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

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.

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.

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.

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.

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.

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.

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.

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.

Spatially confined photoacoustic effects of responsive nanoassembly boosts lysosomal membrane permeabilization and immunotherapy of triple-negative breast cancer

Although immunogenic cell death (ICD) induced by lysosomal membrane permeabilization (LMP) evidently enhance the effectiveness of antitumor immunity for triple-negative breast cancer (TNBC) with poor immunogenicity, their potential is increasingly restricted by the development of other death pathways and the repair of lysosomes by endoplasmic reticulum (ER) during LMP induction. Herein, a polydopamine nanocomposite with i-motif DNA modified and BNN6 loaded is prepared toward boosting LMP and immunotherapy of TNBC by synergy of spatially confined photoacoustic (PA) effects and nitric oxide. Combining the high-frequency pulsed laser (4000 kHz) with the intra-lysosomal assembly of nanocomposites produced spatially confined and significantly boosted PA effects (4.8-fold higher than the individually dispersed particles extracellular), suppressing damage to other cellular components and selectively reducing lysosomal integrity to 19.2 %. Simultaneously, the releasing of nitric oxide inhibited the repair of lysosomes by ER stress, causing exacerbated LMP. Consequently, efficient immune activation was achieved, including the abundant releasing of CRT/HMGB1 (5.93-6.8-fold), the increasing maturation of dendritic cells (3.41-fold), and the fostered recruitment of CD4+/CD8+T cells (3.99-3.78-fold) in vivo. The study paves a new avenue for the rational design and synergy of confined energy conversion and responsive nanostructures to achieve the treatment of low immunogenicity tumors. STATEMENT OF SIGNIFICANCE: A strategy of boosting lysosomal membrane permeabilization (LMP) and concomitantly preventing the repair was developed to address the immunotherapy challenge of triple-negative breast cancer. Spatially confined and significantly enhanced photoacoustic (PA) effects were achieved through DNA-guided pH-responsive assembly of polydopamine nanocomposites in lysosomes and application of a high-frequency pulsed laser. Efficient immunogenic cell death was guaranteed by selective and powerful damage of lysosomal membranes through the significant contrast of PA intensities for dispersed/assembled particles and nitric oxide release induced endoplasmic reticulum stress. The study paves a new avenue for the rational design and synergy of confined energy conversion and responsive nanostructures to achieve the treatment of low immunogenicity tumors.

Engineering Biodegradable Hollow Silica/Iron Composite Nanozymes for Breast Tumor Treatment through Activation of the "Ferroptosis Storm"

The activation of cellular ferroptosis is promising in tumor therapy. However, ferroptosis is parallelly inhibited by antiferroptotic substances, including glutathione peroxidase 4 (GPX4), dihydroorotate dehydrogenase (DHODH), and ferroptosis suppressor protein 1 (FSP1). Thus, it is highly desirable, yet challenging, to simultaneously suppress these three antiferroptotic substances for activating ferroptosis. Here, we rationally designed a hollow iron-doped SiO2-based nanozyme (FeSHS) loaded with brequinar (BQR) and lificiguat (YC-1), named FeSHS/BQR/YC-1-PEG, for tumor ferroptosis activation. FeSHS were developed through the continuous etching of SiO2 nanoparticles by iron ions, which exhibit pH/glutathione-responsive biodegradability, along with mimicking the activities of peroxidase, glutathione oxidase, and NAD(P)H oxidase. Specifically, glutathione depletion and NAD(P)H oxidation by FeSHS will suppress the expression of GPX4 and inhibit FSP1 by disrupting the NAD(P)H/FSP1/ubiquinone axis. In addition, the released BQR can suppress the expression of DHODH. Meanwhile, YC-1 is able to increase the cellular polyunsaturated fatty acids (PUFAs) by destroying the HIF-1α/lipid droplet axis. The elevation of levels of iron and PUFAs while simultaneously disrupting the GPX4/DHODH/FSP1 inhibitory pathways by our designed nanoplatform displayed high therapeutic efficacy both in vitro and in vivo. This work elucidates rationally designing smart nanoplatforms for ferroptosis activation and future tumor treatments.

Calcium-Mediated Cell Adhesion Enhancement-Based Antimetastasis and Synergistic Antitumor Therapy by Conjugated Polymer-Calcium Composite Nanoparticles

Strengthening tumor cellular adhesion through regulating the concentration of extracellular Ca2+ is highly challenging and promising for antimetastasis. Herein, a pH-responsive conjugated polymer-calcium composite nanoparticle (PFV/CaCO3/PDA@PEG) is developed for calcium-mediated cell adhesion enhancement-based antimetastasis and reactive oxygen species (ROS)-triggered calcium overload and photodynamic therapy (PDT) synergistic tumor treatment. PFV/CaCO3/PDA@PEG is mainly equipped with conjugated poly(fluorene-co-vinylene) (PFV-COOH)-composited CaCO3 nanoparticles, which can be rapidly decomposed under the tumor acidic microenvironment, effectively releasing Ca2+ and the photosensitizer PFV-COOH. The high extracellular Ca2+ concentration facilitates the generation of dimers between two adjacent cadherin ectodomains, which greatly enhances cell-cell adhesion and suppresses tumor metastasis. The inhibition rates are 97 and 87% for highly metastatic tumor cells 4T1 and MCF-7, respectively. Such a well-designed nanoparticle also contributes to realizing PDT, mitochondrial dysfunction, and ROS-triggered Ca2+ overload synergistic therapy. Furthermore, PFV/CaCO3/PDA@PEG displayed superior in vivo inhibition of 4T1 tumor growth and demonstrated a marked antimetastatic effect by both intravenous and intratumoral injection modes. Thus, this study provides a powerful strategy for calcium-mediated metastasis inhibition for tumor therapy.

