Functionalized Tumor-Targeting Nanosheets Exhibiting Fe(II) Overloading and GSH Consumption for Ferroptosis Activation in Liver Tumor

Cancer cell membrane-camouflaged curcumin nanoparticles trigger ferroptosis for accurate gastric cancer therapy

Curcumin (CUR) is a hydrophobic polyphenol with considerable antitumor efficiency, but its clinical application is limited because of its poor solubility and low stability in aqueous solution and lack of targeting in vivo. Herein, we fabricated a tumor-targeting drug delivery system by loading CUR and cloaking homologous cancer cell membrane (CM) onto mesoporous silica NPs (MSN-CUR@CM). Characterization analysis showed that MSN-CUR@CM with a size of approximately 70 nm showed high water solubility and biocompatibility. Besides, MSN-CUR@CM exhibited tumor-targeting and excellent anti-gastric cancer efficiency both in vitro and in vivo owing to the cellular self-recognition of CM. In the established xenograft tumor nude mouse model, it was still significantly drug accumulated at the tumor site 72 h post administration. In addition, the mean tumor volume and weight of the MSN-CUR@CM group were was 3.97 and 7.47 times smaller than those of the CUR group. Ferroptosis, a type of non-apoptotic regulated cell death accompanied by iron-dependent lipid peroxidation, was triggered by MSN-CUR@CM. Further analysis demonstrated that MSN-CUR@CUR upregulated heme oxygenase (HO-1) levels whereas it downregulated the expression of glutathione peroxidase 4 (GPX4) in SGC7901 cells in vitro, indicating that the canonical and noncanonical ferroptosis pathways were regulated by MSN-CUR@CM. In conclusion, our study demonstrated that MSN-CUR@CM with high water solubility, biocompatibility, and tumor-targeting properties inhibited gastric cancer both in vitro and in vivo by triggering ferroptosis and provided an admirable cancer therapy efficacy.

Developing an Arene Binuclear Ruthenium(II) Complex to Induce Ferroptosis and Activate the cGAS-STING Pathway: Targeted Inhibiting Growth and Metastasis of Triple Negative Breast Cancer

To effectively inhibit the growth and metastasis of triple-negative breast cancer (TNBC), we developed a high-efficiency and low-toxicity arene ruthenium (Ru) complex based on apoferritin (AFt). To achieve this, we optimized a series of Ru(II) 1,10-phenanthroline-2,9-diformaldehyde thiosemicarbazone complexes by studying their structure-activity relationships to obtain an arene binuclear Ru(II) complex (C5) with significant cytotoxicity and high accumulation in the mitochondria of tumor cells. Subsequently, a C5-AFt nanoparticle (NPs) delivery system was constructed. We found that the C5/C5-AFt NPs effectively inhibited TNBC growth and metastasis with few side effects. The C5-AFt NPs improved the anticancer and targeting abilities of C5 in vivo. Moreover, we confirmed the mechanism by which C5/C5-AFt NPs inhibit tumor growth and metastasis via mitochondrial damage-mediated ferroptosis and activation of the cGAS-STING pathway.

Nanobiotechnology boosts ferroptosis: opportunities and challenges

Ferroptosis, distinct from apoptosis, necrosis, and autophagy, is a unique type of cell death driven by iron-dependent phospholipid peroxidation. Since ferroptosis was defined in 2012, it has received widespread attention from researchers worldwide. From a biochemical perspective, the regulation of ferroptosis is strongly associated with cellular metabolism, primarily including iron metabolism, lipid metabolism, and redox metabolism. The distinctive regulatory mechanism of ferroptosis holds great potential for overcoming drug resistance-a major challenge in treating cancer. The considerable role of nanobiotechnology in disease treatment has been widely reported, but further and more systematic discussion on how nanobiotechnology enhances the therapeutic efficacy on ferroptosis-associated diseases still needs to be improved. Moreover, while the exciting therapeutic potential of ferroptosis in cancer has been relatively well summarized, its applications in other diseases, such as neurodegenerative diseases, cardiovascular and cerebrovascular diseases, and kidney disease, remain underreported. Consequently, it is necessary to fill these gaps to further complete the applications of nanobiotechnology in ferroptosis. In this review, we provide an extensive introduction to the background of ferroptosis and elaborate its regulatory network. Subsequently, we discuss the various advantages of combining nanobiotechnology with ferroptosis to enhance therapeutic efficacy and reduce the side effects of ferroptosis-associated diseases. Finally, we analyze and discuss the feasibility of nanobiotechnology and ferroptosis in improving clinical treatment outcomes based on clinical needs, as well as the current limitations and future directions of nanobiotechnology in the applications of ferroptosis, which will not only provide significant guidance for the clinical applications of ferroptosis and nanobiotechnology but also accelerate their clinical translations.

TiO2-Nanoparticle-Enhanced Sonodynamic Therapy for Prevention of Posterior Capsular Opacification and Ferroptosis Exploration of Its Mechanism

Purpose

To explore the application and potential ferroptosis mechanisms of sonodynamic therapy (SDT) using titanium dioxide nanoparticles (TiO2-NPs) as sonosensitizers for the prevention of posterior capsule opacification (PCO).

Methods

We fabricated TiO2-NP-coated intraocular lenses (TiO2-IOLs) using the spin-coating method, followed by ultrasound activation of the photosensitizer TiO2. In vitro experiments were performed with human lens epithelial cells (HLECs) to explore the appropriate concentration of TiO2 and ultrasonic parameters. Investigations included reactive oxygen species (ROS) generation, glutathione (GSH) depletion, glutathione peroxidase 4 (GPX4) western blot analysis, lipid peroxidation assays, and transcriptomics analysis. Finally, TiO2-IOLs were implanted in rabbit eyes to explore the in vivo performance of SDT.

Results

Through both in vitro and in vivo experiments, the study determined that the ultrasound parameters of 5-minute duration, 1-MHz frequency, 50% duty cycle, and 1.2-W/cm2 intensity were reliable and valid for killing HLECs without damaging other ocular structures. In vitro experiments demonstrated that SDT generated excess ROS, which disrupted the mitochondrial membrane potential and significantly reduced the GSH content. Additionally, the downregulation of GPX4, accumulation of lipid peroxides, and alteration of mitochondrial morphology were observed, suggesting that ferroptosis may be the underlying mechanism. The RNA-sequencing analysis results also showed an increase in the expression of multiple pro-ferroptosis genes and the ferroptosis marker gene PTGS2. Animal experiments preliminarily demonstrated the safety and effectiveness of SDT in treating PCO in vivo.

Conclusions

TiO2-IOLs combined with SDT effectively prevented PCO by generating ROS and intracellular ferroptosis.

Polyhedral magnetic nanoparticles induce apoptosis in gastric cancer stem cells and suppressing tumor growth through magnetic force generation

Gastric cancer is a prevalent malignant tumor worldwide, posing challenges due to its poor prognosis and limited treatment options. Cancer stem cells (CSCs) were demonstrated as a subset of cancer cells responsible for tumor initiation and progression, and their inherent resistance to conventional chemotherapy and radiotherapy critically contributes to tumor recurrence and metastasis. Promoting the eradication of cancer stem cells is crucial for enhancing the efficacy of cancer treatments. This study introduces a novel therapeutic strategy utilizing polyhedral magnetic nanoparticles (PMNPs) functionalized with CD44 antibodies and cell-penetrating peptides (CPPs) to improve uptake by gastric cancer stem cells (MCSCs). PMNPs, synthesized via thermal decomposition, exhibited a diameter of 90 nm ± 9 nm and a saturation magnetization of 79.9 emu/g. Functionalization enhanced their uptake capabilities. Under a rotating magnetic field (RMF) of 15 Hz, PMNPs disrupted cellular structure, leading to apoptosis and ferroptosis in MCSCs. The in vitro studies showed significant reduction in MCSCs viability, while in vivo studies demonstrated tumor growth suppression with minimal side effects and high biocompatibility. This work presents a novel strategy for designing magnetic nanoparticles to mechanically destroy cancer stem cells, offering a more efficient and safety treatment option for gastric cancer.

