Tumor-selective catalytic nanomedicine by nanocatalyst delivery

A robust metal-organic framework-based nanozyme with multienzyme-like properties for synergistic tumor therapy via efficient and sustainable Nitric oxide generation

Nitric oxide (NO)-based gas therapy represents an emerging strategy for cancer treatment, which, however, still suffers from insufficient intracellular NO production for compromised therapeutic efficiency due to limited endogenous hydrogen peroxide (H2O2) concentration and relatively slow NO generation rate. The use of metal-organic framework (MOF) with highly ordered porous structure and functional adjustability to design a multienzyme-like nanozyme provides a simple yet reliable approach for efficient and sustainable NO generation. Herein, a MOF-based nanozyme with multienzyme-like properties is constructed by depositing ultrasmall gold nanoparticles (Au NPs) and subsequently loading a NO donor, l-arginine (l-Arg) on an iron porphyrin integrated MOF, which enables efficient and sustainable NO generation for synergistic tumor therapy. Two notable merits of this design are (i) incorporation of Au NPs with glucose oxidase (GOx)-like property for effectively depleting intratumoral glucose, and simultaneously generating large amounts of H2O2, which is further utilized to initiate the effective production of NO and reactive oxygen species (ROS) by taking advantage of the peroxidase (POD)/NO synthase (NOS)-like activities of iron porphyrin, and (ii) deposition of ultrasmall Au NPs on the MOF for remarkably improving the structural stability of nanocomposites to circumvent the low catalytic efficiency associated with serious aggregation. This nanozyme achieves a high tumor inhibitory rate of 87.3 % with negligible systemic effects in a 4T1-tumor-bearing mice model by integrating NO, and ROS generation and starvation therapy with synergistic efficiency. Such an ingenious integration of multienzyme-like nanozyme and MOF paves a new way for NO-based gas therapy.

Redox-driven hybrid nanoenzyme dynamically activating ferroptosis and disulfidptosis for hepatocellular carcinoma theranostics

Hepatocellular carcinoma (HCC) presents formidable therapeutic challenges due to its pronounced metabolic heterogeneity, particularly arising from spatially uneven glucose availability within the tumor microenvironment (TME). To address this, we developed a glutathione (GSH)-responsive, biomimetic hybrid nanoenzyme system (M@GOx/Fe-HMON) composed of hollow mesoporous organosilica nanoparticles co-loaded with glucose oxidase (GOx) and Fe2+/Fe3+ redox pairs, and cloaked in homologous tumor cell membranes for enhanced targeting. In glucose-rich regions, the nanoenzyme orchestrates a GOx-peroxidase (POD) cascade that produces reactive oxygen species (ROS) via the Fenton reaction, leading to ferroptosis through intensified oxidative stress and GSH depletion. Conversely, under glucose-deficient conditions, the nanoenzyme promotes disulfidptosis by aggravating glucose deprivation, depleting nicotinamide adenine dinucleotide phosphate (NADPH), and impairing cystine metabolism, ultimately resulting in actin cytoskeletal collapse. This dual-action platform dynamically adapts to the tumor's metabolic landscape, selectively inducing ferroptosis or disulfidptosis according to glucose levels, disrupting redox homeostasis and amplifying antitumor efficacy. Notably, this study is the first to integrate ferroptosis and disulfidptosis activation into a single, metabolism-sensitive nanoenzyme system, providing a novel paradigm for exploiting tumor metabolic heterogeneity. Furthermore, the combination of endogenous metabolic regulation with magnetic resonance imaging (MRI)-guided diagnosis introduces an innovative and noninvasive strategy for precision cancer theranostics.

Cascade Catalytic Nanozymes Induce Tumor Ca2+ Overload and Ferroptosis by Reducing Energy Supply and Amplifying Oxidative Stress

Nanozyme-mediated nanocatalytic therapy, by mimicking the activity of redox enzymes, generates highly toxic reactive oxygen species (ROS) within tumor cells, thereby opening a pathway for tumor-specific therapy. However, achieving satisfactory therapeutic outcomes with nanozymes remains challenging due to the inherent complexity of the tumor microenvironment (TME). In this context, we designed a two-dimensional layered double hydroxide (LDH) nanozyme loaded with Au nanoparticles, while incorporating bioactive Ca2+ and Fe3+ ions (denoted as MgCaFe-LDH@Au NSs) to target the specific needs of the TME. The designed nanozyme mimics glucose oxidase to facilitate self-sufficient H2O2 production and simulates catalase and glutathione peroxidase to overcome the adverse conditions of hypoxia and elevated GSH levels in the TME. Subsequently, the nanozyme emulates peroxidase activity to generate ROS, amplifying oxidative stress and causing redox imbalance, ultimately inducing ferroptosis in tumor cells. Moreover, MgCaFe-LDH@Au NSs also function as an inorganic semiconductor sonosensitizer with a tunable band structure, enabling the generation of abundant ROS under ultrasound irradiation to achieve synergistic sonodynamic and catalytic therapy. Notably, the high levels of ROS induced by the nanozyme, along with the interference in tumor ATP synthesis, enhanced the calcium overload in the TME caused by the release of Ca2+ from the nanozyme. In summary, this two-dimensional nanomaterial, through nanozyme and ultrasound-catalyzed synergistic disruption of tumor energy supply and redox balance, exhibited significant therapeutic efficacy in a 4T1 tumor-bearing mouse model. This study also highlights the immense potential of multimetal LDHs as inducers of calcium overload and ferroptosis in tumor therapy.

New insights of transition metal sulfide nanoparticles for tumor precision diagnosis and treatment

Transition metal sulfide nanoparticles (TMSs), with their unique photothermal conversion effects, Fenton-like catalytic activity, engineerable structure, and good biocompatibility, are becoming a cutting-edge research focus in the field of tumor precision diagnosis and therapy. This review systematically explores the groundbreaking potential of TMSs (MxSy, M = Fe, Mn, Cu, Mo, Co, Ni, W, etc.) in tumor precision diagnosis, specific non-invasive treatment, and multimodal synergistic therapy from the perspective of "structural design-function regulation-integrated diagnosis and therapy." The exceptional magnetic properties, photothermal effects, and high X-ray absorption capabilities of TMSs have driven extensive research and widespread application in tumor imaging, including magnetic resonance imaging, photoacoustic imaging, and computed tomography. Furthermore, we delve into mechanistically integrated strategies for various clinical applications, such as phototherapy, chemodynamic therapy, sonodynamic therapy, gas therapy, and immunotherapy. These new approaches demonstrate high specificity, efficacy, and low toxicity compared with traditional clinical treatments, highlighting the significant application value of TMSs in revolutionizing cancer therapy. Finally, the review addresses the opportunities and challenges of employing transition TMSs as nano-formulations for cancer. This review aims to provide new insights into the prospects and hurdles that need to be addressed to fully exploit the potential of TMSs in precision tumor therapy and integrated diagnosis and treatment.

Crystalline Copper Hydroxide Nanosheets with KatG-like Dual Activities for Synergized Nanocatalytic Tumor Therapy

The enzyme-mimicking catalytic activities of inorganic nanomaterials have attracted broad attention recently. Catalase-peroxidase (KatG) is a bifunctional enzyme with both catalase and peroxidase activities that converts hydrogen peroxide (H2O2) into both oxygen (O2) and a radical, respectively. Herein, crystalline Cu(OH)2 nanosheets have been synthesized and demonstrated as inorganic nanocatalysts with KatG-like activity for nanocatalytic tumor therapy. The distinct crystalline structure of the Cu(OH)2 nanosheets features abundant bis(μ-hydroxo)CuIICuII dinuclear catalytically active sites, enabling efficient redox cycling to favor one two-electron transfer for O2 generation (catalatic catalysis) and two consecutive single-electron transfers for hydroxyl radical (•OH) generation (peroxidatic catalysis), successively. During tumor therapy, the O2 generation by the nanomaterial mitigates intratumoral hypoxia and sensitizes cancer cells to oxidative attack, resulting in significantly enhanced anticancer efficacy. This work bridges dual-active nanocatalysis with bifunctional enzymatic catalysis, presenting a crystalline inorganic nanomaterial with KatG-like activity and its synergy for nanocatalytic tumor therapy.

