Glutathione-Depleting Nanomedicines for Synergistic Cancer Therapy

Discrimination of normal/cancer cells in bioimaging through a rolling circle amplification-enhanced red carbon dots-embedded multivalent aptamers nanoplatform

Glutathione (GSH) is a key biomarker closely associated with cancer, and its content varies greatly between normal cells and cancer cells. However, intracellular detection of GSH was challenging because existing probes not only have a long detection time but also have fluorescence in the blue-green region that overlaps with the biological matrix's spontaneous fluorescence, thus affecting the detection accuracy. Therefore, a new red fluorescent nano-probe was needed to rapidly and accurately detected GSH within the biological matrix. Herein, red carbon dots (R-CDs) synthesized via hydrothermal method using N-(4-amino phenyl) acetamide and 4-Bromo-1,2-diaminobenzene as precursors offer enhanced fluorescence that could be quenched by MnO2 nanosheets (MnO2 NS) and restored by GSH. By combining R-CDs with the AS1411 aptamer and using rolling circle amplification, a multivalent aptamer modified R-CDs assembly (Assembly@R-CDs) was created for swift cancer cell targeting. Compared to monomeric aptamer, such multivalent aptamers exhibited higher affinity and selectivity, thereby enhancing the specificity and sensitivity of detection. After the fluorescence of the multivalent assembly was quenched by MnO2 NS (Assembly@R-CDs@MnO2 NS), it could be restored when targeting cancer cells, which could realize the distinction between normal cells and cancer cells. The experiment showed that 4T1 cancer cells took up more Assembly@R-CDs@MnO2 NS than L929 normal cells and generated stronger fluorescence, indicating the high selectivity for cancer cell detection. The potential of such nanosystem for tumor diagnosis combination therapy is promising, especially considering the embedding properties of anthracene drugs such as doxorubicin in DNA carriers.

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

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

Chemical Design of Magnetic Nanomaterials for Imaging and Ferroptosis-Based Cancer Therapy

Ferroptosis, an iron-dependent form of regulatory cell death, has garnered significant interest as a therapeutic target in cancer treatment due to its distinct characteristics, including lipid peroxide generation and redox imbalance. However, its clinical application in oncology is currently limited by issues such as suboptimal efficacy and potential off-target effects. The advent of nanotechnology has provided a new way for overcoming these challenges through the development of activatable magnetic nanoparticles (MNPs). These innovative MNPs are designed to improve the specificity and efficacy of ferroptosis induction. This Review delves into the chemical and biological principles guiding the design of MNPs for ferroptosis-based cancer therapies and imaging-guided therapies. It discusses the regulatory mechanisms and biological attributes of ferroptosis, the chemical composition of MNPs, their mechanism of action as ferroptosis inducers, and their integration with advanced imaging techniques for therapeutic monitoring. Additionally, we examine the convergence of ferroptosis with other therapeutic strategies, including chemodynamic therapy, photothermal therapy, photodynamic therapy, sonodynamic therapy, and immunotherapy, within the context of nanomedicine strategies utilizing MNPs. This Review highlights the potential of these multifunctional MNPs to surpass the limitations of conventional treatments, envisioning a future of drug-resistance-free, precision diagnostics and ferroptosis-based therapies for treating recalcitrant cancers.

Histone deacetylase inhibiting nanoprodrugs for enhanced chemodynamic therapy through multistage downregulating glutathione

The unique redox homeostasis in tumor cells makes chemodynamic therapy (CDT) a promising strategy for cancer treatment. However, high glutathione (GSH) level within tumor cells severely impacts the efficacy of CDT. Therefore, reducing intracellular GSH levels has become an approach to enhance CDT. Here, we propose a HDAC inhibiting nanoprodrug consisting of an amphiphilic reactive oxygen species (ROS)-responsive polyprodrug and a GSH-responsive dimer. The high ROS level in tumor tissues can trigger the release of cinnamaldehyde and ferrocene to upregulate intracellular ROS levels through generation of hydroxyl radicals. Additionally, the dimer can react with intracellular GSH to release histone deacetylase (HDAC) inhibitors for inhibiting HDAC, thereby suppressing GSH synthesis by reducing precursor supply. The multistage depletion of GSH can further enhance oxidative damage of hydroxyl radicals to cancer cells. This study provides a promising HDAC-inhibiting strategy to achieve GSH depletion for enhanced CDT.

One-step construction of bioinspired multi-enzyme mimicking nanozyme as a universal platform for multi-mode sensing and catalytic degradation

Nanozymes, a category of nanomaterials with exceptional enzyme-like activity, exhibit the significant promise to overcome the inherent limitations of natural enzymes. Inspired by the active site structure of natural laccase, a biomimetic MA-Cu nanozyme with three-dimensional network structure was constructed in water system through one-step complexation based on the specific coordination between nitrogen-rich triazine heterocyclic melamine and Cu2+, in a facile, green and economical manner. Compared to natural laccase, MA-Cu possesses superior multi-enzyme mimicking activity, stability and cost-effectiveness. Through comprehensive characterizations, activity tests and theoretical calculations, the catalytic mechanism and the ligand-tunability of enzyme-like activity have been thoroughly investigated. Based on its multi-enzyme-like activities, a multifunctional monitoring platform for sulfide in food, epinephrine in preparations and glutathione in cells was successfully constructed, respectively. Notably, a green degradation and discrimination platform based on MA-Cu for various pollutants was developed, exhibiting distinguished substrate universality and detoxication capacity. As a stable, easily scalable and commercially applicable nanozyme, MA-Cu is expected to become a compelling candidate for replacing natural enzyme, showing excellent prospects in environmental remediation and biosensing.

Recent Advances in Glutathione Depletion-Enhanced Porphyrin-Based nMOFs for Photodynamic Therapy

Photodynamic therapy has established itself as a clinical treatment for certain superficial cancers by converting oxygen into cytotoxic singlet oxygen to eradicate cancer cells. Porphyrin-based nanoscale metal-organic frameworks have emerged as promising photosensitive platforms due to their ability to prevent the hydrophobic aggregation quenching of porphyrin molecules and enhance accumulation at the tumor site, thereby becoming a focal point in photodynamic materials research. However, the elevated levels of glutathione and other reductive substances within cancer cells can alleviate the oxidative stress induced by singlet oxygen from the photodynamic therapy process, thus protecting intracellular biomolecular structures from damage. Consequently, it is crucial to design functionalized nanoplatforms that integrate glutathione depletion with porphyrin-based metal-organic frameworks to significantly boost photodynamic therapy efficacy. Moreover, the excess glutathione within cells can disrupt the structure of porphyrin-based metal-organic frameworks, which not only increases the capacity of porphyrin molecules to generate singlet oxygen upon light exposure but also aids in the recovery of their fluorescence imaging capabilities. Additionally, this specificity minimizes the photosensitizing harm of porphyrin-based metal-organic frameworks to other normal tissues. This review compiles recent advancements in developing porphyrin-based metal-organic frameworks for enhanced phototherapy through glutathione depletion. It aims to promote the further application of porphyrin-based metal-organic frameworks in phototherapy and provide valuable insights for preclinical applications. By highlighting strategies that improve therapeutic outcomes while maintaining safety profiles, this summary seeks to advance the development of more effective and targeted cancer treatments.

The human zinc-binding cysteine proteome

Zinc is an essential micronutrient that regulates a wide range of physiological processes, most often through zinc binding to protein cysteine residues. Despite being critical for modulation of protein function, the cysteine sites in the majority of the human proteome that are subject to zinc binding remain undefined. Here, we develop ZnCPT, a deep and quantitative mapping of the zinc-binding cysteine proteome. We define 6,173 zinc-binding cysteines, uncovering protein families across major domains of biology that are subject to constitutive or inducible zinc binding. ZnCPT enables systematic discovery of zinc-regulated structural, enzymatic, and allosteric functional domains. On this basis, we identify 52 cancer genetic dependencies subject to zinc binding and nominate malignancies sensitive to zinc-induced cytotoxicity. We discover a mechanism of zinc regulation over glutathione reductase (GSR), which drives cell death in GSR-dependent lung cancers. We provide ZnCPT as a resource for understanding mechanisms of zinc regulation of protein function.

