network Synergistic Regulation

Immunotherapeutic efficacy is often limited by poor immunogenicity, immunosuppressive tumor microenvironment (TME), and cytoprotective mechanisms, leading to low immune activation. To this end, here, L-amino acid oxidase (LAAO) loaded gallium-magnesium layered double hydroxide (MG-LAAO) is prepared for significantly enhanced tumor immunotherapy through multi-network synergistic regulation. First, MG-LAAO induces tumor cell pyroptosis by initiating caspase-1/GSDMD and caspase-3/GSDME pathways, further triggering immunogenic cell death (ICD). Then the released Ga3+ induces mitochondrial iron overload, resulting in ferroptosis. In addition, MG-LAAO also hinders autophagy of tumor cells, and reshapes the immunosuppressive tumor microenvironment (TME) by neutralizing H+ and inhibiting lactic acid accumulation, thus destroying the cytoprotective mechanism and avoiding immune escape. Furthermore, this multi-network synergy further activates the cGAS-STING signaling pathway, generating powerful antitumor immunotherapy. This work highlights the critical role of synergies between autophagy block, pyroptosis, ferroptosis, and ICD in tumor immunotherapy, demonstrating the important role of this multi-network synergy in effectively overcoming immunosuppressive TME and enhancing immunogenicity. In particular, the mechanism of gallium-induced pyroptosis is revealed for the first time, providing theoretical support for the design of new materials for tumor immunotherapy in the future.

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.

Orthogonal upconversion nanocarriers for combined photodynamic therapy and precisely triggered gene silencing in combating keloids

Keloids are pathological scars characterized by excessive fibroblast proliferation, abnormal collagen deposition, and chronic inflammation, which often result in high recurrence rates and limited treatment success. Targeting BACH1 with gene therapy has shown promise in regulating fibroblast activity and reducing inflammation. However, effective delivery systems for targeted gene therapy in keloids remain a major challenge. Here, we develop a novel nanocarrier platform based on orthogonal upconversion nanoparticles (OUNCs) to achieve spatiotemporal silencing of BACH1 and combined photodynamic therapy (PDT). The OUNCs are composed of orthogonal upconversion nanoparticles (UCNPs), photosensitizer (Rose Bengal), ROS-sensitive diselenide bonds (SeSe), therapeutic siBACH1, and an active targeting moiety (hyaluronic acid) to specifically target keloid fibroblasts (KFs). We demonstrate that the OUNCs can effectively induce KFs apoptosis, inhibit KFs proliferation, and reduce M2 macrophages recruitment by modulating the Rap1/MEK/ERK signaling pathway. Our study represents a breakthrough in precision therapy for keloids, providing a promising platform that integrates siBACH1-based gene therapy with NIR light-triggered PDT.

Engineered Metal-Organic Framework with Stereotactic Anchoring and Spatial Separation of Porphyrins for Amplified Ultrasound-Mediated Pyroptosis and Cancer Immunotherapy

Ultrasound-mediated reactive oxygen species (ROS) generation is pivotal in specifically inducing pyroptosis of tumor cells. However, the effectiveness of pyroptosis is generally hindered by the constraints of ROS generation efficiency. Herein, a new porphyrin-based metal-organic framework (Fe(TCPP)-MOF) was rationally designed via an innovative dual-solvent strategy to amplify ROS generation for ultrasound-controlled pyroptosis. The crystal structure of Fe(TCPP)-MOF was elucidated by continuous rotation electron diffraction technique, revealing its regular and rigid conformation. The porphyrin molecules were precisely oriented and firmly confined within the scaffold, effectively restricting intramolecular motion. The ample distance of 6.8 Å between two porphyrin molecules, combined with the interaction region indicator visualization, confirmed the absence of π-π stacking interactions in the Fe(TCPP)-MOF framework, thereby avoiding the aggregation-caused quenching effect. Furthermore, the permanent porosity and expansive surface area of Fe(TCPP)-MOF enhanced its interaction with oxygen. These ingenious structural features endowed Fe(TCPP)-MOF with a unique ability to generate a large amount of singlet oxygen under ultrasound activation. Meanwhile, the impetus of ultrasound also accelerated the rate of the Fenton reaction catalyzed by iron ions, significantly boosting the generation of hydroxyl radicals. Benefiting from the dual amplification of ROS, Fe(TCPP)-MOF could efficiently induce tumor cells pyroptosis under ultrasound stimulation, thereby intensifying the potency of cancer immunotherapy.

Nanomaterials evoke pyroptosis boosting cancer immunotherapy

Cancer immunotherapy is currently a very promising therapeutic strategy for treating tumors. However, its effectiveness is restricted by insufficient antigenicity and an immunosuppressive tumor microenvironment (ITME). Pyroptosis, a unique form of programmed cell death (PCD), causes cells to swell and rupture, releasing pro-inflammatory factors that can enhance immunogenicity and remodel the ITME. Nanomaterials, with their distinct advantages and different techniques, are increasingly popular, and nanomaterial-based delivery systems demonstrate significant potential to potentiate, enable, and augment pyroptosis. This review summarizes and discusses the emerging field of nanomaterials-induced pyroptosis, focusing on the mechanisms of nanomaterials-induced pyroptosis pathways and strategies to activate or enhance specific pyroptosis. Additionally, we provide perspectives on the development of this field, aiming to accelerate its further clinical transition.

An "Outer Piezoelectric and Inner Epigenetic" Logic-Gated PANoptosis for Osteosarcoma Sono-Immunotherapy and Bone Regeneration

The precise manipulation of PANoptosis, a newly defined cell death pathway encompassing pyroptosis, apoptosis, and necroptosis, is highly desired to achieve safer cancer immunotherapy with tumor-specific inflammatory responses and minimal side effects. Nonetheless, this objective remains a formidable challenge. Herein, an "AND" logic-gated strategy for accurately localized PANoptosis activation, utilizing composite 3D-printed bioactive glasses scaffolds integrated with epigenetic regulator-loaded porous piezoelectric SrTiO3 nanoparticles is proposed. The "logic-gated" strategy is co-programmed by an "outer" input signal of exogenous ultrasound irradiation to produce reactive oxygen species and an "inner" input signal of acid tumor microenvironment to ensure the epigenetic demethylation regulation, guaranteeing the tumor-specific PANoptosis. Specifically, immunogenic PANoptosis triggers dendritic cell maturation and cytotoxic T cell activation, amplifying antitumor immune responses and significantly suppressing osteosarcoma growth, with a suppression rate of ≈73.47 ± 5.2%. In addition, the well-known bioactivities of Sr-doped scaffolds expedite osteogenic differentiation and reinforce bone regeneration. Therefore, this work provides a paradigm of logic-gated sono-piezoelectric biomaterial platform with concurrently exogenous/endogenous activated PANoptosis for controlled sono-immunotherapy of osteosarcoma, and related bone defects repair.