Hollow CeO2-Based Nanozyme with Self-Accelerated Cascade Reactions for Combined Tumor Therapy

Nanozymes have obvious advantages in improving the efficiency of cancer treatment. However, due to the lack of tissue specificity, low catalytic efficiency, and so on, their clinical applications are limited. Herein, the nanoplatform CeO2@ICG@GOx@HA (CIGH) with self-accelerated cascade reactions is constructed. The as-prepared nanozyme shows the superior oxidase (OXD)-like, superoxide dismutase (SOD)-like, catalase (CAT)-like and peroxidase (POD)-like activities. At the same time, under 808 nm near-infrared (NIR) irradiation, the photodynamic and photothermal capabilities are also significantly enhanced due to the presence of indocyanine green (ICG). We demonstrate that the nanozyme CIGH can efficiently accumulate in the tumor and exhibit amplified cascade antitumor effects with negligible systemic toxicity through the combination of photodynamic therapy (PDT), photothermal therapy (PTT), chemodynamic therapy (CDT) and starvation therapy. The nanozyme prepared in this study provides a promising candidate for catalytic nanomedicines for efficient tumor therapy.

Revealing the Optimization Route of Piezoelectric Sonosensitizers: From Mechanism to Engineering Methods

Piezoelectric catalysis is a novel catalytic technology that has developed rapidly in recent years and has attracted extensive interest among researchers in the field of tumor therapy for its acoustic-sensitizing properties. Nevertheless, researchers are still controversial about the key technical difficulties in the modulation of piezoelectric sonosensitizers for tumor therapy applications, which is undoubtedly a major obstacle to the performance modulation of piezoelectric sonosensitizers. Clarification of this challenge will be beneficial to the design and optimization of piezoelectric sonosensitizers in the future. Here, the authors start from the mechanism of piezoelectric catalysis and elaborate the mechanism and methods of defect engineering and phase engineering for the performance modulation of piezoelectric sonosensitizers based on the energy band theory. The combined therapeutic strategy of piezoelectric sonosensitizers with enzyme catalysis and immunotherapy is introduced. Finally, the challenges and prospects of piezoelectric sonosensitizers are highlighted. Hopefully, the explorations can guide researchers toward the optimization of piezoelectric sonosensitizers and can be applied in their own research.

Wintersweet-like Nanohybrids of Titanium-doped Cerium Vanadate Loaded with Polypyrrole for Tumor Theranostic

Compromises between enhanced on-targeting reactivity and precise real-time monitoring in the tumor microenvironment (TME) are the main roadblocks for catalytic cancer therapy. The hallmark of a high level of hydrogen peroxide (H2O2) and acidic extracellular environment of the hypoxia solid tumor can underpin therapeutic and tracking performance. Herein, this work provides an activatable wintersweet-like nanohybrid consisting of titanium (Ti) doped cerium vanadate nanorods with the modification of polypyrrole (PPy) nanoparticles (CeVO4-Ti@PPy) for combinatorial therapies of breast carcinoma. The Ti dopants in the size-controllable CeVO4 nanorods lower the energy barrier (0.5 eV) of the rate-determining steps and elaborate peroxidase-like (POD-like) activities to improve the generation of toxic hydroxyl radical (·OH) according to the density functional theory (DFT) calculation. The multiple enzyme-like activities, including the intrinsic glutathione peroxidase (GPx) and catalase (CAT), achieve a record-high therapeutic efficiency. Coupling this oxidative stress with the photothermal effects of PPy enables enhanced catalytic tumor necrosis. The exterior PPy heterogeneous structure can be further doped with protons in the local acidic environment to intensify photoacoustic signals, allowing the non-invasive accurate tracking of tumors. The theranostic performance displayed negligible attenuated signals in near-infrared (NIR) windows. This organic-inorganic nanohybrid with a heterogeneous structure provides the potential to improve the overall outcomes of catalytic therapy.

High-Performance NIR-II Fluorescent Type I/II Photosensitizer Enabling Augmented Mild Photothermal Therapy of Tumors by Disrupting Heat Shock Proteins

NIR-II fluorescent photosensitizers as phototheranostic agents hold considerable promise in the application of mild photothermal therapy (MPTT) for tumors, as the reactive oxygen species generated during photodynamic therapy can effectively disrupt heat shock proteins. Nevertheless, the exclusive utilization of these photosensitizers to significantly augment the MPTT efficacy has rarely been substantiated, primarily due to their insufficient photodynamic performance. Herein, the utilization of high-performance NIR-II fluorescent type I/II photosensitizer (AS21:4) is presented as a simple but effective nanoplatform derived from molecule AS2 to enhance the MPTT efficacy of tumors without any additional therapeutic components. By taking advantage of heavy atom effect, AS21:4 as a type I/II photosensitizer demonstrates superior efficacy in producing 1O2 (1O2 quantum yield = 12.4%) and O2 •- among currently available NIR-II fluorescent photosensitizers with absorption exceeding 800 nm. In vitro and in vivo findings demonstrate that the 1O2 and O2 •- generated from AS21:4 induce a substantial reduction in the expression of HSP90, thereby improving the MPTT efficacy. The remarkable phototheranostic performance, substantial tumor accumulation, and prolonged tumor retention of AS21:4, establish it as a simple but superior phototheranostic agent for NIR-II fluorescence imaging-guided MPTT of tumors.