A novel cyanine photosensitizer for sequential dual-site GSH depletion and ROS-potentiated cancer photodynamic therapy

The efficacy of photodynamic therapy (PDT) is often limited by the reductive microenvironment in tumor cells due to the high level of glutathione (GSH) and glutathione peroxidase 4 (GPX4), which maintain redox homeostasis. Therefore, designing a GSH-responsive photosensitizer that depletes intracellular GSH is a promising strategy to enhance PDT selectivity and efficacy. Herein, we present a GSH-selective sequentially responsive theranostic photosensitizer, Cy-Res. This cyanine agent targeting mitochondria effectively depletes two GSH molecules, leading to the generation of abundant ROS and exacerbating oxidative stress. Additionally, it achieves an 80-fold fluorescence enhancement upon response to GSH, enabling selective imaging of tumor cells. By mitigating GSH's impact on PDT, Cy-ResNPs achieves synergistic and efficient PDT treatment of invasive melanoma under low-power irradiation (808 nm, 80 mW/cm2). The inhibitory processes downregulate GPX4, increase apoptotic proteins like Bax, and promote mixed cell death involving both ferroptosis and apoptosis. Overall, this study offers new insights and strategies for the development of GSH-responsive theranostic agents, highlighting their potential for application in tumor diagnosis and therapy.

Nanozyme-mediated glutathione depletion for enhanced ROS-based cancer therapies: a comprehensive review

Nanozymes can improve reactive oxygen species (ROS)-based cancer therapies by targeting cancer cells' antioxidant defense mechanisms, particularly glutathione (GSH) depletion, to overcome ROS-resistant cancer cells. Nanozymes, innovative enzyme-mimetic nanomaterials, can generate ROS, alter the tumor microenvironment (TME), and synergize with photodynamic therapy (PDT), chemodynamic therapy (CDT), radiotherapy, and immunotherapy. This review shows how nanozymes catalyze ROS generation, selectively deplete GSH, and target cancer elimination, offering clear advantages over standard therapies. Nanozymes selectively target cancer cells' antioxidant defenses to improve PDT, CDT, and radiation therapies. To maximize nanozyme-based cancer treatment efficacy, biodistribution, biocompatibility, and tumor heterogeneity must be assessed. To improve cancer treatment, multifunctional, stimuli-responsive nanozymes and synergistic combination drugs should be developed.

Tumor microenvironment-regulated nanoplatform for enhanced chemotherapy, cuproptosis and nonferrous ferroptosis combined cancer therapy

Therapeutic approaches combining various treatments have attracted intensive interests for tumor therapy. Nevertheless, these strategies still face many obstacles, such as overexpressed GSH and hypoxia, owing to the intricate tumor microenvironment (TME). Herein, a versatile nanoplatform, CeO2@CuO2@DOX-RSL3@HA (CCDRH), was initially constructed for promoting the antitumor efficiency via regulation of the TME. The CCDRH was prepared taking mixed valence CeO2 as the nanocarrier, followed by the attachment of CuO2 nanodots, DOX and RSL3 and the camouflaging of hyaluronic acid. The CuO2 could disassemble in the acidic TME to release Cu2+ and H2O2. The POD- and CAT-mimicking activities of CeO2 could convert H2O2 to ˙OH and O2, leading to the enhancement of chemo-chemodynamic therapy. Meanwhile, RSL3 could effectively suppress GPX4 expression, and the overloaded Cu2+ and Ce4+ could deplete excess GSH, resulting in an intensive accumulation of LPO and significant nonferrous ferroptosis. Additionally, Cu+ induces the oligomerization of lipoylated DLAT and downregulates iron-sulfur cluster proteins, resulting in potent cellular cuproptosis. The experimental results revealed that CCDRH exhibited high performance in tumor inhibition, which is attributed to the combined effect of enhanced chemotherapy, ferroptosis and cuproptosis. The study provides a new approach for improving anticancer efficiency via regulation of the TME.

A Hybrid Alloying Nanozyme-Glutathione Inhibitor Co-Delivery System Initiates a Dual-Disruption on Cancer Redox Homeostasis

Altered redox homeostasis has long been observed in cancer cells, which can be exploited for therapeutic benefits. However, reactive oxygen species (ROS) pleiotropy coupling with reductive adaptation in cancer cells poses a formidable challenge for redox dyshomeostasis-based cancer therapy. Herein, a AuPd alloying nanozyme-glutathione (GSH) biosynthesis inhibitor co-delivery system (B-BMES) is developed using dendritic SiO2 as a matrix to target cancer redox homeostasis. By optimizing element composition, the alloying nanozyme in B-BMES exhibits a potent peroxidase (POD)-like activity to trigger ROS insults-mediated redox dyshomeostasis. Such a POD functionality is attributed to the optimized electronic structure and catalytic activity. Simultaneously, the B-BMES abrogates the reductive adaptation by exerting its molecule-targeted GSH suppression, thereby achieving a dual-disruption on cancer redox homeostasis. Camouflaging B-BMES with tumor-homologous cytomembrane, a hybrid nanosystem with biological stability and tumor-targeting ability is further fabricated, which initiates a safe, precise redox disruption-based cancer therapy and sensibilizes standard chemotherapy.

In Situ Transformable Fibrillar Clusters Disrupt Intracellular Copper Metabolic Homeostasis by Comprehensive Blockage of Cuprous Ions Efflux

Dysregulation of copper metabolism is intricately associated with the occurrence and therapeutic management of colorectal cancer. Previous studies have attempted to induce cuproptosis by delivering lethal doses of copper ions into tumor cells, often with systemic safety risks. In vivo, transformable peptide is modular and designed for various tumor-related proteins, which can affect protein function and distribution. Here, a fibrillar transformation peptidic (FTP) nanoparticle is synthesized, which can bind ATP7B membrane proteins (cuprous ions transporter) and transform into nanofibrils/ATP7B clusters, inducing "copper-free cuproptosis" in vivo. Without adding exogenous copper ions, the spherical FTP nanoparticles bound the high distribution regions of ATP7B membrane proteins, transforming into fibrillar networks in situ with prolonged retention. The cage-like fibrillar network would further capture unbound or newly generated free ATP7B membrane proteins, thereby significantly and consistently preventing cuprous ions efflux. The FTP nanoparticles would not undergo in situ fibrillar transformation on the low expression region of ATP7B membrane proteins but enter the cell for safe degradation, which exhibited high specificity and safety in vivo. By disrupting intracellular copper homeostasis, the transformable fibrillar clusters displayed a long-term anti-tumor effect on subcutaneous transplantation and liver metastatic CRC models.

Excessive glutathione intake contributes to chemotherapy resistance in breast cancer: a propensity score matching analysis

BACKGROUND

We aim to explore the impact of excessive glutathione (GSH) intake on chemotherapy sensitivity in breast cancer.

METHODS

Clinicopathological data were collected from 460 breast cancer patients who underwent adjuvant chemotherapy from January 2016 to December 2019 from Zhengzhou University People's Hospital. The clinicopathological characteristics following GSH treatment were collected and compared with those in Non-GSH group after 1:2 propensity score matching (PSM). Intracellular GSH levels and the expression of antioxidant enzymes (NRF2, GPX4 and SOD1) were evaluated in tumor tissues in 51 patients receiving neoadjuvant chemotherapy.

RESULTS

The recurrence rate after adjuvant chemotherapy was significantly higher in the GSH group (n = 28, 31.8%) than that in the Non-GSH group (n = 39, 22.2%; P = 0.010). Additionally, patients in the HGSH group (high GSH intake, ≥ 16 days) exhibited an elevated recurrence rate compared to that in the LGSH group (low GSH intake, < 16 days) (n = 15 (46.8%) vs. n = 52 (22.4%); P = 0.003). Cox regression revealed that High GSH intake, Ki67 ≥ 30%, Triple negative and Lymphovascular invasion were independent risk factors of progression after adjuvant chemotherapy. Among patients receiving neoadjuvant chemotherapy, intracellular GSH levels and the expression levels of antioxidant enzymes (NRF2, GPX4 and SOD1) in the resistant patients were substantially higher (P < 0.001).

CONCLUSIONS

Excessive GSH intake may contribute to chemotherapy resistance in breast cancer, and the levels of intracellular GSH and antioxidant enzymes are elevated in resistant patients after neoadjuvant chemotherapy, indicating that the standardization of GSH intake may assist in reducing chemotherapy resistance.