Nobiletin regulates the proliferation and migration of ovarian cancer A2780 cells via DPP4 and TXNIP

Nobiletin is an active compound extracted from citrus fruits. Research has indicated that nobiletin has a potential inhibitory effect on ovarian cancer (OV). However, the mechanism of action remains unclear. The OV A2780 cells were treated using nobiletin, cell viability was examined using a cell counting kit-8 experiment, and cell migration was examined with a wound healing experiment. Nobiletin targets were retrieved from target databases. Differentially expressed genes (DEG) and weighted gene co-expression network analysis (WGCNA) were conducted on GSE26712 (OV). The intersection of the critical genes for nobiletin's action on OV and gene enrichment and immune infiltration analyses were performed. The Cancer Genome Atlas-OV data and molecular docking helped validate the findings. After adding nobiletin, cell viability and migration significantly decreased (P < 0.01). A total of 88 nobiletin targets and 1288 DEG were identified. The intersection genes were enriched inflammatory response and response to hypoxia. The most related module obtained from WGCNA contained 414 genes (correlation coefficient = 0.77, P < 0.01). DPP4 and TXNIP were recognized as the hub genes. The abundance of macrophages M2 and mast cells activated significantly enhanced with increased DPP4 expression (P < 0.05). The binding energy between DPP4/TXNIP and nobiletin was - 7.012/ - 7.184 kcal/mol, forming 5/2 hydrogen bonds. Nobiletin effectively suppresses the viability and migration of OV A2780 cells. In this process, DPP4 and TXNIP are the key target, immune regulation, and oxidative stress playing significant roles.

Advanced Dual-Mode Microfluidic Sensing Platform Based on Amphiphilic Polymer-Capped Perovskite Nanozymes Induced Photoelectrochemical Signal Amplification and Fluorescence Emission

A novel dual-mode microfluidic sensing platform integrating photoelectrochemical (PEC) and fluorescence (FL) sensors was developed for the sensitive monitoring of heart fatty acid binding protein (h-FABP). First, BiVO4/AgInS2 (BVAIS) composites with excellent photoelectric activity were synthesized as sensing matrices. The BVAIS heterojunction with a well-matched internal energy level structure provided a stable photocurrent. Second, an innovative signal amplification strategy based on octylamine-modified poly(acrylic acid) (OPA)-capped CsPbBr3 (OPCB) nanocrystals (NCs) with excellent catalytic activity and fluorescence property was proposed. On the OPCB nanozyme possessing ascorbate oxidase-like catalytic activity could catalyze the oxidation of ascorbic acid, which achieved quenching of the photocurrent signals by competitively consuming the electron donor. On the other hand, the OPCB NCs that overcame the water stability defect processed good luminescence performance and were able to produce obvious FL signals. Mutually verified dual-response signals effectively enhance the precision of test outcomes and avoid false-positive or false-negative results. Finally, the constructed microfluidic sensing platform realized sensitive detection of h-FABP in the linear range of 0.0001-150 ng/mL (PEC mode) and 0.001-150 ng/mL (FL mode), with detection limits of 36 fg/mL and 0.32 pg/mL, respectively. The present work provided a new perspective for designing an efficient dual-mode sensing strategy to achieve sensitive detection of disease markers.

Antimony Component Schottky Nanoheterojunctions as Ultrasound-Heightened Pyroptosis Initiators for Sonocatalytic Immunotherapy

Pyroptosis, an inflammatory modality of programmed cell death associated with the immune response, can be initiated by bioactive ions and reactive oxygen species (ROS). However, bioactive ion-induced pyroptosis lacks specificity, and further exploration of other ions that can induce pyroptosis in cancer cells is needed. Sonocatalytic therapy (SCT) holds promise due to its exceptional penetration depth; however, the rapid recombination of electron-hole (e--h+) pairs and the complex tumor microenvironment (TME) impede its broader application. Herein, we discovered that antimony (Sb)-based nanomaterials induced pyroptosis in cancer cells. Therefore, Schottky heterojunctions containing Sb component (Sb2Se3@Pt) were effectively designed and constructed via in situ growth of platinum (Pt) nanoparticles (NPs) on Sb2Se3 semiconductor with narrow band gaps, which were utilized as US-heightened pyroptosis initiators to induce highly effective pyroptosis in cancer cells to boost SCT-immunotherapy. Under US irradiation, excited electrons were transferred from Sb2Se3 nanorods (NRs) to the co-catalyst Pt via Schottky junctions, and band bending effectively prevented electron backflow and achieved efficient ROS generation. Moreover, the pores oxidized and depleted the overexpressed GSH in the TME, potentially amplifying ROS generation. The biological effects of the Sb2Se3@Pt nanoheterojunction itself combined with the sonocatalytic amplification of oxidative stress significantly induced Caspase-1/GSDMD-dependent pyroptosis in cancer cells. Therefore, SCT treatment with Sb2Se3@Pt not only effectively restrained tumor proliferation but also induced potent immune memory responses and suppressed tumor recurrence. Furthermore, the integration of this innovative strategy with immune checkpoint blockade (ICB) treatment elicited a systemic immune response, effectively augmenting therapeutic effects and impeding the growth of abscopal tumors. Overall, this study provides further opportunities to explore pyroptosis-mediated SCT-immunotherapy.

