A Mn(III)-Sealed Metal-Organic Framework Nanosystem for Redox-Unlocked Tumor Theranostics

Construction of a Multifunctional Upconversion Nanoplatform Based on Autophagy Inhibition and Photodynamic Therapy Combined with Chemotherapy for Antitumor Therapy

Inhibition of autophagy increases the sensitivity of tumor cells to radiotherapy and chemotherapy and improves the therapeutic effect on tumors. Recently, photodynamic therapy (PDT) combined with chemotherapy has been proven to further improve the efficiency of cancer treatment. As such, combining autophagy inhibition with PDT and chemotherapy may represent a potentially effective new strategy for cancer treatment. However, currently widely studied autophagy inhibitors inevitably produce various toxic side effects due to their inherent pharmacological activity. To overcome this constraint, in this study, we designed an ideal multifunctional upconversion nanoplatform, UCNP-Ce6-EPI@mPPA + NIR (MUCEN). Control, UCNP-EPI@mPPA (MUE), UCNP-EPI@mPPA + NIR (MUEN), Ce6-EPI@mPPA (MCE), Ce6-EPI@mPPA + NIR (MCEN), and UCNP-Ce6-EPI@mPPA (MUCE) groups were set up separately as controls. Based on a combination of autophagy inhibition and PDT, the average particle size of MUCEN was 197 nm, which can simultaneously achieve the double encapsulation of chlorine e6 (Ce6) and epirubicin (EPI). In vitro tests revealed that MUCE was efficiently endocytosed by 4T1 cells under near-infrared light irradiation. Further, in vivo tests revealed that MUCE dramatically inhibited tumor growth. Immunohistochemistry results indicated that MUCE efficiently increased the expression of autophagy inhibitors p62 and LC3 in tumor tissues. The synergistic effect of autophagy inhibition and PDT with MUCE exhibited superior tumor suppression, providing an innovative approach to cancer treatment.

Revolutionizing Tetracycline Hydrochloride Remediation: 3D Motile Light-Driven MOFs Based Micromotors in Harsh Saline Environments

Traditional light-driven metal-organic-frameworks (MOFs)-based micromotors (MOFtors) are typically constrained to two-dimensional (2D) motion under ultraviolet or near-infrared light and often demonstrate instability and susceptibility to ions in high-saline environments. This limitation is particularly relevant to employing micromotors in water purification, as real wastewater is frequently coupled with high salinity. In response to these challenges, ultrastable MOFtors capable of three-dimensional (3D) motion under a broad spectrum of light through thermophoresis and electrophoresis are successfully synthesized. The MOFtors integrated photocatalytic porphyrin MOFs (PCN-224) with a photothermal component made of polypyrrole (PPy) by three distinct methodologies, resulting in micromotors with different motion behavior and catalytic performance. Impressively, the optimized MOFtors display exceptional maximum velocity of 1305 ± 327 µm s-1 under blue light and 2357 ± 453 µm s-1 under UV light. In harsh saline environments, these MOFtors are not only maintain high motility but also exhibit superior tetracycline hydrochloride (TCH) removal efficiency of 3578 ± 510 mg g-1, coupling with sulfate radical-based advanced oxidation processes and peroxymonosulfate. This research underscores the significant potential of highly efficient MOFtors with robust photocatalytic activity in effectively removing TCH in challenging saline conditions, representing a substantial advancement in applying MOFtors within real-world water treatment technologies.

Ultrasmall iridium-encapsulated porphyrin metal-organic frameworks for enhanced photodynamic/catalytic therapy by producing reactive oxygen species storm

Transition metal-coordinated porphyrin metal-organic frameworks (MOFs) were perspective in photodynamic therapy (PDT) and catalytic therapy. However, the tumor hypoxia and the insufficient endogenous hydrogen peroxide (H2O2) seriously limited their efficacies. Herein, by encapsulating ultrasmall iridium (Ir) and modifying glucose oxidase (GOx), an iron-coordinated porphyrin MOF (Fe-MOF) nanoplatform (Fe-MOF@Ir/GOx) was designed to strengthen PDT/catalytic therapy by producing reactive oxygen species (ROS) storm. In this nanoplatform, Fe-MOF showed glutathione (GSH)-responsive degradation, by which porphyrin, GOx and ultrasmall Ir were released. Moreover, ultrasmall Ir possessed dual-activities of catalase (CAT)-like and peroxidase (POD)-like, which provided sufficient oxygen (O2) to enhance PDT efficacy, and hydroxyl radical (·OH) production was also improved by combining Fenton reaction of Fe2+. Further, GOx catalyzed endogenous glucose produced H2O2, also reduced pH value, which accelerated Fenton reaction and resulted in generation of ROS storm. Therefore, the developed Fe-MOF@Ir/GOx nanoplatform demonstrated enhanced PDT/catalytic therapy by producing ROS storm, and also provided a promising strategy to promote degradation/metabolism of inorganic nanoplatforms.

Research Progress of Metal-Organic Frameworks as Drug Delivery Systems

Metal-organic frameworks (MOFs) are composite crystalline materials created through the coordination of metal ions and organic ligands. MOFs have attracted extensive attention in the biomedical field based on the advantages of internal porosity, customizable porosity, and facile surface modification. This review examines the utilization of MOFs in drug delivery systems, focusing on the research progress from the aspects of coloading drug systems, intelligent responsive carriers, biological macromolecule stabilizers, self-driving micro/nanomotors, and multifunctional living carriers. In addition, the current challenges the research faces are also discussed. The review aims to provide a reference for the further application of MOFs as advanced drug delivery systems.

Targeting Hydrogel for Intelligent Recognition and Spatiotemporal Control in Cell-Based Therapeutics

Smart drug platforms based on spatiotemporally controlled release and integration of tumor imaging are expected to overcome the inefficiency and uncertainty of traditional theranostic modes. In this study, a composite consisting of a thermosensitive hydrogel (polyvinyl alcohol-carboxylic acid hydrogel (PCF)) and a multifunctional nanoparticle (Fe3O4@Au/Mn(Zn)-4-carboxyphenyl porphyrin/polydopamine (FAMxP)) is developed to combine tumor immunogenic cell death (ICD)/immune checkpoint blockade (ICB) therapy under the guidance of magnetic resonance imaging (MRI) and fluorescence imaging (FI). It can not only further recognize the target cells through the folate receptor of tumor cells, but also produce thermal dissolution after exposure to near-infrared light to slowly release FAMxP in situ, thereby prolonging the treatment time and avoiding tumor recurrence. As FAMxP entered the tumor cells, it released FAMx in a pH-dependent manner. Chemodynamic, photothermal and photodynamic therapy can cause significant ICD in cancer cells. ICB can thus be further enhanced by injecting anti-programmed cell death ligand 1, improving the effectiveness of tumor treatment. The developed PCF-FAMxP composite hydrogel may represent an updated drug design approach with simple compositions for cooperative MRI/FI-guided targeted therapeutic pathways for tumors.

A Nanoreactor Based on Metal-Organic Frameworks With Triple Synergistic Therapy for Hepatocellular Carcinoma

The transformation of monotherapy into multimodal combined targeted therapy to fully exploit synergistic efficacy is of increasing interest in tumor treatment. In this work, a novel nanodrug-carrying platform based on iron-based MOFs, which is loaded with doxorubicin hydrochloride (DOX), dihydroartemisinin (DHA), and glucose oxidase (GOx), and concurrently covalently linked to the photosensitizer 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) in polydopamine (PDA)-encapsulated MIL-101(Fe) (denoted as MIL-101(Fe)-DOX-DHA@TCPP/GOx@PDA, MDDTG@P), is successfully developed. Upon entering the tumor microenvironment, MDDTG@P catalyzes the hydrogen peroxide (H2O2) into hydroxyl radicals (·OH) and depletes glutathione (GSH); thus, exerting the role of chemodynamic therapy (CDT). The reduced Fe2+ can also activate DHA, further expanding CDT and promoting tumor cell apoptosis. The introduced GOx will rapidly consume glucose and oxygen (O2) in the tumor; while, replenishing H2O2 for Fenton reaction, starving the cancer cells; and thus, realizing starvation and chemodynamic therapy. In addition, the covalent linkage of TCPP endows MDDTG@P with good photodynamic therapeutic (PDT) properties. Therefore, this study develops a nanocarrier platform for triple synergistic chemodynamic/photodynamic/starvation therapy, which has promising applications in the efficient treatment of tumors.