A glycosylated AIE-active Fe(III) photosensitizer activated by the tumor microenvironment for synergistic type I photodynamic and chemodynamic therapy

Photodynamic therapy (PDT) and chemodynamic therapy (CDT) are both promising cancer treatments to inhibit tumor cells by generating highly cytotoxic reactive oxygen species (ROS). Herein, we report a novel tumor microenvironment (TME) stimulus-responsive water-soluble glycosylated photosensitizer (BT-TPE@Fe-Lac), which can serve as a high-efficiency antitumor agent by combining PDT and CDT, based on the coordination of Fe3+ with lactosyl bis(2-pyridylmethyl)amine and an AIE luminogen (benzothiazole-hydroxytetraphenylethene, BT-TPE). BT-TPE@Fe-Lac is stable under physiological conditions and selectively targets HepG2 cells via asialoglycoprotein receptor (ASGPR)-mediated endocytosis. It rapidly dissociates into AIE-active BT-TPE molecules and a lactosyl ferric(III) complex in the acidic lysosomes of cancer cells. Upon exposure to light, BT-TPE produces O2˙- radicals for type I PDT. The ferric(III) complex is reduced to an Fe(II) complex upon depletion of glutathione, which primes the breakdown of endogenous H2O2 within the tumor microenvironment, thus generating highly toxic ˙OH for enhanced CDT. Compared with the monotherapy of PDT or CDT, BT-TPE@Fe-Lac can significantly increase the intracellular ROS levels to induce more tumor cell death under low drug doses and hypoxia-dependent conditions. This strategy leverages the unique properties of the TME to optimize therapeutic outcomes, offering a promising approach for the TME-responsive nanoplatform in advanced cancer therapy.

Disulfide-Bridged Cationic Dinuclear Ir(III) Complex with Aggregation-Induced Emission and Glutathione-Consumption Properties for Elevating Photodynamic Therapy

The ability of photosensitizers (PSs) to generate reactive oxygen species (ROS) is crucial for photodynamic therapy (PDT). However, many traditional PSs face the drawbacks that aggregation-caused quenching (ACQ) and highly expressed glutathione (GSH) in the tumor microenvironment seriously limit their ROS generation ability. Herein, we report two cationic dinuclear iridium complexes, Ir-C-C-Ir and Ir-S-S-Ir, which possess aggregation-induced emission (AIE). Ir-S-S-Ir was constructed for GSH consumption by introducing a disulfide linkage between the two auxiliary ligands with imine units. Quantum chemical calculations revealed that Ir-C-C-Ir and Ir-S-S-Ir possess many degenerate states, which provide more channels for singlet-to-triplet exciton transitions, and then the intersystem crossing rate is increased due to the heavy atom effect of the iridium and sulfur atoms. The ROS production experiments indicated that the singlet oxygen yield of Ir-S-S-Ir was 33 times more than that of the ACQ mononuclear iridium complex Ir-C. Most importantly, Ir-S-S-Ir consumed GSH through a thiol-disulfide exchange reaction, as demonstrated by mass spectrometry and high-performance liquid chromatography. Cell experiments testified that Ir-S-S-Ir consumes GSH in tumor cells, possesses good ROS production capacity, and exhibits an extraordinary PDT effect. This is the first report of an AIE dinuclear iridium complex with a GSH-consuming function.

Mechanisms of ferroptotic and non-ferroptotic organ toxicity of chemotherapy: protective and therapeutic effects of ginger, 6-gingerol and zingerone in preclinical studies

Chemotherapy (CT) is one of the flagship options for the treatment of cancers worldwide. It involves the use of cytotoxic anticancer agents to kill or inhibit the proliferation of cancer cells. However, despite its clinical efficacy, CT triggers side effect toxicities in several organs, which may impact cancer patient's quality of life and treatment outcomes. While the side effect toxicity is consistent with non-ferroptotic mechanisms involving oxidative stress, inflammation, mitochondrial impairment and other aberrant signalling leading to apoptosis and necroptosis, recent studies show that ferroptosis, a non-apoptotic, iron-dependent cell death pathway, is also involved in the pathophysiology of CT organ toxicity. CT provokes organ ferroptosis via system Xc-/GPX-4/GSH/SLC7A11 axis depletion, ferritinophagy, iron overload, lipid peroxidation and upregulation of ferritin-related proteins. Cisplatin (CP) and doxorubicin (DOX) are common CT drugs indicated to induce ferroptosis in vitro and in vivo. Studies have explored natural preventive and therapeutic strategies using ginger rhizome and its major bioactive compounds, 6-gingerol (6G) and zingerone (ZG), to combat mechanisms of CT side effect toxicity. Ginger extract, 6G and ZG mitigate non-ferroptotic oxidative inflammation, apoptosis and mitochondrial dysfunction mechanisms of CT side effect toxicity, but their effects on CT-induced ferroptosis remain unclear. Systematic investigations are, therefore, needed to unfold the roles of ginger, 6G and ZG on ferroptosis involved in CT side effect toxicity, as they are potential natural agents for the prevention of CT toxicity. This review reveals the ferroptotic and non-ferroptotic toxicity mechanisms of CT and the protective mechanisms of ginger, 6G and ZG against CT-induced, ferroptotic and non-ferroptotic organ toxicities.

Glutathione-Depleted Photodynamic Nanoadjuvant for Triggering Nonferrous Ferroptosis to Amplify Radiotherapy of Breast Cancer

Radiotherapy plays a crucial role in the treatment of advanced breast cancer, but the increased antioxidant system, especially the rise in glutathione (GSH), presents a significant obstacle to its effectiveness. To address this challenge, a versatile GSH-depleted photodynamic nanoadjuvant is developed to augment the efficacy of radiotherapy for breast cancer treatment. This nanoadjuvant operates within the tumor microenvironment to effectively deplete intracellular GSH through a sequence of cascaded processes, including GSH exhaustion, biosynthetic inhibition, and photodynamic oxidation. This leads to a notable accumulation of lipid peroxides (LPO) and subsequent suppression of glutathione peroxidase 4 (GPX4) activity. Consequently, the combined GSH depletion induced by the nanoadjuvant markedly promotes nonferrous ferroptosis, thereby contributing to the augmentation of antitumor efficiency during radiotherapy in breast cancer. This work presents an innovative approach to designing and synthesizing biocompatible nanoadjuvants with the goal of improving the efficacy of radiotherapy for breast cancer in prospective clinical scenarios.

Reprogramming the Tumor Immune Microenvironment Through Activatable Photothermal Therapy and GSH depletion Using Liposomal Gold Nanocages to Potentiate Anti-Metastatic Immunotherapy

Cancer immunotherapy offers significant clinical benefits for patients with advanced or metastatic tumors. However, immunotherapeutic efficacy is often hindered by the tumor microenvironment's high redox levels, leading to variable patient outcomes. Herein, a therapeutic liposomal gold nanocage (MGL) is innovatively developed based on photo-triggered hyperthermia and a releasable strategy by combining a glutathione (GSH) depletion to remodel the tumor immune microenvironment, fostering a more robust anti-tumor immune response. MGL comprises a thermosensitive liposome shell and a gold nanocage core loaded with maleimide. The flexible shell promotes efficient uptake by cancer cells, enabling targeted destruction through photothermal therapy while triggering immunogenic cell death and the maturation of antigen-presenting cells. The photoactivated release of maleimide depletes intracellular GSH, increasing tumor cell sensitivity to oxidative stress and thermal damage. Conversely, GSH reduction also diminishes immunosuppressive cell activity, enhances antigen presentation, and activates T cells. Moreover, photothermal immunotherapy decreases elevated levels of heat shock proteins in tumor cells, further increasing their sensitivity to hyperthermia. In summary, MGL elicited a robust systemic antitumor immune response through GSH depletion, facilitating an effective photothermal immunotherapeutic strategy that reprograms the tumor microenvironment and significantly inhibits primary and metastatic tumors. This approach demonstrates considerable translational potential and clinical applicability.

Spatiotemporally Guided Single-Atom Bionanozyme for Targeted Antibiofilm Treatment

The heterogeneous and dynamic microenvironment of biofilms complicates bacterial infection treatment. Nanozyme catalytic therapy has recently been promising in treating biofilm infections. However, active nanozymes designed with the required precision targeting the biofilm microenvironment are lacking. This work proposes a spatiotemporally guided single-atom bionanozyme (BioSAzyme) for targeted antibiofilm therapy based on protein engineering of copper single-atom nanozyme (Cu SAzyme). The Cu SAzyme, synthesized via a novel mechanochemistry-assisted method, features highly accessible Cu-N4 active sites exposed on 2D N-doped carbon, exhibiting excellent triple enzyme-like activities according to experimental results and density functional theory calculations. Inheriting biofunctionality from both glucose oxidase and concanavalin A, BioSAzyme can localize the biofilm glycocalyx and catalyze endogenous glucose into H₂O₂ and gluconic acid, thus triggering multiplex cascade reactions with pH self-adaption to consume glucose and glutathione and generate •OH radicals. This spatiotemporally guided bionanocatalytic agent effectively inhibits E. coli O157: H7 and methicillin-resistant S. aureus biofilms in vitro and in vivo. Taking together, this work opens up new avenues for the rational design of single-atom nanozymes for precise antibiofilm therapy.