Oxygen Vacancy-Rich Manganese Nanoflowers as Ferroptosis Inducers for Tumor Radiotherapy

The combination of ferroptosis and innovative tumor therapy methods offers another promising answer to the problem of tumors. In order to generate effective ferroptosis in tumor cells, iron-based nanomaterials are commonly utilized to introduce foreign iron as a trigger for ferroptosis. However, this usually necessitates the injection of larger doses of iron into the body. These exogenous iron increases are likely to create concealed concerns for symptoms such as liver damage and allergy. Herein, an iron-free radiosensitizer is introduced, oxygen-vacancy-rich MnO2 nanoflowers (ovs-MnO2), that promotes ferroptosis and modifies the tumor microenvironment to assist radiotherapy. ovs-MnO2 with enriched oxygen vacancies on the surface induces the release of intracellular free iron (Fe2+), which functions as an activator of Fenton reaction and enhances the accumulation of intracellular reactive oxygen species. On the other hand, Fe2+ also triggers the ferroptosis and promotes the accumulation of lipid peroxides. Subsequently, the depletion of glutathione and accumulation of lipid peroxidation in tumor cells leads to the inactivation of glutathione peroxidase 4 (GPX4) and ferroptosis, thereby enhancing the therapeutic efficacy of radiotherapy. The nanoplatform provides a novel strategy for generating novel nanomedicines for ferroptosis-assisted radiotherapy.

Exosome-Mediated Communication in Thyroid Cancer: Implications for Prognosis and Therapeutic Targets

Thyroid cancer (THCA) is one of the most common malignancies of the endocrine system. Exosomes have significant value in performing molecular treatments, evaluating the diagnosis and determining tumor prognosis. Thus, the identification of exosome-related genes could be valuable for the diagnosis and potential treatment of THCA. In this study, we examined a set of exosome-related differentially expressed genes (DEGs) (BIRC5, POSTN, TGFBR1, DUSP1, BID, and FGFR2) by taking the intersection between the DEGs of the TCGA-THCA and GeneCards datasets. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of the exosome-related DEGs indicated that these genes were involved in certain biological functions and pathways. Protein‒protein interaction (PPI), mRNA‒miRNA, and mRNA-TF interaction networks were constructed using the 6 exosome-related DEGs as hub genes. Furthermore, we analyzed the correlation between the 6 exosome-related DEGs and immune infiltration. The Genomics of Drug Sensitivity in Cancer (GDSC), the Cancer Cell Line Encyclopedia (CCLE), and the CellMiner database were used to elucidate the relationship between the exosome-related DEGs and drug sensitivity. In addition, we verified that both POSTN and BID were upregulated in papillary thyroid cancer (PTC) patients and that their expression was correlated with cancer progression. The POSTN and BID protein expression levels were further examined in THCA cell lines. These findings provide insights into exosome-related clinical trials and drug development.

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

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

Au-Fe3O4 Janus nanoparticles for imaging-guided near infrared-enhanced ferroptosis therapy in triple negative breast cancer

Triple-negative breast cancer (TNBC) is insensitive to conventional therapy due to its highly invasive nature resulting in poor therapeutic outcomes. Recent studies have shown multiple genes associated with ferroptosis in TNBC, suggesting an opportunity for ferroptosis-based treatment of TNBC. However, the efficiency of present ferroptosis agents for cancer is greatly restricted due to lack of specificity and low intracellular levels of H2O2 in cancer cells. Herein, we report a nano-theranostic platform consisting of gold (Au)-iron oxide (Fe3O4) Janus nanoparticles (GION@RGD) that effectively enhances the tumor-specific Fenton reaction through utilization of near-infrared (NIR) lasers, resulting in the generation of substantial quantities of toxic hydroxyl radicals (•OH). Specifically, Au nanoparticles (NPs) converted NIR light energy into thermal energy, inducing generation of abundant intracellular H2O2, thereby enhancing the iron-induced Fenton reaction. The generated •OH not only lead to apoptosis of malignant tumor cells but also induce the accumulation of lipid peroxides, causing ferroptosis of tumor cells. After functionalizing with the activity-targeting ligand RGD (Arg-Gly-Asp), precise synergistic treatment of TNBC was achieved in vivo under the guidance of Fe3O4 enhanced T2-weighted magnetic resonance imaging (MRI). This synergistic treatment strategy of NIR-enhanced ferroptosis holds promise for the treatment of TNBC.

Ferroptosis: A double-edged sword

Ferroptosis represents a form of programmed cell death that is propelled by iron-dependent lipid peroxidation, thereby being distinguished by the prominent features of iron accumulation and lipid peroxidation. Ferroptosis has been implicated in numerous physiological and pathological phenomena, with mounting indications that it holds significant implications for cancer and other medical conditions. On one side, it demonstrates anti-cancer properties by triggering ferroptosis within malignant cells, and on the other hand, it damages normal cells causing other diseases. Therefore, in this paper, we propose to review the paradoxical regulation of ferroptosis in tumors and other diseases. First, we introduce the development history, concept and mechanism of ferroptosis. The second part focuses on the methods of inducing ferroptosis in tumors. The third section emphasizes the utilization of ferroptosis in different medical conditions and strategies to inhibit ferroptosis. The fourth part elucidates the key contradictions in the control of ferroptosis. Finally, potential research avenues in associated domains are suggested.

Ferroptosis targeting natural compounds as a promising approach for developing potent liver cancer agents

Liver cancer is the second leading cause of cancer-related death worldwide. However, treatment options, including surgical resection, transplantation, and molecular drug therapies, are of limited effectiveness. Recent studies have demonstrated that suppressing ferroptosis might be a pivotal signal for liver cancer initiation, thus providing a new way to combat liver cancer. Ferroptosis is a distinct form of controlled cell death that differs from conventional cell death routes like apoptosis, necrosis, and pyroptosis. It results from intracellular iron overload, which raises iron-dependent reactive oxygen species. This, in turn, leads to the accumulation of lipid peroxides that further result in oxidative damage to cell membranes, disrupt normal functioning, and ultimately speed up the ferroptosis phenomenon. Ferroptosis regulation is intricately linked to cellular physiological processes, encompassing iron metabolism, lipid metabolism, and the equilibrium between oxygen-free radical reactions and lipid peroxidation. This review intends to summarize the natural compounds targeting ferroptosis in liver cancer to offer new therapeutic ideas for liver cancer. Furthermore, it serves as the foundation for identifying and applying chemical medicines and natural chemicals that target ferroptosis to treat liver cancer efficiently.

NADPH Oxidase-Like Nanozyme for High-Efficiency Tumor Therapy Through Increasing Glutathione Consumption and Blocking Glutathione Regeneration

To counteract the high level of reactive oxygen species (ROS) caused by rapid growth, tumor cells resist oxidative stress by accelerating the production and regeneration of intracellular glutathione (GSH). Numerous studies focus on the consumption of GSH, but the regeneration of GSH will enhance the reduction level of tumor cells to resist oxidative stress. Therefore, inhibiting the regeneration of GSH; while, consuming GSH is of great significance for breaking the redox balance of tumor cells. Herein, a simple termed MnOx-coated Au (AMO) nanoflower, as a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) nanoenzyme, is reported for efficient tumor therapy. Au nanoparticles exhibit the capability to catalyze the oxidation of NADPH, hindering GSH regeneration; while, concurrently functioning as a photothermal agent. During the process of eliminating intracellular GSH, MnOx releases Mn2+ that subsequently engages in Fenton-like reactions, ultimately facilitating the implementation of chemodynamic therapy (CDT). Overall, this NOX enzyme-based nanoplatform enhances ROS generation and disrupts the state of reduction equilibrium, inducing apoptosis and ferroptosis by blocking GSH regeneration and increasing GSH consumption, thereby achieving collaborative treatments involving photothermal therapy (PTT), CDT, and catalytic therapy. This research contributes to NADPH and GSH targeted tumor therapy and showcases the potential of nanozymes.

Biomimetic Nanoarchitectonics with Chitosan Nanogels for Collaborative Induction of Ferroptosis and Anticancer Immunity for Cancer Therapy

Immunogenic cell death (ICD) shows promising therapeutic potential for tumor regression. However, the low sensitivity and immunosuppressive state of current cell death manners seriously impede tumor immunogenicity. Ferroptosis characterized by excessive lipid peroxidation, has emerged as a potential strategy to induce ICD and activate antitumor immune responses. However, the effectiveness of ferroptosis is limited by antioxidant regulatory networks, including the glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1) pathways, presenting challenges for its induction. Herein, they propose a novel approach that involves utilizing functionalized chitosan-ferrocene-sodium alginate (CFA) crosslinked nanogels, which are modified to pravastatin (PRV) and M1 macrophage membrane (MM) (designing as CFA/PRV@MM). Specifically, ferrocene boots intracellular reactive oxygen species levels for efficient glutathione (GSH) depletion through Fenton reaction, thus disrupting the GPX4/GSH axis, while PRV intervenes in the mevalonate pathway to inhibit the FSP1/CoQ10 antioxidant axis, thereby synergistically causing pronounced ferroptotic damage and promoting ICD. The CFA/PRV@MM nanogels demonstrate superior therapeutic efficacy in a mouse breast model, resulting in effective tumor ablation and immune response with minimal side effects. RNA transcription analysis reveals that nanogels can significantly affect metabolic progress, as well as immune activation. This research provides valuable insights into the design of ferroptosis induction for cancer immunotherapy.