Self-immolative poly(thiocarbamate) with localized H2S signal amplification for precise cancer imaging and therapy

Hydrogen sulfide is essential in numerous physiological and pathological processes and has emerged as a promising cancer imaging and signaling molecule and a potentially versatile therapeutic agent. However, the endogenous levels of hydrogen sulfide remain insufficient to perform its biological functions, and thus, developing novel strategies that amplify hydrogen sulfide signals at lesion sites is of increasing interest. In this work, a nanoplatform (SNP) based on hydrogen sulfide-responsive self-immolative poly(thiocarbamate) with localized hydrogen sulfide signal amplification capability is developed to encapsulate a hydrogen sulfide-responsive fluorescent probe (e.g., hemicyanine dye; p-Cy) or an anticancer prodrug (e.g., doxorubicin; p-DOX) to form a nanoprobe (SNPp-Cy) or nanomedicine (SNPp-DOX) for cancer imaging and therapy, respectively. SNPp-Cy exhibits a low detection limit for hydrogen sulfide, enabling ultrasensitive detection of small (<2 mm) tumors in female mice. In addition, SNPp-DOX can effectively inhibit the growth of DOX-resistant human breast cancer xenograft, lung metastasis, and patient-derived xenograft tumors in female mice.

Four Birds with One Stone: A Bandgap-Regulated Multifunctional Schottky Heterojunction for Robust Synergistic Antitumor Therapy upon Endo-/Exogenous Stimuli

Considering the profound impact of structure on heterojunction catalysts, the rational design of emerging catalysts with optimized energy band structures is required for antitumor efficiency. Herein, we select titanium nitride (TiN) and Pt to develop a multifunctional Schottky heterojunction named Pt/H-TiN&SRF (PHTS) nanoparticles (NPs) with a narrowed bandgap to accomplish "four birds with one stone" involving enzyo/sono/photo three modals and additional ferroptosis. The in situ-grown Pt NPs acted as electron traps that can cause the energy band to bend upward and form a Schottky barrier, thereby facilitating the separation of electron/hole pairs in exogenous stimulation catalytic therapy. In addition, endogenous catalytic reactions based on peroxidase (POD)- and catalase (CAT)-mimicking activities can also be amplified, triggering intense oxidative stress, in which CAT-like activity decomposes endogenous H2O2 into O2 alleviating hypoxia and provides reactants for sonodynamic therapy. Moreover, PHTS NPs can elicit mild photothermal therapy with boosted photothermal properties as well as ferroptosis with loaded ferroptosis inducer sorafenib for effective tumor ablation and apoptosis-ferroptosis synergistic tumor inhibitory effect. In summary, this paper proposes an attractive design for antitumor strategies and highlights findings for heterojunction catalytic therapy with potential in tumor theranostics.

Nanohybrid-Based Redox Homeostasis Perturbators Escaped from Early Lysosomes toward Amplified Sensitization of Tumor Cells and Photothermally Maneuvered Pyroptosis Therapy

Reactive oxygen species (ROS) hold great potential in tumor pyroptosis therapy, yet they are still limited by short species lifespan and limited diffusion distance. Inducing cells into a metastable state and then applying external energy can effectively trigger pyroptosis, but systemic sensitization still faces challenges, such as limited ROS content, rapid decay, and short treatment windows. Herein, a nanohybrid-based redox homeostasis-perturbator system was designed that synergistically induce early lysosomal escape, autophagy inhibition, and redox perturbation functions to effectively sensitize cells to address these challenges. Specifically, weakly alkaline layered double hydroxide nanosheets (LDH NSs) with pH-responsive degradation properties enabled early lysosomal escape within 4 h, releasing poly(L-dopa) nanoparticles for inducing catechol-quinone redox cycling in the cytoplasm. The intracellular ROS levels were systematically rebounded by 3-4 times in tumor cells and lasted for over 4 h. Subsequently induced lysosomal stress and Ca2+ signaling activation resulted in severe mitochondrial dysfunction, as well as a perilous metastable state. Thereby, sequential near-infrared light was applied to trigger amplified stress through a local photothermal conversion. This led to sufficiently high levels of cleaved caspase-1 and GSDMD activation (2.5-2.8-fold increment) and subsequent pyroptosis response. In addition, OH- released by LDH elevated pH to alleviate the limitation of glutathione depletion by quinones at acidic pH and inhibit protective autophagy. Largely secreted inflammatory factors (2.5-5.6-fold increment), efficient maturation of dendritic cells, and further immune stimulation were boosted for tumor inhibition as a consequence. This study offers a new paradigm and insights into the synergy of internal systematic cellular sensitization and sequential external energy treatment to achieve tumor suppression through pyroptosis.