Russell Mechanism-Mediated Cancer Therapy: A Minireview

The Russell mechanism, proposed by Russell, is a cyclic mechanism for the formation of linear tetroxide intermediates, which can spontaneously produce cytotoxic singlet oxygen (1O2) independent of oxygen, suggesting its anticancer potential. Compared with other mainstream anticancer strategies, the Russell mechanism employed for killing cancer cells does not require external energy input, harsh pH condition, and sufficient oxygen. However, up till now, the applications of Russell mechanism in antitumor therapy have been relatively rare, and there is almost no summary of the Russell mechanism in the cancer therapy field. This minireview introduces the different metal elements-based Russell mechanisms and the relevant research progress in Russell mechanism-based cancer therapy in recent years. At the same time, we briefly discussed the current challenges and future development regarding the applications of Russell mechanism. It is hoped that this review can further expand the research of Russell Mechanism in the biomedical field, and inspire researchers to extend its application fields to antibacterial, antiinflammatory, and wound healing uses.

Curcumin Equipped Nanozyme-Like Metal-Organic Framework Platform for the Targeted Atherosclerosis Treatment with Lipid Regulation and Enhanced Magnetic Resonance Imaging Capability

Atherosclerotic cardiovascular disease (ASCVD) has become the leading cause of death worldwide, and early diagnosis and treatment of atherosclerosis (AS) are crucial for reducing the occurrence of acute cardiovascular events. However, early diagnosis of AS is challenging, and oral anti-AS drugs suffer from limitations like imprecise targeting and low bioavailability. To overcome the aforementioned shortcomings, Cur/MOF@DS is developed, a nanoplatform integrating diagnosis and treatment by loading curcumin (Cur) into metal-organic frameworks with nanozymes and magnetic resonance imaging (MRI) properties. In addition, the surface-modification of dextran sulfate (DS) enables PCN-222(Mn) effectively target scavenger receptor class A in macrophages or foam cells within the plaque region. This nanoplatform employs mechanisms that effectively scavenge excessive reactive oxygen species in the plaque microenvironment, promote macrophage autophagy and regulate macrophage polarization to realize lipid regulation. In vivo and in vitro experiments confirm that this nanoplatform has outstanding MRI performance and anti-AS effects, which may provide a new option for early diagnosis and treatment of AS.

Metal organic framework-based variable-size nanoparticles for tumor microenvironment-responsive drug delivery

Nanoparticles (NPs) have been designed for the treatment of tumors increasingly. However, the drawbacks of single-size NPs are still worth noting, as their circulation and metabolism in the blood are negatively correlated with their accumulation at the tumor site. If the size of single-size NPs is too small, it will be quickly cleared in the blood circulation, while, the size is too large, the distribution of NPs in the tumor site will be reduced, and the widespread distribution of NPs throughout the body will cause systemic toxicity. Therefore, a class of variable-size NPs with metal organic frameworks (MOFs) as the main carrier, and size conversion in compliance with the characteristics of the tumor microenvironment (TME), was designed. MOF-based variable-size NPs can simultaneously extend the time of blood circulation and metabolism, then enhance the targeting ability of the tumor site. In this review, MOF NPs are categorized and exemplified from a new perspective of NP size variation; the advantages, mechanisms, and significance of MOF-based variable-size NPs were summarized, and the potential and challenges in delivering anti-tumor drugs and multimodal combination therapy were discussed.

Efficient Removal of Greenhouse Gases: Machine Learning-Assisted Exploration of Metal-Organic Framework Space

Global warming is a crisis that humanity must face together. With greenhouse gases (GHGs) as the main factor causing global warming, the adoption of relevant processes to eliminate them is essential. With the advantages of high specific surface area, large pore volume, and tunable synthesis, metal-organic frameworks (MOFs) have attracted much attention in GHG storage, adsorption, separation, and catalysis. However, as the pool of MOFs expands rapidly with new syntheses and discoveries, finding a suitable MOF for a particular application is highly challenging. In this regard, high-throughput computational screening is considered the most effective research method for screening a large number of materials to discover high-performance target MOFs. Typically, high-throughput computational screening generates voluminous and multidimensional data, which is well suited for machine learning (ML) training to improve the screening efficiency and explore the relationships between the multidimensional data in depth. This Review summarizes the general process and common methods for using ML to screen MOFs in the field of GHG removal. It also addresses the challenges faced by ML in exploring the MOF space and potential directions for the future development of ML for MOF screening. This aims to enhance the understanding of the integration of ML and MOFs in various fields and broaden the application and development ideas of MOFs.

Chirality of Copper-Amino Acid Nanoparticles Determines Chemodynamic Cancer Therapeutic Outcome

Chirality is a prevalent characteristic in nature, where biological systems exhibit a significant preference for specific enantiomers of biomolecules. However, there is a limited exploration into utilizing nanomaterials' chirality to modulate their interactions with intracellular substances. In this study, self-assembled copper-cysteine chiral nanoparticles and explore the influence of their charity on cancer chemodynamic therapy (CDT) are fabricated. Experimental and molecular dynamics (MD) simulation results demonstrate that the copper-l-cysteine chiral nanoparticles (Cu-l-Cys NPs) exhibit a stronger affinity toward l-glutathione (l-GSH) that is overproduced in cancer cells, compared to the copper-d-cysteine enantiomer (Cu-d-Cys NPs). The interaction between Cu-l-Cys NPs and l-GSH triggers a redox reaction that depletes l-GSH and converts Cu2+ into Cu+. Subsequently, Cu+ catalyzes a Fenton-like reaction, decomposing H2O2 into highly cytotoxic hydroxyl radicals (•OH) for cancer CDT. In vivo, results confirm that Cu-l-Cys NPs with good biocompatibility elicit a pronounced cancer cell death and effectively inhibit tumor growth. This work proposes a new perspective on chirality-enhanced cancer therapy.

Decoding ferroptosis: Revealing the hidden assassin behind cardiovascular diseases

The discovery of regulatory cell death processes has driven innovation in cardiovascular disease (CVD) therapeutic strategies. Over the past decade, ferroptosis, an iron-dependent form of regulated cell death driven by excessive lipid peroxidation, has been shown to drive the development of multiple CVDs. This review provides insights into the evolution of the concept of ferroptosis, the similarities and differences with traditional modes of programmed cell death (e.g., apoptosis, autophagy, and necrosis), as well as the core regulatory mechanisms of ferroptosis (including cystine/glutamate transporter blockade, imbalance of iron metabolism, and lipid peroxidation). In addition, it provides not only a detailed review of the role of ferroptosis and its therapeutic potential in widely studied CVDs such as coronary atherosclerotic heart disease, myocardial infarction, myocardial ischemia/reperfusion injury, heart failure, cardiomyopathy, and aortic aneurysm but also an overview of the phenomenon and therapeutic perspectives of ferroptosis in lesser-addressed CVDs such as cardiac valvulopathy, pulmonary hypertension, and sickle cell disease. This article aims to integrate this knowledge to provide a comprehensive view of ferroptosis in a wide range of CVDs and to drive innovation and progress in therapeutic strategies in this field.

Time and Space Dual-Blockade Strategy for Highly Invasive Nature of Triple-Negative Breast Cancer in Enhanced Sonodynamic Therapy Based on Fe-MOF Nanoplatforms

Triple-negative breast cancer (TNBC), due to its high malignant degree and strong invasion ability, leads to poor prognosis and easy recurrence, so effectively curbing the invasion of TNBC is the key to obtaining the ideal therapeutic effect. Herein, a therapeutic strategy is developed that curbs high invasions of TNBC by inhibiting cell physiological activity and disrupting tumor cell structural function to achieve the time and space dual-blockade. The time blockade is caused by the breakthrough of the tumor-reducing blockade based on the ferroptosis process and the oxidation-toxic free radicals generated by enhanced sonodynamic therapy (SDT). Meanwhile, alkyl radicals from 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIPH) and 1O2 attacked the organelles of tumor cells under ultrasound (US), reducing the physiological activity of the cells. The attack of free radicals on the cytoskeleton, especially on the proteins of F-actin and its assembly pathway, achieves precise space blockade of TNBC. The damage to the cytoskeleton and the suppression of the repair process leads to a significant decline in the ability of tumor cells to metastasize and invade other organs. In summary, the FTM@AM nanoplatforms have a highly effective killing and invasion inhibition effect on invasive TNBC mediated by ultrasound, showcasing promising clinical transformation potential.