DNA-Free Guanosine-Based Polymer Nanoreactors with Multienzyme Activities for Ferroptosis-Apoptosis Combined Antitumor Therapy

Concurrent induction of ferroptosis and apoptosis by enzyme catalysis represents a promising modality for cancer therapy. Inspired by the structures of DNA and G-quadruplex/hemin DNAzyme, a DNA-free guanosine-based polymer nanoreactor (HPG@hemin-GOx) is prepared as a ferroptosis-apoptosis inducer by a one-step assembly of phenylboronic acid-modified hyaluronic acid (HA-PBA), guanosine (G), hemin, and glucose oxidase (GOx). HPG@hemin-GOx shows GOx, peroxidase (POD)-like, catalase (CAT)-like, and glutathione peroxidase (GPX)-like activities. The GOx activity of the nanoreactor can increase intracellular hydrogen peroxide (H2O2) levels by oxidizing glucose in the presence of oxygen. The POD-like activity of HPG@hemin-GOx can then induce the generation of hydroxyl radicals utilizing generated H2O2. Meanwhile, the production of oxygen by the CAT-like activity can facilitate the oxygen-consuming glucose oxidation process of GOx, thus promoting the generation of intracellular reactive oxygen species (ROS). Moreover, the GPX-like activity of HPG@hemin-GOx can deplete intracellular glutathione and thus downregulate GPX4 expression. Consequently, HPG@hemin-GOx induces apoptosis and ferroptosis by ROS-mediated damages of nuclear DNA and mitochondria, and GPX4 depletion-induced lipid peroxidation accumulation, resulting in a strong anticancer effect as demonstrated both in vitro and in vivo. This work provides a method for the construction of polymeric nanoreactors with multienzyme activities for ferroptosis-apoptosis synergistic anticancer therapy.

Pyroptosis-Inducing Biomaterials Pave the Way for Transformative Antitumor Immunotherapy

Pyroptosis can effectively overcome immunosuppression and reactivate antitumor immunity. However, pyroptosis initiation is challenging. First, the underlying biological mechanisms of pyroptosis are complex, and a variety of gasdermin family proteins can be targeted to induce pyroptosis. Second, other intracellular death pathways may also interfere with pyroptosis. The rationally designed gasdermin protein-targeting biomaterials are capable of inducing pyroptosis and have the capacity to stimulate antitumor immune function in a safe and effective manner. This review provides a comprehensive overview of the design, function, and antitumor efficacy of pyroptosis-inducing materials and the associated challenges, with a particular focus on the design options for pyroptosis-inducing biomaterials based on the activation of different gasdermin proteins. This review offers a valuable foundation for the further development of pyroptosis-inducing biomaterials for clinical applications.

Bacteria-Mediated Tumor-Targeting Delivery of Multienzyme-Mimicking Covalent Organic Frameworks Promoting Pyroptosis for Combinatorial Sono-Catalytic Immunotherapy

Pyroptosis, an inflammatory cell death, has attracted great attention for potentiating a strong immune response against tumor cells. However, developing powerful pyroptosis inducers and then activating specific pyroptosis still remains challenging. Herein, a PEG-CuP-COF@∆St nanosystem is rationally designed, consisting of PEG-CuP-COF nanozyme pyroptosis inducers and tumor-targeting bacteria of the Salmonella Typhimurium strain VNP20009 (ΔSt), with an affinity for the tumor hypoxic microenvironment. The PEG-CuP-COF nanozymes possessed excellent sonodynamic performance and multienzyme-mimicking activities to generate reactive oxygen species (ROS) and then induce potent pyroptosis. The superoxide dismutase- and peroxidase-mimicking activities of PEG-CuP-COF catalytically produced hydrogen peroxide (H2O2) and hydroxyl radicals (•OH) which have important value in triggering acute inflammatory responses and pyroptosis. Moreover, PEG-CuP-COF showed outstanding glutathione peroxidase-mimicking activities, impairing the antioxidant defense in tumor cells and enhancing sonodynamic efficiency by making them more vulnerable to ROS-induced damage. During in vivo studies, PEG-CuP-COF@∆St nanosystem with its self-driven property exhibited impressive tumor-targeting capability and activated Caspase-3/gasdermin E-dependent pyroptosis to inhibit tumor growth. More importantly, it induced a powerful immune memory effect to prevent bone metastasis. In summary, this study introduces an innovative approach for combinatorial sono-catalytic immunotherapy using bacteria-mediated tumor-targeting delivery of nanozymes as specific pyroptosis inducers.

Towards precision medicine: design considerations for nanozymes in tumor treatment

Since the discovery of Fe3O4 nanoparticles with enzyme-like activity in 2007, nanozymes have emerged as a promising class of catalysts, offering advantages such as high catalytic efficiency, low cost, mild reaction conditions, and excellent stability. These properties make nanozymes highly suitable for large-scale production. In recent years, the convergence of nanomedicine and nanocatalysis has highlighted the potential of nanozymes in diagnostic and therapeutic applications, particularly in tumor therapy. Despite these advancements, the clinical translation of nanozymes remains hindered by the lack of designs tailored to specific tumor characteristics, limiting their effectiveness in targeted therapy. This review addresses the mechanisms by which nanozymes induce cell death in various tumor types and emphasizes the key design considerations needed to enhance their therapeutic potential. By identifying the challenges and opportunities in the field, this study aims to provide a foundation for future nanozyme development, ultimately contributing to more precise and effective cancer treatments.

Arming oncolytic M1 virus with gasdermin E enhances antitumor efficacy in breast cancer

Pyroptosis, driven by the N-terminal domain of gasdermin proteins (GSDM), promotes antitumor immunity by attracting lymphocytes to the tumor microenvironment (TME). However, current pyroptosis-inducing therapies like drug injections and phototherapy are limited to localized treatments, making them unsuitable for widespread or microscopic metastatic lesions. This study engineered oncolytic M1 viruses (rM1-mGSDME_FL and rM1-mGSDME_NT) to selectively deliver GSDME to tumor cells. These modified viruses enhanced tumor cell death in breast cancer models, suppressed tumor growth, extended survival in mice, and boosted immune cell infiltration, demonstrating significant anticancer potential through pyroptosis induction.

Multifunctional Copper-Phenolic Nanopills Achieve Comprehensive Polyamines Depletion to Provoke Enhanced Pyroptosis and Cuproptosis for Cancer Immunotherapy

The overexpression of polyamines in tumor cells contributes to the establishment of immunosuppressive microenvironment and facilitates tumor growth. Here, it have ingeniously designed multifunctional copper-piceatannol/HA nanopills (Cu-Pic/HA NPs) that effectively cause total intracellular polyamines depletion by inhibiting polyamines synthesis, depleting intracellular polyamines, and impairing polyamines uptake, resulting in enhanced pyroptosis and cuproptosis, thus activating a powerful immune response to achieve anti-tumor therapy. Mitochondrial dysfunction resulting from overall intracellular polyamines depletion not only leads to the surge of copper ions in mitochondria, thereby causing the aggregation of toxic proteins to induce cuproptosis, but also triggers the accumulation of reactive oxygen species (ROS) within mitochondria, which further upregulates the expression of zDHHC5 and zDHHC9 to promote the palmitoylation of gasdermin D (GSDMD) and GSDMD-N, ultimately inducing enhanced pyroptosis. Then the occurrence of enhanced pyroptosis and cuproptosis is conductive to remodel the immunosuppressive tumor microenvironment, thus activating anti-tumor immune responses and ultimately effectively inhibiting tumor growth and metastasis. This therapeutic strategy of enhanced pyroptosis and cuproptosis through comprehensive polyamines depletion provides a novel template for cancer immunotherapy.

