"Electron Transport Chain Interference" Strategy of Amplified Mild-Photothermal Therapy and Defect-Engineered Multi-Enzymatic Activities for Synergistic Tumor-Personalized Suppression

Trapping effect of surface deficient cocrystal synergizes with bimetallic nanoparticles against bacterial infection in wounds

Metal nanoparticles exert broad-spectrum antimicrobial effects through in situ generation of reactive oxygen species (ROS). However, the limited penetrability of ROS restricts the scope of antimicrobial activity of these nanoparticles. Herein, we develop core-shell nanoparticles composed of a surface-defective cocrystal shell and a Cu/Zn bimetallic core. Surface defects are generated by etching myricetin from a berberine-dihydromyricetin cocrystal, and bacterial adsorption efficiency peaks when the cocrystal contains 40 % myricetin. Similarly, Cu2+ doping on the surface of Zn nanoparticles to form a bimetallic core can optimize the ROS generation efficiency by facilitating effective electron transfer. Nanoparticles with this combined core-shell structure not only capture bacteria effectively but also draw bacteria into the ROS-killing range of the metal particles, thereby enhancing activity against drug-resistant bacteria. The feasibility of antibacterial infection was further validated in wounds of mice infected with Escherichia coli and Staphylococcus aureus. This strategy could be used to optimize antimicrobial nanoparticles with ROS-generating functionality and could have an impact on combating bacterial resistance.

A cancer theranostic nanoplatform for second near-infrared fluorescence imaging-guided carbon monoxide-sensitized mild photothermal therapy with ICD induction

Mild-temperature photothermal therapy (mild PTT), utilizing photothermal agents to convert external light into mild heat (<45 °C), holds significant potential as a localized treatment modality to induce cellular thermal damage. This therapeutic strategy not only directly eliminates targeted cells but also induces immunogenic cell death (ICD), activating the immune response. However, the presence of heat shock proteins (HSPs) can significantly reduce the effectiveness of photothermal therapy. Therefore, it is crucial to inhibit HSP repair and minimize damage to surrounding normal cells in order to enhance the efficiency of low-temperature PTT. Additionally, carbon monoxide (CO) has been shown to suppress the upregulation of HSPs in cancer cells under heat treatment. Furthermore, the utilization of second near-infrared (NIR-II) fluorescence particles can improve the precision and suitability of PTT due to their increased penetration depth and novel imaging capabilities. In this study, we developed a NIR-light-activated CO release system using CO-loaded mesoporous organosilica nanoparticles (CO-MON) for enhancing the effectiveness of mild PTT by suppressing HSPs repair through selectively targeted CO delivery. Triiron dodecacarbonyl (Fe3(CO)12), as the source of CO was employed for encapsulation within the pores of the MON. These MON showed emission in the NIR-II range, while also displaying remarkable photostability and a high efficiency in photothermal conversion (34.7 %). Through intratumoral administration, the CO-MON platform demonstrated efficient tumor accumulation and localized photothermal efficacy in vivo. In vitro and in vivo studies demonstrated that this exceptional photothermal effect not only effectively eliminated tumor but also augmented tumor ICD.

Multifunctional nanozymes: Promising applications in clinical diagnosis and cancer treatment

Cancer remains one of the greatest challenges in modern medicine. Traditional chemotherapy drugs often cause severe side effects, including nausea, vomiting, diarrhea, neurotoxicity, liver damage, and nephrotoxicity. In addition to these adverse effects, high recurrence and metastasis rates following treatment pose significant challenges for clinicians. There is an urgent need for novel therapeutic strategies to improve cancer treatment outcomes. In this context, nanozymes-artificial enzyme mimetics-have attracted considerable attention due to their unique advantages, including potent tumor-killing effects, enhanced biocompatibility, and reduced toxicity. Notably, nanozymes can dynamically monitor tumors through imaging and tracing. The multifunctional nanozyme (MN) is a promising research focus, integrating multiple catalytic activities, signal enhancement, sensing capabilities, and diverse modifications within a single nanozyme system. MNs can selectively target tumor regions, facilitating synergistic effects with other cancer therapies while enabling real-time imaging and tumor tracking. In this review, we first categorize MNs based on their composition and structural characteristics. We then discuss the primary mechanisms by which MNs exert their anticancer effects. Additionally, we review three types of MN biosensors and four MN-based therapeutic approaches applied in cancer treatment. Finally, we highlight the current challenges in MN research and provide an outlook on future developments in this field.

Tumor microenvironment-activated and near-infrared light-driven free radicals amplifier for tetra-modal cancer imaging and synergistic treatment

The tumor microenvironment (TME) exhibits a specific feature of hypoxia, which poses significant challenges for oxygen (O2)-dependent treatments. In this study, we developed an intelligent nanoplatform (PEGylated AIPH@MSN/CDs-MnO2, denoted as A@M/C-Mn) by integrating a photosensitizer of red carbon dots (CDs) with a thermolabile initiator-loaded mesoporous silica nanoparticle (AIPH@MSN, denoted as A@M), and then growing manganese dioxide nanosheets (MnO2 NS) in situ and PEGylating the structure to achieve TME-responsive synergistic diagnosis and phototherapy against hypoxic tumors. The outer-layer MnO2 NS has the capability to decompose endogenous hydrogen peroxide (H2O2) in the acidic TME, thereby producing O2 to alleviate hypoxia while releasing Mn2+. This process restores the fluorescence (FL) and photodynamic therapy (PDT) properties of the CDs, enhancing singlet oxygen (1O2) generation upon near-infrared (NIR) laser irradiation. Concomitantly, the exposed CDs induce hyperthermia for photothermal therapy (PTT) and promote the decomposition of AIPH to form cytotoxic alkyl radicals (R) for O2-independent PDT. Importantly, the entire treatment process can be monitored through ultrasound (US)/magnetic resonance (MR)/photoacoustic (PA)/FL imaging, owing to O2 production, Mn2+ release, and CDs activation, respectively. Both in vitro and in vivo results provide evidence that A@M/C-Mn represents a promising theranostic nanoagent for hypoxic tumors.

Supramolecular nanoagent as a dual-blocked thermoresistance inhibitor for effective mild-temperature photothermal therapy

Mild-temperature (<45 °C) photothermal therapy (PTT) is a promising approach to kill cancer cells by inhibiting the expression of heat shock proteins (HSPs) related to thermoresistance, a method commonly applied in most mild-temperature PTT studies. Regrettably, thermoresistance cannot be fully suppressed solely by inhibiting HSPs. Under normal conditions, heat shock factor 1 (HSF-1) remains inactive and forms a complex with HSPs. However, HSF-1 can dissociate from the complex and be activated, leading to the continuous production of significant amounts of HSPs, which in turn triggers thermoresistance upon heating. Therefore, simultaneously inhibiting both HSPs and HSF-1 activities presents a more effective strategy for developing mild-temperature PTT than only inhibiting HSPs. In this work, we focus on the complete blocking of thermoresistance to create a novel supramolecular nanoagent, IQ@NPs, for mild-temperature PTT. IQ@NPs demonstrated excellent drug release, tumor accumulation, and photothermal conversion, resulting in a rapid increase in the temperature of tumor sites to 42.9 °C within 5 min of irradiation. Western blotting revealed that IQ@NPs significantly inhibited the expression of HSPs (HSP90) and HSF-1. After 15 d treatment, tumor growth was significantly suppressed by IQ@NPs through effective mild-temperature PTT. Furthermore, IQ@NPs exhibited satisfactory safety and minimal side effects. This study represents a progressive advancement in mild-temperature PTT.

