Openwork@Dendritic Mesoporous Silica Nanoparticles for Lactate Depletion and Tumor Microenvironment Regulation

A Time-Interval Strategy to Prepare Porous SiO2 Spheres with Adjustable Core-Shell Ratio for Multiple Guest Loading

Porous microspheres with desired pore size and distribution are in high demand for loading various guest materials, especially various pollutants that are several nanometers in size or stably suspended in liquid. Herein, multilevel porous SiO2 microspheres with arbitrarily adjustable core-shell ratios are prepared by solely regulating the time interval between the start of the hydrolysis reaction and the addition of organic solvent. The core-shell ratio of the SiO2 microspheres increases gradually with prolongation of the addition time interval; meanwhile, the specific surface area can be adjusted from 543.2 m2 g-1 to 992.9 m2 g-1, and the average pore diameter varies from 2.3 to 5.7 nm together with a high pore volume reaching 0.91 cm3 g-1. Moreover, the hierarchical core-shell SiO2 microspheres with an adjustable core-shell ratio, a large specific surface area, and a multilevel pore size could be obtained on a large scale. These SiO2 microspheres demonstrate excellent performance in coloading platinum nanoparticles and various dye molecules, suggesting their great potential in treating various pollutants in printing and dyeing wastewater.

Reprogramming the immunosuppressive tumor microenvironment through nanomedicine: an immunometabolism perspective

Increasing evidence indicates that immunotherapy is hindered by a hostile tumor microenvironment (TME) featured with deprivation of critical nutrients and pooling of immunosuppressive metabolites. Tumor cells and immunosuppressive cells outcompete immune effector cells for essential nutrients. Meanwhile, a wide range of tumor cell-derived toxic metabolites exerts negative impacts on anti-tumor immune response, diminishing the efficacy of immunotherapy. Nanomedicine with excellent targetability offers a novel approach to improving cancer immunotherapy via metabolically reprogramming the immunosuppressive TME. Herein, we review recent strategies of enhancing immunotherapeutic effects through rewiring tumor metabolism via nanomedicine. Attention is drawn on immunometabolic tactics for immune cells and stromal cells in the TME via nanomedicine. Additionally, we discuss future directions of developing metabolism-regulating nanomedicine for precise and efficacious cancer immunotherapy.

Lactate Oxidase Disrupts Lactate-Activated RAS and PI3K Oncogenic Signaling

LOX was recently shown to inhibit cancer cell proliferation and tumor growth. The mechanism of this inhibition, however, has been exclusively attributed to LOX depletion of TME lactate, a cancer cell energy source, and production of H2O2, an oxidative stressor. We report that TME lactate triggers the assembly of the lactate receptor hydroxycarboxylic acid receptor 1 (HCAR1)-associated protein complex, which includes GRB2, SOS1, KRAS, GAB1, and PI3K, for the activation of both the RAS and the PI3K oncogenic signaling pathways in breast cancer (BCa) cells. LOX treatment decreased the levels of the proteins in the protein complex via induction of their proteasomal degradation. In addition, LOX inhibited lactate-stimulated expression of the lactate transporters MCT1 and MCT4. Our data suggest that HCAR1 activation by lactate is crucial for the assembly and function of the RAS and PI3K signaling nexus. Shutting down lactate signaling by disrupting this nexus could be detrimental to cancer cells. HCAR1 is therefore a promising target for the control of the RAS and the PI3K signaling required for BCa progression. Thus, our study provides insights into lactate signaling regulation of cancer progression and extends our understanding of LOX's functional mechanisms that are fundamental for exploring its therapeutic potential.

Sono-Triggered Cascade Lactate Depletion by Semiconducting Polymer Nanoreactors for Cuproptosis-Immunotherapy of Pancreatic Cancer

The high level of lactate in tumor microenvironment not only promotes tumor development and metastasis, but also induces immune escape, which often leads to failures of various tumor therapy strategies. We here report a sono-triggered cascade lactate depletion strategy by using semiconducting polymer nanoreactors (SPNLCu) for cancer cuproptosis-immunotherapy. The SPNLCu mainly contain a semiconducting polymer as sonosensitizer, lactate oxidase (LOx) conjugated via a reactive oxygen species (ROS)-cleavable linker and chelated Cu2+. Upon ultrasound (US) irradiation, the semiconducting polymer generates singlet oxygen (1O2) to cut ROS-cleavable linker to allow the release of LOx that catalyzes lactate depletion to produce hydrogen peroxide (H2O2). The Cu2+ will be reduced to Cu+ in tumor microenvironment, which reacts with the produced H2O2 to obtain hydroxyl radical (⋅OH) that further improves LOx release via destroying ROS-cleavable linkers. As such, sono-triggered cascade release of LOx achieves effective lactate depletion, thus relieving immunosuppressive roles of lactate. Moreover, the toxic Cu+ induces cuproptosis to cause immunogenic cell death (ICD) for activating antitumor immunological effect. SPNLCu are used to treat both subcutaneous and deep-tissue orthotopic pancreatic cancer with observably enhanced efficacy in restricting the tumor growths. This study thus provides a precise and effective lactate depletion tactic for cancer therapy.

Nanomaterial-Based Strategies for Preventing Tumor Metastasis by Interrupting the Metastatic Biological Processes

Tumor metastasis is the primary cause of cancer-related deaths. The prevention of tumor metastasis has garnered notable interest and interrupting metastatic biological processes is considered a potential strategy for preventing tumor metastasis. The tumor microenvironment (TME), circulating tumor cells (CTCs), and premetastatic niche (PMN) play crucial roles in metastatic biological processes. These processes can be interrupted using nanomaterials due to their excellent physicochemical properties. However, most studies have focused on only one aspect of tumor metastasis. Here, the hypothesis that nanomaterials can be used to target metastatic biological processes and explore strategies to prevent tumor metastasis is highlighted. First, the metastatic biological processes and strategies involving nanomaterials acting on the TME, CTCs, and PMN to prevent tumor metastasis are briefly summarized. Further, the current challenges and prospects of nanomaterials in preventing tumor metastasis by interrupting metastatic biological processes are discussed. Nanomaterial-and multifunctional nanomaterial-based strategies for preventing tumor metastasis are advantageous for the long-term fight against tumor metastasis and their continued exploration will facilitate rapid progress in the prevention, diagnosis, and treatment of tumor metastasis. Novel perspectives are outlined for developing more effective strategies to prevent tumor metastasis, thereby improving the outcomes of patients with cancer.

A Novel Nanozyme to Enhance Radiotherapy Effects by Lactic Acid Scavenging, ROS Generation, and Hypoxia Mitigation

Uveal melanoma (UM) is a leading intraocular malignancy with a high 5-year mortality rate, and radiotherapy is the primary approach for UM treatment. However, the elevated lactic acid, deficiency in ROS, and hypoxic tumor microenvironment have severely reduced the radiotherapy outcomes. Hence, this study devised a novel CoMnFe-layered double oxides (LDO) nanosheet with multienzyme activities for UM radiotherapy enhancement. On one hand, LDO nanozyme can catalyze hydrogen peroxide (H2O2) in the tumor microenvironment into oxygen and reactive oxygen species (ROS), significantly boosting ROS production during radiotherapy. Simultaneously, LDO efficiently scavenged lactic acid, thereby impeding the DNA and protein repair in tumor cells to synergistically enhance the effect of radiotherapy. Moreover, density functional theory (DFT) calculations decoded the transformation pathway from lactic to pyruvic acid, elucidating a previously unexplored facet of nanozyme activity. The introduction of this innovative nanomaterial paves the way for a novel, targeted, and highly effective therapeutic approach, offering new avenues for the management of UM and other cancer types.

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.