Immunomodulatory metal-based biomaterials for cancer immunotherapy

Cancer immunotherapy, as an emerging cancer treatment approach, harnesses the patient's own immune system to effectively prevent tumor recurrence or metastasis. However, its clinical application has been significantly hindered by relatively low immune response rates. In recent years, metal-based biomaterials have been extensively studied as effective immunomodulators and potential tools for enhancing anti-tumor immune responses, enabling the reversal of immune suppression without inducing toxic side effects. This review introduces the classification of bioactive metal elements and summarizes their immune regulatory mechanisms. In addition, we discuss the immunomodulatory roles of biomaterials constructed from various metals, including aluminum, manganese, gold, calcium, zinc, iron, magnesium, and copper. More importantly, a systematic overview of their applications in enhancing immunotherapy is provided. Finally, the prospects and challenges of metal-based biomaterials with immunomodulatory functions in cancer immunotherapy are outlined.

The advance of ultrasound-enabled diagnostics and therapeutics

Point-of-care ultrasound demonstrates significant potential in biomedical research due to its noninvasive, real-time visualization, cost-effectiveness, and other biological benefits. Ultrasound irradiation can precisely control the mechanical and physicochemical effects on pathogenic lesions, enabling real-time visualization, tunable tissue penetration depth, and therapeutic applications. This review summarizes recent advancements in ultrasound-enabled diagnostics and therapeutics, focusing on mechanochemical effects that can be directly integrated into biomedical applications. Additionally, the structure-functionality relationships of sonotheranostic nanoplatforms are systematically discussed, providing insights into the underlying biological effects. Finally, the limitations of current ultrasonic medicine are discussed, along with potential expansions to facilitate patient-centered translations.

A Bimetallic Nanomodulator to Reverse Immunosuppression via Sonodynamic-Ferroptosis and Lactate Metabolism Modulation

Triple-negative breast cancer (TNBC) responds poorly to immunotherapy due to insufficient immunogenicity and highly immunosuppressive tumor microenvironment (TME). Herein, an intelligent calcium/cobalt-based nanomodulator (Ca,Co)CO3-LND-TCPP@F127-TA (abbreviated as CCLT@FT) is developed to act as a sonodynamic-ferroptosis inducer and metabolic immunoadjuvant to enhance anti-tumor immunotherapy. More details, simultaneous reactive oxygen species (ROS) generation and glutathione (GSH) depletion can be achieved due to the existence of Co2+/Co3+ redox couple in CCLT@FT. Meanwhile, mitochondrial Ca2+ overload and tetrakis(4-carboxyphenyl) porphyrin (TCPP)-mediated sonodynamic therapy (SDT) further amplify the oxidative stress and promote ferroptosis in tumor cells. More impressively, CCLT@FT can modulate lactate metabolism by doping with cobalt and loading with lonidamine (LND, an inhibitor of MCT4), thereby reversing the high-lactate immunosuppressive TME. Furthermore, the combination with immune checkpoint blockade (ICB) therapy is found to achieve superior anti-tumor immunity, which in turn promotes ferroptosis of tumor cells by downregulating SLC7A11 protein, ultimately creating a "cycle" therapy. Overall, this work demonstrates a novel strategy for enhancing anti-tumor immunotherapy based on a closed-loop enhancement therapeutic route between CCLT@FT inducing ferroptosis/lactate metabolism modulation and ICB therapy, providing an alternative and important reference for effective immunotherapy of TNBC.

In situ formed reactive oxygen species-responsive dipyridamole prodrug hydrogel: Spatiotemporal drug delivery for chemoimmunotherapy

In the realm of combined cancer immunotherapy, the strategic combination of therapeutics targeting both cancer cells and macrophages holds immense potential. However, the major challenges remain on how to achieve facile spatiotemporal delivery of these therapies, allowing ease of manipulation and ensuring differential drug release for enhanced synergistic therapeutic effects. In the present study, we introduced a tumor microenvironment (TME)-adapted hydrogel with the phenylboronic acid-modified dipyridamole prodrug (DIPP) as a crosslinker. This prodrug hydrogel scaffold, 3BP@DIPPGel, could be formed in situ by a simple mixture of DIPP and poly(vinyl alcohol) (PVA), and loaded with a high ratio of 3-bromopyruvic acid (3BP). The 3BP@DIPPGel enables spatiotemporal localized delivery of dipyridamole (DIP) and 3BP with distinct release kinetics that effectively reshape the immunosuppressive TME. Upon reactive oxygen species (ROS) stimulation, 3BP@DIPPGel preferentially released 3BP, inducing tumor-specific pyroptosis via the ROS/BAX/caspase-3/GSDME signaling pathway and decreasing the secretion of chemokines such as CCL8 to counteract macrophage recruitment. Subsequently, the crosslinked DIP is released, triggering the tumor-associated macrophages (TAMs) polarization towards the immunostimulatory M1 phenotype via the CCR2/JAK2/STAT3 cascade signaling pathway. This dual action from 3BP@DIPPGel leads to the restoration of tumor cell immunogenicity with high efficacy and activation of immune cells. Furthermore, the 3BP@DIPPGel-based chemoimmunotherapy upregulates the expression of sialic-acid-binding Ig-like lectin 10 and hence sensitizing tumors to anti-CD24 therapy in the tumor-bearing mice. Therefore, this strategy can have significant potential in the prevention of tumor metastases and recurrence. To the best of our understanding, this study represents a pioneering showcase of tumor pyroptosis, induced by glycolytic inhibitors, which can be effectively coordinated with DIP-mediated TAM polarization for immune activation, offering a new paradigm for differentially sustained drug delivery to foster cancer immunotherapy.