Emerging glucose oxidase-delivering nanomedicines for enhanced tumor therapy

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

MXene Loaded With Cu(2- x )Se Nanozyme for Nanocatalytic Tumor Therapy

Traditional tumor treatments (surgery, radiotherapy, chemotherapy, etc.) have certain limitations and can have serious negative effects, such as difficulty in cutting out tumors, damage to normal tissues, and complications. Ordinary nanozymes have low catalytic activity and require higher doses for treatment, which can increase in vivo toxicity and side effects. To address these limitations, we developed a Ti3C2 MXene-based nanocomposite (Ti3C2/Cu(2- x )Se) integrating Cu(2- x )Se nanozymes with dual enzyme-mimicking activities (catalase and peroxidase) and MXene's photothermal properties. The Cu(2- x )Se component catalyzes the decomposition of tumor-overexpressed H2O2 into O2 and cytotoxic ·OH, alleviating hypoxia while inducing oxidative stress. Simultaneously, MXene's high surface area and photothermal capability enhance nanozyme stability, biocompatibility, and catalytic efficiency under near-infrared irradiation. Notably, the photothermal effect amplifies enzymatic activity, enabling synergistic nanocatalytic-photothermal therapy. This synergy not only degrades glutathione to suppress tumor antioxidant defenses but also achieves targeted tumor ablation with reduced dosage requirements. Our work highlights a rational design of MXene-based nanozymes for enhanced multimodal tumor therapy, offering a paradigm for nanocomposite-driven disease treatment.

Nanozymes in biomedicine: Unraveling trends, research foci, and future trajectories via bibliometric insights (from 2007 to 2024)

Nanozymes, a new generation of artificial enzymes, have attracted significant attention in biomedical applications due to their multifunctional properties, multi-enzyme mimicking abilities, cost-effectiveness, and high stability. Leveraging these diverse catalytic activities, an increasing number of nanozyme-based therapeutic strategies have been developed for the treatment of various diseases. Despite substantial research efforts, a significant gap remains in comprehensive studies examining the progression, key areas, current trends, and future directions in this field. This study provides a comprehensive overview of nanozyme applications in biomedical research over the past 17 years, utilizing data from the Web of Science Core Collection, covering the period from January 1, 2007, to October 8, 2024. Advanced bibliometric and visualization tools were employed to facilitate a comprehensive analysis. The results highlight China's dominant role in this field, accounting for 76.83 % of total publications, significantly influencing the evolution of research in this area. Key contributions were made by institutions such as the Chinese Academy of Sciences, the University of Chinese Academy of Sciences, and the University of Science and Technology of China, with Qu Xiaogang as the leading author. The journal ACS Applied Materials & Interfaces has become the most prolific publisher in this field. Keyword analysis indicates that since 2022, research hotspots in this field have increasingly focused on areas such as photothermal therapy, chemodynamic therapy, and ferroptosis. Challenges such as obstacles to clinical translation, limitations in recyclability, and insufficient targeting ability were addressed. The potential applications of emerging interdisciplinary technologies, such as artificial intelligence, machine learning, and organoids, in advancing nanozyme development were explored. This study offers a data-driven roadmap for researchers to navigate the evolving landscape of nanozyme innovation, emphasizing interdisciplinary collaboration in impactful biomedical applications.

Carbohydrate polymer-functionalized metal nanoparticles in cancer therapy: A review

Metal nanoparticles have been emerged as promising candidates in cancer therapy because of their large surface area, optical properties and ROS generation. Therefore, these nanoparticles are able to mediate cell death through hyperthermia, photothermal therapy and ROS-triggered apoptosis. The various metal nanoparticles including gold, silver and iron oxide nanostructures have been exploited for the theranostic application. Moreover, precision oncology and off-targeting features can be improved by metal nanoparticles. The modification of metal nanoparticles with carbohydrate polymers including chitosan, hyaluronic acid, cellulose, agarose, starch and pectin, among others can significantly improve their anti-cancer activities. Carbohydrate polymers have been idea for the purpose of drug delivery due to their biocompatibility, biodegradability and increasing nanoparticle stability. In addition, carbohydrate polymers are able to improve drug delivery, cellular uptake and sustained release of cargo. Such nanoparticles are capable of responding to the specific stimuli in the tumor microenvironment including pH and light. Furthermore, the carbohydrate polymer-modified metal nanoparticles can be utilized for the combination of chemotherapy, phototherapy and immunotherapy. Since the biocompatibility and long-term safety are critical factors for the clinical translation of nanoparticles, the modification of metal nanoparticles with carbohydrate polymers can improve this way to the application in clinic.

Development of iron oxide based-upconversion nanocomposites for cancer therapeutics treatment

Administration of therapeutic strategies alongside magnetic multifunctional nanocomposites has displayed improved cancer prognosis. However, the clinical use of this combination is limited owing to poor bioimaging performance, low biocompatibility, restricted tissue penetration in ultraviolet/visible regions, and low therapeutic efficacy of nanocomposites. To overcome these existing challenges, we designed iron oxide (Fe3O4)-based upconversion nanoparticles (UCNPs). Fe3O4 nanoparticles were synthesized via facile solvothermal method and incorporated into mesoporous silica (mS) layer (Fe3O4@mS). Fe3O4@mS nanoparticles were further decorated onto the surface of the UCNPs as a core material (UCNP-Fe3O4@mS, FMUP). Methotrexate (MTX) an efficient anticancer drug was loaded onto the mesoporous silica to produce FMUP-MTX nanocomposite. The FMUP nanocomposite displayed excellent photothermal therapy and showed 43% photothermal conversion efficiency. The designed nanocomposite has ability to decompose H2O2 to generates hydroxyl radical that promote chemodynamic therapy effect due to attribution of Fenton reaction. FMUP-MTX nanocomposite possessed improved chemotherapeutic performance under NIR laser irradiation. Further, T2-weighted magnetic resonance imaging performance of nanocomposite was observed. In vitro studies shown that cell viability was decreased to 25% under laser irradiation due to the therapeutic effect. In vivo studies exhibited that the FMUP-MTX nanocomposite inhibited the tumor growth with the laser irradiation. Therefore, these nanocomposites can be considered as a promising candidate for cancer therapeutics treatment.

Multifunctional porphyrinic metal-organic framework-based nanoplatform regulating reactive oxygen species achieves efficient imaging-guided cascaded nanocatalytic therapy

The integration of reactive oxygen species (ROS) related photodynamic therapy (PDT) with the strategy of reshaping the tumor microenvironment (TME) has emerged as a potential approach for nanodiagnostic and therapeutic interventions. However, the therapeutic efficacy based on ROS treatments may be hindered by intracellular antioxidants such as glutathione (GSH) and tumor hypoxia. To address these challenges, a nanoplatform based on GSH-responsive multifunctional porphyrinic metal-organic framework (PCN-224@Au@MnO2@HA, PAMH) was proposed. It was developed through a layer-by-layer in-situ growth method. This method avoids the need for high-temperature calcination and complex modification processes while improving the stability of PCN-224 in a phosphate-rich environment. GSH depletion leads to oxidation-reduction imbalance in TME. With the inactivation of GSH peroxidase 4 (GPX4), the content of hydrogen peroxide (H2O2) increases, ultimately triggering lipid peroxidation (LPO) and promoting ferroptosis. The catalase-like activity of Au nanozymes facilitates the generation of oxygen (O2), thereby mitigating tumor hypoxia and downregulating hypoxia-inducing factors (HIF-1α). Due to the presence of porphyrin ligands in PCN-224, the generated O2 can be further converted to toxic singlet oxygen (1O2) under laser irradiation. Additionally, the platform allows near-infrared (NIR) fluorescence imaging, providing real-time information on intracellular GSH changes during PDT and ferroptosis. The PAMH nanoplatform has shown effective inhibition of tumor growth in subcutaneous models via both intravenous and intratumoral injection, indicating its potential in modulating reactive oxygen/sulfur species and reshaping TME, thereby facilitating imaging-guided cascaded nanocatalytic therapy.