A ferroptosis-reinforced nanocatalyst enhances chemodynamic therapy through dual H2O2 production and oxidative stress amplification

The existence of a delicate redox balance in tumors usually leads to cancer treatment failure. Breaking redox homeostasis by amplifying oxidative stress and reducing glutathione (GSH) can accelerate cancer cell death. Herein, we construct a ferroptosis-reinforced nanocatalyst (denoted as HBGL) to amplify intracellular oxidative stress via dual H2O2 production-assisted chemodynamic therapy (CDT). Specifically, a long-circulating liposome is employed to deliver hemin (a natural iron-containing substrate for Fenton reaction and ferroptosis), β-lapachone (a DNA topoisomerase inhibitor with H2O2 generation capacity for chemotherapy), and glucose oxidase (which can consume glucose for starvation therapy and generate H2O2). HBGL can achieve rapid, continuous, and massive H2O2 and •OH production and GSH depletion in cancer cells, resulting in increased intracellular oxidative stress. Additionally, hemin can reinforce the ferroptosis-inducing ability of HBGL, which is reflected in the downregulation of glutathione peroxidase-4 and the accumulation of lipid peroxide. Notably, HBGL can disrupt endo/lysosomes and impair mitochondrial function in cancer cells. HBGL exhibits effective tumor-killing ability without eliciting obvious side effects, indicating its clinical translation potential for synergistic starvation therapy, chemotherapy, ferroptosis therapy, and CDT. Overall, this nanocatalytic liposome may be a promising candidate for achieving potentiated cancer treatment.

pH-Sensitive Glucose-Powered Nanomotors for Enhanced Intracellular Drug Delivery and Ferroptosis Efficiency

We propose a glucose-powered Janus nanomotor where two faces are functionalized with glucose oxidase (GOx) and polydopamine-Fe3+ chelates (PDF), respectively. In the glucose fuel solution, the GOx on the one side of these Janus nanomotors catalytically decomposes glucose fuels into gluconic acid and hydrogen peroxide (H2 O2 ) to drive them at a speed of 2.67 μm/s. The underlying propulsion mechanism is the glucose-based self-diffusiophoresis owing to the generated local glucose concentration gradient by the enzymatic reaction. Based on the enhanced diffusion motion, such nanomotors with catalytic activity increase the uptake towards cells and subsequently exhibit excellent capabilities for Fe3+ ions delivery and H2 O2 generation for enhancing ferroptosis efficiency for inducing cancer cell death. In particular, the Fe3+ ions are released from nanomotors in a slightly acidic environment, and subsequently generate toxic hydroxyl radicals via Fenton reactions, which accumulation reactive oxygen species (ROS) level (~300 %) and further lipid peroxidation (LPO) strengthened ferroptosis therapy for cancer treatment. The as-developed glucose-powered Janus nanomotor with efficient diffusion and Fe ions delivery capabilities show great promise as a potential in biomedical applications.

Fluorinated Iron Metal-Organic Frameworks for Activatable 19F Magnetic Resonance Imaging and Synergistic Therapy of Tumors

Due to their appealing physiochemical properties, metal-organic frameworks (MOFs) have been widely employed in biomedical fields. In this study, we utilize ferric ions and fluorine-containing organic ligands as both structural and functional units to develop a stimulus-responsive nanoagent, 19FIMOF-TA nanoparticles, for activatable 19F magnetic resonance imaging (MRI) and synergistic therapy of tumors. This nanoagent could respond to excess GSH in a tumor microenvironment, discharging fluorinated organic ligands and reduced ferrous ions. The release of these fluorine-containing small molecules results in boosting of the 19F MRI signals, which could be further enhanced by the photothermal effect of this nanoagent to achieve a responsive cascaded amplification of 19F MRI signals for tumor visualization. Meanwhile, ferroptosis promoted by the ferrous ions leads to significant tumor cell death, which is synergistically aggravated by the photothermal effect. The encouraging results illustrate the promising potential of our nanoagent for effective tumor imaging and combinative cancer therapy.

Functionalized Fe-Doped Carbon Dots Exhibiting Dual Glutathione Consumption to Amplify Ferroptosis for Enhanced Cancer Therapy

Nonapoptotic ferroptosis is a promising cancer treatment which offers a solution to the multidrug resistance of conventional apoptosis-induced programmed cancer cell death therapies. Reducing intracellular glutathione (GSH) is essential for inducing excess ROS and has been considered a crucial process to trigger ferroptosis. However, treatments reducing GSH alone have not produced satisfactory effects due to their restricted target. In this regard, FeCDs (Fe3+-modified l-histidine -sourced carbon dots) with dual GSH-consumption capabilities were constructed to engineer ferroptosis by self-amplifying intratumoral oxidative stress. Carbon dots have the ability to consume GSH, and the introduction of Fe3+ can amplify the GSH-consuming ability of CDs, reacting with excess H2O2 in the tumor microenvironment to generate highly oxidized •OH. This is a novel strategy through synergistic self-amplification therapy combining Fe3+ and CDs with GSH-consuming activity. The acid-triggered degradation material (FeCDs@PAE-PEG) was prepared by encapsulating FeCDs in an oil-in-water manner. Compared with other ferroptosis-triggering nanoparticles, the established FeCDs@PAE-PEG is targeted and significantly enhances the consumption efficiency of GSH and accumulation of excess iron without the involvement of infrared light and ultrasound. This synergistic strategy exhibits excellent ferroptosis-inducing ability and antitumor efficacy both in vitro and in vivo and offers great potential for clinical translation of ferroptosis.

Superoxide Dismutase-Like Regulated Fe/Ppa@PDA/B for Synergistically Targeting Ferroptosis/Apoptosis to Enhance Anti-Tumor Efficacy

The cell apoptosis pathway of sonodynamic therapy (SDT) is usually blocked, resulting in limited therapeutic efficacy, therefore, the development of new methods for sensitizing targeted ferroptosis and promoting apoptosis is of great significance to improve the anti-tumor efficacy of SDT. Herein, mesoporous Fe3 O4 nanoparticles (NPs) are synthesized for loading pyropheophorbide-a (ppa), surface-coated by polydopamine (PDA) and further anchored with tumor-targeting moieties of biotin to obtain Fe/ppa@PDA/B NPs. Fe/ppa@PDA/B displayes pH/ultrasound (US) responsive release properties, and magnetic resonance imaging (MRI) functions. Moreover, Fe3 O4 NPs of Fe/ppa@PDA/B as the Fe source for ferroptosis, enhances ferroptosis sensitivity by consuming glutathione (GSH) and producing hydroxyl radical (OH). The quinone groups of PDA layer on Fe/ppa@PDA/B own free electrons, which led to effective superoxide dismutase (SOD) action through superoxide anion (O2 - ) disproportionation to hydrogen peroxide (H2 O2 ) and oxygen (O2 ), thus, overcame hypoxia of SDT and promoted ·OH generation by Fe ions under US trigger, synergistically improves ferroptosis and apoptosis to enhance the anti-tumor efficacy of SDT both in vitro and in vivo. The anti-tumor strategy of synergistic apoptosis and ferroptosis induce by GSH depletion and self-sufficient O2 regulated by SOD provides a new idea for enhancing SDT efficacy.

Biomineralized RuO2 Nanozyme with Multi-Enzyme Activity for Ultrasound-Triggered Peroxynitrite-Boosted Ferroptosis

Ferroptosis, as a non-apoptotic cell death pathway, has attracted increasing attention for cancer therapy. However, the clinical application of ferroptosis-participated modalities is severely limited by the low efficiency owing to the intrinsic intracellular regulation pathways. Herein, chlorin e6 (Ce6) and N-acetyl-l-cysteine-conjugated bovine serum albumin-ruthenium dioxide is elaborately designed and constructed for ultrasound-triggered peroxynitrite-mediated ferroptosis. Upon ultrasound stimulation, the sonosensitizers of Ce6 and RuO2 exhibit highly efficient singlet oxygen (1 O2 ) generation capacity, which is sequentially amplified by superoxide dismutase and catalase-mimicking activity of RuO2 with hypoxia relief. Meanwhile, the S-nitrosothiol group in BCNR breaks off to release nitric oxide (NO) on-demand, which then reacts with 1 O2 forming highly cytotoxic peroxynitrite (ONOO- ) spontaneously. Importantly, BCNR nanozyme with glutathione peroxidase-mimicking activity can consume glutathione (GSH), along with the generated ONOO- downregulates glutathione reductase, avoiding GSH regeneration. The two-parallel approach ensures complete depletion of GSH within the tumor, resulting in the boosted ferroptosis sensitization of cancer cells. Thus, this work presents a superior paradigm for designing peroxynitrite-boosted ferroptosis sensitization cancer therapeutic.