A metal-organic framework (MOF) built on surface-modified Cu nanoparticles eliminates tumors via multiple cascading synergistic therapeutic effects

Tumors produce a hypoxic environment that greatly influences cancer treatment, and conventional chemotherapeutic drugs cannot selectively accumulate in the tumor region because of the lack of a tumor targeting mechanism, causing increased systemic toxicities and side effects. Hence, designing and developing new nanoplatforms that combine multimodal therapeutic regimens is essential to improve tumor therapeutic efficacy. Herein, we report the synthesis of ultrafine Cu nanoparticles loaded with a drug combination of cisplatin (Pt) and 1-methyl-d-tryptophan (1-MT) and externally coated with 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (TCPP) photosensitizer, polydopamine (PDA) and CaO2 of MIL-101(Fe) as a new nanoplatform (Cu@MIL-101@PMTPC). The nanoplatform synergistically combined chemodynamic therapy (CDT), photodynamic therapy (PDT), and immunochemotherapy. The Fe3+ in MIL-101(Fe) and the surface Cu nanoparticles exhibited strong ability to consume intracellular glutathione (GSH), thereby generating a Fenton-like response in the tumor microenvironment (TME) with substantial peroxidase (POD)-like and superoxide dismutase (SOD)-like activities. In this design, we used the indoleamine 2,3-dioxygenase (IDO) inhibitor 1-MT to overcome chemotherapy-induced immune escape phenomena including enhanced CD8+ and CD4+ T cell expression, interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) production, and accelerated immunogenic cell death. The targeted release of cisplatin loaded into Cu@MIL-101@PMTPC also reduced toxic side effects of chemotherapy. TCPP generated a large amount of singlet oxygen (1O2) upon specific laser irradiation to effectively kill tumor cells. CaO2 on the outer layer generated oxygen (O2) and hydrogen peroxide (H2O2) to ameliorate hypoxia in the tumor microenvironment, enhance the PDT effect, and provide a continuous supply of H2O2 for the Fenton-like reaction. Thus, this nanocarrier platform exhibited a powerful chemodynamic, photodynamic, and immunochemotherapeutic cascade, providing a new strategy for cancer treatment.

Multi-level Reactive Oxygen Species Amplifier to Enhance Photo-/Chemo-Dynamic/Ca2+ Overload Synergistic Therapy

Reactive oxygen species (ROS)-involved photodynamic therapy (PDT) and chemodynamic therapy (CDT) hold great promise for tumor treatment. However, hypoxia, insufficient H2O2, and overexpressed glutathione (GSH) in the tumor microenvironment (TME) hinder ROS generation significantly. Herein, we reported CaO2@Cu-TCPP/CUR with O2/H2O2/Ca2+ self-supply and GSH depletion for enhanced PDT/CDT and Ca2+ overload synergistic therapy. CaO2 nanospheres were first prepared and used as templates for guiding the coordination between the carboxyl of tetra-(4-carboxyphenyl)porphine (TCPP) and Cu2+ ions as hollow CaO2@Cu-TCPP, which facilitated GSH-activated TCPP-based PDT and Cu+-mediated CDT. The hollow structure was then loaded with curcumin (CUR) to form CaO2@Cu-TCPP/CUR composites. Cu-TCPP prevented degradation of CaO2, while Cu2+ ions reacted with GSH to deplete GSH, produce Cu+ ions, and release TCPP, CaO2, and CUR. CaO2 reacted with H2O to generate O2, H2O2, and Ca2+ to achieve O2/H2O2/Ca2+ self-supply for TCPP-based PDT, Cu+-mediated CDT, and CUR-enhanced Ca2+ overload therapy. Thus, this multilevel ROS amplifier enhances synergistic therapy with fewer side effects and drug resistance.

One Stone, Three Birds: Design and Synthesis of "All-in-One" Nanoscale Mn-Porphyrin Coordination Polymers for Magnetic Resonance Imaging-Guided Synergistic Photodynamic-Sonodynamic Therapy

Multifunctional nanomaterials with potential applications in both bioimaging and photodynamic-sonodynamic therapy have great advantages in cancer theranostic, but the design and preparation of "all-in-one" type of multifunctional nanomaterials with single component remains challenging. Herein the "all-in-one" type of Mn-PpIX (Protoporphyrin IX) coordination polymers (MnPPs) was reported as efficient nano-photo/sonosensitizers. The MnPPs had an average size of ∼ 110 nm. Upon light/US (ultrasound) irradiation for 5 min, 61.8 % (light) and 32.4 % (US) of DPBF (1.3-diphenyl isobenzofuran) was found to be oxidized by MnPPs, which showed effective ROS (reactive oxygen species) generation for photodynamic/sonodynamic therapy (PDT/SDT). In addition, MnPPs revealed excellent biosafety and could be engulfed by cells to produce intracellular ROS under light/US excitation for efficient killing tumor cells. When MnPPs was injected into mice, the tumor could be monitored via MRI (magnetic resonance imaging). In addition, tumor growth could be significantly inhibited by the synergistic PDT-SDT. Therefore, the present study not only represents MnPPs as an "all-in-one" type of multifunctional nanomaterials for MRI-guided PDT-SDT therapy, but also provides some insights for designing other PpIX-related molecules with the similar structure for bioapplication.

GSH-responsive degradable nanodrug for glucose metabolism intervention and induction of ferroptosis to enhance magnetothermal anti-tumor therapy

The challenges associated with activating ferroptosis for cancer therapy primarily arise from obstacles related to redox and iron homeostasis, which hinder the susceptibility of tumor cells to ferroptosis. However, the specific mechanisms of ferroptosis resistance, especially those intertwined with abnormal metabolic processes within tumor cells, have been consistently underestimated. In response, we present an innovative glutathione-responsive magnetocaloric therapy nanodrug termed LFMP. LFMP consists of lonidamine (LND) loaded into PEG-modified magnetic nanoparticles with a Fe3O4 core and coated with disulfide bonds-bridged mesoporous silica shells. This nanodrug is designed to induce an accelerated ferroptosis-activating state in tumor cells by disrupting homeostasis. Under the dual effects of alternating magnetic fields and high concentrations of glutathione in the tumor microenvironment, LFMP undergoes disintegration, releasing drugs. LND intervenes in cell metabolism by inhibiting glycolysis, ultimately enhancing iron death and leading to synthetic glutathione consumption. The disulfide bonds play a pivotal role in disrupting intracellular redox homeostasis by depleting glutathione and inactivating glutathione peroxidase 4 (GPX4), synergizing with LND to enhance the sensitivity of tumor cells to ferroptosis. This process intensifies oxidative stress, further impairing redox homeostasis. Furthermore, LFMP exacerbates mitochondrial dysfunction, triggering ROS formation and lactate buildup in cancer cells, resulting in increased acidity and subsequent tumor cell death. Importantly, LFMP significantly suppresses tumor cell proliferation with minimal side effects both in vitro and in vivo, exhibiting satisfactory T2-weighted MR imaging properties. In conclusion, this magnetic hyperthermia-based nanomedicine strategy presents a promising and innovative approach for antitumor therapy.

Metal-Organic Framework-Based Nanomedicines for Ferroptotic Cancer Therapy

As an iron-dependent, non-apoptosis, regulated cell death (RCD) modality, ferroptosis has gained growing attention for cancer therapy. With the development of nanomaterials in the biomedical field, ferroptotic cancer nanomedicine is extensively investigated. Amongst various nanomaterials, metal-organic frameworks (MOFs) are hybridized porous materials consisting of metal ions or clusters bridged by organic linkers. The superior properties of MOFs, such as high porosity and cargo loading, ease of surface modification, and good biocompatibility, make them appealing in inducing or sensitizing ferroptotic cell death. There are remarkable achievements in the field of MOF-based ferroptosis cancer therapy. However, this topic is not reviewed. This review will introduce the fundamentals of MOF and ferroptosis machinery, summarize the recent progress of MOF-based ferroptotic anticancer drug delivery, discuss the benefits and problems of MOFs as vehicles and sensitizers for cancer ferroptosis, and provide the perspective on future research direction on this promising field.