Application and Challenge of Metalloporphyrin Sensitizers in Noninvasive Dynamic Tumor Therapy

Dynamic tumor therapies (mainly including photodynamic therapy (PDT) and sonodynamic therapy (SDT)) offer new approaches to cancer treatment. They are often characterized by their noninvasive nature, high selectivity, and low toxicity. Sensitizers are crucial for dynamic therapy. Developing efficient sensitizers with good biocompatibility and controllability is an important aim in dynamic therapy. Porphyrins and metalloporphyrins attract great attention due to their excellent photophysical properties and low cytotoxicity under non-light. Compared to porphyrins, metalloporphyrins show greater potential for dynamic therapy due to their enhanced photochemical and photophysical properties after metal ions coordinate with porphyrin rings. This paper reviews some metalloporphyrin-based sensitizers used in photo/sonodynamic therapy and combined therapy. In addition, the probable challenges and bottlenecks in clinical translation are also discussed.

Intermetallics triggering pyroptosis and disulfidptosis in cancer cells promote anti-tumor immunity

Pyroptosis, an immunogenic programmed cell death, could efficiently activate tumor immunogenicity and reprogram immunosuppressive microenvironment for boosting cancer immunotherapy. However, the overexpression of SLC7A11 promotes glutathione biosynthesis for maintaining redox balance and countering pyroptosis. Herein, we develop intermetallics modified with glucose oxidase (GOx) and soybean phospholipid (SP) as pyroptosis promoters (Pd2Sn@GOx-SP), that not only induce pyroptosis by cascade biocatalysis for remodeling tumor microenvironment and facilitating tumor cell immunogenicity, but also trigger disulfidptosis mediated by cystine accumulation to further promote tumor pyroptosis in female mice. Experiments and density functional theory calculations show that Pd2Sn nanorods with an intermediate size exhibit stronger photothermal and enzyme catalytic activity compared with the other three morphologies investigated. The peroxidase-mimic and oxidase-mimic activities of Pd2Sn cause potent reactive oxygen species (ROS) storms for triggering pyroptosis, which could be self-reinforced by photothermal effect, hydrogen peroxide supply accompanied by glycometabolism, and oxygen production from catalase-mimic activity of Pd2Sn. Moreover, the increase of NADP+/NADPH ratio induced by glucose starvation could pose excessive cystine accumulation and inhibit glutathione synthesis, which could cause disulfidptosis and further augment ROS-mediated pyroptosis, respectively. This two-pronged treatment strategy could represent an alternative therapeutic approach to expand anti-tumor immunotherapy.

Pyroptosis: Induction and inhibition strategies for immunotherapy of diseases

Cell death is a central process for organismal health. Pyroptosis, namely pyroptotic cell death, is recognized as a critical type that disrupts membrane and triggers pro-inflammatory cytokine secretion via gasdermins, providing a robust form of cytolysis. Meanwhile, along with the thorough research, a great deal of evidence has demonstrated the dual effects of pyroptosis in host defense and inflammatory diseases. More importantly, the recent identification of abundant gasdermin-like proteins in bacteria and fungi suggests an ancient origin of pyroptosis-based regulated cell death in the life evolution. In this review, we bring a general overview of pyroptosis pathways focusing on gasdermin structural biology, regulatory mechanisms, and recent progress in induction and inhibition strategies for disease treatment. We look forward to providing an insightful perspective for readers to comprehend the frame and challenges of the pyroptosis field, and to accelerating its clinical application.

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 Alzheimer's disease diagnostics and therapy

Alzheimer's disease (AD) is a progressive neurodegenerative condition that has become an important public health problem of global concern, and the early diagnosis and etiological treatment of AD are currently the focus of research. In the course of clinical treatment, approved clinical drugs mainly serve to slow down the disease process by relieving patients' clinical symptoms. However, these drugs do not target the cause of the disease, and the lack of specificity of these drugs has led to undesirable side effects in treatment. Meanwhile, AD is mainly diagnosed by clinical symptoms and imaging, which does not have the advantage of early diagnosis. Nanozymes have been extensively investigated for the diagnosis and treatment of AD with high stability and specificity. Therefore, this review summarizes the recent advances in various nanozymes for AD diagnosis and therapy, including with peroxidase-like-activity gold nanozymes, iron nanozymes, superoxide dismutase-like- and catalase-like-activity selenium dioxide nanozymes, platinum nanozymes, and peroxidase-like palladium nanozymes, among others. A comprehensive analysis was conducted on the diagnostic and therapeutic characteristics of nanozyme therapy for AD, as well as the prospects and challenges of its clinical application. Our goal is to advance this emerging topic by building on our own work and the new insights we have learned from others. This review will assist researchers to quickly understand relevant nanozymes' therapeutic and diagnostic information and further advance the field of nanozymes in AD.

Photocatalytic Carbon Dots-Triggered Pyroptosis for Whole Cancer Cell Vaccines

Manufacturing whole cancer cell vaccines (WCCV) with both biosafety and efficacy is crucial for tumor immunotherapy. Pyroptotic cancer cells, due to their highly immunogenic properties, present a promising avenue for the development of WCCV. However, the successful development of WCCV based on pyroptotic cancer cells is yet to be accomplished. Here, a facile strategy that utilized photocatalytic carbon dots (CDs) to induce pyroptosis of cancer cells for fabricating WCCV is reported. Photocatalytic CDs are capable of generating substantial amounts of hydroxyl radicals and can effectively decrease cytoplasmic pH values under white light irradiation. This process efficiently triggers cancer cell pyroptosis through the reactive oxygen species (ROS)-mitochondria-caspase 3-gasdermin E pathway and the proton motive force-driven mitochondrial ATP synthesis pathway. Moreover, in vitro, these photocatalytic CDs-induced pyroptotic cancer cells (PCIP) can hyperactivate macrophage (M0-M1) with upregulation of major histocompatibility complex class II expression. In vivo, PCIP induced specific immune-preventive effects in melanoma and breast cancer mouse models through anticancer immune memory, demonstrating effective WCCV. This work provides novel insights for inducing cancer cell pyroptosis and bridges the gap in the fabrication of WCCV based on pyroptotic cancer cells.