Tailoring Indocyanine Green J-Aggregates for Imaging, Cancer Phototherapy, and Drug Delivery: A Review

Indocyanine green J-aggregates (ICG-Jagg) have emerged as a significant subject of interest in biomedical applications due to their unique optical properties, tunable size, and excellent biocompatibility. This comprehensive review aims to provide an in-depth exploration of ICG-Jagg, with a focus on elucidating the diverse facets of their preparation and the factors that influence the preparation process. Additionally, the review discusses their applications in biomedical diagnostics, such as imaging and contrast agents, as well as their utilization in drug delivery and various phototherapeutic interventions.

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.

Copper Single-Atom-Based Metal-Organic Framework for Ultrasound-Enhanced Nanocatalytic Therapy

Chemodynamic therapy (CDT) is an emerging therapeutic modality triggered by endogenous substances in the tumor microenvironment (TME) to generate reactive oxygen species. However, the mild acid pH, low H2O2 concentration, and overexpressed glutathione can suppress the CDT efficiency. Herein, ultrasound (US)-triggered Cu2+-based single-atom nanoenzymes (FA-NH2-UiO-66-Cu, FNUC) are constructed with the performance of target and glutathione depletion. In the TME, the single-atom Cu sites of FNUC consume glutathione and the FNUC:Cu+ generates •OH via peroxidase-like activity. The US-activated FNUC exhibits a fast •OH generation rate, a low Michaelis constant, and a large •OH concentration, indicating the cavitation effect of US promotes the •OH generation. Meanwhile, the tumor target of FNUC is confirmed by NIR-II fluorescence imaging, in which it is modified with IR-1061. Combined with the antitumor performance of FNUC in vitro and in vivo, the novel Cu-based SAzymes can achieve efficient and precise cancer treatment.

A Photoactivated Self-Assembled Nanoreactor for Inducing Cascade-Amplified Oxidative Stress toward Type I Photodynamic Therapy in Hypoxic Tumors

Type I photodynamic therapy (PDT) generates reactive oxygen species (ROS) through oxygen-independent photoreactions, making it a promising method for treating hypoxic tumors. However, the superoxide anion (O2∙-) generated usually exhibits a low oxidation capacity, restricting the antitumor efficacy of PDT in clinical practice. Herein, a photoactivated self-assembled nanoreactor (1-NBS@CeO2) is designed through integration of type I PDT and cerium oxide (CeO2) nanozymes for inducing cascade-amplified oxidative stress in hypoxic tumors. The nanoreactor is constructed though co-assembly of an amphiphilic peptide (1-NBS) and CeO2, giving well-dispersed spherical nanoparticles with enhanced superoxide dismutase (SOD)-like and peroxidase (POD)-like activities. Following light irradiation, 1-NBS@CeO2 undergoes type I photoreactions to generated O2∙-, which is further catalyzed by the nanoreactors, ultimately forming hypertoxic hydroxyl radical (∙OH) through cascade-amplified reactions. The PDT treatment using 1-NBS@CeO2 results in elevation of intracellular ROS and depletion of GSH content in A375 cells, thereby inducing mitochondrial dysfunction and triggering apoptosis and ferroptosis of tumor cells. Importantly, intravenous administration of 1-NBS@CeO2 alongside light irradiation showcases enhances antitumor efficacy and satisfactory biocompatibility in vivo. Together, the self-assembled nanoreactor facilitates cascade-amplified photoreactions for achieving efficacious type I PDT, which holds great promise in developing therapeutic modules towards hypoxic tumors.

Multienzyme-Like Polyoxometalate-Based Single-Atom Enzymes for Cancer-Specific Therapy Through Acid-Triggered Nontoxicity-to-Toxicity Transition

Single-atom enzymes (SAzymes) exhibit great potential for chemodynamic therapy (CDT); while, general application is still challenged by their instability and unavoidable side effects during delivery. Herein, a manganese-based polyoxometalate single-atom enzyme (Mn-POM SAE) is first introduced into tumor-specific CDT, which exhibits tumor microenvironment (TME)-activated transition of nontoxicity-to-toxicity. Different from traditional POM materials, the aggregates of low-toxic Mn-POM SAE nanospheres are obtained at neutral conditions, facilitating efficient delivery and avoiding toxicity problems in normal tissues. Under acid TME conditions, these nanospheres are degraded into smaller units of toxic Mn(II)-PW11; thus, initiating cancer cell-specific therapy. The released active units of Mn(II)-PW11 exhibit excellent multienzyme-like activities (including peroxidase (POD)-like, oxidase (OXD)-like, catalase (CAT)-like, and glutathione peroxidase (Gpx)-like activities) for the synergistic cancer therapy due to the stabilized high valence Mn species (MnIII/MnIV). As demonstrated by both intracellular evaluations and in vivo experiments, ROS is generated to cause damage to lysosome membranes, further facilitating acidification and impaired autophagy to enhance cancer therapy. This study provides a detailed investigation on the acid-triggered releasing of active units and the electron transfer in multienzyme-mimic-like therapy, further enlarging the application of POMs from catalytical engineering into cancer therapy.