Dual source-powered multifunctional Pt/FePc@Mn-MOF spindle-like Janus nanomotors for active CT imaging-guided synergistic photothermal/chemodynamic therapy

Nanomaterials capable of dual therapeutic effects of chemodynamic therapy (CDT) and photothermal therapy (PTT) is an efficacious strategy in cancer treatment. It is still a challenge to achieve complete apoptosis of tumor tissue in CDT/PTT due to the poor permeability of nanomaterials in tumor tissue. Herein, we prepared a dual-source driven Pt/FePc@Mn-MOF spindle-like Janus nanomotor by a facile oriented connection growth method for computed tomography (CT) imaging-guided CDT and PTT. The high catalase (CAT)-like activity of nanomotors allows the generation of oxygen (O2) bubbles by catalyzing the decomposition of endogenous H2O2, which alleviates the hypoxic state of the tumor microenvironment (TME) and simultaneously drive nanomotors. Pt/FePc@Mn-MOF nanomotor with excellent photothermal conversion efficiency exhibited dual peroxidase (POD)-like and oxidase (OXD)-like activities, which can produce large amounts of ROS to obtain PTT enhanced CDT. Meanwhile, near-infrared light, as "optical brakes", can trigger Janus nanomotor to realize self-thermophoretic movement. Chemical/NIR-assisted autonomous propulsion can significantly improve the accumulation of Janus nanomotors in solid tumors and enhance their ability to penetrate tumor tissue, thus brings synergistic enhancement effect to PTT and CDT. Moreover, Mn-MOF in nanomotor can deplete the antioxidant GSH by redox reaction to release massive Mn2+, which introduce Mn2+-based CT imaging properties. This novel dual-source controlled Janus nanomotor offers great potential for multimodal therapeutic medical applications.

Two-Dimensional Nickel Porphyrinic Metal-Organic Framework-Modified Electrode for Electrochemical Sensing

Due to their highly exposed active sites and high aspect ratio caused by their substantial lateral dimension and thin thickness, two-dimensional (2D) metal-organic framework (MOF) nanosheets are currently considered a potential hybrid material for electrochemical sensing. Herein, we present a nickel-based porphyrinic MOF nanosheet as a versatile and robust platform with an enhanced electrochemical detection performance. It is important to note that the nickel porphyrin ligand reacted with Cu(NO3)2·3H2O in a solvothermal process, with polyvinylpyrrolidone (PVP) acting as the surfactant to control the anisotropic development of creating a 2D Cu-TCPP(Ni) MOF nanosheet structure. To realize the exceptional selectivity, sensitivity, and stability of the synthesized 2D Cu-TCPP(Ni) MOF nanosheet, a laser-induced graphene electrode was modified with the MOF nanosheet and employed as a sensor for the detection of p-nitrophenol (p-NP). With a detection range of 0.5-200 μM for differential pulse voltammetry (DPV) and 0.9-300 μM for cyclic voltammetry (CV), the proposed sensor demonstrated enhanced electrochemical performance, with the limit of detection (LOD) for DPV and CV as 0.1 and 0.3 μM, respectively. The outstanding outcome of the sensor is attributed to the 2D Cu-TCPP(Ni) MOF nanosheet's substantial active surface area, innate catalytic activity, and superior adsorption capacity. Furthermore, it is anticipated that the proposed electrode sensor will make it possible to create high-performance electrochemical sensors for environmental point-of-care testing since it successfully detected p-NP in real sample analysis.

Photodynamic O2 Economizer Encapsulated with DNAzyme for Enhancing Mitochondrial Gene-Photodynamic Therapy

Emerging research suggests that mitochondrial DNA is a potential target for cancer treatment. However, achieving precise delivery of deoxyribozymes (DNAzymes) and combining photodynamic therapy (PDT) and DNAzyme-based gene silencing together for enhancing mitochondrial gene-photodynamic synergistic therapy remains challenging. Accordingly, herein, intelligent supramolecular nanomicelles are constructed by encapsulating a DNAzyme into a photodynamic O2 economizer for mitochondrial NO gas-enhanced synergistic gene-photodynamic therapy. The designed nanomicelles demonstrate sensitive acid- and red-light sequence-activated behaviors. After entering the cancer cells and targeting the mitochondria, these micelles will disintegrate and release the DNAzyme and Mn (II) porphyrin in the tumor microenvironment. Mn (II) porphyrin acts as a DNAzyme cofactor to activate the DNAzyme for the cleavage reaction. Subsequently, the NO-carrying donor is decomposed under red light irradiation to generate NO that inhibits cellular respiration, facilitating the conversion of more O2 into singlet oxygen (1 O2 ) in the tumor cells, thereby significantly enhancing the efficacy of PDT. In vitro and in vivo experiments reveal that the proposed system can efficiently target mitochondria and exhibits considerable antitumor effects with negligible systemic toxicity. Thus, this study provides a useful conditional platform for the precise delivery of DNAzymes and a novel strategy for activatable NO gas-enhanced mitochondrial gene-photodynamic therapy.

A Fluorinated BODIPY-Based Zirconium Metal-Organic Framework for In Vivo Enhanced Photodynamic Therapy

Photodynamic therapy (PDT), an emergent noninvasive cancer treatment, is largely dependent on the presence of efficient photosensitizers (PSs) and a sufficient oxygen supply. However, the therapeutic efficacy of PSs is greatly compromised by poor solubility, aggregation tendency, and oxygen depletion within solid tumors during PDT in hypoxic microenvironments. Despite the potential of PS-based metal-organic frameworks (MOFs), addressing hypoxia remains challenging. Boron dipyrromethene (BODIPY) chromophores, with excellent photostability, have exhibited great potential in PDT and bioimaging. However, their practical application suffers from limited chemical stability under harsh MOF synthesis conditions. Herein, we report the synthesis of the first example of a Zr-based MOF, namely, 69-L2, exclusively constructed from the BODIPY-derived ligands via a single-crystal to single-crystal post-synthetic exchange, where a direct solvothermal method is not applicable. To increase the PDT performance in hypoxia, we modify 69-L2 with fluorinated phosphate-functionalized methoxy poly(ethylene glycol). The resulting 69-L2@F is an oxygen carrier, enabling tumor oxygenation and simultaneously acting as a PS for reactive oxygen species (ROS) generation under LED irradiation. We demonstrate that 69-L2@F has an enhanced PDT effect in triple-negative breast cancer MDA-MB-231 cells under both normoxia and hypoxia. Following positive results, we evaluated the in vivo activity of 69-L2@F with a hydrogel, enabling local therapy in a triple-negative breast cancer mice model and achieving exceptional antitumor efficacy in only 2 days. We envision BODIPY-based Zr-MOFs to provide a solution for hypoxia relief and maximize efficacy during in vivo PDT, offering new insights into the design of promising MOF-based PSs for hypoxic tumors.

Spatial targeting of fibrosis-promoting macrophages with nanoscale metal-organic frameworks for idiopathic pulmonary fibrosis therapy

Targeted delivery of therapeutic drugs to fibrosis-promoting macrophages (FPMs) holds promise as a challenging yet effective approach for the treatment of idiopathic pulmonary fibrosis (IPF). Here, nanocarriers composed of Mn-curcumin metal-organic frameworks (MOFs) were utilized to deliver the immune inhibitor BLZ-945 to the lungs, with the goal of depleting fibrosis-promoting macrophages (FPMs) from fibrotic lung tissues. FPM targeting was achieved by functionalizing the nanocarrier surface with an M2-like FPM binding peptide (M2pep). As a result, significant therapeutic benefits were observed through the successful depletion of approximately 80 % of the M2-like macrophages (FPMs) in a bleomycin-induced fibrosis mouse model treated with the designed M2-like FPM-targeting nanoparticle (referred to as M2NP-BLZ@Mn-Cur). Importantly, the released Mn2+ and curcumin after the degradation of M2NP-BLZ@Mn-Cur accumulated in the fibrotic lung tissue, which can alleviate inflammation and oxidative stress reactions, thereby further improving IPF therapy. This study presents a novel strategy with promising prospects for molecular-targeted fibrosis therapy. STATEMENT OF SIGNIFICANCE: Metal-organic frameworks (MOFs)- based nanocarriers equipped with both fibrosis-promoting macrophage (FPM)-specific targeting ability and therapeutic drugs are appealing for pulmonary fibrosis treatment. Here, we prepared M2pep (an M2-like FPM binding peptide)-modified and BLZ945 (a small molecule inhibitor of CSF1/CSF-1R axis)-loaded Mn-curcumin MOF nanoparticles (M2NP-BLZ@Mn-Cur) for pulmonary fibrosis therapy. The functionalized M2NP-BLZ@Mn-Cur nanoparticles can be preferentially taken up by FPMs, resulting in their depletion from fibrotic lung tissues. In addition, Mn2+and curcumin released from the nanocarriers have anti-inflammation and immune regulation effects, which further enhance the antifibrotic effect of the nanoparticles.