Manganese oxide nanomaterials: bridging synthesis and therapeutic innovations for cancer treatment

The advent of precision medicine in oncology emphasizes the urgent need for innovative therapeutic strategies that effectively integrate diagnosis and treatment while minimizing invasiveness. Manganese oxide nanomaterials (MONs) have emerged as a promising class of nanocarriers in biomedicine, particularly for targeted drug delivery and the therapeutic management of tumors. These nanomaterials are characterized by exceptional responsiveness to the tumor microenvironment (TME), high catalytic efficiency, favorable biodegradability, and advanced capabilities in magnetic resonance imaging. These attributes significantly enhance drug delivery, facilitate real-time bioimaging, and enable early tumor detection, thereby improving the precision and effectiveness of cancer therapies. This review highlights the significant advancements in the synthesis and therapeutic applications of MONs, beginning with a comprehensive overview of key synthetic methods, including thermal decomposition, potassium permanganate reduction, exfoliation, adsorption-oxidation, and hydro/solvothermal techniques. We delve into the preparation of MONs and H-MnO₂-based nanomaterials, emphasizing their chemical properties, surface modifications, and toxicity profiles, which are critical for their clinical application. Moreover, we discuss the notable applications of H-MnO₂-based nanomaterials in pH-responsive drug release, overcoming multidrug resistance (MDR), immunotherapy, and the development of nanovaccines for synergistic cancer treatments. By addressing the current challenges in the clinical translation of MONs, we propose future research directions for overcoming these obstacles. By underscoring the potential of MONs to transform cancer treatment paradigms, this review aims to inspire further investigations into their multifunctional applications in oncology, thus ultimately contributing to more effective and personalized therapeutic strategies.

Preparation of Glutathione-Regulated Sorafenib Targeted Nanodrug Delivery System and Its Antihepatocellular Carcinoma Activity

To enhance the therapeutic effect of sorafenib (SOR) on liver cancer, we have developed a targeted nanodrug delivery system with glutathione (GSH) downregulation functionality. The preparation process comprises the synthesis of amino-functionalized mesoporous silica nanoparticles (MSN-NH2), surface modification with ethacrynic acid (EA), loading of SOR into the pores, and final surface coating with hyaluronic acid (HA) to obtain SOR@MSN-EA@HA (SMEH) nanoparticles. SMEH nanoparticles specifically enter tumor cells via CD44 receptor-mediated endocytosis. EA binds to GSH to consume it, while SOR is slowly released from the pores to exert antitumor effects while inhibiting GSH production. This results in sustained oxidative stress in the cells, thus enhancing the antitumor efficacy. Both in vitro and in vivo antitumor experiments as well as hemolysis tests have demonstrated that SMEH nanoparticles can accurately target liver cancer cells, effectively downregulate GSH concentration, exhibit good antitumor effects, and possess excellent safety, showing great potential in tumor treatment.

Nanomaterial-based regulation of redox metabolism for enhancing cancer therapy

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

Advances in smart nanotechnology-supported photodynamic therapy for cancer

Cancer has emerged as a formidable challenge in the 21st century, impacting society, public health, and the economy. Conventional cancer treatments often exhibit limited efficacy and considerable side effects, particularly in managing the advanced stages of the disease. Photodynamic therapy (PDT), a contemporary non-invasive therapeutic approach, employs photosensitizers (PS) in conjunction with precise light wavelengths to selectively target diseased tissues, inducing the generation of reactive oxygen species and ultimately leading to cancer cell apoptosis. In contrast to conventional therapies, PDT presents a lower incidence of side effects and greater precision in targeting. The integration of intelligent nanotechnology into PDT has markedly improved its effectiveness, as evidenced by the remarkable synergistic antitumor effects observed with the utilization of multifunctional nanoplatforms in conjunction with PDT. This paper provides a concise overview of the principles underlying PS and PDT, while also delving into the utilization of nanomaterial-based PDT in the context of cancer treatment.

Diagnosis and Biomarker Screening of Endometrial Cancer Enabled by a Versatile Exosome Metabolic Fingerprint Platform

Exosomes have emerged as a revolutionary tool for liquid biopsy (LB), as they carry specific cargo from cells. Profiling the metabolites of exosomes is crucial for cancer diagnosis and biomarker discovery. Herein, we propose a versatile platform for exosomal metabolite assay of endometrial cancer (EC). The platform is based on a nanostructured composite material comprising gold nanoparticle-coated magnetic COF with aptamer modification (Fe3O4@COF@Au-Apt). The unique design and novel synthesis strategy of Fe3O4@COF@Au-Apt provide the material with a large specific surface area, enabling the efficient and specific isolation of exosomes. The exosomes captured Fe3O4@COF@Au-Apt can be directly used as the laser desorption/ionization mass spectrometry (LDI-MS) matrix for rapid exosomal metabolic patterns. By integrating these functionalities into a single platform, the analytical process is simplified, eliminating the need for additional elution steps and minimizing potential sample loss, resulting in large-scale exosomal metabolic fingerprints. Combining with machine learning algorithms on the metabolic patterns, accurate discrimination between endometrial patients (EGs) and benign controls (CGs) was achieved, and the area under the receiver operating characteristic curve of the blind test cohort was 0.924. Confusion matrix analysis of important metabolic fingerprint features further demonstrates the high accuracy of the proposed approach toward EC diagnosis, with an overall accuracy of 94.1%. Moreover, four metabolites, namely, hydroxychalcone, l-acetylcarnitine, elaidic acid, and glutathione, have been identified as potential biomarkers of EC. These results highlight the great value of the integrated exosome metabolic fingerprint platform in facilitating low-cost and high-throughput characterization of exosomal metabolites for cancer diagnosis and biomarker discovery.

Dual-aptamer-decorated reduction-activated dimeric-prodrug nanoparticles for broad-spectrum treatment of leukemia

Leukemia remains a fatal disease for most affected patients, and a simple and effective therapeutic strategy is urgently needed. Targeted delivery chemo-drugs to leukemia cells shows promise, but the diverse subtypes of leukemia make single-ligand nanomedicine often ineffective. Herein, a dual-aptamer decorated, reduction-responsive dimeric prodrug-based nanoparticle (NP), termed SXP-NPs, was developed using the two leukemia-specific aptamers Sgc8c and XQ-2d, a reduction-responsive podophyllotoxin (POD) dimeric prodrug, and DSPE-PEG2000. Because the receptors of XQ-2d (CD71) and Sgc8c (PTK7) are overexpressed in different subtypes of leukemia cells, SXP-NPs can broadly and selectively recognize these leukemia cells after intravenous administration, subsequently releasing POD in response to the intracellular high-reduction environment to kill the leukemia cells. In vitro experiments showed that these simple SXP-NPs can specifically bind to various leukemia cancer cells and kill them. In vivo experiments revealed that SXP-NPs can remarkably reduce spleen weight, decrease white blood cell counts, and extend overall survival in a preclinical leukemia animal model. The in vitro and in vivo validation demonstrated that SXP-NPs offer several advantages, including high drug-loading potential, broad-spectrum recognition of leukemia cells, reduced systemic toxicity, and enhanced therapeutic effects of the drug. Taken together, this study provides a simple and effective strategy for broad-spectrum leukemia therapy and highlights the clinical potential of SXP-NPs.

Glutathione inhibits lung cancer development by reducing interleukin-6 expression and reversing the Warburg effect

Reduced glutathione (GSH) is widely used as an antioxidant in clinical practice, but whether GSH affects the development of early lung cancer remains unclear. Herein, we investigated the mechanism underlying the anticancer effect of GSH in patients with pulmonary nodules. Thirty patients with pulmonary nodules were treated with GSH intravenously for 10 days at a dose of 1.8 g/d, followed by oral administration of the drug at a dose of 0.4 g three times daily for 6 months. The results showed that GSH treatment promoted nodule absorption and reduced the IL-6 level in the peripheral blood of the patients. GSH reduced IL-6 expression in inflammatory BEAS-2B and lung cancer cells and inhibited the proliferation of lung cancer cell lines in vitro. In addition, GSH reduced IL-6 expression by decreasing ROS via down-regulating PI3K/AKT/FoxO pathways. Finally, GSH reversed the Warburg effect, restored mitochondrial function, and reduced the IL-6 expression via PI3K/AKT/FoxO pathways. The in vivo experiment confirmed that GSH inhibited lung cancer growth, improved mitochondrial function, and reduced the IL-6 expression by regulating key enzymes via the PI3K/AKT/FoxO pathway. In conclusion, we uncovered that GSH exerts an unprecedentedly potent anti-cancer effect to prevent the transformation of lung nodules to lung cancer by improving the mitochondrial function and suppressing inflammation via PI3K/AKT/FoxO pathway. This investigation innovatively positions GSH as a potentially safe and efficacious old drug with new uses, inhibiting inflammation and early lung cancer. The use of the drug offers a promising preventive strategy when administered during the early stages of lung cancer.