Bimetallic nanoreactor mediates cascade amplification of oxidative stress for complementary chemodynamic-immunotherapy of tumor

As a promising tumor treatment, chemodynamic therapy (CDT) can specifically catalyze H2O2 into the cytotoxic hydroxyl radical (·OH) via Fenton/Fenton-like reaction. However, the limited H2O2 and weakly acidic pH in tumor microenvironment (TME) would severely restrict the therapeutic efficiency of CDT. Here, a weakly acid activated, H2O2 self-supplied, hyaluronic acid (HA)-functionalized Ce/Cu bimetallic nanoreactor (CBPNs@HA) is elaborately designed for complementary chemodynamic-immunotherapy. In this nanoreactor, the component of peroxide group and Ce/Cu bimetals played the role of H2O2 self-supply and synergistic catalytic Fenton-like reaction, respectively. Specifically, CBPNs@HA can sensitively respond to TME (pH 6.8) and rapidly degrade to generate Ce4+, Cu+ and H2O2. The high-valence Ce4+ would be reduced by the intracellular glutathione (GSH) to generate Ce3+ and this process could be accelerated by Cu + via synergistic effect of Ce4+/Cu+. Particularly, the low-valence metallic ions (Ce3+ and Cu+) can react with the produced H2O2 to generate a multitude of reactive oxygen species (ROS). These cascaded effects can significantly amplify oxidative stress and seriously disturb the redox balance of tumor cells, inducing the potent immunogenic cell death (ICD) to release tumor-specific antigens and thereby activating the powerful antitumor immune responses. After combined with immune checkpoint blockade (ICB), CBPNs@HA can significantly heighten antitumor effects to inhibit the growth of primary and metastatic tumors, and dramatically prolong the survival lifetime of 4T1 tumor-bearing mice to 60 days. This work provides a materials-based strategy for enhanced CDT and highlights new opportunities for complementary chemodynamic-immunotherapy.

Small molecular fluorescent probes featuring protein-assisted functional amplification for improved biosensing and cancer therapeutics

In recent years, small molecular fluorescent probes have significantly advanced biosensing and cancer therapy, enabling applications such as target detection, cellular imaging, fluorescence-guided surgery, and phototherapy. However, conventional small molecular probes face limitations, including low biocompatibility, poor stability, and weak signal intensity. Protein-coordinated fluorescent probes have emerged as a promising solution, leveraging protein-assisted functional amplification to address these challenges. Mechanisms such as environmental shielding, conformational restriction, charge stabilization, and increased local concentration collectively enhance fluorescence emission and phototherapeutic efficacy. This article reviews recent progress (primarily within the last five years) in protein-coordinated fluorescent probes for biosensing and cancer therapy. It begins with a systematic summary of the interaction strategies between proteins and fluorescent probes and details key mechanisms behind protein-assisted functional amplification. Subsequently, the applications of these probes in biosensing and cancer therapy are comprehensively concluded. Finally, current challenges and future prospects are discussed in depth. This review aims to refine design strategies for protein-coordinated fluorescent probes and inspire innovative approaches in biosensing and cancer therapy.

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.

Enhancing the Reactivity of Nanozymes by Asymmetric Structural Oxygen Vacancy Electron Transfer for Colorimetric Sensing and TAC Analysis

By regulating the electron density of atoms within the reaction active center, the catalytic activity of nanozymes can be precisely controlled, thereby enhancing their reactivity and sensitivity in applications such as colorimetric sensing. In this study, we synthesized metal oxide Fe-MMOov nanozymes, enriched with doping defects and oxygen vacancy defects, by Fe-doped LDH with an ultrathin 2D structure through roasting-induced topological transformation. This process tunes the electron density distribution within the active center atoms of the nanozymes through its intrinsic asymmetric Zn-Ov-Fe doping structure, resulting in excellent POD-like and OXD-like multienzyme activities. This enhancement contributes to the overall effectiveness of nanozymes in applications such as colorimetry. These improvements facilitated its successful application in the total antioxidant capacity (TAC) detection of various fruit juices and commercial beverages. Density functional theory (DFT) calculations revealed that the d-band center of the Fe active center is enhanced by the Ov microenvironment within the Fe-MMOov nanozyme, leading to improved catalytic activity. Based on this, a Fe-MMOov/TMB visual colorimetric system was established and successfully validated for colorimetric detection of analytes such as ascorbic acid, cysteine, and glutathione. It was further integrated with a mobile platform for on-site TAC detection in food samples. This study introduces an approach for nanozyme design in colorimetric sensing while also presenting a rapid, cost-effective, and dependable strategy for the miniaturization, convenience, and widespread applicability of TAC detection. We demonstrate how the introduction of oxygen vacancies into Fe-MMOov nanozymes enhances their catalytic activity, paving the way for the development of more efficient catalysts in colorimetric detection.

Dual-engineered strategy of Ni-CeOv nanozyme with enhanced oxidase activity for sensitive colorimetric detection of total antioxidant capacity

Antioxidants are crucial in the fight against reactive oxygen species and thus in maintaining organismal health, so it is particularly important to realize a rapid and quantitative assay for common antioxidants in life. Current nanozyme-based total antioxidant capacity (TAC) assays face limitations: hydrogen peroxide (H2O2) dependence, noble metal costs, and poor antioxidant discrimination. To address these challenges, we engineered a dual-regulated Ni-doped CeO2 (Ni-CeOv) nanozyme through oxygen vacancy engineering and 3d-2p-4f orbital coupling. Density functional theory (DFT) calculations revealed that Ni doping synergistically affects the spontaneous formation of oxygen vacancies and enhances electron transfer through gradient orbital hybridization, resulting in a 2-fold increase in oxidase-like activity (Vmax = 0.10 μM/s) compared to undoped CeO2. Leveraging this H2O2-independent nanozyme, we developed a portable colorimetric platform capable of both ultra-sensitive detection and antioxidant discrimination through distinct inhibition kinetics. Integration with smartphone-based paper sensors enabled on-site TAC quantification in commercial beverages and cosmetics within 5 min, achieving recovery rates of 98.35-104.41 %, at a cost of only $0.2/assay. This work establishes a paradigm for developing low-cost, field-deployable nanozyme sensors for the detection of TAC.

A simple co-assembly strategy to control the dimensions of nanoparticles for enhanced synergistic therapy

Despite phthalocyanine has excellent photodynamic and photothermal effects as a photosensitizer and photothermal agent, hydrophobicity and aggregation limits its biological application. In this paper, phthalocyanine-cyanine co-assembled nanoparticles were designed to modulate the dimensions and morphology by introducing water-soluble cyanine. The cyanine had the ability to transform the nanomaterials from microrods to nanospheres, thus successfully constructing photoactivated nanomedicines. Their appropriate size effect and improved water solubility conferred the nanoparticles with extended blood circulation time and tumor accumulation capacity. Meanwhile, the fluorescence effect of cyanine enabled the nanoparticles to have the ability of fluorescence imaging. The nanoparticles achieved enhanced PDT/PTT synergistic effect under single laser induction, especially the generation of type I photodynamics.