Lactic acid responsive sequential production of hydrogen peroxide and consumption of glutathione for enhanced ferroptosis tumor therapy

Ferroptosis is characterized by the lethal accumulation of lipid reactive oxygen species (ROS), which has great potential for tumor therapy. However, developing new ferroptosis-inducing strategies by combining nanomaterials with small molecule inducers is important. In this study, an enzyme-gated biodegradable natural-product delivery system based on lactate oxidase (LOD)-gated biodegradable iridium (Ir)-doped hollow mesoporous organosilica nanoparticles (HMONs) loaded with honokiol (HNK) (HNK@Ir-HMONs-LOD, HIHL) is designed to enhance ferroptosis in colon tumor therapy. After reaching the tumor microenvironment, the outer LOD dissociates and releases the HNK to induce ferroptosis. Moreover, the released dopant Ir4+ and disulfide-bridged organosilica frameworks deplete intracellular glutathione (GSH), which is followed by GSH-mediated Ir(IV)/Ir(III) conversion. This leads to the repression of glutathione peroxidase 4 (GPX4) activity and decomposition of intratumoral hydrogen peroxide (H2O2) into hydroxyl radicals (•OH) by Ir3+-mediated Fenton-like reactions. Moreover, LOD efficiently depletes lactic acid to facilitate the generation of H2O2 and boost the Fenton reaction, which in turn enhances ROS generation. With the synergistic effects of these cascade reactions and the release of HNK, notable ferroptosis efficacy was observed both in vitro and in vivo. This combination of natural product-induced and lactic acid-responsive sequential production of H2O2 as well as the consumption of glutathione may provide a new paradigm for achieving effective ferroptosis-based cancer therapy.

Advances in Nanomaterials for Immunotherapeutic Improvement of Cancer Chemotherapy

Immuno-stimulative effect of chemotherapy (ISECT) is recognized as a potential alternative to conventional immunotherapies, however, the clinical application is constrained by its inefficiency. Metronomic chemotherapy, though designed to overcome these limitations, offers inconsistent results, with effectiveness varying based on cancer types, stages, and patient-specific factors. In parallel, a wealth of preclinical nanomaterials holds considerable promise for ISECT improvement by modulating the cancer-immunity cycle. In the area of biomedical nanomaterials, current literature reviews mainly concentrate on a specific category of nanomaterials and nanotechnological perspectives, while two essential issues are still lacking, i.e., a comprehensive analysis addressing the causes for ISECT inefficiency and a thorough summary elaborating the nanomaterials for ISECT improvement. This review thus aims to fill these gaps and catalyze further development in this field. For the first time, this review comprehensively discusses the causes of ISECT inefficiency. It then meticulously categorizes six types of nanomaterials for improving ISECT. Subsequently, practical strategies are further proposed for addressing inefficient ISECT, along with a detailed discussion on exemplary nanomedicines. Finally, this review provides insights into the challenges and perspectives for improving chemo-immunotherapy by innovations in nanomaterials.

Recent progress in lactate oxidase-based drug delivery systems for enhanced cancer therapy

Lactate oxidase (LOX) is a natural enzyme that efficiently consumes lactate. In the presence of oxygen, LOX can catalyse the formation of pyruvate and hydrogen peroxide (H2O2) from lactate. This process led to acidity alleviation, hypoxia, and a further increase in oxidative stress, alleviating the immunosuppressive state of the tumour microenvironment (TME). However, the high cost of LOX preparation and purification, poor stability, and systemic toxicity limited its application in tumour therapy. Therefore, the rational application of drug delivery systems can protect LOX from the organism's environment and maintain its catalytic activity. This paper reviews various LOX-based drug-carrying systems, including inorganic nanocarriers, organic nanocarriers, and inorganic-organic hybrid nanocarriers, as well as other non-nanocarriers, which have been used for tumour therapy in recent years. In addition, this area's challenges and potential for the future are highlighted.

A mesoporous superparamagnetic iron oxide nanoparticle as a generic drug delivery system for tumor ferroptosis therapy

As a famous drug delivery system (DDS), mesoporous organosilica nanoparticles (MON) are degraded slowly in vivo and the degraded components are not useful for cell nutrition or cancer theranostics, and superparamagnetic iron oxide nanoparticles (SPION) are not mesoporous with low drug loading content (DLC). To overcome the problems of MON and SPION, we developed mesoporous SPIONs (MSPIONs) with an average diameter of 70 nm and pore size of 3.9 nm. Sorafenib (SFN) and/or brequinar (BQR) were loaded into the mesopores of MSPION, generating SFN@MSPION, BQR@MSPION and SFN/BQR@MSPION with high DLC of 11.5% (SFN), 10.1% (BQR) and 10.0% (SNF + BQR), demonstrating that our MSPION is a generic DDS. SFN/BQR@MSPION can be used for high performance ferroptosis therapy of tumors because: (1) the released Fe2+/3+ in tumor microenvironment (TME) can produce •OH via Fenton reaction; (2) the released SFN in TME can inhibit the cystine/glutamate reverse transporter, decrease the intracellular glutathione (GSH) and GSH peroxidase 4 levels, and thus enhance reactive oxygen species and lipid peroxide levels; (3) the released BQR in TME can further enhance the intracellular oxidative stress via dihydroorotate dehydrogenase inhibition. The ferroptosis therapeutic mechanism, efficacy and biosafety of MSPION-based DDS were verified on tumor cells and tumor-bearing mice.

Nanocarriers address intracellular barriers for efficient drug delivery, overcoming drug resistance, subcellular targeting and controlled release

The cellular barriers are major bottlenecks for bioactive compounds entering into cells to accomplish their biological functions, which limits their biomedical applications. Nanocarriers have demonstrated high potential and benefits for encapsulating bioactive compounds and efficiently delivering them into target cells by overcoming a cascade of intracellular barriers to achieve desirable therapeutic and diagnostic effects. In this review, we introduce the cellular barriers ahead of drug delivery and nanocarriers, as well as summarize recent advances and strategies of nanocarriers for increasing internalization with cells, promoting intracellular trafficking, overcoming drug resistance, targeting subcellular locations and controlled drug release. Lastly, the future perspectives of nanocarriers for intracellular drug delivery are discussed, which mainly focus on potential challenges and future directions. Our review presents an overview of intracellular drug delivery by nanocarriers, which may encourage the future development of nanocarriers for efficient and precision drug delivery into a wide range of cells and subcellular targets.

Enhancing Bone Regeneration through CDC20-Loaded ZIF-8 Nanoparticles Wrapped in Erythrocyte Membranes with Targeting Aptamer

In the context of bone regeneration, nanoparticles harboring osteogenic factors have emerged as pivotal agents for modulating the differentiation fate of stem cells. However, persistent challenges surrounding biocompatibility, loading efficiency, and precise targeting ability warrant innovative solution. In this study, a novel nanoparticle platform founded upon the zeolitic imidazolate framework-8 (ZIF-8) is introduced. This new design, CDC20@ZIF-8@eM-Apt, involves the envelopment of ZIF-8 within an erythrocyte membrane (eM) cloak, and is coupled with a targeting aptamer. ZIF-8, distinguished by its porosity, biocompatibility, and robust cargo transport capabilities, constitutes the core framework. Cell division cycle protein 20 homolog (CDC20) is illuminated as a new target in bone regeneration. The eM plays a dual role in maintaining nanoparticle stability and facilitating fusion with target cell membranes, while the aptamer orchestrates the specific recruitment of bone marrow mesenchymal stem cells (BMSCs) within bone defect sites. Significantly, CDC20@ZIF-8@eM-Apt amplifies osteogenic differentiation of BMSCs via the inhibition of NF-κB p65, and concurrently catalyzes bone regeneration in two bone defect models. Consequently, CDC20@ZIF-8@eM-Apt introduces a pioneering strategy for tackling bone defects and associated maladies, opening novel avenues in therapeutic intervention.