A multifunctional cascade enzyme system for enhanced starvation/chemodynamic combination therapy against hypoxic tumors

Starvation therapy has shown promise as a cancer treatment, but its efficacy is often limited when used alone. In this work, a multifunctional nanoscale cascade enzyme system, named CaCO3@MnO2-NH2@GOx@PVP (CMGP), was fabricated for enhanced starvation/chemodynamic combination cancer therapy. CMGP is composed of CaCO3 nanoparticles wrapped in a MnO2 shell, with glucose oxidase (GOx) adsorbed and modified with polyvinylpyrrolidone (PVP). MnO2 decomposes H2O2 in cancer cells into O2, which enhances the efficiency of GOx-mediated starvation therapy. CaCO3 can be decomposed in the acidic cancer cell environment, causing Ca2+ overload in cancer cells and inhibiting mitochondrial metabolism. This synergizes with GOx to achieve more efficient starvation therapy. Additionally, the H2O2 and gluconic acid produced during glucose consumption by GOx are utilized by MnO2 with catalase-like activity to enhance O2 production and Mn2+ release. This process accelerates glucose consumption, reactive oxygen species (ROS) generation, and CaCO3 decomposition, promoting the Ca2+ release. CMGP can alleviate tumor hypoxia by cycling the enzymatic cascade reaction, which increases enzyme activity and combines with Ca2+ overload to achieve enhanced combined starvation/chemodynamic therapy. In vitro and in vivo studies demonstrate that CMGP has effective anticancer abilities and good biosafety. It represents a new strategy with great potential for combined cancer therapy.

MOF-Derived Oxygen-Deficient Titania-Mediated Photodynamic/Photothermal-Enhanced Immunotherapy for Tumor Treatment

Immunotherapy has emerged as a revolutionizing therapeutic modality for cancer. However, its efficacy has been largely limited by a weak immune response and an immunosuppressive tumor microenvironment. Herein, we report a metal-organic framework (MOF)-derived titanium oxide nanoparticle (MCTx NP) as an immune booster that can greatly improve the immunotherapy efficacy by inducing "immunogenic cell death" (ICD) and remodeling the tumor microenvironment. The NPs, inheriting the characteristic structure of MIL-125 and enriched with oxygen vacancies (OVs), demonstrate both high photothermal conversion efficiency and a reactive oxygen species (ROS) generation yield upon near-infrared (NIR) activation. Moreover, the NPs can release O2 and reduce glutathione (GSH) in the tumor environment, showcasing their potential to reverse the immunosuppressive microenvironment. In vitro/vivo results demonstrate that MCTx NPs directly kill tumor cells and effectively eliminate primary tumors by exerting dual photodynamic/photothermal therapy under a single NIR irritation. At the same time, MCTx NPs augment the PD-L1 blockade efficacy by potently inducing ICDs and reversing the immunosuppressive tumor microenvironment, including promoting dendritic cell (DC) maturation, decreasing regulatory T cells (Tregs)' infiltration, and increasing cytotoxic T lymphocytes (CTLs) and helper T cells (Ths), resulting in effective distant tumor suppression. This work highlights MCTx NP-mediated photodynamic- and photothermal-enhanced immunotherapy as an effective strategy for tumor treatment.

Engineering Nanozymes for Tumor Therapy via Ferroptosis Self-Amplification

Ferroptosis induction is an emerging strategy for tumor therapy. Reactive oxygen species (ROS) can induce ferroptosis but are easily consumed by overexpressed glutathione (GSH) in tumor cells. Therefore, achieving a large amount of ROS production in tumor cells without being consumed is key to efficiently inducing ferroptosis. In this study, a self-amplifying ferroptosis-inducing therapeutic agent, Pd@CeO2-Fe-Co-WZB117-DSPE-PEG-FA (PCDWD), is designed for tumor therapy. PCDWD exhibits excellent multi-enzyme activities due to the loading of Fe-Co dual atoms with abundant active sites, including peroxidase-like enzymes, catalase-like enzymes, and glutathione oxidases (GSHOx), which undergo catalytic reactions in the tumor microenvironment to produce ROS, thereby inducing ferroptosis. Furthermore, PCDWD can also deplete GSH in tumor cells, thus reducing the consumption of ROS by GSH and inhibiting the expression of GSH peroxidase 4. Moreover, the photothermal effect of PCDWD can not only directly kill tumor cells but also further enhance its own enzyme activities, consequently promoting ferroptosis in tumor cells. In addition, WZB117 can reduce the expression of heat shock protein 90 by inhibiting glucose transport, thereby reducing the thermal resistance of tumor cells and further improving the therapeutic effect. Finally, X-ray computed tomography imaging of PCDWD guides it to achieve efficient tumor therapy.

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.