Mutual boost between free radicals and photothermal effect for synergistic photothermal/thermodynamic antibacterial therapy

Combined treatment is a promising strategy in antibacterial treatment, which could alleviate the shortcomings of monotherapy and achieve better therapeutic effects. In this work, mutual boost between free radical generation and photothermal effect for synergistic photothermal/thermodynamic antibacterial therapy was reported. Mesoporous silica nanoparticles were used as drug carrier for loading dibenzoyl peroxide (BPO). The pores of mesoporous silica nanoparticles were blocked by GSH-responsive polyethylenimine (PEI) layer. 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) was then adsorbed via electrostatic force to prepare the nanosystem. At the site of bacterial infection, the BPO was released and decomposed to aryl radicals. The aryl radicals oxidized ABTS to photothermal reagent of ABTS·+, which produced photothermal effect to enhance the antibacterial effect under 808 nm laser irradiation. Moreover, the photothermal effect accelerated the decomposition of BPO to boost the levels of free radicals as a return, further improved the antibacterial efficiency. The in vitro experiments indicated that the photothermal/thermodynamic therapeutic nanosystem have a synergistic antibacterial effect efficiency (˃95 %) for both E. coli and S. aureus, as well as biofilm disruption and inhibition. This mutual boost between free radical ion generation and photothermal effect provides a new and feasible strategy for the synergistic antibacterial therapy.

Genetically Engineered IL12/CSF1R-Macrophage Membrane-Liposome Hybrid Nanovesicles for NIR-II Fluorescence Imaging-Guided and Membrane-Targeted Mild Photothermal-Immunotherapy of Glioblastoma

It is a big challenge for precision therapy of glioblastoma, mainly due to the existence of blood-brain barrier (BBB), tumor immunosuppressive microenvironment (TIM), and lack of efficient treatment paradigms. Herein, a theranostic nanoplatform for the second near-infrared window (NIR-II) fluorescence imaging-guided membrane-targeted mild photothermal-immunotherapy of glioblastoma using genetically engineered CSF1R/IL12-macrophage membrane (MM)-liposome hybrid nanovesicles, is reported. By mimicking lipophilic membrane probe (Dil) with octadecyl chains, a NIR-II emissive photothermal dye (IRC18), which realizes labeling of nanovesicle lipid bilayers for biodistribution tracing, glioblastoma diagnosis, and molecular imaging of tumoral microenvironment, is synthesized. Importantly, MM and c-RGD-decorated liposome together offer BBB crossing, tumor targeting, and long-term circulation; while, the genetically overexpressed CSF1R and IL12 on MM surface contribute to effective modulation of M2-to-M1 macrophage repolarization and local promotion of T cell cytotoxicity in glioblastoma microenvironment, respectively. Notably, through membrane fusion, IRC18 dyes translocate from nanovesicle lipid bilayers to glioblastoma membranes, which achieve membrane-targeted mild photothermal therapy to ablate primary tumor and induce immunogenic cell death to promote antigen presentation. More importantly, the combined blockade of the CSF1-CSF1R axis and IL-12 enrichment not only reprograms the tumor microenvironment through macrophage M1 repolarization but also activates cytotoxic T cells, ultimately achieving complete glioblastoma eradication. This research provides an efficient theranostic paradigm for glioblastoma treatment.

Multifunctional Hollow Bimetallic Sulfide Nanozyme Enables Imaging-Guided Synergistic Ferrotherapy for Tumor Treatment

The design of nanozymes with controlled properties and well-defined mechanisms holds significant promise for advancing next-generation functional biomaterials for tumor theranostics. Here, we develop a metal-organic framework (MOF)-derived bimetallic sulfide nanozyme, FCS, for ferrotherapy via combined photothermal and catalytic therapies. FCS is synthesized by vulcanizing the zeolitic imidazolate framework-67 (ZIF-67) into cobalt sulfide (Co3S4, CS), followed by ferrous cation exchange, resulting in enhanced near-infrared II photothermal conversion and superior Fenton-like catalytic activity. Theoretical calculations attribute these enhancements to Fe doping, which narrows the band gap, promotes electron transfer to H2O2, and lowers the energy barrier for active oxygen species generation. FCS effectively induces ferroptosis through lipid peroxidation, while supporting T2-weighted magnetic resonance imaging. This study presents a robust strategy for MOF transformation into multifunctional tumor theranostic agents, highlighting the role of metal ion doping in optimizing nanozyme performance.

Closed-loop cascade nanozyme strategy for mutually reinforced catalytic and mild-temperature photothermal therapeutic effects

Nanocatalysis coupled with photothermal therapy is a potent anti-cancer approach, yet its clinical utility is limited by low concentration of tumor substrate, redox interference, and risks of overheating normal tissues. Herein, we propose an innovative closed-loop nanozyme approach that leverages the synergistic effects of catalytic and mild photothermal therapy (mPTT) to address aforementioned challenges. The strategy features a folic acid-functionalized iron single-atom catalyst (FeNC-FA), designed to exhibit exceptional multienzymatic capabilities and an optimal photothermal response. In the system, the engineered FeNC-FA is capable of inducing reactive oxygen species (ROS) storm and depleting glutathione (GSH) in the specific tumor microenvironment (TME) to initiate ferroptosis. Concurrently, the accumulation of ROS effectively cleaves heat shock proteins (HSPs), thereby enhancing mPTT. An intriguing aspect is that the increased temperature within the TME further facilitates the conversion of H2O2 to O2, alleviating hypoxia and providing a positive feedback circuit to boost catalytic therapy. Additionally, the advanced photoacoustic (PA) imaging capabilities of FeNC-FA allow for self-monitoring of their accumulation at tumor sites, thereby guiding the mPTT process. Taken together, it provides a PA image-guided, mutually reinforced catalytic and mild photothermal synergistic tumor therapy both in vitro and in vivo. This targeted and synergistic strategy holds great promise for personalized medicine applications.

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.

Catalase-assembled nanoparticles for PA/CT dual-modality imaging and repair of acute alcoholic gastritis

The development of simple, rapid, sensitive and noninvasive theranostic agents for acute gastritis is crucial. Herein, an engineering catalase-conjugated bismuth nanoparticle was fabricated for near-infrared photoacoustic imaging and computed tomography imaging of acute alcoholic gastritis. This nanoparticle could quickly respond to H2O2 and H+ overexpressed in the microenvironment of acute gastritis in mice, emitting strong signals for precise localization. Additionally, it adhered to the damaged gastric mucosa for an extended period, acting as a long-acting mucosal protector by inhibiting related inflammatory reactions and promoting mucosal repair. The use of this catalase-assembled nanoparticle could extend its residence time in the stomach, thereby reducing the drug dose and treatment duration. These findings of our study underscored the potential of this multifunctional nanoplatform for integrated diagnosis and treatment of gastrointestinal inflammatory diseases.