Intratumoral Lactate Depletion Based on Injectable Nanoparticles-Hydrogel Composite System Synergizes with Immunotherapy against Postablative Hepatocellular Carcinoma Recurrence

Thermal ablation is a crucial therapeutic modality for hepatocellular carcinoma (HCC), but its efficacy is often hindered by the high recurrence rate attributed to insufficient ablation. Furthermore, the residual tumors following insufficient ablation exhibit a more pronounced immunosuppressive state, which accelerates the disease progression and leads to immune checkpoint blockade (ICB) resistance. Herein, evidence is presented that heightened intratumoral lactate accumulation, stemming from the augmented glycolytic activity of postablative residual HCC cells, may serve as a crucial driving force in exacerbating the immunosuppressive state of the tumor microenvironment (TME). To address this, an injectable nanoparticles-hydrogel composite system (LOX-MnO2 @Gel) is designed that gradually releases lactate oxidase (LOX)-loaded hollow mesoporous MnO2 nanoparticles at the tumor site to continuously deplete intratumoral lactate via a cascade catalytic reaction. Using subcutaneous and orthotopic HCC tumor-bearing mouse models, it is confirmed that LOX-MnO2 @Gel-mediated local lactate depletion can transform the immunosuppressive postablative TME into an immunocompetent one and synergizes with ICB therapy to significantly inhibit residual HCC growth and lung metastasis, thereby prolonging the survival of mice postablation. The work proposes an appealing strategy for synergistically combining antitumor metabolic therapy with immunotherapy to combat postablative HCC recurrence.

Controllable synthesis of flower-like hierarchical porous TiO2 at room temperature and its affinity application

Flower-like particles have attracted much attention due to their efficient surface accessible sites and unique hierarchical porous structure. However, their synthesis is usually challenging and requires complex procedures. Herein, we present a simple method for rapid preparation of flower-like hierarchical porous TiO2 (FHP-TiO2) at room temperature for the first time. This method can accurately control the size of FHP-TiO2 from 150 nm to 400 nm by combining co-assembly and Stober reaction. The formation mechanism and influencing factors of FHP-TiO2 were systematically investigated, and its excellent metal oxide affinity was confirmed by theoretical calculations. Due to its hierarchical porous structure, large surface area and high specificity performance, FHP-TiO2 served as an appealing restricted-access adsorbent for specific and efficient enrichment of molecules with phosphate groups in a complex sample matrix, thereby realizing the quantitative analysis of these important biomolecules by coupling with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Moreover, compared with other morphologies (rough surface, and hollow dendritic and mesoporous structure) of TiO2 and flower-like SiO2, FHP-TiO2 showed the best affinity binding ability. This research not only presents a novel approach for tunable room-temperature synthesis of FHP-TiO2 with different sizes, but also expands the application of FHP-TiO2 as an appealing sample-enricher for food safety monitoring and early disease diagnosis.

Advances in Nanodelivery Systems Based on Metabolism Reprogramming Strategies for Enhanced Tumor Therapy

Tumor development and metastasis are closely related to the complexity of the metabolism network. Recently, metabolism reprogramming strategies have attracted much attention in tumor metabolism therapy. Although there is preliminary success of metabolism therapy agents, their therapeutic effects have been restricted by the effective reaching of the tumor sites of drugs. Nanodelivery systems with unique physical properties and elaborate designs can specifically deliver to the tumors. In this review, we first summarize the research progress of nanodelivery systems based on tumor metabolism reprogramming strategies to enhance therapies by depleting glucose, inhibiting glycolysis, depleting lactic acid, inhibiting lipid metabolism, depleting glutamine and glutathione, and disrupting metal metabolisms combined with other therapies, including chemotherapy, radiotherapy, photodynamic therapy, etc. We further discuss in detail the advantages of nanodelivery systems based on tumor metabolism reprogramming strategies for tumor therapy. As well as the opportunities and challenges for integrating nanodelivery systems into tumor metabolism therapy, we analyze the outlook for these emerging areas. This review is expected to improve our understanding of modulating tumor metabolisms for enhanced therapy.

Current Advances on Nanomaterials Interfering with Lactate Metabolism for Tumor Therapy

Increasing numbers of studies have shown that tumor cells prefer fermentative glycolysis over oxidative phosphorylation to provide a vast amount of energy for fast proliferation even under oxygen-sufficient conditions. This metabolic alteration not only favors tumor cell progression and metastasis but also increases lactate accumulation in solid tumors. In addition to serving as a byproduct of glycolytic tumor cells, lactate also plays a central role in the construction of acidic and immunosuppressive tumor microenvironment, resulting in therapeutic tolerance. Recently, targeted drug delivery and inherent therapeutic properties of nanomaterials have attracted great attention, and research on modulating lactate metabolism based on nanomaterials to enhance antitumor therapy has exploded. In this review, the advanced tumor therapy strategies based on nanomaterials that interfere with lactate metabolism are discussed, including inhibiting lactate anabolism, promoting lactate catabolism, and disrupting the "lactate shuttle". Furthermore, recent advances in combining lactate metabolism modulation with other therapies, including chemotherapy, immunotherapy, photothermal therapy, and reactive oxygen species-related therapies, etc., which have achieved cooperatively enhanced therapeutic outcomes, are summarized. Finally, foreseeable challenges and prospective developments are also reviewed for the future development of this field.

Silica nanoparticles: A review of their safety and current strategies to overcome biological barriers

Silica nanoparticles (SNP) have gained tremendous attention in the recent decades. They have been used in many different biomedical fields including diagnosis, biosensing and drug delivery. Medical uses of SNP for anti-cancer, anti-microbial and theranostic applications are especially prominent due to their exceptional performance to deliver many different small molecules and recently biologics (mRNA, siRNA, antigens, antibodies, proteins, and peptides) at targeted sites. The physical and chemical properties of SNP such as large specific surface area, tuneable particle size and porosity, excellent biodegradability and biocompatibility make them an ideal drug delivery and diagnostic platform. Based on the available data and the pre-clinical performance of SNP, recent interest has driven these innovative materials towards clinical application with many of the formulations already in Phase I and Phase II trials. Herein, the progress of SNP in biomedical field is reviewed, and their safety aspects are analysed. Importantly, we critically evaluate the key structural characteristics of SNP to overcome different biological barriers including the blood-brain barrier (BBB), skin, tumour barrier and mucosal barrier. Future directions, potential pathways, and target areas towards rapid clinical translation of SNP are also recommended.

Emerging enzyme-based nanocomposites for catalytic biomedicine

With the promising advances in nanomedicine, numerous strategies have emerged for the diagnosis and treatment of diseases. Among them, enzyme-based multifunctional nanocomposites have attracted a great deal of attention in the field of catalytic biomedicine. These nanocomposites with high catalytic activity are capable of converting low/non-toxic substances into therapeutic ones, thus realizing highly efficient, site-specific therapy with minimal side effects. Enzyme-based nanocomposites for catalytic biomedicine are mainly divided into three types: (i) natural-enzyme based nanocomposites; (ii) artificial-nanozyme based nanocomposites; and (iii) nanocomposites of natural-enzymes and nanozymes. In this review, we discuss key aspects of enzyme-based catalytic biomedicine, including the construction of enzyme-based nanocomposites, their unique properties and applications in catalytic biomedicine. We also highlight the main challenges faced in this field, and provide relevant guidelines for the rational design and extensive application of enzyme-based nanocomposites from our point of view.