All-in-One Engineering Multifunctional Nanoplatforms for Sensitizing Tumor Low-Temperature Photothermal Therapy In Vivo

Low-temperature photothermal therapy (PTT) is a noninvasive method that harnesses the photothermal effect at low temperatures to selectively eliminate tumor cells, while safeguarding normal tissues, minimizing thermal damage, and enhancing treatment safety. First we evaluated the transcriptome of tumor cells at the gene level following low-temperature treatment and observed significant enrichment of genes involved in cell cycle and heat response-related signaling pathways. To address this challenge, we have developed an engineering multifunctional nanoplatform that offered an all-in-one strategy for efficient sensitization of low-temperature PTT. Specifically, we utilized MoS2 nanoparticles as the photothermal core to generate low temperature (40-48 °C). The nanoplatform was coated with DPA to load CPT-11 and Fe2+ and was further modified with PEG and iRGD to enhance tumor specificity (MoS2/Fe@CPT-11-PEG-iRGD). Laser- and acid-triggered release of CPT-11 can significantly increase intracellular H2O2 content, cooperate with Fe2+ ions to increase intracellular lipid ROS content, and activate ferroptosis. Furthermore, CPT-11 induced cell cycle arrest in the temperature-sensitive S-phase, and increased lipid ROS levels contributed to the degradation of HSPs protein expression. This synergistic approach could effectively induce tumor cell death by the sensitized low-temperature PTT and the combination of ferroptosis and chemotherapy. Our nanoplatform can also maximize tumor cell eradication and prolong the survival time of tumor-bearing mice in vivo. The multifunctional approach will provide more possibilities for clinical applications of low-temperature PTT and potential avenues for the development of multiple tumor treatments.

Tumor targeted cancer membrane-camouflaged ultra-small Fe nanoparticles for enhanced collaborative apoptosis and ferroptosis in glioma

Glioma is recognized as the most common and aggressive primary brain tumor in adults. Owing to the occurrence of drug resistance and the failure of drug to penetrate the blood-brain barrier (BBB), there is no effective strategy for the treatment of glioma. The main objective of this study was to develop a biomimetic glioma C6 cell membrane (C6M) derived nanovesicles (DOX-FN/C6M-NVs) loaded with doxorubicin (DOX) and ultra-small Fe nanoparticles (FN) for accomplishing the effective brain tumor-targeted delivery of DOX and improving anti-cancer efficacy via inducing collaborative apoptosis and ferroptosis. The findings revealed that employing C6M-NVs as a carrier significantly improved the therapeutic efficacy by enabling evasion of immune surveillance, facilitating targeted drug delivery to tumor sites, and minimizing cardiotoxicity and adverse effects associated with DOX. DOX-FN/C6M-NVs exhibited more potent anti-tumor effects as compared with free DOX by promoting DOX-mediated apoptosis and accelerating ferroptosis via the mediation of FN. This study suggested that DOX-FN/C6M-NVs as the potential inducer of ferroptosis and apoptosis conferred effective tumor suppression in the treatment of glioma.

A Mitochondria-Targeted Ferroptosis Inducer Activated by Glutathione-Responsive Imaging and Depletion for Triple Negative Breast Cancer Theranostics

Ferroptosis is a new type of iron-dependent programmed cell death characterized by glutathione (GSH) depletion, selenoprotein glutathione peroxidase 4 (GPX4) inactivation, and lipid peroxides accumulation. Mitochondria, as the main source of intracellular energy supply and reactive oxygen species (ROS) generation, play a central role in oxidative phosphorylation and redox homeostasis. Therefore, targeting cancer-cell mitochondria and attacking redox homeostasis is expected to induce robust ferroptosis-mediated anticancer effects. In this work, a theranostic ferroptosis inducer (IR780-SPhF), which can simultaneously achieve the imaging and therapy of triple-negative breast cancer (TNBC) by targeting mitochondria is presented. It is developed from a mitochondria-targeting small molecule (IR780) with cancer-preferential accumulation, enabling it to react with GSH by nucleophilic substitution, resulting in mitochondrial GSH depletion and redox imbalance. More interestingly, IR780-SPhF exhibits GSH-responsive near-infrared fluorescence emission and photoacoustic imaging characteristics, further facilitating diagnosis and treatment with real-time monitoring of TNBC with a highly elevated GSH level. Both in vitro and in vivo results demonstrate that IR780-SPhF exhibits potent anticancer effect, which is significantly stronger than cyclophosphamide, a classic drug commonly recommended for TNBC patients in clinic. Hence, the reported mitochondria-targeted ferroptosis inducer may represent a promising candidate and a prospective strategy for efficient cancer treatment.

Multifaceted Roles of Copper Ions in Anticancer Nanomedicine

The significantly increased copper level in tumor tissues and serum indicates the close association of copper ions with tumor development, making copper ions attractive targets in the development of novel tumor treatment methods. The advanced nanotechnology developed in the past decades provides great potential for tumor therapy, among which Cu-based nanotherapeutic systems have received greater attention. Herein, the multifaceted roles of copper ions in cancer progression are summarized and the recent advances in the copper-based nanostructures or nanomedicines for different kinds of tumor therapies including copper depletion therapy, copper-based cytotoxins, copper-ion-based chemodynamic therapy and its combination with other treatments, and copper-ion-induced ferroptosis and cuproptosis activation are discussed. Furthermore, the perspectives for the further development of copper-ion-based nanomedicines for tumor therapy and clinic translation are presented by the authors.

An injectable and active hydrogel induces mutually enhanced mild magnetic hyperthermia and ferroptosis

Magnetic hyperthermia therapy (MHT) is a promising new modality to deal with solid tumors, yet the low magnetic-heat conversion efficacy, magnetic resonance imaging (MRI) artifacts, easy leakage of magnetic nanoparticles, and thermal resistance are the main obstacles to expand its clinical applications. Herein, a synergistic strategy based on a novel injectable magnetic and ferroptotic hydrogel is proposed to overcome these bottlenecks and boost the antitumor efficacy of MHT. The injectable hydrogel (AAGel) exhibiting a sol-gel transition upon heating is made of arachidonic acid (AA)-modified amphiphilic copolymers. Ferrimagnetic Zn_0.4Fe_2.6O₄ nanocubes with high-efficiency hysteresis loss mechanism are synthesized and co-loaded into AAGel with RSL3, a potent ferroptotic inducer. This system maintains the temperature-responsive sol-gel transition, and provides the capacity of multiple MHT and achieves accurate heating after a single injection owing to the firm anchoring and uniform dispersion of nanocubes in the gel matrix. The high magnetic-heat conversion efficacy of nanocubes coupled with the application of echo limiting effect avoids the MRI artifacts during MHT. Besides the function of magnetic heating, Zn_0.4Fe_2.6O₄ nanocubes combined with multiple MHT can sustain supply of redox-active iron to generate reactive oxygen species and lipid peroxides and accelerate the release of RLS3 from AAGel, thus enhancing the antitumor efficacy of ferroptosis. In turn, the reinforced ferroptosis can alleviate the MHT-triggered thermal resistance of tumors by impairment of the protective heat shock protein 70. The synergy strategy achieves the complete elimination of CT-26 tumors in mice without causing local tumor recurrence and other severe side effects.

Bioactive inorganic nanomaterials for cancer theranostics

Bioactive materials are a special class of biomaterials that can react in vivo to induce a biological response or regulate biological functions, thus achieving a better curative effect than traditional inert biomaterials. For cancer theranostics, compared with organic or polymer nanomaterials, inorganic nanomaterials possess unique physical and chemical properties, have stronger mechanical stability on the basis of maintaining certain bioactivity, and are easy to be compounded with various carriers (polymer carriers, biological carriers, etc.), so as to achieve specific antitumor efficacy. After entering the nanoscale, due to the nano-size effect, high specific surface area and special nanostructures, inorganic nanomaterials exhibit unique biological effects, which significantly influence the interaction with biological organisms. Therefore, the research and applications of bioactive inorganic nanomaterials in cancer theranostics have attracted wide attention. In this review, we mainly summarize the recent progress of bioactive inorganic nanomaterials in cancer theranostics, and also introduce the definition, synthesis and modification strategies of bioactive inorganic nanomaterials. Thereafter, the applications of bioactive inorganic nanomaterials in tumor imaging and antitumor therapy, including tumor microenvironment (TME) regulation, catalytic therapy, gas therapy, regulatory cell death and immunotherapy, are discussed. Finally, the biosafety and challenges of bioactive inorganic nanomaterials are also mentioned, and their future development opportunities are prospected. This review highlights the bioapplication of bioactive inorganic nanomaterials.