Ultra-Small Iron-Based Nanoparticles with Mild Photothermal-Enhanced Cascade Enzyme-Mimic Reactions for Tumor Therapy

Chemodynamic therapy (CDT), which utilizes the catalytic reactions of nanoparticles to inhibit tumor growth, is a promising approach in cancer therapy. However, its efficacy is limited by insufficient hydrogen peroxide (H2O2) concentration in tumor microenvironments and unsatisfactory enzymatic catalytic activity. To overcome these limitations, ultra-small iron-based (USIB) nanoparticles with cascaded superoxide dismutase (SOD)-mimic and peroxidase (POD)-mimic activities have been engineered. USIB nanoparticles initiated by SOD-mimic activity to transform superoxide anions (O2·-) into H2O2, elevating H2O2 levels in the tumor microenvironment and subsequently utilizing POD-mimic activity to convert H2O2 into the more reactive ·OH, thereby achieving the destruction of tumor cells. In addition, USIB nanoparticles possess photothermal conversion capabilities, and their enzymatic activity can be significantly enhanced under mild laser irradiation. Therefore, by addressing the issues of insufficient substrate concentration and low enzymatic catalytic activity, the therapeutic efficiency of CDT has been improved. Our research integrates the cascade catalytic reactions of nanozymes with laser irradiation, effectively inhibiting tumor growth and exhibiting outstanding biosafety, demonstrating promising therapeutic potential.

Effective Amplification of Oxidative Stress and Calcium Manipulation Mediated Mitochondrial Dysfunction Based on Engineered Nanozyme for Primary and Metastatic Breast Cancer Therapy

Herein, an engineered nanocomposite (FZSHC) was constructed containing zinc-based nanozyme(ZS), Hemin and Ca2+ ions with further surface modification of phospholipid and folic acid (FA) for primary and metastatic breast cancer therapy. During therapy, the FZSHC initially accumulated in tumor tissues through enhanced permeability and retention effectand FA receptor-mediated tumor-targeting delivery. After that, the FZSHC further dissociated to free Ca2+ and Hemin loaded ZS in the acidic environment of lysosome. The resulting ZS then generated reactive oxygen species (ROS) and consumed glutathione via peroxidase and glutathione oxidase mimicking enzyme activities to induce the tumor-specific ferroptosis for primary tumor elimination, in which the ROS production could be further promoted by the Hemin catalyzed Fenton-likereactions to amplify oxidative damage and accelerate the ferroptosis. Furthermore, the ROS also influenced calcium metabolism of tumor cells, causingthe Ca2+-overloading and mitochondrial dysfunction in tumor cell salong with the introduction of exogenous Ca2+, which resulted in the suppression of adenosine triphosphate synthesis to hinder the energy supply of tumor cells for significant inhibition of tumor metastasis. Both in vitro and in vivo results demonstrated the remarkable therapeutic slmult1 efficiencyof FZSHC nanozyme in suppressing the growth and metastasis of breastcancer.

Emerging nanocarriers as advanced delivery tools for the treatment of leukemia

The most common type of blood cancer, leukemia, presents global therapeutic challenges like heterogeneity regarding age, sex, race, and a multiple pool of oncogenes and their complex network. In the last few years, nanotechnology has become the potential solution in leukemic resistance, chemotherapeutic failure, and disease-remission risk. Interestingly, the nanocarriers alone sometimes cannot overcome leukemia's obstacles, which demands a more advanced flagship in the nanocarrier segment like modification of the nanocarrier system, external stimuli for synergistic antileukemic effect, etc. This review has highlighted the need for emerging nanocarriers like exosome-like vesicles, nanodiamonds, nanoflower, etc. and biomimetic nanocarriers that reach the bone marrow niche. Notably, the role of nanoparticle-based vaccines in a disease-remission-free life and novel technology for nanocarrier delivery (microfluidics and plasmonic nanobubbles) have been discussed. This review also focuses on the clinical transition barriers of nanocarriers from the research laboratory. The continual research on novel nanocarriers and integration of new technologies to deliver the nanocarriers in the right way is paving the path for enhanced selectivity and efficacy in leukemia. The promising results in precise drug delivery and leukemic cell destruction are showing its great clinical prospects.

NIR-triggered and glucose-powered hollow mesoporous Mo-based single-atom nanozymes for cascade chemodynamic diabetic infection therapy

Diabetic infections/wounds remain to be a threatening challenge as it seriously leads to lower limb amputation with endless pains and subsequent high economic/psychosocial costs. The exceptional peroxidase-like activity of single-atom nanozymes (SAzymes) holds great promise for chemodynamic therapy (CDT) of diabetic infection, but is extremely restricted by the near-neutral pH and insufficient H2O2 levels in physiological conditions. Herein, we innovated a hollow mesoporous molybdenum single-atom nanozyme (HMMo-zyme) featured with catalytic activity, photothermal performance and drug delivery properties for more effective antibacterial therapeutic in diabetic conditions. The glucose oxidase (GOx) was encapsulated into HMMo-zyme with phase-change material (PCM) to form HMMo/GOx@P system, which could be controllably disassembled by near-infrared ray (NIR) to trigger cascade CDT toward bacterial infections. The results revealed that the release of GOx accelerated by NIR could facilitate the continuous conversion of glucose (Glu) into gluconic acid, accompanied by a sharply decrease in pH to establish a low-pH environment that notably enhanced the catalytic activity of HMMo-zyme, which subsequently drives the conversion of generated H2O2 into toxic hydroxyl radicals (·OH) for amplified anti-bacterial treatment. As a proof of the concept, this NIR-assisted HMMo/GOx@P strategy could efficiently inhibit/kill bacteria and suppress tissue inflammations, thereby accelerating the wound healing processes both in in vitro and in vivo diabetic infection models. This study provides a novel strategy that may serve as a promising alternative for antibiotic therapeutics against diabetic infection, thus holding promise for more effective diabetic infection treatment manipulating Mo-based SAzymes.

Ti3C2/CuWO4/Pt nanozyme: photothermal-enhanced chemodynamic antibacterial effects induced by NIR

With the growing issue of antibiotic resistance, it has become increasingly crucial to develop highly efficient antimicrobial materials. While the single-component nanozyme systems exhibited some catalytic activity, their efficiency remains suboptimal. This study presents a Ti3C2/CuWO4/Pt hybrid nanozyme composed of photothermal agents and nanozymes, which leverages the photothermal effect to enhance nanozyme activity and achieve efficient antimicrobial effects. The composite material exhibited peroxidase (POD)-like catalytic activity, effectively converting hydrogen peroxide (H2O2) into hydroxyl radicals (·OH). Meanwhile, the Ti3C2/CuWO4/Pt material demonstrated high photothermal conversion ability, which not only promoted the generation of ·OH under near-infrared (NIR) light irradiation, but also facilitated copper (Cu2+) ions release from the CuWO4 nanozyme, thereby further augmenting its catalytic activity. After 4 to 5 min of light irradiation, the Ti3C2/CuWO4/Pt nanozyme exhibited significant antimicrobial performance against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In summary, this work presents a Ti3C2/CuWO4/Pt nanoplatform that utilizes the photothermal effect to enhance the chemodynamic antimicrobial activity, showcasing its potential applications in antibiotic-free antimicrobial fields.

Applications and enhancement strategies of ROS-based non-invasive therapies in cancer treatment

Reactive oxygen species (ROS) play a crucial role in the pathogenesis of cancer. Non-invasive therapies that promote intracellular ROS generation, including photodynamic therapy (PDT), sonodynamic therapy (SDT), and chemodynamic therapy (CDT), have emerged as novel approaches for cancer treatment. These therapies directly kill tumor cells by generating ROS, and although they show great promise in tumor treatment, many challenges remain to be addressed in practical applications. Firstly, the inherent complexity of the tumor microenvironment (TME), such as hypoxia and elevated glutathione (GSH) levels, hinders ROS generation, thereby significantly diminishing the efficacy of ROS-based therapies. In addition, these therapies are influenced by their intrinsic mechanisms. To overcome these limitations, various nanoparticle (NP) systems have been developed to improve the therapeutic efficacy of non-invasive therapies against tumors. This review first summarizes the mechanisms of ROS generation for each non-invasive therapy and their current limitations, with a particular focus on the enhancement strategies for each therapy based on NP systems. Additionally, various strategies to modulate the TME are highlighted. These strategies aim to amplify ROS generation in non-invasive therapies and enhance their anti-tumor efficiency. Finally, the current challenges and possible solutions for the clinical translation of ROS-based non-invasive therapies are also discussed.