Potentiating dual-directional immunometabolic regulation with nanomedicine to enhance anti-tumor immunotherapy following incomplete photothermal ablation

Photothermal therapy (PTT) is a promising cancer treatment method due to its ability to induce tumor-specific T cell responses and enhance therapeutic outcomes. However, incomplete PTT can leave residual tumors that often lead to new metastases and decreased patient survival in clinical scenarios. This is primarily due to the release of ATP, a damage-associated molecular pattern that quickly transforms into the immunosuppressive metabolite adenosine by CD39, prevalent in the tumor microenvironment, thus promoting tumor immune evasion. This study presents a photothermal nanomedicine fabricated by electrostatic adsorption among the Fe-doped polydiaminopyridine (Fe-PDAP), indocyanine green (ICG), and CD39 inhibitor sodium polyoxotungstate (POM-1). The constructed Fe-PDAP@ICG@POM-1 (FIP) can induce tumor PTT and immunogenic cell death when exposed to a near-infrared laser. Significantly, it can inhibit the ATP-adenosine pathway by dual-directional immunometabolic regulation, resulting in increased ATP levels and decreased adenosine synthesis, which ultimately reverses the immunosuppressive microenvironment and increases the susceptibility of immune checkpoint blockade (aPD-1) therapy. With the aid of aPD-1, the dual-directional immunometabolic regulation strategy mediated by FIP can effectively suppress/eradicate primary and distant tumors and evoke long-term solid immunological memory. This study presents an immunometabolic control strategy to offer a salvage option for treating residual tumors following incomplete PTT.

Iron-Based Metal-Organic Frameworks as Multiple Cascade Synergistic Therapeutic Effect Nano-Drug Delivery Systems for Effective Tumor Elimination

Efforts have been made to improve the therapeutic efficiency of tumor treatments, and metal-organic frameworks (MOFs) have shown excellent potential in tumor therapy. Monotherapy for the treatment of tumors has limited effects due to the limitation of response conditions and inevitable multidrug resistance, which seriously affect the clinical therapeutic effect. In this study, we chose to construct a multiple cascade synergistic tumor drug delivery system MIL-101(Fe)-DOX-TCPP-MnO2@PDA-Ag (MDTM@P-Ag) using MOFs as drug carriers. Under near-infrared (NIR) laser irradiation, 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) and Ag NPs loaded on MDTM@P-Ag can be activated to generate cytotoxic reactive oxygen species (ROS) and achieve photothermal conversion, thus effectively inducing the apoptosis of tumor cells and achieving a combined photodynamic/photothermal therapy. Once released at the tumor site, manganese dioxide (MnO2) can catalyze the decomposition of hydrogen peroxide (H2O2) in the acidic microenvironment of the tumor to generate oxygen (O2) and alleviate the hypoxic environment of the tumor. Fe3+/Mn2+ will mediate a Fenton/Fenton-like reaction to generate cytotoxic hydroxyl radicals (·OH), while depleting the high concentration of glutathione (GSH) in the tumor, thus enhancing the chemodynamic therapeutic effect. The successful preparation of the tumor drug delivery system and its good synergistic chemodynamic/photodynamic/photothermal therapeutic effect in tumor treatment can be demonstrated by the experimental results of material characterization, performance testing and in vitro experiments.

Sulfated Chitosan-Modified CuS Nanocluster: A Versatile Nanoformulation for Simultaneous Antibacterial and Bone Regenerative Therapy in Periodontitis

Periodontitis, a prevalent chronic inflammatory disease worldwide, is triggered by periodontopathogenic bacteria, resulting in the progressive destruction of periodontal tissue, particularly the alveolar bone. To effectively address periodontitis, this study proposed a nanoformulation known as CuS@MSN-SCS. This formulation involves coating citrate-grafted copper sulfide (CuS) nanoparticles with mesoporous silica (MSNs), followed by surface modification using amino groups and sulfated chitosan (SCS) through electrostatic interactions. The objective of this formulation is to achieve efficient bacteria removal by inducing ROS signaling pathways mediated by Cu2+ ions. Additionally, it aims to promote alveolar bone regeneration through Cu2+-induced pro-angiogenesis and SCS-mediated bone regeneration. As anticipated, by regulating the surface charges, the negatively charged CuS nanoparticles capped with sodium citrate were successfully coated with MSNs, and the subsequent introduction of amine groups using (3-aminopropyl)triethoxysilane was followed by the incorporation of SCS through electrostatic interactions, resulting in the formation of CuS@MSN-SCS. The developed nanoformulation was verified to not only significantly exacerbate the oxidative stress of Fusobacterium nucleatum, thereby suppressing bacteria growth and biofilm formation in vitro, but also effectively alleviate the inflammatory response and promote alveolar bone regeneration without evident biotoxicity in an in vivo rat periodontitis model. These findings contribute to the therapeutic effect on periodontitis. Overall, this study successfully developed a nanoformulation for combating bacteria and facilitating alveolar bone regeneration, demonstrating the promising potential for clinical treatment of periodontitis.

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.

An ATPase-Mimicking MXene nanozyme pharmacologically breaks the ironclad defense system for ferroptosis cancer therapy

Anticancer nanomedicines used for ferroptosis therapy generally rely on the direct delivery of Fenton catalysts to drive lipid peroxidation in cancer cells. However, the therapeutic efficacy is limited by the ferroptosis resistance caused by the intracellular anti-ferroptotic signals. Herein, we report the intrinsic ATPase-mimicking activity of a vanadium carbide MXene nanozyme (PVCMs) to pharmacologically modulate the nuclear factor erythroid 2-related factor 2 (Nrf2) program, which is the master anti-ferroptotic mediator in the ironclad defense system in triple-negative breast cancer (TNBC) cells. The PVCMs perform high ATPase-like activity that can effectively and selectively catalyze the dephosphorylation of ATP to generate ADP. Through a cascade mechanism initiated by falling energy status, PVCMs can powerfully hinder the Nrf2 program to selectively drive ferroptosis in TNBC cells in response to PVCMs-induced glutathione depletion. This study provides a paradigm for the use of pharmacologically active nanozymes to moderate specific cellular signals and elicit desirable pharmacological activities for therapeutic applications.