Simple ROS-responsive micelles loaded Shikonin for efficient ovarian cancer targeting therapy by disrupting intracellular redox homeostasis

Ovarian cancer is the most common malignant tumor in women. Shikonin (SHK), an herbal extract from Chinese medicine, shows promise in treating ovarian cancer by inducing reactive oxygen species (ROS). However, its clinical use is limited by poor tumor targeting and low bioavailability, and its therapeutic potential is further compromised by the elevated levels of antioxidants such as glutathione (GSH) within tumor cells. In this study, a novel formulation of ROS-responsive micelles loaded with SHK was developed using hyaluronic acid-phenylboronic acid pinacol ester conjugation (HA-PBAP) for targeted therapy of ovarian cancer through disruption of intracellular redox homeostasis. The SHK@HA-PBAP exhibits targeted delivery to ovarian cancer cells through the interaction between HA and CD44 receptors. Upon internalization by cancer cells, the high levels of intracellular ROS triggered the degradation of SHK@HA-PBAP and simultaneously released SHK and generated GSH scavenger quinone methide (QM). The SHK and QM released from the SHK@HA-PBAP effectively induce the production of ROS and deplete intracellular GSH, leading to the disruption of intracellular redox homeostasis and subsequent induction of cell death. These characteristics collectively inhibit the growth of ovarian cancer. In vitro and in vivo studies have demonstrated that SHK@HA-PBAP micelles exhibit superior antitumor efficacy compared to free SHK in both A2780 cells and A2780 tumor-bearing mice. The ROS-responsive SHK@HA-PBA presents a promising therapeutic approach for the treatment of ovarian cancer.

Atomically precise copper nanoclusters mediated Fenton-like reaction for cancer chemodynamic therapy

We developed stable luminescent morpholine-appended copper nanoclusters CuNCs@MorMB with an ultra-small size (<3 nm) and a long emission lifetime (577 ns). They mediate a Fenton-like reaction to produce reactive hydroxyl radicals (˙OH), subsequently depleting antioxidant glutathione levels for cancer chemodynamic therapy (CDT).

Enhanced docetaxel therapeutic effect using dual targeted SRL-2 and TA1 aptamer conjugated micelles in inhibition Balb/c mice breast cancer model

Effective targeting and delivery of large amounts of medications into the cancer cells enhance their therapeutic efficacy through saturation of cellular defensive mechanisms, which is the most privilege of nano drug delivery systems (NDDS) compared to traditional approaches. Herein, we designed dual-pH/redox responsive DTX-loaded poly (β-amino ester) (PBAS) micelles decorated with a chimeric peptide and TA1 aptamer. In vitro and in vivo results demonstrated that the designed nanoplatform possessed an undetectable nature in the blood circulation, but after exposure to the tumor microenvironment (TME) of 4T1 breast cancer, it suddenly changed into dual targeting nanoparticles (NPs) (containing two ligands, SRL-2 and TA1 aptamer). The dual targeting NPs destruction in the high GSH and low pH conditions of the cancer cells led to amplified DTX release (around 70% at 24 h). The IC50 value of DTX-loaded MMP-9 sensitive heptapeptide/TA1 aptamer-modified poly (β-amino ester) (MST@PBAS) micelles and free DTX after 48 h of exposure was determined to be 1.5 µg/ml and 7.5 µg/ml, respectively. The nano-formulated DTX exhibited cytotoxicity that was 5-fold stronger than free DTX (Pvalue˂0.001). Cell cycle assay test results showed that following exposure to MST@PBAS micelles, a considerable rise in the sub G1 population (48%) suggested that apoptosis by cell cycle arrest had occurred. DTX-loaded MST@PBAS micelles revealed significantly higher (Pvalue ˂ 0.001) levels of early apoptosis (59.8%) than free DTX (44.7%). Interestingly, in vitro uptake studies showed a significantly higher TME accumulation of dual targeted NPs (6-fold) compared to single targeted NPs (Pvalue < 0.001) which further confirmed by in vivo biodistribution and fluorescent TUNEL assay experiments. NPs treated groups demonstrated notable tumor growth inhibition in 4T1 tumor bearing Balb/c mice by only 1/10th of the DTX therapeutic dose (TD) as a drug model. In conclusion, cleverly designed nanostructures here demonstrated improved anticancer effects by enhancing tumor targeting, delivering chemotherapeutic agents more accurately, promoting drug release, reducing the therapeutic dosage, and lowering side effects of anticancer drugs.

Glutathione-Disrupting Nanotherapeutics Potentiate Ferroptosis for Treating Luminal Androgen Receptor-Positive Triple-Negative Breast Cancer

The refractory luminal androgen receptor (LAR) subtype of triple-negative breast cancer (TNBC) patients is challenged by significant resistance to neoadjuvant chemotherapy and increased immunosuppression. Regarding the distinct upregulation of glutathione (GSH) and glutathione peroxidase 4 (GPX4) in LAR TNBC tumors, we herein designed a GSH-depleting phospholipid derivative (BPP) and propose a BPP-based nanotherapeutics of RSL-3 (GDNS), aiming to deplete intracellular GSH and repress GPX4 activity, thereby potentiating ferroptosis for treating LAR-subtype TNBC. GDNS treatment drastically downregulated the expression of GSH and GPX4, resulting in a 33.88-fold enhancement of lipid peroxidation and significant relief of immunosuppression in the 4T1 TNBC model. Moreover, GDNS and its combination with antibody against programed cell death protein 1 (antiPD-1) retarded tumor growth and produced 2.83-fold prolongation of survival in the LAR-positive TNBC model. Therefore, the GSH-disrupting GDNS represents an encouraging strategy to potentiate ferroptosis for treating refractory LAR-subtype TNBC.

Paclitaxel Prodrug Enables Glutathione Depletion to Boost Cancer Treatment

Herein, we constructed a paclitaxel (PTX) prodrug (PA) by conjugating PTX with acrylic acid as a cysteine-depleting agent. The as-synthesized PA can assemble with diacylphosphatidylethanolamine-PEG2000 to form stable nanoparticles (PA NPs). After endocytosis into cells, PA NPs can specifically react with cysteine and trigger release of PTX for chemotherapy. On the other hand, the depletion of cysteine can greatly downregulate the intracellular content of glutathione and lead to oxidative stress outburst-provoking ferroptosis. The released PTX can elicit antitumor immune response by inducing immunogenic cell death, thus promoting dendritic cells maturation and cascaded cytotoxic T lymphocytes activation, which not only produces a robust immunotherapy effect but also synergizes the ferroptosis therapy by inhibiting cysteine transport via the release of interferon-γ in the activated immune system. As a result, PA NPs exhibit favorable in vitro and in vivo antitumor performance with reduced systemic toxicity. Our work highlights the potential of simple molecular design of prodrugs for enhancing the therapeutic efficacy toward malignant cancer.

A simple Ag-MoS2 hybrid nanozyme-based sensor array for colorimetric identification of biothiols and cancer cells

The intracellular levels of biothiols are associated with various diseases including cancer, and biothiols are regarded as tumor biomarker. Due to the similarity of the molecular structure of biothiols, the development of simple, rapid, efficient, and sensitive colorimetric sensor arrays holds great promise for clinical cancer diagnosis. Here, we developed a simple Ag-MoS2 hybrid nanozyme-based sensor array for colorimetric identification of biothiols and cancer cells. The novel Ag-MoS2 nanoprobe was synthesized in a simple and efficient way through the in situ self-reduction reaction between MoS2 and noble metal precursor. Benefiting from to the formation of heterogeneous metal structures, the peroxidase (POD)-like catalytic activity of the synthesized Ag-MoS2 hybrid nanocomposites is significantly enhanced compared to MoS2 alone. Moreover, the catalytic activity of Ag-MoS2 nanozyme was correlated with the pH of the reaction solution and the inhibitory effects of the three biothiols on the nanozyme-triggered chromogenic system differed in the specific pH environments. Therefore, each sensing unit of this electronic tongue generated differential colorimetric fingerprints of different biothiols. After principal component analysis (PCA), the developed novel colorimetric sensor array can accurately discriminate biothiols between different types, various concentrations, and different mixture proportions. Further, the sensor array was used for the colorimetric identification of real serum and cellular samples, demonstrating its great potential in tumor diagnostic applications.