Magnetic Janus Particles: Synthesis and Multifunctional Applications

Magnetic Janus particles (MJPs) with compositional compartmentalization and strong magnetic responsiveness play a pivotal role in various application fields, such as biotechnology, medicine, and materials science. However, comprehensive reviews of the field of MJPs remain limited. Here, this article attempts to fill the gap by reviewing the current common synthetic strategies for MJPs, including masking, microfluidics, self-assembly, phase separation, and seeded emulsion polymerization, among others. It then covers the multifunctional applications of MJPs, beneficial from their magnetic properties and anisotropic topological structure, primarily involving environmental remediation, biomedicine, smart displays, interfacial catalysis, emulsion stabilization, and structured liquid materials are presented, as well. Finally, the current challenges and future perspectives for MJPs are also discussed, aiming to fully harness the potential for broader applications.

Immobilized Multi-Enzyme/Nanozyme Biomimetic Cascade Catalysis for Biosensing Applications

Multiple enzyme-induced cascade catalysis has an indispensable role in the process of complex life activities, and is widely used to construct robust biosensors for analyzing various targets. The immobilized multi-enzyme cascade catalysis system is a novel biomimetic catalysis strategy that immobilizes various enzymes with different functions in stable carriers to simulate the synergistic catalysis of multiple enzymes in biological systems, which enables high stability of enzymes and efficiency enzymatic cascade catalysis. Nanozymes, a type of nanomaterial with intrinsic enzyme-like characteristics and excellent stabilities, are also widely applied instead of enzymes to construct immobilized cascade systems, achieving better catalytic performance and reaction stability. Due to good stability, reusability, and remarkably high efficiency, the immobilized multi-enzyme/nanozyme biomimetic cascade catalysis systems show distinct advantages in promoting signal transduction and amplification, thereby attracting vast research interest in biosensing applications. This review focuses on the research progress of the immobilized multi-enzyme/nanozyme biomimetic cascade catalysis systems in recent years. The construction approaches, factors affecting the efficiency, and applications for sensitive biosensing are discussed in detail. Further, their challenges and outlooks for future study are also provided.

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

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

Mixed-valence vanadium-doped mesoporous bioactive glass for treatment of tumor-associated bone defects

Vanadium is a bioactive trace element with variable valence. Its pentavalent form has been confirmed to be capable of predominantly regulating the early and mid-stage osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) without tumor inhibition, while its tetravalent form exhibits tumor inhibition but only primarily modulates late osteogenic differentiation and angiogenesis. In this study, a multifunctional bone tissue scaffold consisting of mixed-valence vanadium-doped mesoporous bioactive glass and poly(lactic-co-glycolic acid) (V(IV/V)-MBG/PLGA) was developed to simultaneously inhibit the recurrence of osteosarcoma and promote the regeneration of operative bone defects. The in vitro results showed that the V(IV) and V(V) species could be sustainably released from V(IV/V)-MBG and complementarily enhance the proliferation, osteogenic differentiation, and mineralization of BMSCs by activating multiple signaling pathways throughout the whole osteogenesis process. More importantly, the co-existence of mixed-valent vanadium species was able to continuously stimulate the generation of excessive ROS and the depletion of GSH by synergistically supplying an appropriate ratio of V(IV) and V(V) to thermodynamically and kinetically maintain the stable self-circulation of the valence state alteration, thus inducing UMR-106 cell death. In a rat model, V(IV/V)-MBG/PLGA scaffolds effectively suppressed tumor invasion and promoted bone regeneration. These results suggest that V(IV/V)-MBG/PLGA scaffolds are a promising strategy for treating tumor-associated bone defects, offering dual tumor inhibition and bone regeneration.

Engineering nanozyme immunomodulator with magnetic targeting effect for cascade-enzyodynamic and ultrasound-reinforced metallo-immunotherapy in prostate carcinoma

Conventional immunotherapy exhibits low response rates due to the immunosuppressive tumor microenvironment (TME). To overcome this limitation, this study introduces ZFPG nanoparticles (ZFPG NPs) with ZnFe2O4@Pt cores and glucose oxidase (GOx) shells. The ZFPG NPs possess five-enzyme activities, good sonosensitivity, and remarkable magnetic targeting properties, which facilitate sono-metallo-immunotherapy for prostate cancer treatment in male mice. Specifically, the magnetic targeting ability effectively improves their accumulation in tumors while still showing enrichment in the liver and kidneys. The multienzyme cascade catalysis and sonosensitivity of these NPs effectively deplete glutathione and glucose, and enhance the generation and utilization of H2O2, thereby inducing multiple ROS bursts. Furthermore, these comprehensive effects up-regulate the HMOX1 to promote the Fe2+ and lipid peroxides accumulation, thereby inducing immunogenic ferroptosis. This strategy facilitates anti-tumor immunity by ameliorating the immunosuppressive TME and inhibiting lung metastatic progression. This joint warfare strategy offers a powerful solution to address conventional immunotherapy limitations.

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

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

Ultrathin 2D Cu-Porphyrin MOF Nanosheet Loaded Fe3O4 Nanoparticles As a Multifunctional Nanoplatform for Synergetic Chemodynamic and Photodynamic Therapy Independent of O2

In this study, we developed a multifunctional nanoplatform to address the limitations of strictly acidic pH for the Fenton reaction involving Fe3O4 and the low efficiency of mono treatments. The hybrid material, Fe3O4@Cu-TCPP, was assembled through hydrophobic interactions of polyvinylpyrrolidone (PVP) coated on its surface. The efficiency of the Fenton reaction using Fe3O4 was significantly enhanced by the photo-Fenton process in the presence of Cu-TCPP. The generation of hydroxyl radicals by Fe3O4@Cu-TCPP was markedly increased under laser irradiation (λ = 660 nm) in solution. Fe3O4@Cu-TCPP demonstrated a robust ability to produce reactive oxygen species through chemodynamic and photodynamic processes independent of that of O2. In vivo experimental results indicated that Fe3O4@Cu-TCPP facilitated T2-weighted magnetic resonance imaging-mediated synergistic chemodynamic and photodynamic therapies in a 4T1 mouse model.

Bioengineering stimuli-responsive organic-inorganic nanoarchitetures based on carboxymethylcellulose-poly-l-lysine nanoplexes: Unlocking the potential for bioimaging and multimodal chemodynamic-magnetothermal therapy of brain cancer cells

Regrettably, glioblastoma multiforme (GBM) remains the deadliest form of brain cancer, where the early diagnosis plays a pivotal role in the patient's therapy and prognosis. Hence, we report for the first time the design, synthesis, and characterization of new hybrid organic-inorganic stimuli-responsive nanoplexes (NPX) for bioimaging and killing brain cancer cells (GBM, U-87). These nanoplexes were built through coupling two nanoconjugates, produced using a facile, sustainable, green aqueous colloidal process ("bottom-up"). One nanocomponent was based on cationic epsilon-poly-l-lysine polypeptide (εPL) conjugated with ZnS quantum dots (QDs) acting as chemical ligand and cell-penetrating peptide (CPP) for bioimaging of cancer cells (QD@εPL). The second nanocomponent was based on anionic carboxymethylcellulose (CMC) polysaccharide surrounding superparamagnetic magnetite "nanozymes" (MNZ) behaving as a capping macromolecular shell (MNZ@CMC) for killing cancer cells through chemodynamic therapy (CDT) and magnetohyperthermia (MHT). The results demonstrated the effective production of supramolecular aqueous colloidal nanoplexes (QD@εPL_MNZ@CMC, NPX) integrated into single nanoplatforms, mainly electrostatically stabilized by εPL/CMC biomolecules with anticancer activity against U-87 cells using 2D and 3D spheroid models. They displayed nanotheranostics (i.e., diagnosis and therapy) behavior credited to the photonic activity of QD@εPL with luminescent intracellular bioimaging, amalgamated with a dual-mode killing effect of GBM cancer cells through CDT by nanozyme-induced biocatalysis and as "nanoheaters" by magnetically-responsive hyperthermia therapy.