Nanoparticle-mediated cell pyroptosis: a new therapeutic strategy for inflammatory diseases and cancer

Pyroptosis, a lytic form of cell death mediated by the gasdermin family, is characterized by cell swelling and membrane rupture. Inducing pyroptosis in cancer cells can enhance antitumor immune responses and is a promising strategy for cancer therapy. However, excessive pyroptosis may trigger the development of inflammatory diseases due to immoderate and continuous inflammatory reactions. Nanomaterials and nanobiotechnology, renowned for their unique advantages and diverse structures, have garnered increasing attention owing to their potential to induce pyroptosis in diseases such as cancer. A nano-delivery system for drug-induced pyroptosis in cancer cells can overcome the limitations of small molecules. Furthermore, nanomedicines can directly induce and manipulate pyroptosis. This review summarizes and discusses the latest advancements in nanoparticle-based treatments with pyroptosis among inflammatory diseases and cancer, focusing on their functions and mechanisms and providing valuable insights into selecting nanodrugs for pyroptosis. However, the clinical application of these strategies still faces challenges owing to a limited understanding of nanobiological interactions. Finally, future perspectives on the emerging field of pyroptotic nanomaterials are presented.

Research progress on the effect of pyroptosis on the occurrence, development, invasion and metastasis of colorectal cancer

Pyroptosis is a type of programmed cell death mediated by gasdermines (GSDMs). The N-terminal domain of GSDMs forms pores in the plasma membrane, causing cell membrane rupture and the release of cell contents, leading to an inflammatory response and mediating pyrodeath. Pyroptosis plays an important role in inflammatory diseases and malignant tumors. With the further study of pyroptosis, an increasing number of studies have shown that the pyroptosis pathway can regulate the tumor microenvironment and antitumor immunity of colorectal cancer and is closely related to the occurrence, development, treatment and prognosis of colorectal cancer. This review aimed to explore the molecular mechanism of pyroptosis and the role of pyroptosis in the occurrence, development, treatment and prognosis of colorectal cancer (CRC) and to provide ideas for the clinical diagnosis and treatment of CRC.

Oxygen-carrying semiconducting polymer nanoprodrugs induce sono-pyroptosis for deep-tissue tumor treatment

Sonodynamic therapy (SDT) has been explored for cancer therapy, especially for deep tumors due to its low tissue penetration restriction. The therapeutic efficacy of SDT is limited due to the complicated tumor microenvironment. This study reports the construction of oxygen-carrying semiconducting polymer nanoprodrugs (OSPNpro) for deep tumor treatment via combining amplified SDT with pyroptosis. An oxygen carrier perfluorohexane, sonodynamic semiconducting polymer as the sonosensitizer, and reactive oxygen species (ROS)-responsive prodrug are co-loaded into a nanoparticle system, leading to the formation of these polymer nanoprodrugs. Such OSPNpro show an effective accumulation in tumor tissues after systemic administration, in which they deliver oxygen to relieve tumor hypoxia microenvironment and thus mediate amplified SDT via producing ROS under ultrasound (US) irradiation, even when the tumors are covered with a 2-cm chicken breast tissue. In addition, the ROS-responsive prodrugs are activated by the generated ROS to trigger pyroptosis of tumor cells. Such a sono-pyroptosis induces a strong antitumor immunity with obviously higher level infiltrations of effector immune cells into tumors. Therefore, OSPNpro-based combinational therapy can greatly inhibit the growth of 2-cm chicken breast tissue-covered deep tumors and suppress tumor metastasis. This study offers a prodrug nanoplatform for treatment of deep tumor via sono-pyroptosis strategy.

Nanozyme-Catalyzed Colorimetric Detection of the Total Antioxidant Capacity in Body Fluids by Paper-Based Microfluidic Chips

Total antioxidants play a crucial role in human health, and detection of the total antioxidant capacity (TAC) has broad application prospects in fields such as food safety, environmental assessment, and disease diagnosis. However, a long detection time, cumbersome steps, high cost, reliance on professional equipment, and nonportability still remain significant challenges. In this work, an efficient strategy of point-of-care testing (POCT) of the TAC in body fluids by nanozyme-catalyzed colorimetric paper-based microfluidic sensors is proposed. The paper-based microfluidic sensors coupled with a smartphone can reduce testing costs and provide portability. The nanozyme prepared by the solvothermal method presents Michaelis constants of 0.11 and 0.129 mM for H2O2 and TMB, respectively. A method for immobilizing nanozymes and chromogenic agents on a paper-based microfluidic chip is established. Based on smartphone photography and image grayscale extraction, the TAC can be qualitatively detected with a detection limit and linear range of 33.4 and 50-700 μM, respectively. Furthermore, the proposed sensor can realize the one-step quantitative analysis of the TAC in body fluids (blood, saliva, and sweat) within 15 min. The proposed nanozyme-catalyzed colorimetric paper-based microfluidic sensors presented in this study exhibit promising application prospects in the fields of biochemical analysis and POCT.

A nanozyme-functionalized bilayer hydrogel scaffold for modulating the inflammatory microenvironment to promote osteochondral regeneration

BACKGROUND

The incidence of osteochondral defects caused by trauma, arthritis or tumours is increasing annually, but progress has not been made in terms of treatment methods. Due to the heterogeneous structure and biological characteristics of cartilage and subchondral bone, the integration of osteochondral repair is still a challenge.

RESULTS

In the present study, a novel bilayer hydrogel scaffold was designed based on anatomical characteristics to imitate superficial cartilage and subchondral bone. The scaffold showed favourable biocompatibility, and the addition of an antioxidant nanozyme (LiMn2O4) promoted reactive oxygen species (ROS) scavenging by upregulating antioxidant proteins. The cartilage layer effectively protects against chondrocyte degradation in the inflammatory microenvironment. Subchondral bionic hydrogel scaffolds promote osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs) by regulating the AMPK pathway in vitro. Finally, an in vivo rat preclinical osteochondral defect model confirmed that the bilayer hydrogel scaffold efficiently promoted cartilage and subchondral bone regeneration.

CONCLUSIONS

In general, our biomimetic hydrogel scaffold with the ability to regulate the inflammatory microenvironment can effectively repair osteochondral defects. This strategy provides a promising method for regenerating tissues with heterogeneous structures and biological characteristics.