NaYF4 :Yb/Er@Mn3 O4 @GOX Nanocomposite for Upconversion Fluorescence Imaging and Synergistic Cascade Cancer Therapy by Apoptosis and Ferroptosis

The cell elimination strategy based on reactive oxygen species (ROS) is a promising method for tumor therapy. However, its efficacy is significantly limited by ROS deficiency caused by H2 O2 substrate deficiency and up-regulation of cellular antioxidant defense induced by high glutathione (GSH) content in tumor cells. To overcome these obstacles, a multifunctional self-cascaded nanocomposite: glucose oxidase (GOX) loaded NaYF4 :Yb/Er@Mn3 O4 (UC@Mn3 O4 , labeled as UCMn) is constructed. Only in tumor microenvironment, it can be specifically activated through a series of cascades to boost ROS production via a strategy of open source (H2 O2 self-supplying ability). The increased ROS can enhance lipid peroxidation and induce tumor cell apoptosis by activating the protein caspase. More importantly, the nanozyme can consume GSH to inhibit glutathione peroxidase 4 (GPX4) activity, which limits tumor cell resistance to oxidative damage and triggers the tumor cell ferroptosis. Therefore, this strategy is expected to overcome the resistance of tumor to oxidative damage and achieve efficient oxidative damage of tumor. Further, degradation of the Mn3 O4 layer induced by GSH and acidic environment can promote the fluorescence recovery of UC fluorescent nuclear for tumor imaging to complete efficient integration of diagnosis and treatment for tumor.

Versatile Multi-Wavelength Light-Responsive Metal-Organic Frameworks Micromotor through Porphyrin Metalation for Water Sterilization

Traditional metal-organic frameworks (MOFs) based micro/nanomotors (MOFtors) can achieve three-dimensional (3D) motion mainly depending on noble metal (e.g., Pt), toxic fuels (e.g., hydrogen peroxide), and surfactants, or under external magnetic fields. In this study, light-driven MOFtors are constructed based on PCN-224(H) and regulated their photothermal and photochemical properties responding to the light of different wavelengths through porphyrin metalation. The resulting PCN-224(Fe) MOFtors presented a strong 3D motion at a maximum speed of 1234.9 ± 367.5 µm s-1 under visible light due to the various gradient fields by the photothermal and photochemical effects. Such MOFtors exhibit excellent water sterilization performance. Under optimal conditions, the PCN-224(Cu) MOFtors presented the best antibacterial performance of 99.4%, which improved by 23.4% compared to its static counterpart and 43.7% compared to static PCN-224(H). The underlying mechanism demonstrates that metal doping could increase the production of reactive oxygen species (ROS) and result in a more positive surface charge under light, which are short-distance effective sterilizing ingredients. Furthermore, the motion of MOFtors appears very important to extend the short-distance effective sterilization and thus synergistically improve the antibacterial performance. This work provides a new idea for preparing and developing light-driven MOFtors with multi-responsive properties.

Cutting-Edge Research in Nanoscience and Nanotechnology: Celebrating the 130th Anniversary of Wuhan University

Thanks to the fast-paced progress of microscopic theories and nanotechnologies, a tremendous world of fundamental science and applications has opened up at the nanoscale. Ranging from quantum physics to chemical and biological mechanisms and from device functionality to materials engineering, nanoresearch has become an essential part of various fields. As one of the top universities in China, Wuhan University (WHU) aims to promote cutting-edge nanoresearch in multiple disciplines by leveraging comprehensive academic programs established throughout 130 years of history. As visible in prestigious scientific journals such as ACS Nano, WHU has made impactful advancements in various frontiers, including nanophotonics, functional nanomaterials and devices, biomedical nanomaterials, nanochemistry, and environmental science. In light of these contributions, WHU will be committed to serving talents and scientists wholeheartedly, fully supporting international collaborations and continuously driving innovative research.

Mn(II)-hemoporfin-based metal-organic frameworks as a theranostic nanoplatform for MRI-guided sonodynamic therapy

Imaging-guided therapy holds great potential for enhancing therapeutic performance in a personalized way. However, it is still challenging to develop appropriate multifunctional materials to overcome the limitations of current all-in-one theranostic agents. In this study, we developed a one-for-all theranostic nanoplatform called Mn(II)-hemoporfin MOFs, designed specifically for MRI-guided sonodynamic tumor therapy. The formation of MOF structures not only improves imaging but also enhances therapeutic effects through collective actions. Furthermore, by modifying polyethylene glycol (PEG), Mn(II)-hemoporfin-PEG was able to enhance permeability and retention effects, ensuring long circulation in the blood and accumulation in the tumor. MRI enhancement provided by Mn(II)-hemoporfin-PEG remained localized at the tumor site, with Mn(II)-hemoporfin-PEG demonstrating 88.6% efficacy in sonodynamic therapy testing in vivo. Mn(II)-hemoporfin-PEG exhibits excellent longitudinal relaxation, MRI effects, and sonodynamic performance, making it a promising alternative for clinical cancer treatment.

Electrochemiluminescence resonance energy transfer immunoassay based on a porphyrin metal-organic framework and AuNPs/NSG for the sensitive detection of zearalenone

In this study, a novel electrochemiluminescence resonance energy transfer (ECL-RET) immunoassay was developed for the first time for the detection of zearalenone (ZEN). A porphyrin metal-organic framework (PCN-222), an emerging porphyrin-based ECL luminophore, was prepared by a simple hydrothermal method using tetrakis(4-carboxyphenyl) porphyrin, which has excellent ECL emission as well as good ECL efficiency. Because the ECL emission spectrum of PCN-222 is highly matched to the absorption spectrum of gold nanoparticle-modified graphene oxide (AuNPs/NSG) nanocomposites, they were used as donor-acceptor counterparts in this work for the ECL-RET strategy. Under optimal conditions, the ECL immunosensor showed a sensitive response to ZEN in a wide detection range, with a linearity of 0.0005-1000 ng mL-1 and a detection limit of 0.15 pg mL-1. In addition, the sensor showed good potential for application in the detection of wheat and corn samples, providing a new approach for the detection of mycotoxin-like contaminants such as ZEN in food grains.

Copper-Bacteriochlorin Nanosheet as a Specific Pyroptosis Inducer for Robust Tumor Immunotherapy

Pyroptosis is increasingly considered a new weathervane in cancer immune therapy. However, triggering specific pyroptotic tumor cell death while preserving normal cells still remains a major challenge. Herein, a brand-new pyroptosis inducer, copper-bacteriochlorin nanosheet (Cu-TBB), is designed. The synthesized Cu-TBB can be activated to an "on" state in the tumor microenvironment with glutathione (GSH) overexpression, leading to the release of Cu+ and TBB, respectively. Intriguingly, the released Cu+ can drive cascade reactions to produce O2 -• and highly toxic ·OH in cells. Additionally, the released TBB can also generate O2 -• and 1 O2 upon 750 nm laser irradiation. Encouragingly, both Cu+ -driven cascade reactions and photodynamic therapy pathways result in potent pyroptosis along with dendritic cell maturation and T cell priming, thus simultaneously eliminating the primary tumors and inhibiting the distant tumor growth and metastases. Conclusively, the well-designed Cu-TBB nanosheet is shown to trigger specific pyroptosis in vitro and in vivo, leading to enhanced tumor immunogenicity and antitumor efficacy while minimizing systemic side effects.

Metal-Organic Frameworks@Au Nanoreactor as an Oxidative Stress Amplifier for Enhanced Tumor Photodynamic Therapy through the Alleviation of Hypoxemia and the Depletion of Glutathione

Recently, photodynamic therapy (PDT) based on the generation of cytotoxic reactive oxygen species (ROS) has drawn great attention in tumor treatment. However, the hypoxia tumor microenvironment (TME) inhibits the generation efficacy of ROS, and the high glutathione (GSH) level in TME could neutralize the generated ROS, both of which strongly reduce the therapeutic efficiency of PDT. In this work, we first constructed the porphyrinic metal-organic framework PCN-224. Then Au nanoparticles were decorated on the PCN-224 to obtain the PCN-224@Au. The decorated Au nanoparticles could not only produce O2 through the decomposition of H2O2 in tumor sites for enhancing the generation of 1O2 in PDT but also deplete glutathione through the strong interactions between Au and sulfhydryl groups on glutathione to weaken the antioxidant ability of tumor cells, thus amplifying the 1O2 damage to cancer cells. The in vitro and in vivo experiments totally exhibited that the as-prepared PCN-224@Au nanoreactor can be used as an oxidative stress amplifier for enhanced PDT, which provides a promising candidate to conquer the limitation of intratumor hypoxia and high GSH level on PDT of cancer.