Nanozyme-based synergistic therapeutic strategies against tumors

Cancer remains a global health threat, with traditional treatments limited by adverse effects and drug resistance. Nanozyme-based catalytic therapy with high stability and controllable activity provides targeted and specific in situ tumor treatment to address these challenges. More intriguingly, the tremendous advances in nanotechnology have enabled nanozymes to rival the catalytic activity of natural enzymes, presenting an exciting opportunity for innovating antitumor nanodrugs. This review systematically summarizes the latest progresses in nanozyme-based anticancer catalytic therapy, with a particular focus on various synergistic antitumor strategies, including other functional enzymes, drugs, exogenous stimuli and radiotherapy. These combinations not only enhance the efficacy of cancer treatment and reduce systemic toxicity but also offer insights into the development of potent antitumor nanodrugs.

Glucose oxidase-driven self-accelerating drug release nanosystem based on metal-phenolic networks orchestrates tumor chemotherapy and ferroptosis-based therapy

Nanocarriers responding to tumor microenvironment have been extensively exploited to improve the antitumor outcome of chemotherapeutic drugs. However, selectively and completely releasing drugs within the tumor remains a challenge, thereby limiting the therapeutic effect of drug delivery nanosystem. To tackle this challenge, a metal-phenolic networks (MPNs)-based nanosystem (F-MGD) showing the capability of self-accelerating drug release was originally fabricated in this study. Glucose oxidase (GOx) encapsulated in F-MGD could conduct the glucose transformation in tumor to cause the oxygen consumption and the production of gluconic acid and H2O2. Therefore, F-MGD with acid and hypoxia sensitivities thoroughly disintegrated under the aggravated acidity and hypoxia to achieve a more complete drug release. Besides, the product of H2O2 was readily decomposed into hydroxyl radicals via the iron ion-mediated Fenton reaction, which markedly augmented the oxidative stress in tumor cells and promoted ferroptosis. The results of both in vitro and in vivo assays demonstrated the significant antitumor efficacy of F-MGD. Collectively, this study proposes a strategy to expedite drug release in tumor and improve the tumor treatment effect by combining ferroptosis-based therapy and chemotherapy.

Resensitizing β-Lactams by Reprogramming Purine Metabolism in Small Colony Variant for Osteomyelitis Treatment

Small colony variant (SCV) is strongly linked to antibiotic resistance and the persistence of osteomyelitis. However, the intrinsic phenotypic instability of SCV has hindered a thorough investigation of its pathogenic mechanisms. In this study, phenotypically stable SCV strains are successfully recovered from clinical specimens, characterized by elevated drug resistance and reduced immunogenicity. Multi-omics analysis revealed that the acquired high drug resistance is associated with altered flux in the purine metabolism pathway, attributable to mutations in the hypoxanthine phosphoribosyltransferase (hpt) gene. Furthermore, this study innovatively discovered that lonidamine, an inhibitor of cellular energy metabolism, can effectively mitigate SCV resistance to β-lactam antibiotics, thereby facilitating its eradication. The underlying mechanism involves the reprogramming of purine metabolism. Therefore, a co-delivery system for lonidamine and oxacillin is constructed with amino-modified dendritic mesoporous silica as a carrier, which showed high efficacy and safety in combating SCV both in vitro and in vivo experiments. Overall, this study elucidated the pathogenic mechanisms of a class of clinically isolated SCV isolates with hpt mutations and provided a paradigm for treating SCV-associated osteomyelitis by reprogramming purine metabolism.

Cascade catalytic multilayer modified intraocular lens for enhanced and safer posterior capsule opacification prevention

Posterior capsule opacification (PCO) is the most common complication after cataract surgery. It is primarily caused by the proliferation, migration, and adhesion of residual lens epithelial cells within the capsular bag following phacoemulsification and intraocular lens (IOL) implantation. Although investigations of surface modification onto IOL have partially reduced PCO development in recent years, there are still challenges in long-term efficacy and intraocular biocompatibility. In this study, a cascade catalytic system is constructed using natural enzymes onto mesoporous silica nanoparticles (MSNs), which are subsequently fixed to the surface of IOL through layer-by-layer self-assemble of alternating positive and negative charges. The cascade catalytic reaction is trigged simply by glucose within the pouch to produce reactive oxygen species (ROS) without introducing any toxic drugs or external energy, attempting to minimize the possible toxic side effects to surrounding tissues. In vivo and in vitro experiments indicate the effective inhibition of PCO and favorable intraocular compatibility of the cascade catalytic platform modified IOL. More importantly, the modified IOL retains good optical performance and imaging quality, demonstrating promising prospects for application. This study provides a new possibility for enhanced and safer PCO prevention, playing great significance in clinical treatment. STATEMENT OF SIGNIFICANCE: Cascade catalytic nanoparticles-loaded multilayer modified IOL is obtained via LbL technique. The multilayer coating improves both the loading capacity and the activity of the cascade catalytic nanoparticles. The cascade catalytic reaction is trigged by glucose, producing ROS that efficiently induces apoptosis and death of remaining cells on IOL without introducing any toxic drugs or external energy. The innovative IOL provides a promising approach for enhanced and safer prevention of PCO.

Rational Design of Genetically Engineered Mitochondrial-Targeting Nanozymes for Alleviating Myocardial Ischemic-Reperfusion Injury

The development of mitochondria-targeting nanozymes holds significant promise for treating myocardial ischemia-reperfusion (IR) injury but faces significant biological barriers. To overcome these obstacles, we herein utilized genetically engineered ferritin nanocages (i.e., imFTn) to develop mitochondria-targeting nanozymes consisting of three ferritin subunit assembly modules: an IR-injured cardiomyocyte-targeting module, a lysosome-escaping module, and a mitochondria-targeting module. Using imFTn as a nanozyme platform, we developed nanozymes capable of efficiently catalyzing the l-Arg substrate to produce NO. The imFTn-Ru exhibits NO-generating activities, reduces mitochondrial reactive oxygen species generation, inhibits mitochondrial permeability transition pore opening, and enhances mitochondrial membrane potential. Furthermore, imFTn-Ru provides synergistic effects by specifically targeting myocardial IR-injured tissues, facilitating their accumulation in mitochondria, and protecting mitochondria against myocardial IR-induced injury in both in vitro and in vivo models. This study underscores a rational approach to designing nanozymes for targeting specific subcellular organelles in the treatment of IR injury.

Enhancing Ferroptosis-Mediated Radiosensitization via Synergistic Disulfidptosis Induction

Ferroptosis plays an important role in radiotherapy (RT), and the induction of ferroptosis can effectively sensitize radiotherapy. However, the therapeutic efficiency is always affected by ferroptosis resistance, especially SLC7A11 (Solute Carrier Family 7 Member 11)-cystine-cysteine-GSH (glutathione)-GPX4 (glutathione peroxidase 4) pathway-mediated resistance. In this study, tumor-microenvironment self-activated high-Z element-containing nanoferroptosis inducers, PEGylated Fe-Bi-SS metal-organic frameworks (FBSP MOFs), were developed to sensitize RT. Unexpectedly, ferroptosis-resistant SLC7A11 would be self-adaptively upregulated, leading to self-responsive ferroptosis resistance. Since the conversion from SLC7A11-transported cystine to cysteine is highly glucose-dependent, glucose oxidase (GOx) was incorporated in the MOFs, causing the depletion of NADPH (nicotinamide adenine dinucleotide phosphate) to terminate the conversion from cystine to cysteine, relieving the self-adaptive ferroptosis resistance. Excitingly, the accumulation of cystine would synergistically lead to disulfide stress and trigger disulfidptosis, making a new contribution to enhance therapeutic efficiency. Moreover, the hydrogen peroxide produced during glucose oxidation could also cascade-react with the Fenton reaction, therefore enhancing ferropotosis. Both in vitro and in vivo results suggested that therapeutic efficiency of ferroptosis-mediated radiosensitization could be enhanced benefiting from synergistic disulfidptosis induction, indicating that disulfidptosis might be an efficient strategy to relieve ferroptosis resistance and enhance RT efficiency.