Injectable and adhesive MgO2-potentiated hydrogel with sequential tumor synergistic therapy and osteogenesis for challenging postsurgical osteosarcoma treatment

The clinical treatment of osteosarcoma faces great challenges of residual tumor cells leading to tumor recurrence and irregular bone defects difficult to repair after surgery removal of the primary tumor tissue. We developed an injectable and in-situ cross-linkable hydrogel (named MOG hydrogel) using MgO2 nanoparticles and dopamine-conjugated gelatin as main components. MgO2 was rationally designed as a multifunctional active ingredient to mediate in situ gelation, tumor therapy, and bone repair sequentially. The 10MOG (with 10 mg/mL MgO2 content) showed excellent gel stability, injectability, shape adaptability, tissue adhesion, and rapid hemostatic ability. Importantly, 10MOG exhibited ideal sequential H2O2 and Mg2+ release property. The released H2O2 synergized with photothermal therapy for enhanced tumor recurrence suppression, and the sustainable Mg2+ release efficiently promoted bone regeneration. The MOG hydrogel, possessing excellent on-demand antitumor and osteogenic capabilities in vitro and in vivo, exhibited tremendous potential in the clinical application for challenging postsurgical osteosarcoma treatment.

Biocatalytic cascade reactions for management of diseases

Biocatalytic cascade reactions, which evolve from the confinement of multiple enzymes within living cells, represent a promising strategy for disease management. Using tailor-made nanoplatforms, reactions induced by multiple enzymes and/or nanozymes can be precisely triggered at pathogenic sites. These promote further cascade reactions that generate therapeutic species prompting effective therapeutic outcomes with minimal side effects. Over the past few years, this approach has seen widespread applications in disease management. This review attempts to critically assess and summarize the recent advances in the use of biocatalytic cascade reactions for the management of diseases. Emphasis is placed on the design of cascade catalytic systems of high efficiency and selectivity and the implementation of specific cascade processes that respond to the endogenous substances produced in the pathological processes. The various types of biocatalytic cascade reactions are outlined according to the timeline of the catalytic steps through a series of reported examples. The challenges and outlook in the field are also discussed to encourage the further development of personalized treatments based on biocatalytic cascade reactions.

Rational Design of Nanozymes for Engineered Cascade Catalytic Cancer Therapy

Nanozymes have shown significant potential in cancer catalytic therapy by strategically catalyzing tumor-associated substances and metabolites into toxic reactive oxygen species (ROS) in situ, thereby inducing oxidative stress and promoting cancer cell death. However, within the complex tumor microenvironment (TME), the rational design of nanozymes and factors like activity, reaction substrates, and the TME itself significantly influence the efficiency of ROS generation. To address these limitations, recent research has focused on exploring the factors that affect activity and developing nanozyme-based cascade catalytic systems, which can trigger two or more cascade catalytic processes within tumors, thereby producing more therapeutic substances and achieving efficient and stable cancer therapy with minimal side effects. This area has shown remarkable progress. This Perspective provides a comprehensive overview of nanozymes, covering their classification and fundamentals. The regulation of nanozyme activity and efficient strategies of rational design are discussed in detail. Furthermore, representative paradigms for the successful construction of cascade catalytic systems for cancer treatment are summarized with a focus on revealing the underlying catalytic mechanisms. Finally, we address the current challenges and future prospects for the development of nanozyme-based cascade catalytic systems in biomedical applications.

Mitochondrial-Targeted Multifunctional Platinum-Based Nano "Terminal-Sensitive Projectile" for Enhanced Cancer Chemotherapy Efficacy

Platinum-based anticancer drugs exert their effects by forming adducts within nuclear DNA (nDNA), inhibiting transcription and inducing apoptosis in cancer cells. However, tumor cells have evolved mechanisms to resist these drugs. Given mitochondria's role in cancer and their lack of nucleotide excision repair (NER), targeting mitochondrial DNA (mtDNA) offers a strategy. Herein, a platinum-based terminal-sensitive projectile (TSB) which comprises a heterofunctional tetravalent platinum prodrug as the primary warhead, complemented by a guidance system incorporating triphenylphosphine (TPP) and a secondary warhead, FFa (Fenofibric acid) was developed. TSB was then encapsulated within IR780 coupling DSPE-PEG2K for enhanced delivery (NTSB). This design allows the TSB to be precisely targeted into intertumoral mitochondria as its targeting terminal, releasing free oxaliplatin (OXA) and FFa upon reaching its terminal destination. The accumulation of OXA leads to cross-linking with mtDNA, causing mitochondrial dysfunction, while FFa disrupts the electron transport chain (ETC), impairing oxidative phosphorylation (OXPHOS). Furthermore, under near-infrared (NIR) irradiation, the IR780 component generates a phototherapeutic thermal effect and reactive oxygen species (ROS), which deplete intracellular glutathione (GSH) levels and facilitate Pt cross-linking with mtDNA. Both in vitro and in vivo studies have demonstrated that this comprehensive approach significantly enhances the sensitivity of tumor cells to platinum-based chemotherapeutic drugs.

Progress in the Computer-Aided Analysis in Multiple Aspects of Nanocatalysis Research

Making the utmost of the differences and advantages of multiple disciplines, interdisciplinary integration breaks the science boundaries and accelerates the progress in mutual quests. As an organic connection of material science, enzymology, and biomedicine, nanozyme-related research is further supported by computer technology, which injects in new vitality, and contributes to in-depth understanding, unprecedented insights, and broadened application possibilities. Utilizing computer-aided first-principles method, high-speed and high-throughput mathematic, physic, and chemic models are introduced to perform atomic-level kinetic analysis for nanocatalytic reaction process, and theoretically illustrate the underlying nanozymetic mechanism and structure-function relationship. On this basis, nanozymes with desirable properties can be designed and demand-oriented synthesized without repeated trial-and-error experiments. Besides that, computational analysis and device also play an indispensable role in nanozyme-based detecting methods to realize automatic readouts with improved accuracy and reproducibility. Here, this work focuses on the crossing of nanocatalysis research and computational technology, to inspire the research in computer-aided analysis in nanozyme field to a greater extent.

Ce12V6 Clusters with Multi-Enzymatic Activities for Sepsis Treatment

Artificial enzymes, especially nanozymes, have attracted wide attention due to their controlled catalytic activity, selectivity, and stability. The rising Cerium-based nanozymes exhibit unique SOD-like activity, and Vanadium-based nanozymes always hold excellent GPx-like activity. However, most inflammatory diseases involve polymerase biocatalytic processes that require multi-enzyme activities. The nanocomposite can fulfill multi-enzymatic activity simultaneously, but large nanoparticles (>10 nm) cannot be excreted rapidly, leading to biosafety challenges. Herein, atomically precise Ce12V6 clusters with a size of 2.19 nm are constructed. The Ce12V6 clusters show excellent glutathione peroxidase (GPx) -like activity with a significantly lower Michaelis-Menten constant (Km, 0.0125 mM versus 0.03 mM of natural counterpart) and good activities mimic superoxide dismutase (SOD) and peroxidase (POD). The Ce12V6 clusters exhibit the ability to scavenge the ROS including O2 ·- and H2O2 via the cascade reactions of multi-enzymatic activities. Further, the Ce12V6 clusters modulate the proinflammatory cytokines including tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) and consequently rescue the multi-organ failure in the lipopolysaccharide (LPS)-induced sepsis mouse model. With excellent biocompatibility, the Ce12V6 clusters show promise in the treatment of sepsis.