The advancements in targets for ferroptosis in liver diseases

Ferroptosis is a type of regulated cell death caused by iron overload and lipid peroxidation, and its core is an imbalance of redox reactions. Recent studies showed that ferroptosis played a dual role in liver diseases, that was, as a therapeutic target and a pathogenic factor. Therefore, herein, we summarized the role of ferroptosis in liver diseases, reviewed the part of available targets, such as drugs, small molecules, and nanomaterials, that acted on ferroptosis in liver diseases, and discussed the current challenges and prospects.

In-situ fabrication of novel Au nanoclusters-Cu2+@sodium alginate/hyaluronic acid nanohybrid gels for cuproptosis enhanced photothermal/photodynamic/chemodynamic therapy via tumor microenvironment regulation

Multimodal combined therapy (MCT) is an emerging avenue to eliminate tumor cells by the synergistic effect of various therapeutic methods. However, the complex tumor microenvironment (TME) is becoming the key barrier to the therapeutic effect of MCT due to the excessive existence of H⁺ ions, H₂O₂, and glutathione (GSH), the lack of O₂, and the relaxation of ferroptosis. To overcome these limitations, smart nanohybrid gels with excellent biocompatibility, stability and targeting function were prepared by using gold nanoclusters as cores and an in situ cross-linking composite gel of sodium alginate (SA)/hyaluronic acid (HA) as the shell. The obtained Au NCs-Cu²⁺@SA-HA core-shell nanohybrid gels possessed near-infrared light response synergistically benefitting photothermal imaging guided photothermal therapy (PTT) and photodynamic therapy (PDT). Meanwhile, the H⁺-triggered release of Cu²⁺ ions from the nanohybrid gels not only induces cuproptosis to avoid the relaxation of ferroptosis, but also catalyzes H₂O₂ in the TME to generate O₂ to simultaneously improve the hypoxic microenvironment and PDT effect. Furthermore, the released Cu²⁺ ions could consume the excessive GSH to form Cu⁺ ions effectively, which caused the formation of hydroxyl free radicals (·OH) to kill tumor cells, synergistically realizing GSH consumption-enhanced PDT and chemodynamic therapy (CDT). Hence, the novel design in our work provides another research avenue for cuproptosis-enhanced PTT/PDT/CDT via TME modulation.

Highly Penetrable Drug-Loaded Nanomotors for Photothermal-Enhanced Ferroptosis Treatment of Tumor

A kind of drug-loaded nanomotors with deep penetration was developed to improve the therapeutic effect of ferroptosis on tumor. The nanomotors were constructed by co-loading hemin and ferrocene (Fc) on the surface of bowl-shaped polydopamine (PDA) nanoparticles. The near-infrared response of PDA makes the nanomotor have high tumor penetration capability. In vitro experiments show that the nanomotors can exhibit good biocompatibility, high light to heat conversion efficiency, and deep tumor permeability. It is worth noting that under the catalysis of H2O2 overexpressed in the tumor microenvironment, the Fenton-like reagents hemin and Fc loaded on the nanomotors can increase the concentration of toxic •OH. Furthermore, hemin can consume glutathione in tumor cells and trigger the up-regulation of heme oxygenase-1, which can efficiently decompose hemin to Fe2+, thus producing the Fenton reaction and causing a ferroptosis effect. Notably, thanks to the photothermal effect of PDA, it can enhance the generation of reactive oxygen species and thus intervene in the Fenton reaction process, thereby enhancing the ferroptosis effect photothermally. In vivo antitumor results show that the drug-loaded nanomotors with high penetrability showed an effective antitumor therapeutic effect.

Clustered Cobalt Nanodots Initiate Ferroptosis by Upregulating Heme Oxygenase 1 for Radiotherapy Sensitization

High cobalt (Co) levels in tumors are associated with good clinical prognosis. An anticancer regimen that increases intratumoral Co through targeted nanomaterial delivery is proposed in this study. Bovine serum albumin and cobalt dichloride are applied to prepare cobaltous oxide nanodots using a facile biomineralization strategy. After iRGD peptide conjugation, the nanodots are loaded into dendritic mesoporous silica nanoparticles, generating a biocompatible product iCoDMSN. This nanocomposite accumulates in tumors after intravenous injection by deep tissue penetration and can be used for photoacoustic imaging. Proteomics research and molecular biology experiments reveal that iCoDMSN is a potent ferroptosis inducer in cancer cells. Mechanistically, iCoDMSNs upregulate heme oxygenase 1 (HMOX1), which increases transferrin receptors and reduces solute carrier family 40 member 1 (SLC40A1), resulting in Fe²⁺ accumulation and ferroptosis initiation. Furthermore, upregulated nuclear factor erythroid 2-related factor 2 (NRF2), arising from the reduction in Kelch-like ECH-associated protein 1 (KEAP1) expression, is responsible for HMOX1 enhancement after iCoDMSN treatment. Owing to intensified ferroptosis, iCoDMSN acts as an efficient radiotherapy enhancer to eliminate cancer cells in vitro and in vivo. This study demonstrates a versatile Co-based nanomaterial that primes ferroptosis by expanding the labile iron pool in cancer cells, providing a promising tumor radiotherapy sensitizer.

Specific activation of cGAS-STING pathway by nanotherapeutics-mediated ferroptosis evoked endogenous signaling for boosting systemic tumor immunotherapy

Activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway could effectively initiate antitumor immunity, but specific activation of STING pathway is still an enormous challenge. Herein, a ferroptosis-induced mitochondrial DNA (mtDNA)-guided tumor immunotherapy nanoplatform (designated as HBMn-FA) was elaborately developed for activating and boosting STING-based immunotherapy. On the one hand, the high-levels of reactive oxygen species (ROS) in tumor cells induced by HBMn-FA-mediated ferroptosis elicited mitochondrial stress to cause the release of endogenous signaling mtDNA, which specifically initiate cGAS-STING pathway with the cooperation of Mn²⁺. On the other hand, the tumor-derived cytosolic double-stranded DNA (dsDNA) from debris of death cells caused by HBMn-FA further activated the cGAS-STING pathway in antigen-presenting cells (e.g., DCs). This bridging of ferroptosis and cGAS-STING pathway could expeditiously prime systemic antitumor immunity and enhance the therapeutic efficacy of checkpoint blockade to suppress tumor growth in both localized and metastatic tumor models. The designed nanotherapeutic platform paves the way for novel tumor immunotherapy strategies that are based on specific activation of STING pathway.

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.

Fluorescence Imaging-Incorporated Transcriptome Study of Glutathione Depletion-Enhanced Ferroptosis Therapy via Targeting Gold Nanoclusters

Ferroptosis plays an important role in tumor inhibition and is a new type of programmed cell death. Recent studies have shown that glutathione (GSH) depletion is an effective method to enhance the therapeutic efficacy of ferroptosis; however, a systematic investigation of the phenomenon is limited. Herein, we provide a facile fluorescence imaging-incorporated transcriptome strategy to visualize the process and explore the mechanism of GSH depletion-enhanced ferroptosis. The proposed multifunctional nanoplatform is achieved using simple transferrin receptor aptamer-functionalized fluorescent gold nanoclusters (termed TfRA-AuNCs), which exhibit efficient hydroxyl radical generation and GSH-depleting capabilities. Live cell fluorescence imaging results revealed that TfRA-AuNCs were endocytosed into 4T1 cells and were mostly distributed in lysosomes. In vitro results indicated that TfRA-AuNCs enhanced the ferroptosis effect in 4T1 cells. Importantly, transcriptome analysis indicated that 4T1 cells treated with TfRA-AuNCs regulated the expression change of ferroptosis-related genes, and the Kyoto Encyclopedia of Genes and Genomes pathway identified the GSH metabolism pathway involved in ferroptosis, thus revealing the exact molecular mechanism of ferroptosis induced by TfRA-AuNCs at the RNA level. Furthermore, in vivo results confirmed the tumor inhibition effect, tumor-targeted fluorescence imaging, and long-term biocompatibility after TfRA-AuNC treatment. This study introduces a new possibility for the mechanistic study of nanoagent-induced ferroptosis in tumor treatment.