A DNA origami-based enzymatic cascade nanoreactor for chemodynamic cancer therapy and activation of antitumor immunity

Chemodynamic therapy (CDT) is a promising and potent therapeutic strategy for the treatment of cancer. We developed a DNA origami-based enzymatic cascade nanoreactor (DOECN) containing spatially well-organized Au nanoparticles and ferric oxide (Fe2O3) nanoclusters for targeted delivery and inhibition of tumor cell growth. The DOECN can synergistically promote the generation of hydrogen peroxide (H2O2), consumption of glutathione, and creation of an acidic environment, thereby amplifying the Fenton-type reaction and producing abundant reactive oxygen species, such as hydroxyl radicals (•OH), for augmenting the CDT outcome. The DOECN is decorated with targeting groups to achieve efficient cellular uptake and efficiently induce tumor cell apoptosis, ferroptosis, and immunogenetic cell death, thus realizing potent anticancer therapeutic effects. Intravenous injection of the DOECN effectively promoted the maturation of dendritic cells, triggered adaptive T cell responses, and suppressed tumor growth in a murine cancer model. The DOECN provides a programmable platform for the integration of multiple therapeutic components, showing great potential for combined cancer therapy.

Tumor microenvironment-responsive engineered hybrid nanomedicine for photodynamic-immunotherapy via multi-pronged amplification of reactive oxygen species

Reactive oxygen species (ROS) is promising in cancer therapy by accelerating tumor cell death, whose therapeutic efficacy, however, is greatly limited by the hypoxia in the tumor microenvironment (TME) and the antioxidant defense. Amplification of oxidative stress has been successfully employed for tumor therapy, but the interactions between cancer cells and the other factors of TME usually lead to inadequate tumor treatments. To tackle this issue, we develop a pH/redox dual-responsive nanomedicine based on the remodeling of cancer-associated fibroblasts (CAFs) for multi-pronged amplification of ROS (ZnPP@FQOS). It is demonstrated that ROS generated by ZnPP@FQOS is endogenously/exogenously multiply amplified owing to the CAFs remodeling and down-regulation of anti-oxidative stress in cancer cells, ultimately achieving the efficient photodynamic therapy in a female tumor-bearing mouse model. More importantly, ZnPP@FQOS is verified to enable the stimulation of enhanced immune responses and systemic immunity. This strategy remarkably potentiates the efficacy of photodynamic-immunotherapy, thus providing a promising enlightenment for tumor therapy.

Tumor Integrin-Targeted Glucose Oxidase Enzyme Promotes ROS-Mediated Cell Death that Combines with Interferon Alpha Therapy for Tumor Control

Although heightened intratumoral levels of reactive oxygen species (ROS) are typically associated with a suppressive tumor microenvironment, under certain conditions ROS contribute to tumor elimination. Treatment approaches, including some chemotherapy and radiation protocols, increase cancer cell ROS levels that influence their mechanism of cell death and subsequent recognition by the immune system. Furthermore, activated myeloid cells rapidly generate ROS upon encounter with pathogens or infected cells to eliminate disease, and recently, this effector function has been noted in cancer contexts as well. Collectively, ROS-induced cancer cell death may help initiate adaptive antitumor immune responses that could synergize with current approved immunotherapies, for improved control of solid tumors. In this work, we explore the use of glucose oxidase, an enzyme which produces hydrogen peroxide, a type of ROS, to therapeutically mimic the endogenous oxidative burst from myeloid cells to promote antigen generation within the tumor microenvironment. We engineer the enzyme to target pan-tumor-expressed integrins both as a tumor-agnostic therapeutic approach and as a strategy to prolong local enzyme activity following intratumoral administration. We found the targeted enzyme potently induced cancer cell death and enhanced cross-presentation by dendritic cells in vitro and further combined with interferon alpha for long-term tumor control in murine MC38 tumors in vivo. Optimizing the single-dose administration of this enzyme overcomes limitations with immunogenicity noted for other prooxidant enzyme approaches. Overall, our results suggest ROS-induced cell death can be harnessed for tumor control and highlight the potential use of designed enzyme therapies alongside immunotherapy against cancer.

Application progress of nanomaterials in the treatment of prostate cancer

Prostate cancer is one of the most common malignant tumors in men, which seriously threatens the survival and quality of life of patients. At present, there are serious limitations in the treatment of prostate cancer, such as drug tolerance, drug resistance and easy recurrence. Sonodynamic therapy and chemodynamic therapy are two emerging tumor treatment methods, which activate specific drugs or sonosensitizers through sound waves or chemicals to produce reactive oxygen species and kill tumor cells. Nanomaterials are a kind of nanoscale materials with many excellent physical properties such as high targeting, drug release regulation and therapeutic monitoring. Sonodynamic therapy and chemodynamic therapy combined with the application of nanomaterials can improve the therapeutic effect of prostate cancer, reduce side effects and enhance tumor immune response. This article reviews the application progress of nanomaterials in the treatment of prostate cancer, especially the mechanism, advantages and challenges of nanomaterials in sonodynamic therapy and chemodynamic therapy, which provides new ideas and prospects for research in this field.

Catalytic Biomaterials-Activated In Situ Chemical Reactions: Strategic Modulation and Enhanced Disease Treatment

Chemical reactions underpin biological processes, and imbalances in critical biochemical pathways within organisms can lead to the onset of severe diseases. Within this context, the emerging field of "Nanocatalytic Medicine" leverages nanomaterials as catalysts to modulate fundamental chemical reactions specific to the microenvironments of diseases. This approach is designed to facilitate the targeted synthesis and localized accumulation of therapeutic agents, thus enhancing treatment efficacy and precision while simultaneously reducing systemic side effects. The effectiveness of these nanocatalytic strategies critically hinges on a profound understanding of chemical kinetics and the intricate interplay of reactions within particular pathological microenvironments to ensure targeted and effective catalytic actions. This review methodically explores in situ catalytic reactions and their associated biomaterials, emphasizing regulatory strategies that control therapeutic responses. Furthermore, the discussion encapsulates the crucial elements-reactants, catalysts, and reaction conditions/environments-necessary for optimizing the thermodynamics and kinetics of these reactions, while rigorously addressing both the biochemical and biophysical dimensions of the disease microenvironments to enhance therapeutic outcomes. It seeks to clarify the mechanisms underpinning catalytic biomaterials and evaluate their potential to revolutionize treatment strategies across various pathological conditions.

Recent advances in ferrocene-based nanomedicines for enhanced chemodynamic therapy

Malignant tumors have been a serious threat to human health with their increasing incidence. Difficulties with conventional treatments are toxicity, drug resistance, and recurrence. For this reason, non-invasive treatment modalities such as photothermal therapy (PTT), photodynamic therapy (PDT), chemodynamic therapy (CDT), and others have received much attention. Among them, Ferrocene (Fc)-based nanomedicines for enhanced Chemodynamic Therapy (ECDT) is a new therapeutic strategy based on the Fenton reaction. Based on ferrocene's good biocompatibility, potentiation in medicinal chemistry, and good stability of divalent iron ions, scientists are increasingly using it as a Fenton's iron donor for tumor therapy. Such ferrocene-based ECDT nanoplatforms have shown remarkable promise for clinical applications and have significantly increased the efficacy of CDT treatment. Ferrocene-based nanomedicines exhibit exceptional consistency owing to their low toxicity, high stability, enhanced bioavailability, and a multitude of advantages over conventional approaches to cancer treatment. As a consequence, a number of tactics have been investigated in recent years to raise the effectiveness of ferrocene-based ECDT. In this review, we detail the different forms and strategies used to enhance Ferrocene-based ECDT efficiency.