Redox-manipulating nanocarriers for anticancer drug delivery: a systematic review

Spatiotemporally controlled cargo release is a key advantage of nanocarriers in anti-tumor therapy. Various external or internal stimuli-responsive nanomedicines have been reported for their ability to increase drug levels at the diseased site and enhance therapeutic efficacy through a triggered release mechanism. Redox-manipulating nanocarriers, by exploiting the redox imbalances in tumor tissues, can achieve precise drug release, enhancing therapeutic efficacy while minimizing damage to healthy cells. As a typical redox-sensitive bond, the disulfide bond is considered a promising tool for designing tumor-specific, stimulus-responsive drug delivery systems (DDS). The intracellular redox imbalance caused by tumor microenvironment (TME) regulation has emerged as an appealing therapeutic target for cancer treatment. Sustained glutathione (GSH) depletion in the TME by redox-manipulating nanocarriers can exacerbate oxidative stress through the exchange of disulfide-thiol bonds, thereby enhancing the efficacy of ROS-based cancer therapy. Intriguingly, GSH depletion is simultaneously associated with glutathione peroxidase 4 (GPX4) inhibition and dihydrolipoamide S-acetyltransferase (DLAT) oligomerization, triggering mechanisms such as ferroptosis and cuproptosis, which increase the sensitivity of tumor cells. Hence, in this review, we present a comprehensive summary of the advances in disulfide based redox-manipulating nanocarriers for anticancer drug delivery and provide an overview of some representative achievements for combinational therapy and theragnostic. The high concentration of GSH in the TME enables the engineering of redox-responsive nanocarriers for GSH-triggered on-demand drug delivery, which relies on the thiol-disulfide exchange reaction between GSH and disulfide-containing vehicles. Conversely, redox-manipulating nanocarriers can deplete GSH, thereby enhancing the efficacy of ROS-based treatment nanoplatforms. In brief, we summarize the up-to-date developments of the redox-manipulating nanocarriers for cancer therapy based on DDS and provide viewpoints for the establishment of more stringent anti-tumor nanoplatform.

pH-sensitive and redox-responsive poly(tetraethylene glycol) nanoparticle-based platform for cancer treatment

Effective drug delivery with precise tumour targeting is crucial for cancer treatment. To address the challenges posed by the specificity and complexity of the tumour microenvironment, we developed a poly(tetraethylene glycol)-based disulfide nanoparticle (NP) platform and explored its potential in cancer treatment, focusing on drug loading and controlled release performance. Poly(tetraethylene glycol) NPs were characterised using nuclear magnetic resonance spectroscopy, mass spectrometry, and ultraviolet-visible spectroscopy. Additionally, we evaluated physicochemical properties, including dynamic light scattering, zeta potential analysis, drug loading capacity (DLC), and drug loading efficiency (DLE). The impact of NPs on the mouse colorectal cancer cell line (CT26) and NIH3T3 cells was assessed using a cytotoxicity assay, live/dead staining assay, flow cytometry, and confocal fluorescence microscopy. The experimental results align with the expected chemical structure and physicochemical properties of poly(tetraethylene glycol) NPs. These NPs exhibit high DLE (78.7%) and DLC (12%), with minimal changes in particle size over time in different media.In vitroexperiments revealed that the NPs can induce significant cytotoxicity and apoptosis in CT26 cells. Cellular uptake notably increases with increasing concentration and exposure time. The confocal microscopic analysis confirmed the effective distribution and accumulation of NPs within cells. In conclusion, poly(tetraethylene glycol) NPs hold promise for improving drug-delivery efficiency, offering potential advancements in cancer treatment.

A self-assembled copper-artemisinin nanoprodrug as an efficient reactive oxygen species amplified cascade system for cancer treatment

Chemodynamic therapy (CDT) is a tumor-specific intervention methodology, which is based on the upregulation of reactive oxygen species (ROS) content by triggering the Fenton or Fenton-like reaction within the tumor microenvironment (TME). However, there are still challenges in achieving high-efficiency CDT on account of both the limited intracellular hydrogen peroxide (H2O2) and delivery efficiency of Fenton metal ions. Copper-based nanotherapeutic systems have attracted extensive attention and have been widely applied in the construction of nanotherapeutic systems and multimodal synergistic therapy. Herein, we propose a strategy to synergize chemotherapy drugs that upregulate intracellular ROS content with chemodynamic therapy and construct an artemisinin-copper nanoprodrug for proof-of-concept. With the proposed biomimetic self-assembly strategy, we successfully construct an injectable nanoprodrug with suitable size distribution and high drug loading content (68.1 wt%) through the self-assembly of amphiphilic artemisinin prodrug and copper ions. After reaching the TME, both Cu2+ ions and free AH drugs can be released from AHCu nanoprodrugs. Subsequently, the disassembled Cu2+ ions are converted into Cu+ ions by consuming the intracellular GSH. The generated Cu+ ions serve as a highly efficient Fenton-like reagent for robust ROS generation from both AH and tumor-over-produced H2O2. Results show that the nanoprodrug can realize the cascade amplification of ROS generation via artemisinin delivery and subsequent in situ Fenton-like reaction and a high tumor inhibition rate of 62.48% in vivo. This work provides a promising strategy for the design and development of an efficient nanoprodrug for tumor-specific treatment.

Targeting nanoplatform synergistic glutathione depletion-enhanced chemodynamic, microwave dynamic, and selective-microwave thermal to treat lung cancer bone metastasis

Once bone metastasis occurs in lung cancer, the efficiency of treatment can be greatly reduced. Current mainstream treatments are focused on inhibiting cancer cell growth and preventing bone destruction. Microwave ablation (MWA) has been used to treat bone tumors. However, MWA may damage the surrounding normal tissues. Therefore, it could be beneficial to develop a nanocarrier combined with microwave to treat bone metastasis. Herein, a microwave-responsive nanoplatform (MgFe2O4@ZOL) was constructed. MgFe2O4@ZOL NPs release the cargos of Fe3+, Mg2+ and zoledronic acid (ZOL) in the acidic tumor microenvironment (TME). Fe3+ can deplete intracellular glutathione (GSH) and catalyze H2O2 to generate •OH, resulting in chemodynamic therapy (CDT). In addition, the microwave can significantly enhance the production of reactive oxygen species (ROS), thereby enabling the effective implementation of microwave dynamic therapy (MDT). Moreover, Mg2+ and ZOL promote osteoblast differentiation. In addition, MgFe2O4@ZOL NPs could target and selectively heat tumor tissue and enhance the effect of microwave thermal therapy (MTT). Both in vitro and in vivo experiments revealed that synergistic targeting, GSH depletion-enhanced CDT, MDT, and selective MTT exhibited significant antitumor efficacy and bone repair. This multimodal combination therapy provides a promising strategy for the treatment of bone metastasis in lung cancer patients.

Intraparticle Electron Transfer for Long-Lasting Tumor Chemodynamic Therapy

Chemodynamic therapy (CDT) is a novel tumor treatment method by using hydroxyl radicals (•OH) to kill cancer cells. However, its therapeutic effects are strictly confined by the short lifespan of •OH and reduced •OH generation speed. Herein, an effective CDT is achieved by both improving •OH lifetime and long-lasting generating •OH through intraparticle electron transfer within heterogeneous nanoparticles (NPs). These heterogeneous NPs are composed of evenly distributed Cu and Fe3O4 (CFO NPs) with large interaction interfaces, and electrons tend to transfer from Cu to Fe3O4 for the appearance of ≡Cu2+ and increase in ≡Fe2+. The generated ≡Cu2+ can interact with GSH, which prolongs the lifespan of •OH, produces ≡Cu+ for higher speed •OH generation with H2O2, and induces cell ferroptosis for tumor therapy. The improved ≡Fe2+ can also improve the •OH release under H2O2 until Cu is depleted. As a result, a sustainable •OH generation is achieved to promote cell apoptosis for effective tumor therapy. Since H2O2 and GSH are only overexpressed at tumor, and CFO NPs can degrade in the tumor microenvironment, these NPs are with high biosafety and can be metabolized by urine. This work provides a novel biomaterial for effective cancer CDT through intraparticle electron transfer.

Photodynamic therapy of cancer using graphene nanomaterials

INTRODUCTION

High incidence and fatality rates of cancer remain a global challenge. The success of conventional treatment modalities is being questioned on account of adverse effects. Photodynamic therapy (PDT) is a potential alternative. It utilizes a combination of photosensitizer (PS), light and oxygen to target the tissues locally, thereby minimizing the damage to neighboring healthy tissues. Conventional PSs suffer from poor selectivity, high hydrophobicity and sub-optimal yield of active radicals. Graphene nanomaterials (GNs) exhibit interesting particulate and photophysical properties in the context of their use in PDT.

AREA COVERED

We focus on describing the mechanistic aspects of PDT-mediated elimination of cancer cells and the subsequent development of adaptive immunity. After covering up-to-date literature on the significant enhancement of PDT capability with GNs, we have discussed the probability of combining PDT with chemo-, immuno-, and photothermal therapy to make the treatment more effective.