Engineering Phage Nanocarriers Integrated with Bio-Intelligent Plasmids for Personalized and Tunable Enzyme Delivery to Enhance Chemodynamic Therapy

Customizable and number-tunable enzyme delivery nanocarriers will be useful in tumor therapy. Herein, a phage vehicle, T4-Lox-DNA-Fe (TLDF), which adeptly modulates enzyme numbers using phage display technology to remodel the tumor microenvironment (TME) is presented. Regarding the demand for lactic acid in tumors, each phage is engineered to display 720 lactate oxidase (Lox), contributing to the depletion of lactic acid to restructure the tumor's energy metabolism. The phage vehicle incorporated dextran iron (Fe) with Fenton reaction capabilities. H2O2 is generated through the Lox catalytic reaction, amplifying the H2O2 supply for dextran iron-based chemodynamic therapy (CDT). Drawing inspiration from the erythropoietin (EPO) biosynthetic process, an EPO enhancer is constructed to impart the EPO-Keap1 plasmid (DNA) with tumor hypoxia-activated functionality, disrupting the redox homeostasis of the TME. Lox consumes local oxygen, and positive feedback between the Lox and the plasmid promotes the expression of kelch ECH Associated Protein 1 (Keap1). Consequently, the downregulation of the antioxidant transcription factor Nrf2, in synergy with CDT, amplifies the oxidative killing effect, leading to tumor suppression of up to 78%. This study seamlessly integrates adaptable T4 phage vehicles with bio-intelligent plasmids, presenting a promising approach for tumor therapy.

Progress and Challenges in Tumor Ferroptosis Treatment Strategies: A Comprehensive Review of Metal Complexes and Nanomedicine

Ferroptosis is a new form of regulated cell death featuring iron-dependent lipid peroxides accumulation to kill tumor cells. A growing body of evidence has shown the potential of ferroptosis-based cancer therapy in eradicating refractory malignancies that are resistant to apoptosis-based conventional therapies. In recent years, studies have reported a number of ferroptosis inducers that can increase the vulnerability of tumor cells to ferroptosis by regulating ferroptosis-related signaling pathways. Encouraged by the rapid development of ferroptosis-driven cancer therapies, interdisciplinary fields that combine ferroptosis, pharmaceutical chemistry, and nanotechnology are focused. First, the prerequisites and metabolic pathways for ferroptosis are briefly introduced. Then, in detail emerging ferroptosis inducers designed to boost ferroptosis-induced tumor therapy, including metal complexes, metal-based nanoparticles, and metal-free nanoparticles are summarized. Subsequently, the application of synergistic strategies that combine ferroptosis with apoptosis and other regulated cell death for cancer therapy, with emphasis on the use of both cuproptosis and ferroptosis to induce redox dysregulation in tumor and intracellular bimetallic copper/iron metabolism disorders during tumor treatment is discussed. Finally, challenges associated with clinical translation and potential future directions for potentiating cancer ferroptosis therapies are highlighted.

Single-Atom Cu Nanozyme-Loaded Bone Scaffolds for Ferroptosis-Synergized Mild Photothermal Therapy in Osteosarcoma Treatment

The rapid multiplication of residual tumor cells and poor reconstruction quality of new bone are considered the major challenges in the postoperative treatment of osteosarcoma. It is a promising candidate for composite bone scaffold which combines photothermal therapy (PTT) and bone regeneration induction for the local treatment of osteosarcoma. However, it is inevitable to damage the normal tissues around the tumor due to the hyperthermia of PTT, while mild heat therapy shows a limited effect on antitumor treatment as the damage can be easily repaired by stress-induced heat shock proteins (HSP). This study reports a new type of single-atom Cu nanozyme-loaded bone scaffolds, which exhibit exceptional photothermal conversion properties as well as peroxidase and glutathione oxidase mimicking activities in vitro experiments. This leads to lipid peroxidation (LPO) and reactive oxygen species (ROS) upregulation, ultimately causing ferroptosis. The accumulation of LPO and ROS also contributes to HSP70 inactivation, maximizing PTT efficiency against tumors at an appropriate therapeutic temperature and minimizing the damage to surrounding normal tissues. Further, the bone scaffold promotes bone regeneration via a continuous release of bioactive ions (Ca2+, P5+, Si4+, and Cu2+). The results of in vivo experiments reveal that scaffolds inhibit tumor growth and promote bone repair.