Stimuli responsive nanosonosensitizers for sonodynamic therapy

Sonodynamic therapy (SDT) has gained significant attention in the treatment of deep tumors and multidrug-resistant (MDR) bacterial infections due to its high tissue penetration depth, high spatiotemporal selectivity, and noninvasive therapeutic method. SDT combines low-intensity ultrasound (US) and sonosensitizers to produce lethal reactive oxygen species (ROS) and external damage, which is the main mechanism behind this therapy. However, traditional organic small-molecule sonosensitizers display poor water solubility, strong phototoxicity, and insufficient targeting ability. Inorganic sonosensitizers, on the other hand, have low ROS yield and poor biocompatibility. These drawbacks have hindered SDT's clinical transformation and application. Hence, designing stimuli-responsive nano-sonosensitizers that make use of the lesion's local microenvironment characteristics and US stimulation is an excellent alternative for achieving efficient, specific, and safe treatment. In this review, we provide a comprehensive overview of the currently accepted mechanisms in SDT and discuss the application of responsive nano-sonosensitizers in the treatment of tumor and bacterial infections. Additionally, we emphasize the significance of the principle and process of response, based on the classification of response patterns. Finally, this review emphasizes the potential limitations and future perspectives of SDT that need to be addressed to promote its clinical transformation.

Self-Assembled Copper-Based Nanoparticles for Glutathione Activated and Enzymatic Cascade-Enhanced Ferroptosis and Immunotherapy in Cancer Treatment

As an emerging cancer treatment strategy, ferroptosis is greatly restricted by excessive glutathione (GSH) in tumor microenvironment (TME) and low reactive oxygen species (ROS) generation efficiency. Here, this work designs self-assembled copper-alanine nanoparticles (CACG) loaded with glucose oxidase (GOx) and cinnamaldehyde (Cin) for in situ glutathione activated and enzymatic cascade-enhanced ferroptosis and immunotherapy. In response to GSH-rich and acidic TME, CACG allows to effectively co-deliver Cu2+ , Cin, and GOx into tumors. Released Cin consumes GSH through Michael addition, accompanying with the reduction of Cu2+ into Cu+ for further GSH depletion. With the cascade of Cu+ -catalyzed Fenton reactions and enzyme-catalyzed reactions by GOx, CACG could get rid of the restriction of insufficient hydrogen peroxide in TME, leading to a robust and constant generation of ROS. With the high efficiency of GSH depletion and ROS production, ferroptosis is significantly enhanced by CACG in vivo. Moreover, elevated oxidative stress triggers robust immune responses by promoting dendritic cells maturation and T cell infiltration. The in vivo results prove that CACG could efficiently inhibit tumor growth in 4T1 tumor-bearing mouse model without causing obvious systemic toxicity, suggesting the great potential of CACG in enhancing ferroptosis and immunotherapy for effective cancer treatment.

Mineralized Porphyrin Metal-Organic Framework for Improved Tumor Elimination and Combined Immunotherapy

Calcium ion therapy is a potential anticancer treatment. However, the cellular calcium-buffering mechanism limited the effectiveness of calcium ion therapy. Here, we constructed a mineralized porphyrin metal-organic framework (PCa) to produce calcium ions and reactive oxygen species (ROS), which destroyed cell calcium buffering capacity and amplified the cell damage caused by calcium overload. In addition, PCa could induce cell immunogenic death to release tumor-associated antigen (TAA) and be used as an adjuvant. Thus, PCa could increase DC maturation and promote the antitumor activity of CD8⁺ T cells. For mice experiment, PCa not only showed excellent tumor elimination on the subcutaneous breast tumor but also achieved obvious antimetastasis effect in the metastatic tumor model. This nanosystem could eliminate the primary tumor and boost effective antitumor immunotherapy for comprehensive anticancer treatment.

Target-Responsive Metal-Organic Framework Nanosystem with Synergetic Sensitive Detection and Controllable Degradation against the Pesticide Triazophos in Contaminated Samples for Environment Assessment and Food Safety

Developing sensitive practical sensors for monitoring pesticide residues in edible foods and environmental samples is vital for food safety and environmental protection. Enzyme-inhibited biosensors offer effective alternative sensing strategies by using the inherent characteristics of pesticides. To further improve the degradation function of pesticide sensors, here, a target-triggered porphyrin metal-organic framework (MOF)-based nanosystem was designed with the synergetic bifunction of sensitive detection and controllable degradation of the triazophos pesticide. As a result of triazophos-inhibited glutathione consumption, the MOF collapsed and released the ligand porphyrin, leading to the recovery of fluorescence and photosensitization of the free porphyrin. The fluorescence recovery resulted in a sensitive detection limit of 0.6 ng mL^-1 for triazophos, which was also applied for the determination of contaminated samples and bioaccumulation in rice. Furthermore, the target-activated photocatalytic ability of porphyrin endowed the system with the ability to effectively generate reactive oxygen species for degrading triazophos with a removal rate of ∼85%, achieving eco-friendly synergetic detection and photodegradation in a controllable way. Therefore, the intelligent multifunctional MOF system demonstrated the potential of programmable systems for jointly controllable tracking and elimination of pesticide residues in the environment and opened a new avenue for designing a precise mechanism for stimulus-triggered degradation of pesticide residues accompanied by sensitive detection for environmental friendliness and food safety.

Aptamer modified Zr-based porphyrinic nanoscale metal-organic frameworks for active-targeted chemo-photodynamic therapy of tumors

Active-targeted nanoplatforms could specifically target tumors compared to normal cells, making them a promising therapeutic agent. The aptamer is a kind of short DNA or RNA sequence that can specifically bind to target molecules, and could be widely used as the active targeting agents of nanoplatforms to achieve active-targeted therapy of tumors. Herein, an aptamer modified nanoplatform DOX@PCN@Apt-M was designed for active-targeted chemo-photodynamic therapy of tumors. Zr-based porphyrinic nanoscale metal organic framework PCN-224 was synthesized through a one-pot reaction, which could produce cytotoxic 1O2 for efficient treatment of tumor cells. To improve the therapeutic effect of the tumor, the anticancer drug doxorubicin (DOX) was loaded into PCN-224 to form DOX@PCN-224 for tumor combination therapy. Active-targeted combination therapy achieved by modifying the MUC1 aptamer (Apt-M) onto DOX@PCN-224 surface can not only further reduce the dosage of therapeutic agents, but also reduce their toxic and side effects on normal tissues. In vitro, experimental results indicated that DOX@PCN@Apt-M exhibited enhanced combined therapeutic effect and active targeting efficiency under 808 nm laser irradiation for MCF-7 tumor cells. Based on PCN-224 nanocarriers and aptamer MUC1, this work provides a novel strategy for precisely targeting MCF-7 tumor cells.

Redox Imbalance Triggered Intratumoral Cascade Reaction for Tumor "turn on" Imaging and Synergistic Therapy

The redox homeostasis in tumors enhances their antioxidant defense ability, limiting reactive oxygen species mediated tumor therapy efficacy. The development of strategies for specific and continuous disruption of the redox homeostasis in tumor cells facilitates the improvement of the cancer therapeutic effect by promoting the apoptosis of tumor cells. Herein, a responsively biodegradable targeting multifunctional integrated nanosphere (HDMn-QDs/PEG-FA) is designed to enhance the anti-tumor efficacy by triggering intratumoral cascade reactions to effectively disrupt intracellular redox homeostasis. Once HDMn-QDs/PEG-FA enters tumor cells, manganese dioxide (MnO₂ ) shell on the surface of nanosphere consumes glutathione (GSH) to produce Mn²⁺ , enabling enhanced chemodynamic therapy (CDT) via a Fenton-like reaction and T₁ -weighted magnetic resonance imaging. Meanwhile, the degradation of MnO₂ can also cause the fluorescence recovery of quantum dots conjugated on the surface of the shell, realizing "turn-on" fluorescence imaging. In addition, the doxorubicin is released because of the cleavage of the embedded SS bond in the hybrid core framework by GSH. A superior synergistic therapeutic efficiency combined CDT and chemotherapy is shown by HDMn-QDs/PEG-FA in vivo. The tumor-inhibition rate reaches to 94.8% and does not cause normal tissue damage due to the good targeting and tumor microenvironment-specific response.