Emerging nanotechnological approaches to regulating tumor vasculature for cancer therapy

Abnormal angiogenesis stands for one of the most striking manifestations of malignant tumor. The pathologically and structurally abnormal tumor vasculature facilitates a hostile tumor microenvironment, providing an ideal refuge exclusively for cancer cells. The emergence of vascular regulation drugs has introduced a distinctive class of therapeutics capable of influencing nutrition supply and drug delivery efficacy without the need to penetrate a series of physical barriers to reach tumor cells. Nanomedicines have been further developed for more precise regulation of tumor vasculature with the capacity of co-delivering multiple active pharmaceutical ingredients, which overall reduces the systemic toxicity and boosts the therapeutic efficacy of free drugs. Additionally, precise structure design enables the integration of specific functional motifs, such as surface-targeting ligands, droppable shells, degradable framework, or stimuli-responsive components into nanomedicines, which can improve tissue-specific accumulation, enhance tissue penetration, and realize the controlled and stimulus-triggered release of the loaded cargo. This review describes the morphological and functional characteristics of tumor blood vessels and summarizes the pivotal molecular targets commonly used in nanomedicine design, and then highlights the recent cutting-edge advancements utilizing nanotechnologies for precise regulation of tumor vasculature. Finally, the challenges and future directions of this field are discussed.

Dual-inhibition of lactate metabolism and Prussian blue-mediated radical generation for enhanced chemodynamic therapy and antimetastatic effect

Numerous research studies have proved that lactate is pivotal in tumor proliferation, metastasis, and recurrence, so disrupting the lactate metabolism in the tumor microenvironment (TME) has become one of the effective methods of tumor treatment. Herein, we have developed a versatile nanoparticle (HCLP NP) based on hollow Prussian blue (HPB) as the functional carrier for loading α-cyano-4-hydroxycinnamate (CHC), and lactate oxidase (LOD), followed by coating with polyethylene glycol to enhance chemodynamic therapy (CDT) and the antimetastatic effect of cancer. The obtained HCLP NPs would be degraded under endogenous mild acidity within the TME to simultaneously release CHC and LOD. CHC inhibits the expression of monocarboxylate transporter 1 in tumors, thereby interrupting the uptake of lactate from the outside and alleviating tumor hypoxia by reducing lactate aerobic respiration. Meanwhile, the released LOD can catalyze the decomposition of lactate into hydrogen peroxide, further enhancing the efficacy of CDT by generating plenty of toxic reactive oxygen species through the Fenton reaction. The strong absorbance at about 800 nm endows HCLP NPs with excellent photoacoustic imaging properties. Both in vitro and in vivo studies have demonstrated that HCLP NPs can inhibit tumor growth and metastasis, providing a new possibility for tumor therapy.

Lactate-Oxidase-Instructed Cancer Diagnosis and Therapy

Lactate oxidase (LOx) has attracted extensive interest in cancer diagnosis and therapy in recent years owing to its specific catalysis on l-lactate; its catalytic process consumes oxygen (O₂ ) and generates a large amount of hydrogen peroxide (H₂ O₂ ) and pyruvate. Given high levels of lactate in tumor tissues and its tight correlation with tumor growth, metastasis, and recurrence, LOx-based biosensors including H₂ O₂ -based, O₂ -based, pH-sensitive, and electrochemical have been designed for cancer diagnosis, and various LOx-based cancer therapy strategies including lactate-depletion-based metabolic cancer therapy/immunotherapy, hypoxia-activated chemotherapy, H₂ O₂ -based chemodynamic therapy, and multimodal synergistic cancer therapy have also been developed. In this review, the lactate-specific catalytic properties of LOx are introduced, and the recent advances on LOx-instructed cancer diagnostic or therapeutic platforms and corresponding biological applications are summarized. Additionally, the challenges and potential of LOx-based nanomedicines are highlighted.

Mesoporous nanodrug delivery system: a powerful tool for a new paradigm of remodeling of the tumor microenvironment

Tumor microenvironment (TME) plays an important role in tumor progression, metastasis and therapy resistance. Remodeling the TME has recently been deemed an attractive tumor therapeutic strategy. Due to its complexity and heterogeneity, remodeling the TME still faces great challenges. With the great advantage of drug loading ability, tumor accumulation, multifactor controllability, and persistent guest molecule release ability, mesoporous nanodrug delivery systems (MNDDSs) have been widely used as effective antitumor drug delivery tools as well as remolding TME. This review summarizes the components and characteristics of the TME, as well as the crosstalk between the TME and cancer cells and focuses on the important role of drug delivery strategies based on MNDDSs in targeted remodeling TME metabolic and synergistic anticancer therapy.

Photothermal "nano-dot" reactivate "immune-hot" for tumor treatment via reprogramming cancer cells metabolism

Cancer immunotherapy, despite its enormous application prospect, is trapped in the abnormal lactic acid metabolism of tumor cells that usually causes an immunosuppressive tumor microenvironment (ITM). Inducing immunogenic cell death (ICD) not only sensitizes cancer cells to carcer immunity, but also leads to a great increase in tumor-specific antigens. It improves tumor condition from "immune-cold" to "immune-hot". Herein, a near-infrared photothermal agent NR840 was developed and encapsulated into tumor-targeted polymer DSPE-PEG-cRGD and carried lactate oxidase (LOX) by electrostatic interaction, forming self-assembling "nano-dot" PLNR840 with high loading capacity for synergistic antitumor photo-immunotherapy. In this strategy, PLNR840 was swallowed by cancer cells, then dye NR840 was excited at 808 nm to generate heat inducing tumor cell necrosis, which further caused ICD. LOX could serve as a catalyst, reducing lactic acid efflux via regulation of cell metabolism. More importantly, the consumption of intratumoral lactic acid could substantially reverse ITM, including promoting the polarization of tumor-associated macrophages from M2 to M1 type, inhibiting the viability of regulatory T cells for sensitizing photothermal therapy (PTT). After the combination of αPD-L1 (programmed cell death protein ligand 1), PLNR840 restored CD8⁺ T-cell activity that thoroughly cleaned the pulmonary metastasis of breast cancer in 4T1 mouse model and cured hepatocellular carcinoma in Hepa1-6 mouse model. This study provided an effective PTT strategy to boost "immune-hot" and reprogrammed tumor metabolism for antitumor immunotherapy.

Engineering lactate-modulating nanomedicines for cancer therapy

Lactate in tumors has long been considered "metabolic junk" derived from the glycolysis of cancer cells and utilized only as a biomarker of malignancy, but is presently believed to be a pivotal regulator of tumor development, maintenance and metastasis. Indeed, tumor lactate can be a "fuel" for energy supply and functions as a signaling molecule, which actively contributes to tumor progression, angiogenesis, immunosuppression, therapeutic resistance, etc., thus providing promising opportunities for cancer treatment. However, the current approaches for regulating lactate homeostasis with available agents are still challenging, which is mainly due to the short half-life, low bioavailability and poor specificity of these agents and their unsatisfactory therapeutic outcomes. In recent years, lactate modulation nanomedicines have emerged as a charming and efficient strategy for fighting cancer, which play important roles in optimizing the delivery of lactate-modulating agents for more precise and effective modulation and treatment. Integrating specific lactate-modulating functions in diverse therapeutic nanomedicines may overcome the intrinsic restrictions of different therapeutic modalities by remodeling the pathological microenvironment for achieving enhanced cancer therapy. In this review, the most recent advances in the engineering of functional nanomedicines that can modulate tumor lactate for cancer therapy are summarized and discussed, and the fundamental mechanisms by which lactate modulation benefits various therapeutics are elucidated. Finally, the challenges and perspectives of this emerging strategy in the anti-tumor field are highlighted.