Ultrathin high-entropy hydrotalcites-based injectable hydrogel with programmed bactericidal and anti-inflammatory effects to accelerate drug-resistant bacterial infected wound healing

Drug-resistant bacteria infected wounds often bring high risks of delayed healing process and even death. Sonodynamic therapy (SDT) can efficiently kill drug-resistant bacteria. However, superabundant reactive oxygen species (ROS) generated during SDT inevitably trigger significant inflammatory responses, hindering tissue remodeling. Herein, we develop intelligent ultrathin high-entropy hydrotalcites (UHE-HTs)-based injectable thermal-responsive hydrogel loaded with nicotinamide mononucleotide (UHE-HTs/PFN), aiming to achieve programmed antibacterial and anti-inflammatory effects. In the early infection stage, sonosensitive UHE-HTs/PFN hydrogel simultaneously can trigger rapid production of singlet oxygen (1O2) under ultrasound and efficient MDR bacterial sterilization. After halting ultrasonic irradiation, oxidoreductase-mimicking catalysis and nicotinamide mononucleotide release of UHE-HTs/PFN hydrogel effectively reduce ROS levels at wound sites, dampening the NF-κB inflammatory pathway. Such inhibited NF-κB expression can not only reduce the production of pro-inflammatory cytokines and inflammatory responses, but also significantly down-regulate the pyroptosis pathways (NLRP3/ASC/Casp-1) and inhibit pyroptosis that leads to inflammation. Moreover, significantly reduced ROS levels and synergistic release of Mg2+ reverse pro-inflammatory immune microenvironment. Both in vitro and in vivo assays demonstrate that UHE-HTs/PFN hydrogel can transform the adverse infected wound environment into a regenerative one by eradicating drug-resistant bacteria, scavenging ROS, and synergistic anti-inflammation. Therefore, this work develop an intelligent UHE-HTs/PFN hydrogel act as a "lever" that effectively achieve a balance between ROS generation and annihilation, rebuilding harmonious bactericidal and anti-inflammatory effects to remedy drug-resistant bacteria infected wound.

Recent advances in chemodynamic nanotherapeutics to overcome multidrug resistance in cancers

Multidrug resistance (MDR) has become a major challenge in cancer therapy, it results in the failure of chemotherapy and anticancer drug development. Chemodynamic therapy (CDT), an emerging cancer treatment strategy, has been reported as a novel approach for cancer treatment characterized by low toxicity and minimal side effects. By generating robust cytotoxic hydroxyl radicals (·OH) via Fenton/Fenton-like reaction, CDT may cause cellular damage and oxidative stress-induced cell death. In recent years, many therapies based on CDT and/or combined with other treatment modalities are reported and exhibit exciting treatment efficacy in cancer treatment, such as photothermal therapy, photodynamic therapy, sonodynamic therapy, chemotherapy, starvation therapy and gas therapy etc. These combination therapies exhibit synergistic effects, significantly improving anticancer outcomes compared to CDT alone. Herein, we provide a comprehensive overview of CDT-based strategies in cancer treatment, highlighting developments of CDT and CDT-based combination strategies in tumor therapy, especially in overcoming MDR challenges. Finally, the opportunities and challenges of CDT and CDT-combination therapy in the clinical application are also addressed.

Mitochondrial-uncoupling nanomedicine for self-heating and immunometabolism regulation in cancer cells

Developing endogenous hyperthermia offers a promising strategy to address challenges with current exogenous hyperthermia techniques in clinics. Herein, a CD44-targeted and thermal-responsive nanocarrier was developed for the simultaneous delivery of 2,4-dinitrophenol and syrosingopine. The objective was to induce endogenous hyperthermia and regulate immunometabolism, ultimately augmenting anti-tumour immune responses. Dinitrophenol as mitochondrial uncoupler can convert electrochemical potential energy of inner mitochondrial membrane into heat, facilitating endogenous hyperthermia. Meanwhile, syrosingopine not only inhibits excessive lactate efflux caused by dinitrophenol but also downregulates tumour cell glycolysis, thus alleviating immunosuppression and heat shock protein (HSP)-dependent thermo-resistance through immunometabolism regulation. The synergistic effects of endogenous hyperthermia and immunometabolism regulation by this nanomedicine have potential to enhance tumor immunogenicity, reshape the tumour immune microenvironment, and effectively suppress the growth of subcutaneous tumours and patient-derived organoids in triple-negative breast cancer. Therefore, the endogenous hyperthermia strategy developed in this study would revolutionize hyperthermia for cancer treatment.

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

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

One-Pot Synthesis of Oxygen Vacancy-Rich Amorphous/Crystalline Heterophase CaWO4 Nanoparticles for Enhanced Radiodynamic-Immunotherapy

Radiodynamic therapy that employs X-rays to trigger localized reactive oxygen species (ROS) generation can tackle the tissue penetration issue of phototherapy. Although calcium tungstate (CaWO4) shows great potential as a radiodynamic agent benefiting from its strong X-ray absorption and the ability to generate electron-hole (e--h+) pairs, slow charge carrier transfer and fast e--h+ recombination greatly limit its ROS-generating performance. Herein, via a one-pot wet-chemical method, oxygen vacancy-rich amorphous/crystalline heterophase CaWO4 nanoparticles (Ov-a/c-CaWO4 NPs) with enhanced radiodynamic effect are synthesized for radiodynamic-immunotherapy of cancer. The phase composition and oxygen vacancy content of CaWO4 can be easily tuned by adjusting the solvothermal temperature. More intriguingly, the amorphous/crystalline interfaces and abundant oxygen vacancies accelerate charge carrier transfer and suppress e--h+ recombination, respectively, enabling synergistically improved ROS production from X-ray-irradiated Ov-a/c-CaWO4 NPs. In addition to directly inducing oxidative damage of cancer cells, radiodynamic generation of ROS also boosts immunogenic cell death to provoke a systemic antitumor immune response, thereby allowing the inhibition of both primary and distant tumors as well as cancer metastasis. This study establishes a synergistic enhancement strategy involving the integration of phase and defect engineering to improve the ROS generation capacity of radiodynamic-immunotherapeutic anticancer nanoagents.

L-Arginine-Modified Selenium Nanozymes Targeting M1 Macrophages for Oral Treatment of Ulcerative Colitis

Ulcerative colitis (UC) involves persistent inflammation in the colon and rectum, with excessive reactive oxygen species (ROS) accumulation. This ROS buildup damages colonic epithelial cells and disrupts intestinal flora, worsening disease progression. Current antioxidant therapies are limited due to their instability in the gut and lack of targeting, hindering precise intervention at the lesion site. This study prepares an L-Arginine-modified selenium nanozyme (Se-CA) for the targeted oral treatment of UC. Se-CA specifically targets M1-type macrophages at sites of inflammation by binding to cationic amino acid transporter protein 2 on the surface of M1-type macrophages. In vitro studies show that Se-CA scavenges reactive ROS and reactive nitrogen species (RNS) in artificial gastric acid and intestinal fluids, and inhibits iron death in intestinal epithelial cells. In mice model of ulcerative colitis, oral administration of Se-CA is effective in the treatment of colitis through its anti-inflammatory and antioxidant properties, inhibition of iron death and regulation of intestinal flora. In conclusion, this work provides new insights into the targeted oral treatment of UC.