Fluorinated Titanium Oxide (TiO2-xFx) Nanospindles as Ultrasound-Triggered Pyroptosis Inducers to Boost Sonodynamic Immunotherapy

Pyroptosis is an inflammatory form of programmed cell death associated with the immune system that can be induced by reactive oxygen species (ROS). As a therapeutic strategy with better penetration depth, sonodynamic therapy (SDT) is expected to induce pyroptosis of cancer cells and boost the immune response. However, it is still a limited problem to precisely adjust the structure of sonosensitizers to exhibit satisfactory sono-catalytic properties. Herein, fluorinated titanium oxide (TiO2-xFx) sonosensitizers were developed to induce pyroptosis under ultrasound (US) to boost antitumor immune responses, enabling highly effective SDT. On the one hand, the introduction of F atoms significantly reduced the adsorption energy of TiO2-xFx for oxygen and water, which is conducive to the occurrence of sono-catalytic reactions. On the other hand, the process of F replacing O increased the oxygen vacancies of the sonosensitizer and shortened the band gap, which enabled powerful ROS generation ability under US stimulation. In this case, large amounts of ROS could effectively kill cancer cells by inducing mitochondrial damage and disrupting oxidative homeostasis, leading to significant cell pyroptosis. Moreover, SDT treatment with TiO2-xFx not only suppressed tumor proliferation but also elicited robust immune memory effects and hindered tumor recurrence. This work highlighted the importance of precisely regulating the structure of sonosensitizers to achieve efficient ROS generation for inducing pyroptosis, which sets the stage for the further development of SDT-immunotherapy.

Dual Starvations Induce Pyroptosis for Orthotopic Pancreatic Cancer Therapy through Simultaneous Deprivation of Glucose and Glutamine

Pancreatic cancer is a highly fatal disease, and existing treatment methods are ineffective, so it is urgent to develop new effective treatment strategies. The high dependence of pancreatic cancer cells on glucose and glutamine suggests that disrupting this dependency could serve as an alternative strategy for pancreatic cancer therapy. We identified the vital genes glucose transporter 1 (GLUT1) and alanine-serine-cysteine transporter 2 (ASCT2) through bioinformatics analysis, which regulate glucose and glutamine metabolism in pancreatic cancer, respectively. Human serum albumin nanoparticles (HSA NPs) for delivery of GLUT1 and ASCT2 inhibitors, BAY-876/V-9302@HSA NPs, were prepared by a self-assembly process. This nanodrug inhibits glucose and glutamine uptake of pancreatic cancer cells through the released BAY-876 and V-9302, leading to nutrition deprivation and oxidative stress. The inhibition of glutamine leads to the inhibition of the synthesis of the glutathione, which further aggravates oxidative stress. Both of them lead to a significant increase in reactive oxygen species, activating caspase 1 and GSDMD and finally inducing pyroptosis. This study provides a new effective strategy for orthotopic pancreatic cancer treatment by dual starvation-induced pyroptosis. The study for screening metabolic targets using bioinformatics analysis followed by constructing nanodrugs loaded with inhibitors will inspire future targeted metabolic therapy for pancreatic cancer.

A Cascade-Amplified Pyroptosis Inducer: Optimizing Oxidative Stress Microenvironment by Self-Supplying Reactive Nitrogen Species Enables Potent Cancer Immunotherapy

Selective generation of sufficient pyroptosis inducers at the tumor site without external stimulation holds immense significance for a longer duration of immunotherapy. Here, we report a cascade-amplified pyroptosis inducer CSCCPT/SNAP that utilizes reactive nitrogen species (RNS), self-supplied from the diffusion-controlled reaction between reactive oxygen species (ROS) and nitric oxide (NO) to potentiate pyroptosis and immunotherapy, while both endogenous mitochondrial ROS stimulated by released camptothecin and released NO initiate pyroptosis. Mechanistically, cascade amplification of the antitumor immune response is prompted by the cooperation of ROS and NO and enhanced by RNS with a long lifetime, which could be used as a pyroptosis trigger to effectively compensate for the inherent drawbacks of ROS, resulting in long-lasting pyroptosis for favoring immunotherapy. Tumor growth is efficiently inhibited in mouse melanoma tumors through the facilitation of reactive oxygen/nitrogen species (RONS)-NO synergy. In summary, our therapeutic approach utilizes supramolecular engineering and nanotechnology to integrate ROS producers and NO donors of tumor-specific stimulus responses into a system that guarantees synchronous generation of these two reactive species to elicit pyroptosis-evoked immune response, while using self-supplied RNS as a pyroptosis amplifier. RONS-NO synergy achieves enhanced and sustained pyroptosis and antitumor immune responses for robust cancer immunotherapy.

Nanomaterials Enhance Pyroptosis-Based Tumor Immunotherapy

Pyroptosis, a pro-inflammatory and lytic programmed cell death pathway, possesses great potential for antitumor immunotherapy. By releasing cellular contents and a large number of pro-inflammatory factors, tumor cell pyroptosis can promote dendritic cell maturation, increase the intratumoral infiltration of cytotoxic T cells and natural killer cells, and reduce the number of immunosuppressive cells within the tumor. However, the efficient induction of pyroptosis and prevention of damage to normal tissues or cells is an urgent concern to be addressed. Recently, a wide variety of nanoplatforms have been designed to precisely trigger pyroptosis and activate the antitumor immune responses. This review provides an update on the progress in nanotechnology for enhancing pyroptosis-based tumor immunotherapy. Nanomaterials have shown great advantages in triggering pyroptosis by delivering pyroptosis initiators to tumors, increasing oxidative stress in tumor cells, and inducing intracellular osmotic pressure changes or ion imbalances. In addition, the challenges and future perspectives in this field are proposed to advance the clinical translation of pyroptosis-inducing nanomedicines.

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

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

Ultrasound-augmented enzyodynamic-Ca2+ overload synergetic tumor nanotherapy

The excessive intracellular Ca2+ can induce oxidative stress, mitochondrial damage and cell apoptosis, which has been extensively explored for tumor therapy. However, the low Ca2+ accumulation originated from Ca2+-based nanosystems substantially weakens the therapeutic effect. Herein, a functional plant polyphenol-appended enzyodynamic nanozyme system CaFe2O4@BSA-curcumin (abbreviation as CFO-CUR) has been rationally designed and engineered to achieve magnified Ca2+ accumulation process, deleterious reactive oxygen species (ROS) production, as well as mitochondrial dysfunction through enzyodynamic-Ca2+ overload synergistic effect. The exogenous Ca2+ released by CaFe2O4 nanozymes under the weakly acidic tumor microenvironment and Ca2+ efflux inhibition by curcumin boost mitochondria-dominant antineoplastic efficiency. The presence of Fe components with multivalent characteristic depletes endogenous glutathione and outputs the incremental ROS due to the oxidase-, peroxidase-, glutathione peroxidase-mimicking activities. The ROS burst-triggered regulation of Ca2+ channels and pumps strengthens the intracellular Ca2+ accumulation. Especially, the exogenous ultrasound stimulation further amplifies mitochondrial damage. Both in vitro and in vivo experimental results affirm the ultrasound-augmented enzyodynamic-Ca2+ overload synergetic tumor inhibition outcomes. This study highlights the role of ultrasound coupled with functional nanozyme in the homeostasis imbalance and function disorder of mitochondria for highly efficient tumor treatment.