Acidity-Biodegradable Iridium-Coordinated Nanosheets for Amplified Ferroptotic Cell Death Through Multiple Regulatory Pathways

Ferroptosis-based treatment strategies display the potential to suppress some malignant tumors with intrinsic apoptosis resistance. However, current related cancer treatments are still hampered by insufficient intracellular reactive oxygen species (ROS) levels and Fe²⁺ contents, posing considerable challenges for their clinical translation. Herein, an intracellular acid-biodegradable iridium-coordinated nanosheets (Ir-Hemin) with sonodynamic therapy (SDT) properties to effectively induce ferroptosis in tumor cells through multiple regulatory pathways are proposed. Under ultrasound (US) irradiation, Ir-Hemin nanosheets act as nanosonosensitizers to effectively generate ROS, subsequently causing the accumulation of lipid peroxides (LPO) and inducing ferroptotic cell death. Furthermore, these Ir-Hemin nanosheets decompose quickly to release hemin and Ir(IV), which deplete intracellular glutathione (GSH) to deactivate the enzyme glutathione peroxidase 4 (GPX4) and initiate the ferroptosis pathway. Specifically, the released hemin enables heme oxygenase 1 (HO-1) upregulation for endogenous ferrous ion supplementation, which compensates for the toxicity concerns brought about by the large uptake of exogenous iron. Surprisingly, Ir-Hemin nanosheets exhibit high tumor accumulation and trigger effective ferroptosis for tumor therapy. These Ir-Hemin nanosheets display pronounced synergistic anticancer efficacy under US stimulation both in vitro and in vivo, providing a strong rationale for the application of ferroptosis in cancer treatment.

Amphiphilic Dendrimer Doping Enhanced pH-Sensitivity of Liposomal Vesicle for Effective Co-delivery toward Synergistic Ferroptosis-Apoptosis Therapy of Hepatocellular Carcinoma

Ferroptosis, characterized by the accumulation of reactive oxygen species and lipid peroxides, has emerged as an attractive strategy to reverse drug resistance. Of particular interest is the ferroptosis-apoptosis combination therapy for cancer treatment. Herein, a nanoplatform is reported for effective co-delivery of the anticancer drug sorafenib (S) and the ferroptosis inducer hemin (H), toward synergistic ferroptosis-apoptosis therapy of advanced hepatocellular carcinoma (HCC) as a proof-of-concept study. Liposome is an excellent delivery system; however, it is not sufficiently responsive to the acidic tumor microenvironment (TME) for tumor-targeted drug delivery. The pH-sensitive vesicles are therefore developed (SH-AD-L) by incorporating amphiphilic dendrimers (AD) into liposomes for controlled and pH-stimulated release of sorafenib and hemin in the acidic TME, thanks to the protonation of numerous amine functionalities in AD. Importantly, SH-AD-L not only blocked glutathione synthesis to disrupt the antioxidant system, but also increased intracellular Fe²⁺ and ·OH concentrations to amplify oxidative stress, both of which contribute to enhanced ferroptosis. Remarkably, high levels of ·OH also augmented sorafenib-mediated apoptosis in tumor cells. This study demonstrates the efficacy of ferroptosis-apoptosis combination therapy, as well as the promise of the AD-doped TME-responsive vesicles for drug delivery in combination therapy to treat advanced HCC.

Copper-Based Metal-Organic Framework Induces NO Generation for Synergistic Tumor Therapy and Antimetastasis Activity

The interaction between platelets and circulating tumor cells (CTCs) contributes to distal tumor metastasis by protecting CTCs from immunological assault and shear stress, which can be disrupted by nitric oxide (NO) through inhibiting platelet-mediated adhesion. To eradicate primitive tumors and inhibit CTC-based pulmonary metastasis, a novel biomimetic nanomedicine (mCuMNO) is designed by encapsulating Cu⁺ -responsive S-nitrosoglutathione as a NO donor into a copper-based metal-organic framework (CuM). This work discovers that mCuMNO can target tumor regions and deplete local glutathione (GSH) to reduce Cu²⁺ to Cu⁺ , followed by triggering NO release and hydroxyl radicals (·OH) production, thereby interrupting platelet/CTC interplay and contributing to chemodynamic therapy. Detailed studies demonstrate that mCuMNO exhibits high efficiency and safety in tumor therapy and antimetastasis activity, sheding new light on the development of CuM-based tumor synthetic therapy.

GSK-J1-loaded, hyaluronic acid-decorated metal-organic frameworks for the treatment of ovarian cancer

Despite intensive research, ovarian cancer has the highest mortality rates among gynecological malignancies, partly because of its rapid acquisition of chemoresistance to platinum therapy. Hence, strategies are needed to effectively treat carboplatin-resistant ovarian cancer. In this study, we designed and prepared hyaluronic acid-decorated metal-organic frameworks for the targeted delivery of GSK-J1, a JMJD3 demethylase inhibitor (HA@MOF@GSK-J1) for the synergistic treatment of carboplatin-resistant ovarian cancer. HA@MOF@GSK-J1 showed outstanding effectiveness in the inhibition of ovarian cancer in vitro. Furthermore, HA@MOF@GSK-J1 demonstrated higher induction of apoptosis, reduced cell motility, and diminished cell spheroids by attenuating HER2 activity through the effectual activation of H3K27 methylation in its promoter area. Finally, our in vivo results confirmed that HA@MOF@GSK-J1 had better treatment efficacy for carboplatin-resistant ovarian tumor xenografts. Our results highlight the potential of HA@MOF@GSK-J1 as an effective strategy to improve the treatment of carboplatin-resistant ovarian cancer.

Oxygen-boosted biomimetic nanoplatform for synergetic phototherapy/ferroptosis activation and reversal of immune-suppressed tumor microenvironment

Photodynamic therapy (PDT) induces apoptosis of cancer cells by generating cytotoxic reactive oxygen species, the therapeutic effect of which, however, is impeded by intrinsic/inducible apoptosis-resistant mechanisms in cancer cells and hypoxia of tumor microenvironment (TME); also, PDT-induced anti-tumor immunity activation is insufficient. To deal with these obstacles, a novel biomimetic nanoplatform is fabricated for the precise delivery of photosensitizer chlorin e6 (Ce6), hemin and PEP20 (CD47 inhibitory peptide), integrating oxygen-boosted PDT, ferroptosis activation and CD47-SIRPα blockade. Hemin's catalase-mimetic activity alleviates TME hypoxia and enhances PDT. The nanoplatform activates ferroptosis via both classical (down-regulating glutathione peroxidase 4 pathway) and non-classical (inducing Fe²⁺ overload) modes. Besides the role of hemin in consuming glutathione and up-regulating heme oxygenase-1 expression, interestingly, we observe that Ce6 enhance ferroptosis activation via both classical and non-classical modes. The anti-cancer immunity is reinforced by combining PEP20-mediated CD47-SIRPα blockade and PDT-mediated T cell activation, efficiently suppressing primary tumor growth and metastasis. PEP20 has been revealed for the first time to sensitize ferroptosis by down-regulating system Xc^-. This work sheds new light on the mechanisms of PDT-ferroptosis activation interplay and bridges immunotherapy and ferroptosis activation, laying the theoretical foundation for novel combinational modes of cancer treatment.

Glutamine Transporter SLC1A5 Regulates Ionizing Radiation-Derived Oxidative Damage and Ferroptosis

Ionizing radiation-derived oxidative stress and ferroptosis are one of the most important biological effects on destroying the liver tumor, whereas radioresistance of liver tumor remains a leading cause of radiotherapy (RT) failure mainly because of the protective antiferroptosis, in which oxidative stress and subsequent lipid peroxidation are the key initiators. Thus, it is of great importance to overcome ferroptosis resistance to improve the therapeutic efficacy of RT in liver tumor patients. Irradiation-resistant HepG2 cells (HepG2-IRR) were established by long-term exposure to X-ray (2 to 8 Gy), and targeted metabolomics analysis revealed an obvious increase in intracellular amino acids in HepG2-IRR cells upon ferroptosis stress. Among these amino acids with obvious changes, N-acetylglutamine, a derivative of glutamine, is essential for the redox homeostasis and progression of tumor cells. Interestingly, the treatment of glutamine starvation could promote the ferroptosis effect significantly, whereas glutamine supplementation reversed the ferroptosis effect completely. Consistent with the changes in amino acids pattern, the glutamine transporter SLC1A5 was verified in liver tumor samples from TCGA training and validation cohorts as an independent prognostic amino acid-ferroptosis gene (AFG). A risk score for screening prognosis based on the SLC1A5, SLC7A11, ASNS, and TXNRD1 demonstrated that a high-risk score was correlated with poor survival. In vitro studies had shown that the knockdown of SLC1A5 resulted in a significant decrease in cell viability and promoted lipid peroxidation and oxidative damage introduced by irradiation (10 Gy). Collectively, our findings indicated that SLC1A5 may act as a suppressor gene against ferroptosis and can be a potential target for ionizing radiation mediated effects.