Insights into the Effect of Catalytic Intratumoral Lactate Depletion on Metabolic Reprogramming and Immune Activation for Antitumoral Activity

Lactate, a characteristic metabolite of the tumor microenvironment (TME), drives immunosuppression and promotes tumor progression. Material-engineered strategies for intratumoral lactate modulations demonstrate their promise for tumor immunotherapy. However, understanding of the inherent interconnections of material-enabled lactate regulation, metabolism, and immunity in the TME is scarce. To address this issue, urchin-like catalysts of the encapsulated Gd-doped CeO₂ , syrosingopine, and lactate oxidase are used in ZIF-8 (USL, where U, S, and L represent the urchin-like Gd-doped CeO₂ @ZIF-8, syrosingopine, and lactate oxidase, respectively) and orthotopic tumor models. The instructive relationships of intratumoral lactate depletion, metabolic reprogramming, and immune activation for catalytic immunotherapy of tumors is illustrated. The catalysts efficiently oxidize intratumoral lactate and significantly promote tumor cell apoptosis by in situ-generated ·OH, thereby reducing glucose supply and inducing mitochondrial damage via lactate depletion, thus reprogramming glycometabolism. Subsequently, such catalytic metabolic reprogramming evokes both local and systemic antitumor immunity by activating M1-polarizaed macrophages and CD8⁺ T cells, leading to potent antitumor immunity. This study provides valuable mechanistic insights into material-interfered tumor therapy through intratumoral lactate depletion and consequential connection with metabolic reprogramming and immunity remodeling, which is thought to enhance the efficacy of immunotherapy.

A metabolic intervention strategy to break evolutionary adaptability of tumor for reinforced immunotherapy

The typical hallmark of tumor evolution is metabolic dysregulation. In addition to secreting immunoregulatory metabolites, tumor cells and various immune cells display different metabolic pathways and plasticity. Harnessing the metabolic differences to reduce the tumor and immunosuppressive cells while enhancing the activity of positive immunoregulatory cells is a promising strategy. We develop a nanoplatform (CLCeMOF) based on cerium metal-organic framework (CeMOF) by lactate oxidase (LOX) modification and glutaminase inhibitor (CB839) loading. The cascade catalytic reactions induced by CLCeMOF generate reactive oxygen species "storm" to elicit immune responses. Meanwhile, LOX-mediated metabolite lactate exhaustion relieves the immunosuppressive tumor microenvironment, preparing the ground for intracellular regulation. Most noticeably, the immunometabolic checkpoint blockade therapy, as a result of glutamine antagonism, is exploited for overall cell mobilization. It is found that CLCeMOF inhibited glutamine metabolism-dependent cells (tumor cells, immunosuppressive cells, etc.), increased infiltration of dendritic cells, and especially reprogrammed CD8+ T lymphocytes with considerable metabolic flexibility toward a highly activated, long-lived, and memory-like phenotype. Such an idea intervenes both metabolite (lactate) and cellular metabolic pathway, which essentially alters overall cell fates toward the desired situation. Collectively, the metabolic intervention strategy is bound to break the evolutionary adaptability of tumors for reinforced immunotherapy.

Lactate oxidase/catalase-displaying nanoparticles efficiently consume lactate in the tumor microenvironment to effectively suppress tumor growth

The aggressive proliferation of tumor cells often requires increased glucose uptake and excessive anaerobic glycolysis, leading to the massive production and secretion of lactate to form a unique tumor microenvironment (TME). Therefore, regulating appropriate lactate levels in the TME would be a promising approach to control tumor cell proliferation and immune suppression. To effectively consume lactate in the TME, lactate oxidase (LOX) and catalase (CAT) were displayed onto Aquifex aeolicus lumazine synthase protein nanoparticles (AaLS) to form either AaLS/LOX or AaLS/LOX/CAT. These complexes successfully consumed lactate produced by CT26 murine colon carcinoma cells under both normoxic and hypoxic conditions. Specifically, AaLS/LOX generated a large amount of H₂O₂ with complete lactate consumption to induce drastic necrotic cell death regardless of culture condition. However, AaLS/LOX/CAT generated residual H₂O₂, leading to necrotic cell death only under hypoxic condition similar to the TME. While the local administration of AaLS/LOX to the tumor site resulted in mice death, that of AaLS/LOX/CAT significantly suppressed tumor growth without any severe side effects. AaLS/LOX/CAT effectively consumed lactate to produce adequate amounts of H₂O₂ which sufficiently suppress tumor growth and adequately modulate the TME, transforming environments that are favorable to tumor suppressive neutrophils but adverse to tumor-supportive tumor-associated macrophages. Collectively, these findings showed that the modular functionalization of protein nanoparticles with multiple metabolic enzymes may offer the opportunity to develop new enzyme complex-based therapeutic tools that can modulate the TME by controlling cancer metabolism.

Lactate in the tumor microenvironment: A rising star for targeted tumor therapy

Metabolic reprogramming is one of fourteen hallmarks of tumor cells, among which aerobic glycolysis, often known as the "Warburg effect," is essential to the fast proliferation and aggressive metastasis of tumor cells. Lactate, on the other hand, as a ubiquitous molecule in the tumor microenvironment (TME), is generated primarily by tumor cells undergoing glycolysis. To prevent intracellular acidification, malignant cells often remove lactate along with H⁺, yet the acidification of TME is inevitable. Not only does the highly concentrated lactate within the TME serve as a substrate to supply energy to the malignant cells, but it also works as a signal to activate multiple pathways that enhance tumor metastasis and invasion, intratumoral angiogenesis, as well as immune escape. In this review, we aim to discuss the latest findings on lactate metabolism in tumor cells, particularly the capacity of extracellular lactate to influence cells in the tumor microenvironment. In addition, we examine current treatment techniques employing existing medications that target and interfere with lactate generation and transport in cancer therapy. New research shows that targeting lactate metabolism, lactate-regulated cells, and lactate action pathways are viable cancer therapy strategies.

O2-Supplying Nanozymes Alleviate Hypoxia and Deplete Lactate to Eliminate Tumors and Activate Antitumor Immunity

Direct hypoxia alleviation and lactate depletion in the tumor microenvironment (TME) are promising for effective cancer therapy but still very challenging. To address this challenge, the current research directly reshapes the TME for inhibiting tumor growth and activating the antitumor immunity using a drug-free nanozyme. Herein, the acid-sensitive nanozymes were constructed based on peroxidized layered double hydroxide nanoparticles for O₂ self-supply and self-boosted lactate depletion. The coloading of partially cross-linked catalase and lactate oxidase enabled the acid-sensitive nanozymes to promote three reactions, that is, (1) H₂O₂ generation from MgO₂ hydrolysis (30% at pH 7.4 vs 63% at pH 6.0 in 8 h); (2) O₂ generation from H₂O₂ (12% at pH 7.4 vs 21% at pH 6.0 in 2 h); and (3) lactate depletion by in situ generated O₂ (50% under hypoxia vs 75% under normoxia in 24 h in vitro) in parallel or tandem. These promoted reactions together efficiently induced colon cancer cell apoptosis under the hypoxic conditions, significantly inhibited tumor growth (>95%), and suppressed distant tumor growth upon seven administrations in every 3 days and moreover transformed the immunosuppressive tumor into "hot" one in the colon tumor-bearing mouse model. This is the first example for a nanozyme that supplies sufficient O₂ for hypoxia relief and lactate depletion, thus providing a new insight into drug-free nanomaterial-mediated TME-targeted cancer therapy.