Preclinical advance in nanoliposome-mediated photothermal therapy in liver cancer

Liver cancer is a highly lethal malignant tumor with a high incidence worldwide. Therefore, its treatment has long been a focus of medical research. Although traditional treatment methods such as surgery, radiotherapy, and chemotherapy have increased the survival rate of patients, their efficacy remains unsatisfactory owing to the nonspecific distribution of drugs, high toxicity, and drug resistance of tumor tissues. In recent years, the application of nanotechnology in the medical field has opened a new avenue for the treatment of liver cancer. Among these treatment methods, photothermal therapy (PTT) based on nanoliposomes has attracted wide attention owing to its unique targeting and high efficiency. This article reviews the latest preclinical research progress of nanoliposome-based PTT for liver cancer and its metastasis, discusses the preclinical challenges in this field, and proposes directions for improvement, with the aim of improving the effectiveness of liver cancer treatment.

High Entropy 2D Layered Double Hydroxide Nanosheet Toward Cascaded Nanozyme-Initiated Chemodynamic and Immune Synergistic Therapy

High-entropy nanomaterials (HEMs) are a hot topic in the fields of energy and catalysis. However, in terms of promising biomedical applications, potential therapeutic studies involving HEMs are unprecedented. Herein, we demonstrated high entropy two-dimensional layered double hydroxide (HE-LDH) nanoplatforms with versatile physicochemical advantages that reprogram the tumor microenvironment (TME) and provide antitumor treatment via cascaded nanoenzyme-initiated chemodynamic and immune synergistic therapy. In response to the TME, the multifunctional HE-LDHs sequentially release metal ions, such as Co2+, Fe3+, and Cu2+, exhibiting exquisite superoxide dismutase (SOD), peroxidase (POD), and glutathione peroxidase (GPX) activities. The multiple enzymatic activities convert specific tumor metabolites into a continuous supply of cytotoxic reactive oxygen species (ROS) to relieve hypoxia under a TME. Thus, HE-LDHs facilitate robust nanozyme-initiated chemodynamic therapy (NCDT), achieving high therapeutic efficacy without obvious side effects. In addition, the release of Zn2+ from the HE-LDH matrix triggers the cyclic GMP-AMP synthase/stimulator of interferon gene (cGAS/STING) signaling pathway, boosting the innate immunotherapeutic efficacy. The intratumoral applications of the nanocomposite in tumor-bearing mice models indicate that HE-LDH-mediated NCDT and immune synergistic therapy effectively upregulated the expression of relevant antitumor cytokines and induced cytotoxic T lymphocyte infiltration, showing superior efficacy in inhibiting tumor growth. Therefore, this work opens a new research direction toward synchronized NCDT and immunotherapy of tumors using HEMs for advanced healthcare.

Self-Regenerating Photothermal Agents for Tandem Photothermal and Thermodynamic Tumor Therapy

Small molecule-based photothermal agents (PTAs) hold promising future for photothermal therapy; however, unexpected inactivation exerts negative impacts on their application clinically. Herein, a self-regenerating PTA strategy is proposed by integrating 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS•+) with a thermodynamic agent (TDA) 2,2'-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIPH). Under NIR laser, the photothermal effect of ABTS•+ accelerates the production of alkyl radicals by AIPH, which activates the regeneration of ABTS•+, thus creating a continuous positive feedback loop between photothermal and thermodynamic effects. The combination of ABTS•+ regeneration and alkyl radical production leads to the tandem photothermal and thermodynamic tumor therapy. In vitro and in vivo experiments confirm that the synergistic action of thermal ablation, radical damage, and oxidative stress effectively realizes tumor suppression. This work offers a promising approach to address the unwanted inactivation of PTAs and provides valuable insights for optimizing combination therapy.

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.

Current advances in nanozyme-based nanodynamic therapies for cancer

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

Engineering Semiconducting Polymeric Nanoagonists Potentiate cGAS-STING Pathway Activation and Elicit Long Term Memory Against Recurrence in Breast Cancer

Triple-negative breast cancer has an immunologically "cold" microenvironment, which leads to resistance to current immunotherapy. The activation of stimulator of interferon genes (STING) pathway has been thought a promising strategy to enhance immunotherapy efficacy. In this study, we adopted a comprehensive strategy that integrates innate immune responses with tumor-targeting photothermal therapy (PTT) to simultaneously tackle multiple immune-suppressive mechanisms in breast cancer. This semiconducting polymeric nanoagonists (DPTT-Mn Lipo NPs) mediated PTT can effectively initiate tumor cell apoptosis and induce ICD, thereby reprogramming the immunosuppressive TME and activating STING. We confirmed the modulation of the TME through the PTT-mediated ICD effect and the transactivation of the cGAS-STING pathway in immune cells of the TME due to the released dsDNA via ICD, such as macrophages and DCs. Indeed, DPTT-Mn Lipo NPs-mediated PTT promoted M1 polarization of tumor-associated macrophages, augmented T-cell infiltration, facilitated dendritic cell (DC) maturation, and regulated type I interferon factor secretion, leading to efficient tumor suppression. Most importantly, the combination of DPTT-Mn Lipo NPs-based PTT with a checkpoint blockade therapy (anti-PD-1) can elicit long-term immune memory besides tumor eradication. Collectively, this nano-system can systemically activate antitumor immunity through STING activation and potentially establish long-term memory against tumor recurrence.

Trojan Horse Bioheterojunction Empowers Adhesive Hydrogel with Robust Antibacterial Activity and Sensing Capacity for Infected Cutaneous Regeneration

Strategic integration of adhesive hydrogels with phototherapy-based antibacterial properties has been extensively leveraged in infected tissue repair. Nevertheless, the interference of bacterial heat shock proteins and antioxidant defense systems attenuates the bactericidal potency of phototherapy. To address this imposing predicament, a Trojan horse bioheterojunction (Th-bioHJ) incorporating liquid metal and copper sulfide is devised to confer an adhesive hydrogel with multimodal and comprehensive antibacterial properties for remedying infectious wounds. Th-bioHJ generates phototherapeutic effects and interrupts the electron transport chain with the Trojan horse strategy, achieving rapid and robust sterilization. Additionally, Th-bioHJ promotes cell migration and angiogenesis. In vivo studies elucidate the remarkable efficacy of Th-bioHJ hydrogel in rapidly eradicating bacteria, promoting angiogenesis and boosting infectious cutaneous regeneration. Meanwhile, the Th-bioHJ hydrogel demonstrates exceptional biointerface adhesion and sensing capabilities for real-time motion monitoring. This study provides groundbreaking insights into the innovative application of an adhesive hydrogel in the management of infected wounds.