Identification of immune-related ferroptosis prognostic marker and in-depth bioinformatics exploration of multi-omics mechanisms in thyroid cancer

Background: Factors such as variations in thyroid carcinoma (THCA) gene characteristics could influence the clinical outcome. Ferroptosis and immunity have been verified to play an essential role in various cancers, and could affect the cancer patients’ prognosis. However, their relationship to the progression and prognosis of many types of THCA remains unclear.

Methods: First, we extracted prognosis-related immune-related genes and ferroptosis-related genes from 2 databases for co-expression analysis to obtain prognosis-related differentially expressed immune-related ferroptosis genes (PR-DE-IRFeGs), and screened BID and CDKN2A for building a prognostic model. Subsequently, multiple validation methods were used to test the model’s performance and compare its performance with other 4 external models. Then, we explored the mechanism of immunity and ferroptosis in the occurrence, development and prognosis of THCA from the perspectives of anti-tumor immunity, CDKN2A-related competitive endogenous RNA regulatory, copy number variations and high frequency gene mutation. Finally, we evaluated this model’s clinical practice value.

Results: BID and CDKN2A were identified as prognostic risk and protective factors, respectively. External data and qRT-PCR experiment also validated their differential expression. The model’s excellent performance has been repeatedly verified and outperformed other models. Risk scores were significantly associated with most immune cells/functions. Risk score/2 PR-DE-IRFeGs expression was strongly associated with BRAF/NRAS/HRAS mutation. Single copy number deletion of CDKN2A is associated with upregulation of CDKN2A expression and worse prognosis. The predicted regulatory network consisting of CYTOR, hsa-miRNA-873-5p and CDKN2A was shown to significantly affect prognosis. The model and corresponding nomogram have been shown to have excellent clinical practice value.

Conclusion: The model can effectively predict the THCA patients’ prognosis and guide clinical treatment. Ferroptosis and immunity may be involved in the THCA’s progression through antitumor immunity and BRAF/NRAS/HRAS mutation. CYTOR-hsa-miRNA-873-5p-CDKN2A regulatory networks and single copy number deletion of CDKN2A may also affect THCA′ progression and prognosis.

Facile synthesis of a glutathione-depleting Cu(II)-half-salamo-based coordination polymer for enhanced chemodynamic therapy

Chemodynamic therapy (CDT), utilizing Fenton catalysts to convert intracellular H₂O₂ into toxic hydroxyl radicals (˙OH) to kill cancer cells, has a wide application prospect in tumor treatment because of its high selectivity. Its anticancer effect, however, is unsatisfactory due to the overexpressed glutathione (GSH). Herein, a GSH-depleting Cu(II)-half-salamo-based coordination polymer (CuCP) was prepared and validated by single crystal X-ray crystallography, Hirshfeld surface analyses and DFT calculations. The Cu(II) ions in the coordination polymer are five-coordinated bearing slightly twisted square pyramidal coordination environments and are bridged by phenoxy and alkoxy groups. After internalization by tumor cells, the CuCP could be biodegraded and reduced by GSH to generate a large amount of Cu(I), simultaneously depleting GSH. Subsequently, the Cu(I) ions interact with H₂O₂ to generate toxic ˙OH through a Fenton-like reaction to enhance their anticancer efficacy. Our study provides useful insights into designing smarter metal-based anticancer agents to improve the CDT efficiency in cancer therapy.

Albumin-assembled copper-bismuth bimetallic sulfide bioactive nanosphere as an amplifier of oxidative stress for enhanced radio-chemodynamic combination therapy

The tumor microenvironment with overexpressed hydrogen peroxide (H2O2) and reinforced antioxidative system (glutathione, GSH) becomes a double-edged sword for the accessibility of nano-therapy. Since reactive oxygen species (ROS) are easily quenched by the developed antioxidative network, ROS-based treatments such as chemodynamic therapy (CDT) and radiotherapy (RT) for killing cancer cells are severely attenuated. To overcome such limitations, a bioactive nanosphere system is developed to regulate intracellular oxidative stress for enhanced radio-chemodynamic combination therapy by using bovine serum albumin (BSA) based bioactive nanospheres that are BSA assembled with in situ generated copper-bismuth sulfide nanodots and diallyl trisulfide (DATS). The copper-bismuth sulfide nanodots react with H2O2 to produce •OH and release Cu2+. Then, the Cu2+ further depletes GSH to generate Cu+ for more •OH generation in the way of Fenton-like reaction. Such a cascade reaction can initiate •OH generation and GSH consumption to realize CDT. The elevation of ROS triggered by the DATS from BBCD nanospheres further augments the breaking of redox balance for the increased oxidative stress in 4T1 cells. With the sensitization of increased oxidative stress and high Z element Bi, an enhanced radio-chemodynamic combination therapy is achieved. The current work provides an enhanced radio-chemodynamic combination treatment for the majority of solid tumors by using the co-assembled bioactive nanospheres as an amplifier of oxidative stress.

Copper-based metal-organic frameworks for biomedical applications

Metal-organic frameworks (MOFs) are a class of important porous, crystalline materials composed of metal ions (clusters) and organic ligands. Owing to the unique redox chemistry, photochemical and electrical property, and catalytic activity of Cu^2+/+, copper-based MOFs (Cu-MOFs) have been recently and extensively explored in various biomedical fields. In this review, we first make a brief introduction to the synthesis of Cu-MOFs and their composites, and highlight the recent synthetic strategies of two most studied representatives, three-dimensional HKUST-1 and two-dimensional Cu-TCPP. The recent advances of Cu-MOFs in the applications of cancer treatment, bacterial inhibition, biosensing, biocatalysis, and wound healing are summarized and discussed. Furthermore, we propose a prospect of the future development of Cu-MOFs in biomedical fields and beyond.

Cu-Hemin Nanosheets and Indocyanine Green Co-Loaded Hydrogel for Photothermal Therapy and Amplified Photodynamic Therapy

Near-infrared (NIR) organic small molecule indocyanine green (ICG) could respond well to 808 nm laser to promote local high temperature and ROS generation for realizing photothermal therapy (PTT)/photodynamic therapy (PDT). However, the high content of GSH in the tumor microenvironment (TME) limited the further therapeutic performance of ICG. Herein, injectable agarose in situ forming NIR-responsive hydrogels (CIH) incorporating Cu-Hemin and ICG were prepared for the first time. When CIH system was located to the tumor tissue through local injection, the ICG in the hydrogel could efficiently convert the light energy emitted by the 808 nm laser into thermal energy, resulting in the heating and softening of the hydrogel matrix, which releases the Cu-Hemin. Then, the over-expressed GSH in the TME could also down-regulated by Cu-Hemin, which amplified ICG-mediated PDT. In vivo experiments validated that ICG-based PDT/PTT and Cu-Hemin-mediated glutathione depletion could eliminate cancer tissues with admirable safety. This hydrogel-based GSH-depletion strategy is instructive to improve the objective response rate of PDT.

Free-Radical Cascade Generated by AIPH/Fe3O4-Coloaded Nanoparticles Enhances MRI-Guided Chemo/Thermodynamic Hypoxic Tumor Therapy

Free radicals, including reactive oxygen species (ROS), play a critical role in determining cell's fate. When the level of free radicals is increased to a fatal value, it causes cancer cells to undergo senescence or cell death. Strategies that target this mechanism offer promising therapies against cancer. However, efficient and sustainable systems that generate free radicals, especially oxygen-independent systems, remain deficient. Herein, functionalized PLGA-based nanocomposites that efficiently co-deliver magnetic nanoparticles and 2,2'-azobis[2-(2-imidazolin-2-yl) propane]-dihydrochloride (AIPH) were fabricated to achieve photothermal-induced thermodynamic therapy combined with macrophage polarization strategies; this therapy targets hypoxic tumors through the generation of an oxygen-independent free-radical cascade. These hybrid NPs can accumulate in the tumor microenvironment, and the encapsulated MNPs not only serve as contrast agents for enhanced magnetic resonance imaging but also exhibit the expected photothermal conversion and trigger the decomposition of AIPH to generate free radicals, thus causing cancer cell death. More importantly, the cell debris from apoptotic or necrotic cancer cells carries nondegraded MNPs, which can be endocytosed by recruited TAMs. MNPs can further induce TAMs to polarize to the M1 subtype to subsequently generate ROS. This study provides an alternative method for the generation of an oxygen-independent free-radical cascade for tumor co-therapy guided by magnetic resonance imaging PTT/TDT.