Harnessing bioactive nanomaterials in modulating tumor glycolysis-associated metabolism

Glycolytic reprogramming is emerging as a hallmark of various cancers and a promising therapeutic target. Nanotechnology is revolutionizing the anti-tumor therapeutic approaches associated with glycolysis. Finely controlled chemical composition and nanostructure provide nanomaterials unique advantages, enabling an excellent platform for integrated drug delivery, biochemical modulation and combination therapy. Recent studies have shown promising potential of nanotherapeutic strategies in modulating tumor glycolytic metabolism alone or in combination with other treatments such as chemotherapy, radiotherapy and immunotherapy. To foster more innovation in this cutting-edge and interdisciplinary field, this review summarizes recent understandings of the origin and development of tumor glycolysis, then provides the latest advances in how nanomaterials modulate tumor glycolysis-related metabolism. The interplay of nanochemistry, metabolism and immunity is highlighted. Ultimately, the challenges and opportunities are presented.

A composite hydrogel containing resveratrol-laden nanoparticles and platelet-derived extracellular vesicles promotes wound healing in diabetic mice

Diabetic wounds are difficult to heal because of persistent inflammation and limited angiogenesis. Resveratrol (RES) is an anti-inflammatory and antioxidant agent. Platelet-derived extracellular vesicles (PDEVs) are rich in growth factors and cytokines, which promote proliferation and angiogenesis. However, single drug treatment has limited efficacy and delivery efficiency. Bioengineering can improve the limited effect of single drugs by combining drugs and materials to obtain complementary or cooperative bioengineered drugs. In this study, gelatin methacrylate (GelMA) and silk fibroin glycidyl methacrylate (SFMA) were used to synthesize GelMA/SFMA composite hydrogels with suitable mechanical properties, swelling ratio and biodegradability. The composite hydrogel was used as a wound dressing for sustained drug release. RES was loaded into mesoporous silica nanoparticles (MSNs) to synthesize MSN-RES to enhance the release dynamic, and MSN-RES and PDEVs were combined with the composite hydrogels to form GelMA/SFMA/MSN-RES/PDEVs hydrogels. The GelMA/SFMA/MSN-RES/PDEVs had low cytotoxicity and good biocompatibility, inhibited macrophage iNOS expression, and promoted the tube formation by human umbilical vein endothelial cells (HUVECs) in vitro. In a diabetic mouse wound model, the GelMA/SFMA/MSN-RES/PDEVs hydrogels decreased the expression of pro-inflammatory factors TNF-α and iNOS, increased the expression of anti-inflammatory factors TGF-β1 and Arg-1, promoted angiogenesis, and accelerated wound healing. Interestingly, the GelMA/SFMA/MSN-RES/PDEVs hydrogels promoted the expression of extracellular purinergic signaling pathway-related CD73 and adenosine 2A receptor (A2A-R). Therefore, the GelMA/SFMA/MSN-RES/PDEVs hydrogels could be used as wound dressings to regulate the inflammation and angiogenesis of diabetic wounds and accelerate wound healing. STATEMENT OF SIGNIFICANCE: Drugs often fail to function because of a continuous oxidative stress microenvironment and inflammation. Here, a GelMA/SFMA hydrogel, with enhanced mechanical properties and liquid absorption ability, is proposed for sustained release of drugs. In addition to carrying platelet-derived extracellular vesicles (PDEVs) with pro-angiogenic effects, the hydrogels were also loaded with nanoparticle-encapsulated resveratrol with anti-inflammatory activities, aiming to reduce inflammation and oxidative stress in the wound microenvironment, such that the wound could receive proliferative repair signals to achieve sequential treatment and heal quickly. We also experimentally predicted that the regulatory mechanism of the GelMA/SFMA/MSN-RES/PDEVs in wound healing might be related to the extracellular purinergic signaling pathway.

Engineering Single-Atom Iron Nanozymes with Radiation-Enhanced Self-Cascade Catalysis and Self-Supplied H2O2 for Radio-enzymatic Therapy

Single-atom nanozymes (SAzymes), with individually isolated metal atom as active sites, have shown tremendous potential as enzyme-based drugs for enzymatic therapy. However, using SAzymes in tumor theranostics remains challenging because of deficient enzymatic activity and insufficient endogenous H₂O₂. We develop an external-field-enhanced catalysis by an atom-level engineered FeN₄-centered nanozyme (FeN₄-SAzyme) for radio-enzymatic therapy. This FeN₄-SAzyme exhibits peroxidase-like activity capable of catalyzing H₂O₂ into hydroxyl radicals and converting single-site Fe^II species to Fe^III for subsequent glutathione oxidase-like activity. Density functional theory calculations are used to rationalize the origin of the single-site self-cascade enzymatic activity. Importantly, using X-rays can improve the overall single-site cascade enzymatic reaction process via promoting the conversion frequency of Fe^II/Fe^III. As a H₂O₂ producer, natural glucose oxidase is further decorated onto the surface of FeN₄-SAzyme to yield the final construct GOD@FeN₄-SAzyme. The resulting GOD@FeN₄-SAzyme not only supplies in situ H₂O₂ to continuously produce highly toxic hydroxyl radicals but also induces the localized deposition of radiation dose, subsequently inducing intensive apoptosis and ferroptosis in vitro. Such a synergistic effect of radiotherapy and self-cascade enzymatic therapy allows for improved tumor growth inhibition with minimal side effects in vivo. Collectively, this work demonstrates the introduction of external fields to enhance enzyme-like performance of nanozymes without changing their properties and highlights a robust therapeutic capable of self-supplying H₂O₂ and amplifying self-cascade reactions to address the limitations of enzymatic treatment.

Erianin-Loaded Photo-Responsive Dendrimer Mesoporous Silica Nanoparticles: Exploration of a Psoriasis Treatment Method

Psoriasis is a chronic inflammatory skin disorder accompanied by excessive keratinocyte proliferation. Erianin (Eri) is an ideal drug candidate for inhibiting proliferation and inducing apoptosis in the treatment of psoriasis. However, Eri’s poor water solubility and low penetration activity across the skin hinder its application in local medicine. In this study, we developed a novel photo-responsive dendritic mesoporous silica nanoparticle-based carrier to deliver erianin, improved its bioavailability, and achieved sustained-release effects. Spiropyran (SP), 3-aminopropyltriethoxysilane (APTES), and perfluorodecyltriethoxysilane (PFDTES) were conjugated to the outer surface, which allowed Eri to be released in response to UV radiation. The physicochemical properties of photo-responsive dendritic mesoporous silica nanoparticles (Eri-DMSN@FSP) were characterized via multiple techniques, such as using a Fourier-transform infrared spectrometer, a high-resolution transmission electron microscope, and nuclear magnetic resonance (NMR) spectroscopy. The anti-proliferative properties and light-triggered release of erianin-loaded photo-responsive dendritic mesoporous silica nanoparticles were assessed via the MTT assay and a drug release study in vitro. Erianin-loaded photo-responsive dendritic mesoporous silica nanoparticles (UV) exhibit a significantly enhanced HaCat cell-inhibiting efficacy compared to other formulations, as demonstrated by their extremely low cell viability of 10.0% (concentration: 500 mg/mL), indicating their capability to release a drug that responds to UV radiation. The cellular uptake of photo-responsive dendritic mesoporous silica nanoparticles (DMSN@FSP) was observed via confocal laser scanning microscopy (CLSM). These experimental results show that Eri-DMSN@FSP could be effectively endocytosed into cells and respond to ultraviolet light to release Eri, achieving a more effective psoriasis treatment. Therefore, this drug delivery system may be a promising strategy for addressing the question of Eri’s delivery and psoriasis therapy.