EXPERT OPINION

GNs can be synthesized in various size ranges, and their biocompatibility can be improved through surface functionalization and doping. These can be used as PS to generate ROS or conjugated with other PS molecules for treating deep-seated tumors. With increasing evidence on biosafety, such materials offer hope as antitumor therapeutics.

Optimized Two-Photon Imaging by Stimuli-Responsive Peptide Self-Assembly Facilitates Self-Assisted Counteraction of Cisplatin-Resistance in Cancer Cells

Accurate diagnosis and effective treatment of tumors remain significant clinical challenges. While fluorescence imaging is essential for tumor detection, it has limitations in terms of specificity, penetration depth, and emission wavelength. Here, we report a novel glutathione (GSH)-responsive peptide self-assembly excimer probe (pSE) that optimizes two-photon tumor imaging and self-assisted counteraction of the cisplatin resistance in cancer cells. The GSH-responsive self-assembly of pSE induces a monomer-excimer transition of coumarin, promoting a near-infrared redshift of fluorescence emission under two-photon excitation. This process enhances penetration depth and minimizes interference from biological autofluorescence. Moreover, the intracellular self-assembly of pSE impacts GSH homeostasis, modulates relevant signaling pathways, and significantly reduces GSTP1 expression, resulting in decreased cisplatin efflux in cisplatin-resistant cancer cells. The proposed self-assembled excimer probe not only distinguishes cancer cells from normal cells but also enhances the efficacy of cisplatin chemotherapy, offering significant potential in tumor diagnosis and overcoming cisplatin-resistant tumors.

Self-Assembled Aza-Boron-Dipyrromethene-Based H2S Prodrug for Synergistic Ferroptosis-Enabled Gas and Sonodynamic Tumor Therapies

Glioblastoma multiforme (GBM) is the most aggressive and lethal subtype of gliomas of the central nervous system. The efficacy of sonodynamic therapy (SDT) against GBM is significantly reduced by the expression of apoptosis-inhibitory proteins in GBM cells. In this study, an intelligent nanoplatform (denoted as Aza-BD@PC NPs) based on the aza-boron-dipyrromethene dye and phenyl chlorothionocarbonate-modified DSPE-PEG molecules is developed for synergistic ferroptosis-enabled gas therapy (GT) and SDT of GBM. Once internalized by GBM cells, Aza-BD@PC NPs showed effective cysteine (Cys) consumption and Cys-triggered hydrogen sulfide (H2S) release for ferroptosis-enabled GT, thereby disrupting homeostasis in the intracellular environment, affecting GBM cell metabolism, and inhibiting GBM cell proliferation. Additionally, the released Aza-BD generated abundant singlet oxygen (1O2) under ultrasound irradiation for favorable SDT. In vivo and in vitro evaluations demonstrated that the combined functions of Cys consumption, H2S production, and 1O2 production induced significant death of GBM cells and markedly inhibited tumor growth, with an impressive inhibition rate of up to 97.5%. Collectively, this study constructed a cascade nanoreactor with satisfactory Cys depletion performance, excellent H2S release capability, and prominent reactive oxygen species production ability under ultrasound irradiation for the synergistic ferroptosis-enabled GT and SDT of gliomas.

Manganese-induced Photothermal-Ferroptosis for Synergistic Tumor Therapy

Ferroptosis-related tumor therapy based on nanomedicines has recently gained significant attention. However, the therapeutic performance is still hindered by the tumor's physical barriers such as the fibrotic tumor matrix and elevated interstitial fluid pressure, as well as chemical barriers like glutathione (GSH) overabundance. These physicochemical barriers impede the bioavailability of nanomedicines and compromise the therapeutic efficacy of lipid reactive oxygen species (ROS). Thus, this study pioneers a manganese-mediated overcoming of physicochemical barriers in the tumor microenvironment using organosilica-based nanomedicine (MMONs), which bolsters the synergy of photothermal-ferroptosis treatment. The MMONs display commendable proficiency in overcoming tumor physical barriers, due to their MnO2-mediated shape-morphing and softness-transformation ability, which facilitates augmented cellular internalization, enhanced tumor accumulation, and superior drug penetration. Also, the MMONs possess excellent capability in chemical barrier overcoming, including MnO2-mediated dual GSH clearance and enhanced ROS generation, which facilitates ferroptosis and heat shock protein inhibition. Notably, the resulting integration of physical and chemical barrier overcoming leads to amplified photothermal-ferroptosis synergistic tumor therapy both in vitro and in vivo. Accordingly, the comparative proteomic analysis has identified promoted ferroptosis with a transient inhibitory response observed in the mitochondria. This research aims to improve treatment strategies to better fight the complex defenses of tumors.

A multifunctional nanoplatform for chemotherapy and nanocatalytic synergistic cancer therapy achieved by amplified lipid peroxidation

Traditional cancer chemotherapy suffers from low efficacy and severe side effects, limiting its use as a first-line treatment. To address this issue, we investigated a novel way to induce lipid peroxidation (LPO), which plays an essential role in ferroptosis and may be useful against cancer cells and tumors. In this study, a pH-responsive synergistic cancer therapy nanoplatform was prepared using CaCO3 co-loaded with oleanolic acid (OA) and lipoxygenase (LOX), resulting in the formation OLCaP NP. This nanoplatform exhibited good drug release properties in an acidic tumor environment owing to the presence of CaCO3. As a result of acidic stimulation at tumor sites, the OLCaP NP released OA and LOX. OA, a chemotherapeutic drug with anticancer activity, is already known to promote the apoptosis of cancer cells, and LOX is a natural enzyme that catalyzes the oxidation of polyunsaturated fatty acids, leading to the accumulation of lipid peroxides and promoting the apoptosis of cancer cells. More importantly, OA upregulated the expression of acyl-coenzyme A synthetase long-chain family member 4 (ACSL4), which promoted enzyme-mediated LPO. Based on our combined chemotherapy and nanocatalytic therapy, the OLCaP NP not only had remarkable antitumor ability but also upregulated ACSL4 expression, allowing further amplification of LPO to inhibit tumor growth. These findings demonstrate the potential of this nanoplatform to enhance the therapeutic efficacy against tumors by inducing oxidative stress and disrupting lipid metabolism, highlighting its clinical potential for improved cancer treatment. STATEMENT OF SIGNIFICANCE: This study presents a novel nanoplatform that combines oleanolic acid (OA), a chemotherapeutic drug, and lipoxygenase (LOX), which oxidizes polyunsaturated fatty acids to trigger apoptosis, for targeted cancer therapy. Unlike traditional treatments, our nanoplatform exhibits pH-responsive drug release, specifically in acidic tumor environments. This innovation enhances the therapeutic effects of OA and LOX, upregulating acyl-CoA synthetase long-chain family member 4 expression and amplifying lipid peroxidation to promote tumor cell apoptosis. Our findings significantly advance the existing literature by demonstrating a synergistic approach that combines chemotherapy and nanocatalytic therapy. The scientific impact of this work lies in its potential to improve cancer treatment efficacy and specificity, offering a promising strategy for clinical applications and future research in cancer therapy.

Comprehensive analyses show the enhancement effect of exogenous melatonin on fluroxypyr-meptyl multiple phase metabolisms in Oryza sativa for reducing environmental risks

The role of melatonin (MT), an essential phytohormone controlling the physiological and biochemical reactions of plants to biotic and abiotic stress, in alleviating pesticide phytotoxicity remains unclear. This study explores the effects of MT (0 and 200 mg/L) and six doses of fluroxypyr-meptyl (FLUME) (0-0.14 mg/L) on the physiological response of rice (Oryza sativa). FLUME exposure inhibited the growth of rice seedlings, with MT treatment ameliorating this effect. To determine the biochemical processes and catalytic events involved in FLUME breakdown in rice, six rice root and shoot libraries exposed to either FLUME or FLUME-MT were generated and then subjected to RNA-Seq-LC-Q-TOF-HRMS/MS analyses. The results showed that 1510 root genes and 139 shoot genes exhibited higher upregulation in plants treated with an ecologically realistic FLUME concentration and MT than in those treated with FLUME alone. Gene enrichment analysis revealed numerous FLUME-degradative enzymes operating in xenobiotic tolerance to environmental stress and molecular metabolism. Regarding the FLUME degradation process, certain differentially expressed genes were responsible for producing important enzymes, such as cytochrome P450, glycosyltransferases, and acetyltransferases. Four metabolites and ten conjugates in the pathways involving hydrolysis, malonylation, reduction, glycosylation, or acetylation were characterized using LC-Q-TOF-HRMS/MS to support FLUME-degradative metabolism. Overall, external application of MT can increase rice tolerance to FLUME-induced oxidative stress by reducing phytotoxicity and FLUME accumulation. This study provides insights into MT's role in facilitating FLUME degradation, with potential implications for engineering genotypes supporting FLUME degradation in paddy crops.