Nanoscale MOFs in nanomedicine applications: from drug delivery to therapeutic agents

Metal-organic frameworks (MOFs) hold great promise for widespread applications in biomedicine and nanomedicine. MOFs are one of the most fascinating nanocarriers for drug delivery, benefiting from their high porosity and facile modification. Furthermore, the tailored components of MOFs can be therapeutic agents for various treatments, including drugs as organic ligands of MOFs, active metal as central metal ions of MOFs, and their combinations as carrier-free MOF-based nanodrug. In this review, the advances in delivery systems and applications as therapeutic agents for nanoscale MOF-based materials are summarized. The challenges of MOFs in clinical translation and the future directions in the field of MOFs therapy are also discussed. We hope that more researchers will focus their attention on advancing and translating MOF-based nanodrugs into pre-clinical and clinical applications.

Glutathione-responsive and -exhausting metal nanomedicines for robust synergistic cancer therapy

Due to their rapid and uncontrolled proliferation, cancer cells are characterized by overexpression of glutathione (GSH), which impairs reactive oxygen species (ROS)-based therapy and weakens the chemotherapeutic agent-induced toxification. Extensive efforts have been made in the past few years to improve therapeutic outcomes by depleting intracellular GSH. Special focus has been given to the anticancer applications of varieties of metal nanomedicines with GSH responsiveness and exhaustion capacity. In this review, we introduce several GSH-responsive and -exhausting metal nanomedicines that can specifically ablate tumors based on the high concentration of intracellular GSH in cancer cells. These include inorganic nanomaterials, metal-organic frameworks (MOFs), and platinum-based nanomaterials. We then discuss in detail the metal nanomedicines that have been extensively applied in synergistic cancer therapy, including chemotherapy, photodynamic therapy (PDT), sonodynamic therapy (SDT), chemodynamic therapy (CDT), ferroptotic therapy, and radiotherapy. Finally, we present the horizons and challenges in the field for future development.

A copper-metal organic framework enhances the photothermal and chemodynamic properties of polydopamine for melanoma therapy

The combination of photothermal treatment and chemodynamic therapy has attracted extensive attention for improving therapeutic effects and compensating the insufficiency of monotherapy. In this work, a copper-metal organic framework (Cu-BTC) was used to augment the photothermal effect of polydopamine (PDA) and endow it with a chemodynamic ability by constructing a Cu-BTC@PDA nanocomposite. Density functional theory calculations revealed that the plasmonic vibrations formed by the d-d transition of Cu at the Fermi level in Cu-BTC@PDA could enhance the photothermal performance of PDA. In addition, more Cu²⁺ released from Cu-BTC@PDA in the acidic microenvironment of the tumor was then reduced to Cu⁺ by glutathione (GSH) and further catalyzed H₂O₂ to generate more toxic hydroxyl radical (•OH), which synergized with photothermal treatment for melanoma therapy. Furthermore, Cu-BTC@PDA could quickly and effectively kill bacteria under the action of PTT, and the sustained release of Cu ions could contribute to the long-term and stable bacteriostatic ability of the material. This sustained release of Cu ions could also promote the cell migration and angiogenesis, and upregulate the expression of COL-, TGF-, and VEGF-related genes to accelerate wound healing. This multifunctional nanomaterial has potential application in the treatment of melanoma and repair of wounds. STATEMENT OF SIGNIFICANCE: We constructed a multifunctional nanoplatform (Cu-BTC@PDA) by two steps. This nanoplatform can not only perform cascade catalysis in the tumor microenvironment to generate more toxic hydroxyl radical (•OH), but also synergize with photothermal treatment for melanoma therapy. Additionally, Cu-BTC@PDA possesses enhanced photothermal performance through the plasmonic vibrations formed by the d-d transition of Cu at the Fermi level in Cu-BTC@PDA, which is revealed by DFT calculations. And Cu-BTC@PDA shows good antitumor, antibacterial, and wound healing properties in vivo and in vitro. Such a multifunctional nanomaterial has potential application in the treatment of melanoma and repair of wounds.

Fe-MnO2 nanosheets loading dihydroartemisinin for ferroptosis and immunotherapy

Ferroptosis has emerged as a therapeutic tactic to trigger cancer cell death driven by abnormal accumulation of reactive oxygen species (ROS). However, a single ferroptosis treatment modality is often limited. In this work, a combination therapy of ferroptosis and immunotherapy for cancer was proposed. Specifically, a versatile nanodrug was designed for the multiple treatment of hepatocellular carcinoma (HCC) by loading dihydroartemisinin (DHA) on Fe³⁺-doped MnO₂ nanosheets (Fe-MnO₂/DHA). Firstly, Fe-MnO₂/DHA was degraded by glutathione (GSH) in the tumor microenvironment (TME) to release Fe²⁺, Mn²⁺ and DHA, leading to aberrant ROS accumulation due to Fenton/Fenton-like reaction. Secondly, breakage of endoperoxide bridge from DHA was caused by Fe²⁺ to further induce oxidative stress. Thirdly, the depleted GSH promoted the inactivation of glutathione peroxidase 4 (GPX4), resulting in lipid peroxide (LPO) accumulation. The resulting LPO and ROS could induce ferroptosis and apoptosis of liver cancer cells. Furthermore, Fe-MnO₂/DHA mediated three-pronged stimulation of oxidative stress, resulting in high levels of targeted immunogenic cell death (ICD). It could enhance the infiltration of CD4⁺ T and CD8⁺ T cells, and promote macrophage polarization. DHA also acted as an immunomodulator to inhibit regulatory T cells (Tregs) for systemic antitumor. Overall, Fe-MnO₂/DHA presents a multi-modal therapy for HCC driven by ferroptosis, apoptosis and immune activation, significantly advancing synergistic cancer treatment.

Reactive oxygen species-upregulating nanomedicines towards enhanced cancer therapy

Reactive oxygen species (ROS) play a crucial role in physiological and pathological processes, emerging as a therapeutic target in cancer. Owing to the high concentration of ROS in solid tumor tissues, ROS-based treatments, such as photodynamic therapy and chemodynamic therapy, and ROS-responsive drug delivery systems have been widely explored to powerfully and specifically suppress tumors. However, their anticancer efficacy is still hampered by the heterogeneous ROS levels, and thus comprehensively upregulating the ROS levels in tumor tissues can ensure an enhanced therapeutic effect, which can further sensitize and/or synergize with other therapies to inhibit tumor growth and metastasis. Herein, we review the recently emerging drug delivery strategies and technologies for increasing the H₂O₂, ˙OH, ¹O₂, and ˙O₂^- concentrations in cancer cells, including the efficient delivery of natural enzymes, nanozymes, small molecular biological molecules, and nanoscale Fenton-reagents and semiconductors and neutralization of intracellular antioxidant substances and localized input of mechanical and electromagnetic waves (such as ultrasound, near infrared light, microwaves, and X-rays). The applications of these ROS-upregulating nanosystems in enhancing and synergizing cancer therapies including chemotherapy, chemodynamic therapy, phototherapy, and immunotherapy are surveyed. In addition, we discuss the challenges of ROS-upregulating systems and the prospects for future studies.

DUCNP@Mn-MOF/FOE as a Highly Selective and Bioavailable Drug Delivery System for Synergistic Combination Cancer Therapy

Heterostructures comprising lanthanide-doped upconversion nanoparticles (DUCNPs) and metal-organic frameworks (MOFs) are emerging as promising nanosystems for integrating medical diagnosis and treatment. Here, the DUCNP@Mn-MOF nanocarrier was developed, which showed good efficiency for loading and delivering a cytotoxic antitumor agent (3-F-10-OH-evodiamine, FOE). The combined advantages of the pH-responsive and peroxidase-like properties of Mn-MOF and the unique optical features of DUCNPs granted the DUCNP@Mn-MOF/FOE system synergistic chemodynamic and chemotherapeutic effects. The DUCNP@Mn-MOF nanocarrier effectively overcame the intrinsic limitations of FOE, such as its unfavorable physicochemical properties and limited in vivo potency. This complexed nanosystem was responsive to the tumor microenvironment and showed excellent tumor targeting capability. Thus, DUCNP@Mn-MOF/FOE exhibited highly selective and bioavailable drug delivery properties and is promising for cancer therapy. In a mouse breast cancer model, DUCNP@Mn-MOF/FOE inhibited tumor growth without significant toxicity. Therefore, the proposed nanosystem represents a promising theragnostic platform for multimodal combination diagnosis and therapy of tumors.