New opportunities for immunomodulation of the tumour microenvironment using chemical tools

Immunotherapy is recognised as an attractive method for the treatment of cancer, and numerous treatment strategies have emerged over recent years. Investigations of the tumour microenvironment (TME) have led to the identification of many potential therapeutic targets and methods. However, many recently applied immunotherapies are based on previously identified strategies, such as boosting the immune response by combining commonly used stimulators, and the release of drugs through changes in pH. Although methodological improvements such as structural optimisation and combining strategies can be undertaken, applying those novel targets and methods in immunotherapy remains an important goal. In this review, we summarise the latest research on the TME, and discuss how small molecules, immune cells, and their interactions with tumour cells can be regulated in the TME. Additionally, the techniques currently employed for delivery of these agents to the TME are also mentioned. Strategies to modulate cell phenotypes and interactions between immune cells and tumours are mainly discussed. We consider both modulatory and targeting methods aiming to bridge the gap between the TME and chemical modulation thereof.

Recent advances in mesoporous silica nanoparticle-based targeted drug-delivery systems for cancer therapy

Targeted drug-delivery systems are a growing research topic in tumor treatment. In recent years, mesoporous silica nanoparticles (MSNs) have been extensively studied and applied in noninvasive and biocompatible drug-delivery systems for tumor therapy due to their outstanding advantages, which include high surface area, large pore volume, tunable pore size, easy surface modification and stable framework. The advances in the application of MSNs for anticancer drug targeting are covered and highlighted in this review, and the challenges and prospects of MSN-based targeted drug-delivery systems are discussed. This review provides new insights for researchers interested in targeted drug-delivery systems against cancer.

Versatile synthesis of dendritic mesoporous rare earth-based nanoparticles

Rare earth-based nanomaterials that have abundant optical, magnetic, and catalytic characteristics have many applications. The controllable introduction of mesoporous channels can further enhance its performance, such as exposing more active sites of rare earth and improving the loading capacity, yet remains a challenge. Here, we report a universal viscosity-mediated assembly strategy and successfully endowed rare earth-based nanoparticles with central divergent dendritic mesopores. More than 40 kinds of dendritic mesoporous rare earth-based (DM-REX) nanoparticles with desired composition (single or multiple rare earth elements, high-entropy compounds, etc.), particle diameter (80 to 500 nanometers), pore size (3 to 20 nanometers), phase (amorphous hydroxides, crystalline oxides, and fluorides), and architecture were synthesized. Theoretically, a DM-REX nanoparticle library with 393,213 kinds of possible combinations can be constructed on the basis of this versatile method, which provides a very broad platform for the application of rare earth-based nanomaterials with rational designed functions and structures.

Silica-based Nanoparticles for Enzyme Immobilization and Delivery

Enzymes play an indispensable role in biosystems, catalyzing a variety of chemical and biochemical reactions with exceptionally high efficiency and selectivity. These features render them uniquely positioned in developing novel catalytic systems and therapeutics. However, their practical application is largely hindered by the vulnerability, low reusability and the inability to overcome the biological barriers of enzymes. Silica-based nanoparticles (SNPs) are a classic family of nanomaterials with tunable physicochemical properties, making them ideal candidates to address the intrinsic shortcomings of natural enzymes. SNPs not only improve the activity and durability of enzymes, but also provide precise spatiotemporal control over their intracellular as well as systemic biodistributions for boosting the catalytic outcome. Herein, the recent progress in SNPs for enzyme immobilization and delivery is summarized. The therapeutic applications, including cancer therapy and bacterial inhibition, are particularly highlighted. Our perspectives in this field, including current challenges and possible future research directions are also provided.

Long circulation and tumor-targeting biomimetic nanoparticles for efficient chemo/photothermal synergistic therapy

Photothermal therapy combined with chemotherapy based on nanomedicine has been considered a promising strategy for improving therapeutic efficacy in a tumor. However, nanomedicine can be easily cleared by the immune system without specific surface engineering modifications, thus affecting the ultimate efficacy. Herein, multifunctional biomimetic nanoparticles (Bio-RBCm@PDA@MSN-DOX) with enhanced long circulation and targeting ability are constructed by coating large pore-sized mesoporous silica (MSN) with polydopamine (PDA) layers in a biotin modified red blood cell membrane (Bio-RBCm) for efficient chemo/photothermal synergistic therapy. It is demonstrated that Bio-RBCm@PDA@MSN-DOX presents high photothermal conversion efficiency (40.17%) and enhanced capability to accelerate the release of the anticancer drug (doxorubicin, DOX), thus showing a good synergistic therapeutic effect in cell experiments. More importantly, with the assistance of the biotin and RBC membrane, Bio-RBCm@PDA@MSN-DOX can successfully evade immune clearance and effectively target transport to HeLa tumor sites, finally accomplishing up to 98.95% tumor inhibition with negligible side effects to normal tissues. This multilayer structure presents a valuable model for future therapeutic applications with safe and effective tumor chemotherapy and photothermal therapy.

Mn2+ /Fe3+ /Co2+ and Tetrasulfide Bond Co-Incorporated Dendritic Mesoporous Organosilica as Multifunctional Nanocarriers: One-Step Synthesis and Applications for Cancer Therapy

Enriching the application of multifunctional dendritic mesoporous organosilica (DMOS) is still challenging in anti-cancer research. Herein, manganese ions, iron ions, or cobalt ions and tetrasulfide bonds are co-incorporated into the framework of DMOS to yield multifunctional nanoparticles denoted as Mn-DMOS, Fe-DMOS, or Co-DMOS by directly doping metal ions during the synthetic process. Due to co-incorporation of metal ions and tetrasulfide bonds, these designed nanocarriers have more functions rather than only for cargo delivery. As proof of concept, the nanocomposite is established based on Mn-DMOS as an efficient nanocarrier for indocyanine green (ICG) delivery and modification with polyethylene glycol. In the tumor microenvironment, the generated hydrogen sulfide (H₂ S) arising from the reaction between tetrasulfide bond and over-expressed glutathione (GSH) causes mitochondrial injury to reduce cellular respiration. The released Mn²⁺ from the rapidly decomposed nanocomposite catalyzes the endogenous hydrogen peroxide to produce oxygen (O₂ ). The photothermal effect from the released ICG initiated by the near-infrared light induces cancer cells apoptosis and simultaneously enhances the content of blood O₂ at tumor sites. Therefore, due to the GSH depletion and trimodal O₂ compensation, the photodynamic therapy efficiency of ICG has significantly improved. In brief, these designed nanocarriers will play advanced roles in cancer therapy.

Dual Closed-Loop of Catalyzed Lactate Depletion and Immune Response to Potentiate Photothermal Immunotherapy

Lactate accumulation in the solid tumor is highly relevant to the immunosuppressive tumor microenvironment (TME). Targeting lactate metabolism significantly enhances the efficacy of immunotherapy. However, lactate depletion by lactate oxidase (LOX) consumes oxygen and results in the aggravated hypoxia situation, counteracting the benefit of lactate depletion. Beyond the TME regulation, it is necessary to initiate the effective immunity cycle for therapeutic purposes. In this fashion, dual close-loop of catalyzed lactate depletion and immune response by a rational material design are established to address this issue. Here, we constructed PEG-modified mesoporous polydopamine nanoparticles with Cu2+ chelation and LOX encapsulation (denoted as mCuLP). After mCuLP nanosystems targeting into the tumor sites, released LOX consumes lactate to H2O2. Subsequently, the produced H2O2 is further catalyzed by Cu2+-chelated mPDA to produce oxygen, supplying the oxygen source for the closed-loop of lactate depletion. Meanwhile, the mild PTT caused by the photothermal mPDA induces ICD of tumor cells to promote DC maturation and then T lymphocyte infiltration to kill tumor cells, which forms another closed-loop for cancer immunity. Therefore, this dual closed-loop strategy of mCuLP nanosystems effectively inhibits tumor growth, providing a promising treatment modality to cancer immunotherapy.