Programmed Targeting Pyruvate Metabolism Therapy Amplified Single-Atom Nanozyme-Activated Pyroptosis for Immunotherapy

Increasing cellular immunogenicity and reshaping the immune tumor microenvironment (TME) are crucial for antitumor immunotherapy. Herein, this work develops a novel single-atom nanozyme pyroptosis initiator: UK5099 and pyruvate oxidase (POx)-co-loaded Cu-NS single-atom nanozyme (Cu-NS@UK@POx), that not only trigger pyroptosis through cascade biocatalysis to boost the immunogenicity of tumor cells, but also remodel the immunosuppressive TME by targeting pyruvate metabolism. By replacing N with weakly electronegative S, the original spatial symmetry of the Cu-N4 electron distribution is changed and the enzyme-catalyzed process is effectively regulated. Compared to spatially symmetric Cu-N4 single-atom nanozymes (Cu-N4 SA), the S-doped spatially asymmetric single-atom nanozymes (Cu-NS SA) exhibit stronger oxidase activities, including peroxidase (POD), nicotinamide adenine dinucleotide (NADH) oxidase (NOx), L-cysteine oxidase (LCO), and glutathione oxidase (GSHOx), which can cause enough reactive oxygen species (ROS) storms to trigger pyroptosis. Moreover, the synergistic effect of Cu-NS SA, UK5099, and POx can target pyruvate metabolism, which not only improves the immune TME but also increases the degree of pyroptosis. This study provides a two-pronged treatment strategy that can significantly activate antitumor immunotherapy effects via ROS storms, NADH/glutathione/L-cysteine consumption, pyruvate oxidation, and lactic acid (LA)/ATP depletion, triggering pyroptosis and regulating metabolism. This work provides a broad vision for expanding antitumor immunotherapy.

Antioxidant Enzymes and Their Potential Use in Breast Cancer Treatment

According to the World Health Organization (WHO), breast cancer (BC) is the deadliest and the most common type of cancer worldwide in women. Several factors associated with BC exert their effects by modulating the state of stress. They can induce genetic mutations or alterations in cell growth, encouraging neoplastic development and the production of reactive oxygen species (ROS). ROS are able to activate many signal transduction pathways, producing an inflammatory environment that leads to the suppression of programmed cell death and the promotion of tumor proliferation, angiogenesis, and metastasis; these effects promote the development and progression of malignant neoplasms. However, cells have both non-enzymatic and enzymatic antioxidant systems that protect them by neutralizing the harmful effects of ROS. In this sense, antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), thioredoxin reductase (TrxR), and peroxiredoxin (Prx) protect the body from diseases caused by oxidative damage. In this review, we will discuss mechanisms through which some enzymatic antioxidants inhibit or promote carcinogenesis, as well as the new therapeutic proposals developed to complement traditional treatments.

Gas-Amplified Metalloimmunotherapy with Dual Activation of Pyroptosis and the STING Pathway for Remodeling the Immunosuppressive Cervical Cancer Microenvironment

The immunosuppressive microenvironment of cervical cancer significantly hampers the effectiveness of immunotherapy. Herein, PEGylated manganese-doped calcium sulfide nanoparticles (MCSP) were developed to effectively enhance the antitumor immune response of the cervical cancer through gas-amplified metalloimmunotherapy with dual activation of pyroptosis and STING pathway. The bioactive MCSP exhibited the ability to rapidly release Ca2+, Mn2+, and H2S in response to the tumor microenvironment. H2S disrupted the calcium buffer system of cancer cells by interfering with the oxidative phosphorylation pathway, leading to calcium overload-triggered pyroptosis. On the other hand, H2S-mediated mitochondrial dysfunction further promoted the release of mitochondrial DNA (mtDNA), enhancing the activation effect of Mn2+ on the cGAS-STING signaling axis and thereby activating immunosuppressed dendritic cells. The released H2S acted as an important synergist between Mn2+ and Ca2+ by modulating dual signaling mechanisms to bridge innate and adaptive immune responses. The combination of MCSP NPs and PD-1 immunotherapy achieved synergistic antitumor effects and effectively inhibited tumor growth. This study reveals the potential collaboration between H2S gas therapy and metalloimmunotherapy and provides an idea for the design of nanoimmunomodulators for rational regulation of the immunosuppressive tumor microenvironment.

Transition-Metal-Based Nanozymes: Synthesis, Mechanisms of Therapeutic Action, and Applications in Cancer Treatment

Cancer, as one of the leading causes of death worldwide, drives the advancement of cutting-edge technologies for cancer treatment. Transition-metal-based nanozymes emerge as promising therapeutic nanodrugs that provide a reference for cancer therapy. In this review, we present recent breakthrough nanozymes for cancer treatment. First, we comprehensively outline the preparation strategies involved in creating transition-metal-based nanozymes, including hydrothermal method, solvothermal method, chemical reduction method, biomimetic mineralization method, and sol-gel method. Subsequently, we elucidate the catalytic mechanisms (catalase (CAT)-like activities), peroxidase (POD)-like activities), oxidase (OXD)-like activities) and superoxide dismutase (SOD)-like activities) of transition-metal-based nanozymes along with their activity regulation strategies such as morphology control, size manipulation, modulation, composition adjustment and surface modification under environmental stimulation. Furthermore, we elaborate on the diverse applications of transition-metal-based nanozymes in anticancer therapies encompassing radiotherapy (RT), chemodynamic therapy (CDT), photodynamic therapy (PDT), photothermal therapy (PTT), sonodynamic therapy (SDT), immunotherapy, and synergistic therapy. Finally, the challenges faced by transition-metal-based nanozymes are discussed alongside future research directions. The purpose of this review is to offer scientific guidance that will enhance the clinical applications of nanozymes based on transition metals.