Covalent Organic Framework Nanobowls as Activatable Nanosensitizers for Tumor-Specific and Ferroptosis-Augmented Sonodynamic Therapy

Covalent organic frameworks (COFs) have attracted increasing attention for biomedical applications. COFs-based nanosensitizers with uniform nanoscale morphology and tumor-specific curative effects are in high demand; however, their synthesis is yet challenging. In this study, distinct COF nanobowls are synthesized in a controlled manner and engineered as activatable nanosensitizers with tumor-specific sonodynamic activity. High crystallinity ensures an ordered porous structure of COF nanobowls for the efficient loading of the small-molecule sonosensitizer rose bengal (RB). To circumvent non-specific damage to normal tissues, the sonosensitization effect is specifically inhibited by the in situ growth of manganese oxide (MnOx ) on RB-loaded COFs. Upon reaction with tumor-overexpressed glutathione (GSH), the "gatekeeper" MnOx is rapidly decomposed to recover the reactive oxygen species (ROS) generation capability of the COF nanosensitizers under ultrasound irradiation. Increased intracellular ROS stress and GSH consumption concomitantly induce ferroptosis to improve sonodynamic efficacy. Additionally, the unconventional bowl-shaped morphology renders the nanosensitizers with enhanced tumor accumulation and retention. The combination of tumor-specific sonodynamic therapy and ferroptosis achieves high efficacy in killing cancer cells and inhibiting tumor growth. This study paves the way for the development of COF nanosensitizers with unconventional morphologies for biomedicine, offering a paradigm to realize activatable and ferroptosis-augmented sonodynamic tumor therapy.

Mesoporous polydopamine-based nanoplatform for enhanced tumor chemodynamic therapy through the reducibility weakening strategy

Polydopamine (PDA)-based Fenton agents attract increasing attention in tumor photothermal-enhanced chemodynamic therapy (CDT) due to their good biocompatibility and excellent loading capacity. However, PDA tends to eliminate the Fenton reaction-generated hydroxyl radical (∙OH) by its strong reducibility, which is an intractable hinder to the efficacy of CDT that need to be solved. Herein, a kind of mesoporous PDA-gold-manganese dioxide (MPDA-Au-MnO₂, MPAM) nanoplatform was constructed for photothermal-enhanced CDT against tumor through the reducibility weakening strategy. The reducibility of original MPDA is effectively weakened by the oxidation role of HAuCl₄ and KMnO₄ during the preparation process, reducing the ∙OH scavenging ability of MPDA and benefiting the production of ∙OH. The MnO₂ shell could react with GSH to release Mn²⁺, acting as the Fenton-like agent to generate ∙OH. The exposed Au NPs can further deplete GSH through the Au-S bond interaction. MPDA acts as the photothermal agent to generate hyperthermia under laser irradiation. MPAM shows excellent intracellular GSH scavenging ability and enhanced ∙OH production ability. After intravenous injection, MPAM can significantly suppress the growth of tumors under laser irradiation, meanwhile showing good biosafety. The developed MPDA-based nanoplatform can not only display good potential in further tumor treatments but also provide meaningful enlightenment for developing high-performance PDA or MPDA-based nanoplatforms in CDT-related applications.

Nucleic acid drug vectors for diagnosis and treatment of brain diseases

Nucleic acid drugs have the advantages of rich target selection, simple in design, good and enduring effect. They have been demonstrated to have irreplaceable superiority in brain disease treatment, while vectors are a decisive factor in therapeutic efficacy. Strict physiological barriers, such as degradation and clearance in circulation, blood-brain barrier, cellular uptake, endosome/lysosome barriers, release, obstruct the delivery of nucleic acid drugs to the brain by the vectors. Nucleic acid drugs against a single target are inefficient in treating brain diseases of complex pathogenesis. Differences between individual patients lead to severe uncertainties in brain disease treatment with nucleic acid drugs. In this Review, we briefly summarize the classification of nucleic acid drugs. Next, we discuss physiological barriers during drug delivery and universal coping strategies and introduce the application methods of these universal strategies to nucleic acid drug vectors. Subsequently, we explore nucleic acid drug-based multidrug regimens for the combination treatment of brain diseases and the construction of the corresponding vectors. In the following, we address the feasibility of patient stratification and personalized therapy through diagnostic information from medical imaging and the manner of introducing contrast agents into vectors. Finally, we take a perspective on the future feasibility and remaining challenges of vector-based integrated diagnosis and gene therapy for brain diseases.

Integrated manganese (III)-doped nanosystem for optimizing photothermal ablation: Amplifying hyperthermia-induced STING pathway and enhancing antitumor immunity

Despite the great promise initially demonstrated by photothermal ablation (PTA) therapy, its inability to completely ablate large tumors is problematic, because this has been found to result in residual tumors at ablation margins and bring a relative high rate of subsequent recurrences and metastases. To address this issue, we herein report a smart photothermal nanosystem (PBM) based on FDA-approved Prussian blue (PB) nanoparticles, doped with Mn (III) to suppress the tumor debris left by incomplete ablation. Notably, our study demonstrated that PTA-induced hyperthermia plays a crucial role in initiating the cGAS-STING pathway by generating damaged cytosolic DNA. This PBM nanosystem, which consumes glutathione and continuously releases Mn(II), further amplifies the PTA-induced cGAS-STING pathway in CT26 colon and 4T1 breast tumor models. Moreover, treatment with PBM following PTA boosted the robust immune response in situ and extended to the whole body with a remarkable suppression effect on both local residual and distant tumors. This work, which improves the antitumor efficacy of nonablated areas utilizing hyperthermia-enhanced immune therapy, may therefore provide a promising adjuvant antitumor strategy for the issue of incomplete ablation. STATEMENT OF SIGNIFICANCE: This work discovered, for the first time, that photothermal ablation-induced hyperthermia plays a crucial role in initiating the cGAS-STING pathway. Taking advantage of this finding, we developed a smart photothermal material (PBM) tailored for incomplete tumor ablation. This integrated Mn(III)-doped nanosystem (PBM) demonstrated superior therapeutic benefits due to the thermal ablation process and immune enhancement. As the photothermal ablation-induced cGAS-STING pathway was triggered, the released Mn(III) consumes GSH while continuously transferred to Mn(II), which further amplified STING activation and facilitated a more robust antitumor immunity, thereby remarkably inhibiting both local residual and distant tumors in virtue of the biological changes under thermal ablation.

Synthesis of porphyrin-based 2D ytterbium metal organic frameworks for efficient photodynamic therapy

Photodynamic therapy (PDT), which relies on the photo-induced reactive oxygen species (ROS) to trigger tumor cells apoptosis, has attracted intense focus over the decades due to the minimum invasion, high-precision and controllable therapeutic processes. Tetra(4-carboxyphenyl) porphin (TCPP), as an effective PDT photosensitizer, can harness photons and generate singlet oxygen species (¹O₂) upon illumination; however, poor solubility and low loading rate greatly limit its further use. Although TCPP-based metal-organic-frameworks (MOFs) has been proposed to address these concerns, the relatively large size still limits their biomedical applications. Therefore, in this study, TCPP molecules are coordinated with Yb³⁺, growing into 2D Yb-TCPP MOFs by a wet chemical method; the as-prepared Yb-TCPP MOFs are around 200 nm in size and possess high ¹O₂ generation efficiency with low cytotoxicity. Due to TCPP is appeared as the organic frameworks of Yb-TCPP MOFs, the low loading rate problem is largely addressed; in addition, the absorbance of Yb-TCPP MOFs has been greatly expanded compared with free TCPP molecules due to the coordination with Yb³⁺, allowing the illumination at longer wavelength range, e.g. 655 nm, that possesses high penetration depth and low phototoxicity. Overall, we have prepared 2D Yb-TCPP MOFs suitable for the in vitro anticancer effect, revealing the potential of Yb-TCPP MOFs as the future anticancer agent.