Dendritic Fibrous Nanosilica: Discovery, Synthesis, Formation Mechanism, Catalysis, and CO2 Capture-Conversion

ConspectusSilica-based mesoporous nanomaterials have been widely used for a range of applications. Although mesopore materials (such as MCM-41 and SBA-15) possess high surface area, due to their tubular pore structures, pore accessibility is restricted, which causes limitations in mass transport. A new nanosilica was needed to overcome these challenges, including better accessibility, controllable particle size, and good stability. In 2010, my group invented dendritic fibrous nanosilica (DFNS), which has now become a family of novel nanosilicas. DFNS has several unique properties: (i) Tunable particle sizes (50 to 1200 nm), (ii) high surface area (500 to 1200 m²/g), (iii) tunable pore volume (0.32 to 2.18 cm³/g), (iv) wide pore size distribution (3.7 to 25 nm) characterized by radially oriented pores, (v) controllable fiber density (number of fibers per sphere), (vi) variable pore size and pore volume, (vi) high thermal (∼800 °C) and hydrothermal stability, and (vii) mechanical stability (∼130 MPa). DFNS possesses unique dendritic fibrous morphology, and hence can be reached from all sides and easily accessible. DFNS can now be synthesized using a open refluxing protocol, which allowed the scale-up of the process with a sustainable E-factor. In the last 12 years, the DFNS family of materials has been extensively studied for their formation mechanism and range of applications such as catalysis, solar energy harvesting, CO₂ capture, CO₂ conversion, sensing, biomedicine, energy storage and many more.This Account discusses the invention of DFNS, its synthesis with tunable particle size, textural properties (surface area, pore volume, and pore size), and fiber density. In addition, the DFNS formation mechanism via the complex interplay of self-assembly, the dynamics, and coalescence of bicontinuous microemulsion droplets (BMDs) is discussed. Finally, applications of DFNS in a range of fields, that include catalysis, photocatalysis, synthesis of plasmonic black gold, nanosponges of aluminosilicates, CO₂ capture, and CO₂ conversion to fuel, are presented.

Tumor-Derived Lactate Creates a Favorable Niche for Tumor via Supplying Energy Source for Tumor and Modulating the Tumor Microenvironment

Tumor evolution is influenced by events involving tumor cells and the environment in which they live, known as the tumor microenvironment (TME). TME is a functional and structural niche composed of tumor cells, endothelial cells (ECs), cancer-associated fibroblasts (CAFs), mesenchymal stromal cells (MSCs), and a subset of immune cells (macrophages, dendritic cells, natural killer cells, T cells, B cells). Otto Warburg revealed the Warburg effect in 1923, a characteristic metabolic mechanism of tumor cells that performs high glucose uptake and excessive lactate formation even in abundant oxygen. Tumor tissues excrete a large amount of lactate into the extracellular microenvironment in response to TME’s hypoxic or semi-hypoxic state. High lactate concentrations in tumor biopsies have been linked to metastasis and poor clinical outcome. This indicates that the metabolite may play a role in carcinogenesis and lead to immune escape in TME. Lactate is now recognized as an essential carbon source for cellular metabolism and as a signaling molecule in TME, forming an active niche that influences tumor progression. This review summarized the advanced literature demonstrating the functional role of lactate in TME remodeling, elucidating how lactate shapes the behavior and the phenotype of both tumor cells and tumor-associated cells. We also concluded the intriguing interactions of multiple immune cells in TME. Additionally, we demonstrated how lactate functioned as a novel function factor by being used in a new histone modification, histone lysine lactylation, and to regulate gene expression in TME. Ultimately, because lactate created a favorable niche for tumor progression, we summarized potential anti-tumor strategies targeting lactate metabolism and signaling to investigate better cancer treatment.

Regulating Acidosis and Relieving Hypoxia by Platelet Membrane-Coated Nanoparticle for Enhancing Tumor Chemotherapy

Acidosis and hypoxia of tumor remain a great challenge for cancer therapy. Herein, we developed Hb-LOX-DOX-ZIF8@platelet membrane nanoparticles (H-L-D-Z@PM NPs) to address this problem. Lactate oxidase (LOX) could deplete intratumoral lactate adequately and amplify oxidative stress efficiently. In the meantime, hemoglobin (Hb) was intended to deliver oxygen, relieve hypoxia, and boost the catalytic activity of LOX. The coated PM bestowed active tumor-targeting ability and good biocompatibility to these nanoparticles. Moreover, the encapsulation of zeolitic imidazolate framework-8 (ZIF8) offered the acid response capacity to nanoparticles. With the synergism of chemotherapy drug doxorubicin (DOX), these H-L-D-Z@PM NPs appeared to have excellent antitumor competence. Collectively, this study offered a new strategy for enhancing tumor chemotherapy by regulating acidosis and relieving hypoxia.

Targeting the Negative Feedback of Adenosine-A2AR Metabolic Pathway by a Tailored Nanoinhibitor for Photothermal Immunotherapy

The metabolite adenosine plays an important immunosuppressive role in the tumor microenvironment (TME) through its ligation with the metabolic checkpoint adenosine 2A receptor (A2AR). Here, an adenosine-A2AR negative feedback pathway is highlighted during photothermal-induced immunogenic cell death (ICD). Adenosine, hydrolyzed from ATP, is amplified during the photothermal-induced ICD process. It is possible to achieve a robust ICD-based immunotherapy via targeting the adenosine-A2AR metabolic pathway. In this regard, an A2AR inhibitor-loaded polydopamine nanocarrier masked by an acid-sensitive PEG shell is designed to enable tumor-specific delivery and photothermal-induced ICD simultaneously. Upon reaching the acidic TME, the PEG shell selectively detaches and exposes the adhesive polydopamine layer, causing the inhibitors to accumulate at the tumor tissue. The accumulated inhibitors attenuate adenosine's metabolically suppressive effect and strengthen the ICD immune response. It occurs through promoting dendritic cell (DC) activation, increasing CD8+ T lymphocyte infiltration, and reducing the myeloid-derived suppressor cell (MDSC) population. Furthermore, this synergistic therapy significantly regresses the primary tumor, inhibits distal tumor growth, and prevents lung metastasis. The study highlights a strategy to enhance the immunotherapy efficacy of ICD by blocking the metabolic checkpoint A2AR using advanced nanomaterials.

Redox dyshomeostasis strategy for tumor therapy based on nanomaterials chemistry

Redox homeostasis, as an innate cellular defense mechanism, not only contributes to malignant transformation and metastasis of tumors, but also seriously restricts reactive oxygen species (ROS)-mediated tumor therapies, such as chemotherapy, radiotherapy, photodynamic therapy (PDT), and chemodynamic therapy (CDT). Therefore, the development of the redox dyshomeostasis (RDH) strategy based on nanomaterials chemistry is of great significance for developing highly efficient tumor therapy. This review will firstly introduce the basic definition and function of cellular redox homeostasis and RDH. Subsequently, the current representative progress of the nanomaterial-based RDH strategy for tumor therapy is evaluated, summarized and discussed. This strategy can be categorized into three groups: (1) regulation of oxidizing species; (2) regulation of reducing species and (3) regulation of both of them. Furthermore, the current limitations and potential future directions for this field will be briefly discussed. We expect that this review could attract positive attention in the chemistry, materials science, and biomedicine fields and further promote their interdisciplinary integration.

This review summarizes the current progress of the redox dyshomeostasis (RDH) strategy for tumor therapy. This strategy makes tumor cells more sensitive to current therapy patterns through using nanomaterials to disrupt redox homeostasis.