A Versatile Nanozyme-Based NADH Circulating Oxidation Reactor for Tumor Therapy through Triple Cellular Metabolism Disruption

Nanozyme-based metabolic regulation triggered by tumor-specific endogenous stimuli has emerged as a promising therapeutic strategy for tumors. The current efficacy, however, is constrained by the limited concentration of endogenous substrates and the metabolic plasticity of tumors. Consequently, the implementation of efficient metabolic regulation in tumor therapy is urgently needed. Herein, a versatile nanozyme-based nicotinamide adenine dinucleotide (NADH) circulating oxidation nanoreactor is reported. First, the synthesized cobalt-doped hollow carbon spheres (Co-HCS) possess NADH oxidase (NOX)-mimicking activity for the NADH oxidation to disrupt oxidative phosphorylation (OXPHOS) pathway of tumor cells. Second, the substrate-cycle manner of Co-HCS can be used for NADH circulating oxidation to overcome the limitation of substrate deficiency. Finally, 2-Deoxy-D-glucose (2-DG) and 6-aminonicotinamide (6-AN) are introduced to block glycolysis and pentose phosphate pathway (PPP), thus creating a versatile nanozyme-based NADH circulating oxidation nanoreactor (Co-HCS/D/A) for tumor therapy through triple cellular metabolism disruption. In vitro and in vivo results demonstrate that the designed nanoreactor not only enhances the catalytic efficiency but also disrupts the tumor metabolic homeostasis, leading to efficient therapy outcome. This study develops a novel NADH circulating oxidation nanoreactor for tumor therapy through triple cellular metabolism disruption, which addresses the limitations of current nanozyme-based metabolism regulation for tumor therapy.

Piezoelectric Catalysis Induces Tumor Cell Senescence to Boost Chemo-Immunotherapy

Cellular senescence, a vulnerable state of growth arrest, has been regarded as a potential strategy to weaken the resistance of tumor cells, leading to dramatic improvements in treatment efficacy. However, a selective and efficient strategy for inducing local tumor cellular senescence has not yet been reported. Herein, piezoelectric catalysis is utilized to reduce intracellular NAD+ to NADH for local tumor cell senescence for the first time. In detail, a biocompatible nanomedicine (BTO/Rh-D@M) is constructed by wrapping the piezoelectric BaTiO3/(Cp*RhCl2)2 (BTO/Rh) and doxorubicin (DOX) in the homologous cytomembrane with tumor target. After tumors are stimulated by ultrasound, negative and positive charges are generated on the BTO/Rh by piezoelectric catalysis, which reduce the intracellular NAD+ to NADH for cellular senescence and oxidize H2O to reactive oxygen species (ROS) for mitochondrial damage. Thus, the therapeutic efficacy of tumor immunogenic cell death-induced chemo-immunotherapy is boosted by combining cellular senescence, DOX, and ROS. The results indicate that 23.9% of the piezoelectric catalysis-treated tumor cells senesced, and solid tumors in mice disappeared completely after therapy. Collectively, this study highlights a novel strategy to realize cellular senescence utilizing piezoelectric catalysis and the significance of inducing tumor cellular senescence to improve therapeutic efficacy.

Copper peroxide nanodot-decorated gold nanostar/silica nanorod Janus nanostructure with NIR-II photothermal and acid-triggered hydroxyl radical generation properties for the effective treatment of wound infections

Recently, bacterial infections have become a global crisis, greatly threatening the health of human beings. The development of a non-antibiotic biomaterial is recognized as an alternative way for the effective treatment of bacterial infections. In the present work, a multifunctional copper peroxide (CP) nanodot-decorated gold nanostar (GNS)/silica nanorod (SiNR) Janus nanostructure (GNS@CP/SiNR) with excellent antibacterial activity was reported. Due to the formation of the Janus nanostructure, GNS@CP/SiNR displayed strong plasmonic resonance absorbance in the near infrared (NIR)-II region that enabled the nanosystem to achieve mild photothermal therapy (MPTT). In acidic conditions, CP decorated on GNS@CP/SiNR dissociated rapidly by releasing Cu2+ and H2O2, which subsequently transformed to ˙OH via the Fenton-like reaction for chemodynamic therapy (CDT). As a result, GNS@CP/SiNR could effectively inhibit both Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), and eradicate the associated bacterial biofilms by exerting the synergistic MPTT/CDT antibacterial effect. Moreover, GNS@CP/SiNR was also demonstrated to be effective in treating wound infections, as verified on the S. aureus-infected full thickness excision wound rat model. Our mechanism study revealed that the synergistic MPTT/CDT effect of GNS@CP/SiNR firstly caused bacterial membrane damage, followed by boosting intracellular ROS via the severe oxidative stress effect, which subsequently caused the depletion of intracellular GSH and DNA damage, finally leading to the death of bacteria.

Photothermal therapy: a novel potential treatment for prostate cancer

Prostate cancer (PCa) is a leading cause of cancer-related death in men, and most PCa patients treated with androgen deprivation therapy will progress to metastatic castration-resistant prostate cancer (mCRPC) due to the lack of efficient treatment. Recently, lots of research indicated that photothermal therapy (PTT) was a promising alternative that provided an accurate and efficient prostate cancer therapy. A photothermic agent (PTA) is a basic component of PPT and is divided into organic and inorganic PTAs. Besides, the combination of PTT and other therapies, such as photodynamic therapy (PDT), immunotherapy (IT), chemotherapy (CT), etc., provides an more efficient strategy for PCa therapy. Here, we introduce basic information about PTT and summarize the PTT treatment strategies for prostate cancer. Based on recent works, we think the combination of PPT and other therapies provides a novel possibility for PCa, especially CRPC clinical treatment.