Photocatalytic therapy via photoinduced redox imbalance in biological system

Redox balance is essential for sustaining normal physiological metabolic activities of life. In this study, we present a photocatalytic system to perturb the balance of NADH/NAD+ in oxygen-free conditions, achieving photocatalytic therapy to cure anaerobic bacterial infected periodontitis. Under light irradiation, the catalyst TBSMSPy+ can bind bacterial DNA and initiate the generation of radical species through a multi-step electron transfer process. It catalyzes the conversion from NADH to NAD+ (the turnover frequency up to 60.7 min-1), inhibits ATP synthesis, disrupts the energy supply required for DNA replication, and successfully accomplishes photocatalytic sterilization in an oxygen-free environment. The catalyst participates in the redox reaction, interfering with the balance of NADH/NAD+ contents under irradiation, so we termed this action as photoinduced redox imbalance. Additionally, animal experiments in male rats also validate that the TBSMSPy+ could effectively catalyze the NADH oxidation, suppress metabolism and stimulate osteogenesis. Our research substantiates the concept of photoinduced redox imbalance and the application of photocatalytic therapy, further advocating the development of such catalyst based on photoinduced redox imbalance strategy for oxygen-free phototherapy.

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

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

A strategy of "adding fuel to the flames" enables a self-accelerating cycle of ferroptosis-cuproptosis for potent antitumor therapy

Cuproptosis in antitumor therapy faces challenges from copper homeostasis efflux mechanisms and high glutathione (GSH) levels in tumor cells, hindering copper accumulation and treatment efficacy. Herein, we propose a strategy of "adding fuel to the flames" for potent antitumor therapy through a self-accelerating cycle of ferroptosis-cuproptosis. Disulfiram (DSF) loaded hollow mesoporous copper-iron sulfide (HMCIS) nanoparticle with conjugation of polyethylene glycol (PEG) and folic acid (FA) (i.e., DSF@HMCIS-PEG-FA) was developed to swiftly release DSF, H2S, Cu2+, and Fe2+ in the acidic tumor microenvironment (TME). The hydrogen peroxide (H2O2) levels and acidity within tumor cells enhanced by the released H2S induce acceleration of Fenton (Fe2+) and Fenton-like (Cu2+) reactions, enabling the powerful tumor ferroptosis efficacy. The released DSF acts as a role of "fuel", intensifying catalytic effect ("flame") in tumor cells through the sustainable Fenton chemistry (i.e., "add fuel to the flames"). Robust ferroptosis in tumor cells is characterized by serious mitochondrial damage and GSH depletion, leading to excess intracellular copper that triggers cuproptosis. Cuproptosis disrupts mitochondria, compromises iron-sulfur (Fe-S) proteins, and elevates intracellular oxidative stress by releasing free Fe3+. These interconnected processes form a self-accelerating cycle of ferroptosis-cuproptosis with potent antitumor capabilities, as validated in both cancer cells and tumor-bearing mice.

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.

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.

Photothermally Reinforced Nanozyme Remodeling Tumor Microenvironment of Redox and Metabolic Homeostasis to Enhance Ferroptosis in Tumor Therapy

The acidity and high GSH level in the tumor microenvironment (TME) greatly limit the antitumor activity of nanozymes. Thus, enhancing nanozymes' activity is fundamentally challenging in tumor therapy. Although the combination of photothermal therapy (PTT) and nanozymes can enhance the catalytic activity, cancer cells will overexpress heat shock proteins (HSPs) at high temperature, aggravating the heat resistance of tumor cells, which in turn compromises the outcome of chemodynamic therapy. Herein, we propose an iron-doped metal-organic framework nanozyme (IB@Fe-ZIF8@PDFA) that can be activated under the weak acidity and high level of GSH, demonstrating the activities of GSH oxidation (GSH-OXD), peroxidase (POD), and NADH oxidase (NADH-OXD). Under laser irradiation, it displays photothermal-enhanced multienzyme activities to simultaneously eliminate tumors and inhibit tumor metastasis. While consuming endogenous GSH, IB@Fe-ZIF8@PDFA promotes the decomposition of H2O2 into ·OH, enhancing ferroptosis in tumor cells. Surprisingly, IB@Fe-ZIF8@PDFA nanozyme can oxide NADH and subsequently limit the ATP supply, reducing the expression of HSPs and significantly weakening the heat resistance of tumor cells during PTT. Meanwhile, H2O2 is generated during this procedure, which can endogenously replenish the consumed H2O2. Thus, this IB@Fe-ZIF8@PDFA nanozyme constitutes a self-cascading platform to consume GSH and NADH, endogenously replenish the H2O2 and continuously generate ·OH to facilitate ferroptosis by disrupting the redox and metabolic homeostasis in tumor cells, achieving tumor elimination and tumor metastasis inhibition.

Fe-based nanozyme with photothermal activity prepared from polymerization-induced self-assembly assays boosts the recovery of bacteria-infected wounds

Nowadays, the overuse of antibiotics has escalated bacterial infections into an increasingly severe global health threat. Developing non-antibiotic treatments has emerged as a promising strategy for treating bacterial infections. Notably, nanozyme-based composite materials have garnered growing interest. Therefore, the efficient preparation of nanozyme is important. Herein, we have presented an efficient method to prepare Fe-based nanozyme through polymerization-induced self-assembly assay to kill bacteria efficiently, which could significantly enhance the healing of infected wounds. Through polymerization-induced self-assembly assay, a large number of uniformly sized micelles, bearing imidazole groups, could be efficiently prepared. These nanoparticles subsequently chelate with Fe ions, followed by pyrolysis and etching processes, resulting in the production of uniformly small-sized nanozymes with high adsorption activity in the near-infrared region. The composite materials could effectively eradicate bacteria via a synergistic strategy of photothermal and catalytic therapies under infected microenvironments. In vivo animal models with full-thickness wounds showed that combination therapy not only eradicates 98 % of the bacteria but also significantly accelerates wound healing. This work underscores the utility of polymerization-induced self-assembly in the preparation of nanozymes and reveals promising applications of nanozymes in wound healing. STATEMENT OF SIGNIFICANCE: This research introduces a functional nanozyme with photothermal activity, synthesized through polymerization-induced self-assembly, offering a promising non-antibiotic strategy to combat bacterial infections. This strategy enhances wound healing by combining photothermal and catalytic therapies, effectively eradicating drug-resistant bacteria while minimizing damage to healthy tissue. Our findings hold significant implications for the development of advanced antibacterial treatments and offer a robust assay to prepare nanozyme with small sizes. The prepared functional nanoparticles have a potential in wound healing, addressing a critical need in the face of rising antibiotic resistance.

Highly sensitive hydrolytic nanozyme-based sensors for colorimetric detection of aluminum ions

Hydrolytic nanozyme-based visual colorimetry has emerged as a promising strategy for the detection of aluminum ions. However, most studies focus on simulating the structure of natural enzymes while neglecting to regulate the rate of hydrolysis-related steps, leading to low enzyme-like activity for hydrolytic nanozymes. Herein, we constructed a ruthenium dioxide (RuO2) in situ embedded cerium oxide (CeO2) nanozyme (RuO2/CeO2) with a Lewis acid-base pair (Ce-O-Ru-OH), which can simulate the catalytic behavior of phosphatase (PPase) and can be quantitatively quenched by Al3+ to achieve accurate and sensitive Al3+ colorimetric sensing detection. The incorporation of Ru into CeO2 nanorods accelerates the dissociation of H2O, followed by subsequent combination of hydroxide species to Lewis acidic Ce-O sites. This synergistic effect facilitates substrate activation and significantly enhances the hydrolysis activity of the nanozyme. The results show that the RuO2/CeO2 nanozyme exhibits a limit of detection as low as 0.5 ng/mL. We also demonstrate their efficacy in detecting Al3+ in various practical food samples. This study offers novel insights into the advancement of highly sensitive hydrolytic nanozyme engineering for sensing applications.