Metastable FeSe2 nanosheets as a one-for-all platform for stepwise synergistic tumor therapy

The urgent need to curb the rampant rise in cancer has impelled the rapid development of nanomedicine. Under the above issue, transition metal compounds have received special attention considering their physicochemical and biochemical properties. However, how to take full advantage of the valuable characteristics of nanomaterials based on their spatial structures and chemical components for synergistic tumor therapy is a worthwhile exploration. In this work, a tailored two-dimensional (2D) FeSe2 nanosheet (NS) platform is proposed, which integrates enzyme activity and drug efficacy through the regulation of itsstability. Specifically, metastable FeSe2 NSs can serve as dual nanozymes in an intact state, depleting GSH and increasing ROS to induce oxidative stress in the tumor microenvironment (TME). With the gradual degradation of the FeSe2 in TME, its degraded products can amplify the Fenton reaction and GSH consumption, enhance the expression of inflammatory factors, and achieve effective near-infrared (NIR)-light irradiation-enhanced synergistic photothermal therapy (PTT) and chemodynamic therapy (CDT). Our exploration further confirmed such a strategy that may integrate carrier activity and drug action into a metastable nanoplatform for tumor synergistic therapy. These results prompt the consideration of the rational design of a one-for-all carrier that can exhibit multifunctional properties and nanomedicine efficacy for versatile therapeutic applications in the future.

Maleimide functionalized polycaprolactone micelles for glutathione quenching and doxorubicin delivery

High glutathione production is known to be one of the defense mechanisms by which many cancer cells survive elevated oxidative stress. By explicitly targeting glutathione in these cancer cells and diminishing its levels, oxidative stress can be intensified, ultimately triggering apoptosis or programmed cell death. Herein, we developed a novel approach by creating maleimide-functionalized polycaprolactone polymers, specifically using 2,3-diiodomaleimide functionality to reduce the level of glutathione in cancer cells. Polycaprolactone was chosen to conjugate the 2,3-diiodomaleimide functionality due to its biodegradable and biocompatible properties. The amphiphilic block copolymer was synthesized using PEG as a macroinitiator to make corresponding polymeric micelles. The resulting 2,3-diiodomaleimide-conjugated polycaprolactone micelles effectively quenched glutathione, even at low concentrations (0.01 mg mL-1). Furthermore, we loaded these micelles with the anticancer drug doxorubicin (DOX), which exhibited pH-dependent drug release. We obtained a loading capacity (LC) of 3.5% for the micelles, one of the highest LC reported among functional PCL-based micelles. Moreover, the enhanced LC doesn't affect their release profile. Cytotoxicity experiments demonstrated that empty and DOX-loaded micelles inhibited cancer cell growth, with the DOX-loaded micelles displaying the highest cytotoxicity. The ability of the polymer to quench intracellular GSH was also confirmed. This approach of attaching maleimide to polycaprolactone polymers shows promise in depleting elevated glutathione levels in cancer cells, potentially improving cancer treatment efficacy.

Diselenide-Containing Polymer Based on New Antitumor Mechanism as Efficient GSH Depletion Agent for Ferroptosis Therapy

Glutathione (GSH) depletion-induced ferroptosis has emerged as a promising treatment for malignant cancer. It works by inactivating glutathione peroxidase 4 (GPX4) and facilitating lipid peroxidation. However, effectively delivering inducers and depleting intracellular GSH remains challenging due to the short half-lives and high hydrophobicity of small-molecule ferroptosis inducers. These inducers often require additional carriers. Herein, diselenide-containing polymers can consume GSH to induce ferroptosis for pancreatic cancer therapy. The diselenide bonds are controllably built into the backbone of the polycarbonate with a targeting peptide CRGD (Cys-Arg-Gly-Asp), which allows for self-assembly into stable nanoparticles (denoted CRNSe) for self-delivery. Significantly, at a concentration of 12 µg mL-1, CRNSe binds to the active site cysteine of GSH resulting in a thorough depletion of GSH. In contrast, the disulfide-containing analog only causes a slight decrease in GSH level. Moreover, the depletion of GSH inactivates GPX4, ultimately inducing ferroptosis due to the accumulation of lipid peroxide in BxPC-3 cells. Both in vitro and in vivo studies have demonstrated that CRNSe exhibits potent tumor suppressive ability with few side effects on normal tissue. This study validates the anti-tumor mechanism of diselenide-containing polymers in addition to apoptosis and also provides a new strategy for inherently inducing ferroptosis in cancer therapy.

XPO1 inhibition displays anti-leukemia efficacy against DNMT3A-mutant acute myeloid leukemia via downregulating glutathione pathway

Acute myeloid leukemia (AML) patients with DNA methyltransferase 3A (DNMT3A) mutation display poor prognosis, and targeted therapy is not available currently. Our previous study identified increased expression of Exportin1 (XPO1) in DNMT3AR882H AML patients. Therefore, we further investigated the therapeutic effect of XPO1 inhibition on DNMT3AR882H AML. Three types of DNMT3AR882H AML cell lines were generated, and XPO1 was significantly upregulated in all DNMT3AR882H cells compared with the wild-type (WT) cells. The XPO1 inhibitor selinexor displayed higher potential in the inhibition of proliferation, promotion of apoptosis, and blockage of the cell cycle in DNMT3AR882H cells than WT cells. Selinexor also significantly inhibited the proliferation of subcutaneous tumors in DNMT3AR882H AML model mice. Primary cells with DNMT3A mutations were more sensitive to selinexor in chemotherapy-naive AML patients. RNA sequencing of selinexor treated AML cells revealed that the majority of metabolic pathways were downregulated after selinexor treatment, with the most significant change in the glutathione metabolic pathway. Glutathione inhibitor L-Buthionine-(S, R)-sulfoximine (BSO) significantly enhanced the apoptosis-inducing effect of selinexor in DNMT3AWT/DNMT3AR882H AML cells. In conclusion, our work reveals that selinexor displays anti-leukemia efficacy against DNMT3AR882H AML via downregulating glutathione pathway. Combination of selinexor and BSO provides novel therapeutic strategy for AML treatment.

Rapid Glutathione Analysis with SERS Microneedles for Deep Glioblastoma Tissue Differentiation

Rapid tissue differentiation at the molecular level is a prerequisite for precise surgical resection, which is of special value for the treatment of malignant tumors, such as glioblastoma (GBM). Herein, a SERS-active microneedle is prepared by modifying glutathione (GSH)-responsive molecules, 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), on the surface of Au@Ag substrates for the distinction of different GBM tissues. Since the Raman signals on the surface of the DTNB@Au@Ag microneedle can be collected by both portable and benchtop Raman spectrometers, the distribution of GSH in different tissues at centimeter scale can be displayed through Raman spectroscopy and Raman imaging, and the entire analysis process can be accomplished within 12 min. Accordingly, in vivo brain tissues of orthotopic GBM xenograft mice and ex vivo tissues of GBM patients are accurately differentiated with the microneedle, and the results are well consistent with tissue staining and postoperative pathological reports. In addition, the outline of tumor, peritumoral, and normal tissues can be indicated by the DTNB@Au@Ag microneedle for at least 56 days. Considering that the tumor tissues are quickly discriminated at the molecular level without the restriction of depth, the DTNB@Au@Ag microneedle is promising to be a powerful intraoperative diagnostic tool for surgery navigation.

Synthesis of a catalytic nanomaterial from polypyrrole and a pro-apoptotic peptide to target mitochondria for multimodal cancer therapy

Development of biocompatible nanomaterials with mitochondria-targeting and multimodal therapeutic activities is important for cancer treatment. Herein, we designed and synthesized a multifunctional pyrrole-based nanomaterial with photothermal effects and mitochondria-targeting properties from polypyrrole and the pro-apoptotic peptide KLA. Different from traditional strategies for the preparation of PPy nanoparticles, we innovatively used the KLA peptide as the template and CuCl2 as the catalyst to trigger the oxidative polymerization of pyrrole for PPy-KLA-Cu nanoparticle formation. Besides, due to the presence of mixed-valence Cu(I)/Cu(II) states, PPy-KLA-Cu nanoparticles also exhibited multienzyme-like activities, such as peroxidase, ascorbate oxidase and glutathione peroxidase activities, which can be exploited to elevate the intracellular ROS level and simultaneously consume GSH in cancer cells. More importantly, the heat generated by PPy-KLA-Cu nanoparticles from NIR irradiation could enhance the nanozymatic activities for ROS elevation and increase the KLA-induced anticancer activity via mitochondrial dysfunction, realizing multimodal treatment of cancer cells with improved therapeutic efficacy.