Microenvironmental modulation breaks intrinsic pH limitations of nanozymes to boost their activities

Functional nanomaterials with enzyme-mimicking activities, termed as nanozymes, have found wide applications in various fields. However, the deviation between the working and optimal pHs of nanozymes has been limiting their practical applications. Here we develop a strategy to modulate the microenvironmental pHs of metal-organic framework (MOF) nanozymes by confining polyacids or polybases (serving as Brønsted acids or bases). The confinement of poly(acrylic acid) (PAA) into the channels of peroxidase-mimicking PCN-222-Fe (PCN = porous coordination network) nanozyme lowers its microenvironmental pH, enabling it to perform its best activity at pH 7.4 and to solve pH mismatch in cascade systems coupled with acid-denatured oxidases. Experimental investigations and molecular dynamics simulations reveal that PAA not only donates protons but also holds protons through the salt bridges between hydroniums and deprotonated carboxyl groups in neutral pH condition. Therefore, the confinement of poly(ethylene imine) increases the microenvironmental pH, leading to the enhanced hydrolase-mimicking activity of MOF nanozymes. This strategy is expected to pave a promising way for designing high-performance nanozymes and nanocatalysts for practical applications.

Ultrasound-responsive nanoparticles for nitric oxide release to inhibit the growth of breast cancer

Gas therapy represents a promising strategy for cancer treatment, with nitric oxide (NO) therapy showing particular potential in tumor therapy. However, ensuring sufficient production of NO remains a significant challenge. Leveraging ultrasound-responsive nanoparticles to promote the release of NO is an emerging way to solve this challenge. In this study, we successfully constructed ultrasound-responsive nanoparticles, which consisted of poly (D, L-lactide-co-glycolic acid) (PLGA) nanoparticles, natural L-arginine (LA), and superparamagnetic iron oxide nanoparticles (SPIO, Fe3O4 NPs), denote as Fe3O4-LA-PLGA NPs. The Fe3O4-LA-PLGA NPs exhibited effective therapeutic effects both in vitro and in vivo, particularly in NO-assisted antitumor gas therapy and photoacoustic (PA) imaging properties. Upon exposure to ultrasound irradiation, LA and Fe3O4 NPs were rapidly released from the PLGA NPs. It was demonstrated that LA could spontaneously react with hydrogen peroxide (H2O2) present in the tumor microenvironment to generate NO for gas therapy. Concurrently, Fe3O4 NPs could rapidly react with H2O2 to produce a substantial quantity of reactive oxygen species (ROS), which can oxidize LA to further facilitate the release of NO. In conclusion, the proposed ultrasound-responsive NO delivery platform exhibits significant potential in effectively inhibiting the growth of breast cancer.

GSH-Depleting and H2O2 Self-Supplying Calcium Peroxide-Based Nanoplatforms for Efficient Bacterial Eradication via Photothermal-Enhanced Chemodynamic Therapy

Chemodynamic therapy (CDT), an innovative approach for treating bacterial infections, has garnered significant attention due to its ability to generate hydroxyl radicals (•OH) via Fenton/Fenton-like reactions. However, the effectiveness of CDT is considerably hindered by the limited availability of endogenous hydrogen peroxide (H2O2) and the overexpression of glutathione (GSH) within the infection microenvironment. To address these limitations, a multifunctional nanoplatform with self-supplying H2O2, GSH-depletion properties, and photothermal properties was developed through a straightforward and mild strategy. This platform employs calcium peroxide (CaO2) as the core, coated with silica (SiO2) to enhance stability and further modified with a Cu(II)-doped polydopamine (PDA) layer, forming a core-shell structured CaO2@SiO2@PDA-Cu (CSPC). The Cu(II) released by CSPC, combined with the H2O2 produced from CaO2 degradation, participates in a Fenton-like reaction to generate toxic •OH radicals. Additionally, Cu(II)-mediated redox reactions deplete overexpressed GSH, thereby enhancing CDT efficacy. Upon coordination with Cu(II), the photothermal properties of PDA are significantly enhanced, achieving a photothermal conversion efficiency of up to 43%. The hyperthermia induced by photothermal therapy (PTT) further increases •OH production, augmenting CDT. The CSPC nanomaterials demonstrated outstanding synergistic photothermal bactericidal activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) at 60 μg/mL, achieving complete eradication. Moreover, CSPC eliminated 65.90 ± 3.46% of the S. aureus biofilm under near-infrared (NIR) irradiation. In vivo experiments demonstrated that CSPC treatment effectively eradicated bacteria, with a bacterial survival rate of 6.56 ± 3.28%, and accelerated wound healing, reducing the relative wound size to 7.0 ± 2.6%. Therefore, this study successfully developed versatile nanomaterials that significantly enhance the PTT/CDT dual-mode antibacterial performance.

Supramolecular assembly of Polydopamine@Fe nanoparticles with near-infrared light-accelerated cascade catalysis applied for synergistic photothermal-enhanced chemodynamic therapy

Chemodynamic therapy (CDT) via Fenton-like reaction is greatly attractive owing to its capability to generate highly cytotoxic •OH radicals from tumoral hydrogen peroxide (H2O2). However, the antitumor efficacy of CDT is often challenged by the relatively low radical generation efficiency and the high levels of antioxidative glutathione (GSH) in tumor microenvironment. Herein, an innovative photothermal Fenton-like catalyst, Fe-chelated polydopamine (PDA@Fe) nanoparticle, with excellent GSH-depleting capability is constructed via one-step molecular assembly strategy for dual-modal imaging-guided synergetic photothermal-enhanced chemodynamic therapy. Fe(III) ions in PDA@Fe nanoparticles can consume the GSH overexpressed in tumor microenvironment to avoid the potential •OH consumption, while the as-produced Fe(II) ions subsequently convert tumoral H2O2 into cytotoxic •OH radicals through the Fenton reaction. Notably, PDA@Fe nanoparticles demonstrate excellent near-infrared light absorption that results in superior photothermal conversion ability, which further boosts above-mentioned cascade catalysis to yield more •OH radicals for enhanced CDT. Taken together with T1-weighted magnetic resonance imaging (MRI) contrast enhancement (r1 = 8.13 mM-1 s-1) and strong photoacoustic (PA) imaging signal of PDA@Fe nanoparticles, this design finally realizes the synergistic photothermal-chemodynamic therapy. Overall, this work offers a new promising paradigm to effectively accommodate both imaging and therapy functions in one well-defined framework for personalized precision disease treatment.

In situ hydrogel based on Cu-Fe3O4 nanoclusters exploits oxidative stress and the ferroptosis/cuproptosis pathway for chemodynamic therapy

Chemodynamic therapy (CDT) involving the use of metal nanozymes presents new opportunities for the treatment of deep-seated tumors. However, the lower ROS catalytic rate and dependence on high H2O2 concentrations affect therapeutic efficacy. To address this issue, a hydrogel was constructed for the treatment of osteosarcoma by combining Cu-Fe3O4 nanozymes (NCs) and artemisinin (AS) coencapsulated in situ with sodium alginate (ALG) and calcium ions. This hydrogel can release nanoparticles and AS within tumor tissue for an extended period of time, utilizing the multienzyme activity of NCs to achieve ROS accumulation. The carbon radicals (•C) generated from the interaction of Fe2+/Cu2+ with AS amplify oxidative stress, leading to tumor cell damage. Simultaneously, the NCs activate ferroptosis via the GPX4 pathway by depleting GSH and activate cuproptosis via the DLAT pathway by causing intracellular copper overload, enhancing therapeutic efficacy. In vitro experiments confirmed that the NCs-AS-ALG hydrogel has an excellent tumor cell killing effect, while in vivo experimental results demonstrated that it can effectively eliminate tumors with excellent biocompatibility, providing a new approach for osteosarcoma treatment.