A Nucleophilicity-Engineered DNA Ligation Blockade Nanoradiosensitizer Induces Irreversible DNA Damage to Overcome Cancer Radioresistance

During fractionated radiotherapy, DNA damage repair intensifies in tumor cells, culminating in cancer radioresistance and subsequent radiotherapy failure. Despite the recent development of nanoradiosensitizers targeting specific DNA damage repair pathways, the persistence of repair mechanisms involving multiple pathways remains inevitable. To address this challenge, a nucleophilicity-engineered DNA ligation blockade nanoradiosensitizer (DLBN) comprising Au/CeO2 heteronanostructure modified with trans-acting activator of transcription peptides is reported, which targets and inhibits the DNA ligation inside cancer cell nuclei via heterointerface-mediated dephosphorylation of DNA, a crucial step in overcoming cancer radioresistance. First, the Schottky-type heteronanostructure of cancer cell nucleus-targeting DLBN effectively intensifies radiation-induced DNA damage via catalase-mimetic activity and radiation-triggered catalytic reactions. Notably, by leveraging Au/CeO2 heterointerface, DLBN spontaneously dissociates H2O to hydroxide, a nucleophile with higher nucleophilicity, thereby exhibiting remarkable dephosphorylation capability at DNA nicks through facilitated nucleophilic attack. This enables the blockade of DNA ligation, a pivotal step in all DNA damage repair pathways, effectively interrupting the repair process. Consequently, DLBN resensitizes radioresistant cells by overcoming therapy-induced radioresistance, leading to a substantial accumulation of unrepaired DNA damage. These findings offer insight into the dephosphorylation of DNA within nuclei, and underscore the potential of heteronanostructure-based nanoradiosensitizer to block DNA ligation against therapy-induced radioresistance.

Design and regulation of defective electrocatalysts

Electrocatalysts are the key components of electrochemical energy storage and conversion devices. High performance electrocatalysts can effectively reduce the energy barrier of the chemical reactions, thereby improving the conversion efficiency of energy devices. The electrocatalytic reaction mainly experiences adsorption and desorption of molecules (reactants, intermediates and products) on a catalyst surface, accompanied by charge transfer processes. Therefore, surface control of electrocatalysts plays a pivotal role in catalyst design and optimization. In recent years, many studies have revealed that the rational design and regulation of a defect structure can result in rearrangement of the atomic structure on the catalyst surface, thereby efficaciously promoting the electrocatalytic performance. However, the relationship between defects and catalytic properties still remains to be understood. In this review, the types of defects, synthesis methods and characterization techniques are comprehensively summarized, and then the intrinsic relationship between defects and electrocatalytic performance is discussed. Moreover, the application and development of defects are reviewed in detail. Finally, the challenges existing in defective electrocatalysts are summarized and prospected, and the future research direction is also suggested. We hope that this review will provide some principal guidance and reference for researchers engaged in defect and catalysis research, better help researchers understand the research status and development trends in the field of defects and catalysis, and expand the application of high-performance defective electrocatalysts to the field of electrocatalytic engineering.

Radiation-activated PD-L1 aptamer-functionalized nanoradiosensitizer to potentiate antitumor immunity in combined radioimmunotherapy and photothermal therapy

Reactive oxygen species (ROS)-mediated immunogenic cell death (ICD) is crucial in radioimmunotherapy by boosting innate antitumor immunity. However, the hypoxic tumor microenvironment (TME) often impedes ROS production, limiting the efficacy of radiotherapy. To tackle this challenge, a combination therapy involving radiotherapy and immune checkpoint blockade (ICB) with anti-programmed death-ligand 1 (PD-L1) has been explored to enhance antitumor effects and reprogram the immunosuppressive TME. Here, we introduce a novel PD-L1 aptamer-functionalized nanoradiosensitizer designed to augment radiotherapy by increasing X-ray deposition specifically at the tumor site. This innovative X-ray-activated nanoradiosensitizer, comprising gold-MnO2 nanoflowers, efficiently enhances ROS generation under single low-dose radiation and repolarizes M2-like macrophages, thereby boosting antitumor immunity. Additionally, the ICB inhibitor BMS-202 synergizes with the PD-L1 aptamer-assisted nanoradiosensitizer to block the PD-L1 receptor, promoting T cell activation. Furthermore, this nanoradiosensitizer exhibits exceptional photothermal conversion efficiency, amplifying the ICD effect. The PD-L1-targeted nanoradiosensitizer effectively inhibits primary tumor growth and eliminates distant tumors, underscoring the potential of this strategy in optimizing both radioimmunotherapy and photothermal therapy.

Recent advances in biomaterials based near-infrared mild photothermal therapy for biomedical application: A review

Mild photothermal therapy (MPTT) generates heat therapeutic effect at the temperature below 45 °C under near-infrared (NIR) irradiation, which has the advantages of controllable treatment efficacy, lower hyperthermia temperatures, reduced dosage, and minimized damage to surrounding tissues. Despite significant progress has been achieved in MPTT, it remains primarily in the stage of basic and clinical research and has not yet seen widespread clinical adoption. Herein, a comprehensive overview of the recent NIR MPTT development was provided, aiming to emphasize the mechanism and obstacles, summarize the used photothermal agents, and introduce various biomedical applications such as anti-tumor, wound healing, and vascular disease treatment. The challenges of MPTT were proposed with potential solutions, and the future development direction in MPTT was outlooked to enhance the prospects for clinical translation.

In situ engineered magnesium alloy implant for preventing postsurgical tumor recurrence

Invasive tumors are difficult to be completely resected in clinical surgery due to the lack of clear resection margins, which greatly increases the risk of postoperative recurrence. However, chemotherapy and radiotherapy as the traditional means of postoperative adjuvant therapy, are limited in postoperative applications, such as multi-drug resistance and low sensitivity, etc. Therefore, an engineered magnesium alloy rod is designed as a postoperative implant to completely remove postoperative residual tumor tissue and inhibit tumor recurrence by gas and mild magnetic hyperthermia therapy (MMHT). As a reactive metal, magnesium alloy responds to the acidic tumor microenvironment by continuously generating hydrogen. The in-situ generation of hydrogen not only protects the surrounding normal tissue, but also enables the magnesium alloy to achieve MMHT under low-intensity alternating magnetic field (AMF). Furthermore, the numerous reactive oxygen species (ROS) produced by heat stress will combine with nitric oxide (NO) generated in situ, to produce more toxic reactive nitrogen species (RNS) storm. In summary, engineered magnesium alloy can completely remove residual tumor tissue and inhibit tumor recurrence by MMHT and RNS storm under low-intensity AMF, and the biodegradability of magnesium alloy makes great potential for clinical application.