Ferroptosis-Driven Nanotherapeutics to Reverse Drug Resistance in Tumor Microenvironment

Ferroptosis, characterized by iron-dependent lipid reactive oxygen species (ROS) accumulation, is non-apoptotic programmed cell death highly relevant to tumor development. It was found to manipulate oncogenes and resistant mutations of cancer cells via lipid metabolism pathways converging on phospholipid glutathione peroxidase (GPX4) that squanders lipid peroxides (L-OOH) to block the iron-mediated reactions of peroxides, thus rendering resistant cancer cells vulnerable to ferroptotic cell death. By accumulating ROS and lipid peroxidation (LPO) products to lethal levels in tumor microenvironment (TME), ferroptosis-driven nanotherapeutics show a superior ability of eradicating aggressive malignancies than traditional therapeutic modalities, especially for the drug-resistant tumors with high metastasis tendency. Moreover, Fenton reaction, inhibition of GPX-4, and exogenous regulation of LPO are three major therapeutic strategies to induce ferroptosis in cancer cells, which were generally applied in ferroptosis-driven nanotherapeutics. In this review, we elaborate current trends of ferroptosis-driven nanotherapeutics to reverse drug resistance of tumors in anticancer fields at the intersection of cancer biology, materials science, and chemistry. Finally, their challenges and perspectives toward feasible translational studies are spotlighted, which would ignite the hope of anti-resistant cancer treatment.

Multifunctional "ball-rod" Janus nanoparticles boosting Fenton reaction for ferroptosis therapy of non-small cell lung cancer

Ferroptosis is a newly found cell death mechanism, which could bypass apoptosis and reverse multidrug resistance of tumors. However, efficient induction of tumor ferroptosis remains a challenge. In this study, multifunctional "ball-rod" Janus nanoparticles (FTG/L&SMD) were constructed for non-small cell lung cancer (NSCLC) ferroptosis treatment. Protected by tannic acid (TA), FTG/L&SMD maintains long-term function in blood circulation, while modification by 2, 3-dimethylmaleic anhydride (DMMA) confers the FTG/L&SMD with pH-responsive charge reversal. Glucose oxidase (GOD) on FTG/L&SMD catalyzes glucose to produce H₂O₂. Then, iron ion converts H₂O₂ to highly active hydroxyl radicals (OH•) via Fenton reaction, leading to lethal lipid peroxidation (LPO) accumulation. Meanwhile, TA reduces Fe³⁺ to Fe²⁺ to boost Fenton reaction cycle. Sor down-regulated glutathione peroxidase 4 (GPX4) expression in another pathway to induce ferroptosis synergistically. In vitro studies have shown that compared with sorafenib (Sor), FTG/L&SMD not only has more efficient tumor targeting and higher cytotoxicity, but also inhibits tumor migration. In vivo antitumor therapy experiments demonstrate that FTG/L&SMD inhibits tumor growth efficiently, and its toxicity is negligible. In general, FTG/L&SMD can initiate Fenton reaction cycle and reinforced ferroptosis to kill tumor cells, which is a promising anti-tumor nano-drug for NSCLC.

Multi-activity cobalt ferrite/MXene nanoenzymes for drug-free phototherapy in bacterial infection treatment

Drug-free antibacterial strategies are of great significance for pathogenic bacterial infection treatment in clinical practice. Phototherapy with antibacterial function plays a vital role in mainstream germicidal research. However, phototherapy could lead to residual heat and excess reactive oxygen species (ROS), which are the main side-effects during antibacterial treatment. Unique CoFe2O4/MXene (CM) nanoenzymes, which were fabricated with electrostatic interactions, have been designed to conquer those challenges caused by side-effects of phototherapy in our research. The CM nanoenzymes possess many promising properties including photothermal and photodynamic induced phototherapy and mimic peroxidase (POD), glutathione oxidase (GSHOx), and catalase (CAT). Upon treatment with near-infrared (NIR) light, CM nanoenzymes can create a local high-temperature circumstance as well as raise bacterial membrane permeability. Furthermore, the photodynamic process and multi-enzyme-mimicking activities of CM enzymes boost the interbacterial ROS level. Herein, bacteria can hardly survive in synergistic phototherapy and multi-enzyme-mimicking catalytic therapy in vitro and in vivo. Meanwhile, the CM nanoenzymes exhibit excellent biocompatibility in vitro and in vivo. Overall, this research establishes a strong foundation for effectively employing nanoenzymes, leading to a new way to cure bacterial infections.

Biomimetic GBM-targeted drug delivery system boosting ferroptosis for immunotherapy of orthotopic drug-resistant GBM

Background

Clinical studies have shown that the efficacy of programmed cell death receptor-1/programmed cell death ligand-1 (PD-1/PD-L1) inhibitors on glioblastoma (GBM) is much lower than what is expected because of the low immunogenicity of GBM. Ferroptosis of cancer cells can induce the maturation of dendritic cells (DC cells) and increase the activity of T cell. The activated T cells release IFN-γ, which subsequently induces the ferroptosis of cancer cells. Thus, the aim of this paper is to set up a new GBM-targeted drug delivery system (Fe₃O₄-siPD-L1@M_-BV2) to boost ferroptosis for immunotherapy of drug-resistant GBM.

Results

Fe₃O₄-siPD-L1@M_-BV2 significantly increased the accumulation of siPD-L1 and Fe²⁺ in orthotopic drug-resistant GBM tissue in mice. Fe₃O₄-siPD-L1@M_-BV2 markedly decreased the protein expression of PD-L1 and increased the ratio between effector T cells and regulatory T cells in orthotopic drug-resistant GBM tissue. Moreover, Fe₃O₄-siPD-L1@M_-BV2 induced ferroptosis of GBM cells and maturation of DC cell, and it also increased the ratio between M1-type microglia and M2-type microglia in orthotopic drug-resistant GBM tissue. Finally, the growth of orthotopic drug-resistant GBM in mice was significantly inhibited by Fe₃O₄-siPD-L1@M_-BV2.

Conclusion

The mutual cascade amplification effect between ferroptosis and immune reactivation induced by Fe₃O₄-siPD-L1@M_-BV2 significantly inhibited the growth of orthotopic drug-resistant GBM and prolonged the survival time of orthotopic drug-resistant GBM mice.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01360-6.

Fe(III)-Shikonin Supramolecular Nanomedicine for Combined Therapy of Tumor via Ferroptosis and Necroptosis

Most of the antitumor chemotherapeutic drugs execute the therapeutic performance upon eliciting tumor cell apoptosis, which may cause chemoresistance of tumors. Design of novel drugs to eradicate apoptosis-resistant tumors via non-apoptotic cell death pathways is promising for improving the long-term chemotherapeutic efficacy. Herein, a Fe(III)-Shikonin metal-polyphenol-coordinated supramolecular nanomedicine for combined therapy of tumor via ferroptosis and necroptosis is designed. The construction of the nanomedicine based on the coordinated self-assembly between Fe³⁺ and Shikonin not only overcomes the shortcomings of Shikonin including its low bioavailability and high toxicity toward normal tissues, but also integrates the theranostics functions of Fe ions. Under the exposure of the high concentration of glutathione (GSH) in tumor cells, the as-prepared nanomedicine will disassemble into Fe²⁺ and Shikonin, followed by stimulating the tumor cell death through ferroptosis and necroptosis. In addition, benefiting from the stealth effect of polyethylene glycol (PEG) and the targeting ability of cyclo(Arg-Gly-Asp-d-Phe-Lys) (cRGD) to α_v β₃ -integrin, NH₂ -PEG-cRGD-modified nanomedicine exhibits a GSH-responsive therapy toward 4T1 tumor in vivo and self-enhanced longitudinal relaxation (T₁ )-weighted imaging property. Since the self-assembly of natural Shikonin and human body-necessary Fe element is facile and feasible, the work may provide a promising supramolecular nanomedicine for next-generation chemotherapeutic applications.