Bimetallic clusterzymes-loaded dendritic mesoporous silica particle regulate arthritis microenvironment via ROS scavenging and YAP1 stabilization

Clusterzymes are synthetic enzymes exhibiting substantial catalytic activity and selectivity, which are uniquely driven by single-atom constructs. A dramatic increase in antioxidant capacity, 158 times more than natural trolox, is noted when single-atom copper is incorporated into gold-based clusterzymes to form Au24Cu1. Considering the inflammatory and mildly acidic microenvironment characteristic of osteoarthritis (OA), pH-dependent dendritic mesoporous silica nanoparticles (DMSNs) coupled with PEG have been employed as a delivery system for the spatial-temporal release of clusterzymes within active articular regions, thereby enhancing the duration of effectiveness. Nonetheless, achieving high therapeutic efficacy remains a significant challenge. Herein, we describe the construction of a Clusterzymes-DMSNs-PEG complex (CDP) which remarkably diminishes reactive oxygen species (ROS) and stabilizes the chondroprotective protein YAP by inhibiting the Hippo pathway. In the rabbit ACLT (anterior cruciate ligament transection) model, the CDP complex demonstrated inhibition of matrix metalloproteinase activity, preservation of type II collagen and aggregation protein secretion, thus prolonging the clusterzymes' protective influence on joint cartilage structure. Our research underscores the efficacy of the CDP complex in ROS-scavenging, enabled by the release of clusterzymes in response to an inflammatory and slightly acidic environment, leading to the obstruction of the Hippo pathway and downstream NF-κB signaling pathway. This study illuminates the design, composition, and use of DMSNs and clusterzymes in biomedicine, thus charting a promising course for the development of novel therapeutic strategies in alleviating OA.

Metal-chelated polydopamine nanomaterials: Nanoarchitectonics and applications in biomedicine, catalysis, and energy storage

Polydopamine (PDA)-based materials inspired by the adhesive proteins of mussels have attracted increasing attention owing to the universal adhesiveness, antioxidant activity, fluorescence quenching ability, excellent biocompatibility, and especially photothermal conversion capability. The high binding ability of PDA to a variety of metal ions offers a paradigm for the exploration of metal-chelated polydopamine nanomaterials with fantastic properties and functions. This review systematically summarizes the latest progress of metal-chelated polydopamine nanomaterials for the applications in biomedicine, catalysis, and energy storage. Different fabrication strategies for metal-chelated polydopamine nanomaterials with various composition, structure, size, and surface chemistry, such as the pre-functionalization method, the one-pot co-assembly method, and the post-modification method, are summarized. Furthermore, emerging applications of metal-chelated polydopamine nanomaterials in the fields ranging from cancer therapy, theranostics, antibacterial, catalysis to energy storage are highlighted. Additionally, the critical remaining challenges and future directions of this area are discussed to promote the further development and practical applications of PDA-based materials.

Engineering Strain-Defects to Enhance Enzymatic Therapy and Induce Ferroptosis

The effect of mimetic enzyme catalysis is often limited by insufficient activity and a single therapy is not sufficient to meet the application requirements. In this study, a multifunctional nanozyme, MMSR-pS-PEG, is designed and fabricated by modifying poly (ethylene glycol) grafted phosphorylated serine (pS-PEG) on mesoporous hollow MnMoOx spheres, followed by loading sorafenib (SRF) into the pores. Strain engineering-induced oxygen defects endow the nanozyme with enhanced dual-enzymatic activity to mimic catalase and oxidase-like activities, which catalyze the conversion of endogenous H2O2 into oxygen and subsequently into superoxide ions in the acidic tumor microenvironment. Moreover, as an n-type semiconductor, MnMoOx generates reactive oxygen species by separating electrons and holes upon ultrasonic irradiation and simultaneously deplete glutathione by holes, thereby further augmenting its catalytic effect. As a ferroptosis inducer, SRF restrains the system xc - and indirectly inhibits glutathione synthesis, synergistically interacting with the nanozyme to stimulate ferroptosis by promoting lipid peroxidation and accumulation and the downregulation of glutathione peroxidase 4. These results provide valuable insights into the design of enzymatic therapy with high performance and highlight a promising approach for the synergism of ferroptosis and enzymatic tumor therapy.

Utilizing stimuli-responsive nanoparticles to deliver and enhance the anti-tumor effects of bilirubin

Bilirubin (BR) is among the most potent endogenous antioxidants that originates from the heme catabolic pathway. Despite being considered as a dangerous and cytotoxic waste product at high concentrations, BR has potent antioxidant effects leading to the reduction of oxidative stress and inflammation, which play an important role in the development and progression of cancer. The purpose of this study is to introduce PEGylated BR nanoparticles (NPs), themselves or in combination with other anti-cancer agents. BR is effective when loaded into various nanoparticles and used in cancer therapy. Interestingly, BRNPs can be manipulated to create stimuli-responsive carriers providing a sustained and controlled, as well as on-demand, release of drug in response to internal or external factors such as reactive oxygen species, glutathione, light, enzymes, and acidic pH. This review suggests that BRNPs have the potential as tumor microenvironment-responsive delivery systems for effective targeting of various types of cancers.

Nanomaterial-based regulation of redox metabolism for enhancing cancer therapy

Altered redox metabolism is one of the hallmarks of tumor cells, which not only contributes to tumor proliferation, metastasis, and immune evasion, but also has great relevance to therapeutic resistance. Therefore, regulation of redox metabolism of tumor cells has been proposed as an attractive therapeutic strategy to inhibit tumor growth and reverse therapeutic resistance. In this respect, nanomedicines have exhibited significant therapeutic advantages as intensively reported in recent studies. In this review, we would like to summarize the latest advances in nanomaterial-assisted strategies for redox metabolic regulation therapy, with a focus on the regulation of redox metabolism-related metabolite levels, enzyme activity, and signaling pathways. In the end, future expectations and challenges of such emerging strategies have been discussed, hoping to enlighten and promote their further development for meeting the various demands of advanced cancer therapies. It is highly expected that these therapeutic strategies based on redox metabolism regulation will play a more important role in the field of nanomedicine.

A Universal Approach for High-Yield Synthesis of Single-Crystalline Ordered Macro-Microporous Metal-Organic Frameworks

Despite the excellent properties of single-crystalline ordered macro-microporous MOFs (SOM-MOFs) compared to conventional MOFs, their further development has been hindered by the lack of versatile and high-yielding preparation protocols. This study introduces an innovative universal fabrication method that can easily solve the two major challenges of precursor stabilization and crystallization modulation, enabling the efficient synthesis of various SOM-MOFs with high yields. Notably, our approach has successfully yielded SOM-MIL-88A, a novel MOF showcasing exceptional stability in both water and acidic solutions, a remarkable achievement unprecedented in prior SOM-MOF research. SOM-MIL-88A has demonstrated exponentially improved performance over conventional MIL-88A in adsorption, catalysis, immobilized enzymes, and composite biosensing. Furthermore, our versatile protocol has been successfully applied to synthesize SOM-HKUST-1 and SOM-ZIF-8, resulting in significantly improved yields (increase by about 10-fold and 2-fold, respectively, compared to the previously reported protocol). This groundbreaking achievement marks a pivotal advancement in the preparation of diverse SOM-MOFs with tailored properties, presenting exciting prospects for future research on MOFs.

Enzyme-Mimetic, Cascade Catalysis-Based Triblock Polypeptide-Assembled Micelles for Enhanced Chemodynamic Therapy

Peptides and their conjugates are appealing as molecular scaffolds for constructing supramolecular biomaterials from the bottom up. Through strategic sequence design and interaction modulation, these peptides can self-assemble into diverse nanostructures that can, in turn, mimic the structural and catalytic functions of contemporary proteins. Here, inspired by the histidine brace active site identified in the metalloenzyme, we developed a triblock polypeptide with a hydrophobic polyleucine segment, a hydrophilic polylysine segment, and a terminal oligohistidine segment. This polypeptide demonstrates tunable and adaptive self-assembly morphologies. Moreover, copper ions can interact with the oligohistidine chelator and mediate the supramolecular assembly, generating metal-ligand centers for redox flow. The triblock polypeptide-based peptide micelles show Fenton-type activity with high substrate affinity when coassembled with copper ions. We have also engineered therapeutic micelles by coassembling two polypeptides, one integrated with copper ions and the other conjugated with glucose oxidase. This coassembled nanoplatform shows high in vitro and in vivo antitumor efficacy through a mechanism that combines triggered starvation and chemodynamic therapy. The versatility of this polypeptide sequence, which is compatible with various metal ions and functional ligands, paves the way for a broad spectrum of therapeutic and diagnostic applications.