Pulmonary Delivery of Theranostic Nanoclusters for Lung Cancer Ferroptosis with Enhanced Chemodynamic/Radiation Synergistic Therapy

Zinc Doping Engineering in ZnxFe3-xO4 Heterostructures for Enhancing Photodynamic Therapy in the Near-Infrared-II Region

Currently, photodynamic therapy (PDT) is restricted by the laser penetration depth. Except for PDT at 1064 nm wavelength excitation, the development of other NIR-II-activated nanomaterials with a higher response depth is still hindered and rarely reported in the literature. To overcome these problems, we fabricated a nanoplatform with heterostructures that generate reactive oxygen species (ROS) and ferrite nanoparticles under a high concentration of zinc doping (ZnxFe3-xO4 NPs), which can achieve oxidative damage of tumor cells under near-infrared (NIR) illumination. The recombination of photoelectrons and holes has been markedly inhibited due to the formation of heterostructures in the interfaces, thus greatly enhancing the capability for ROS and oxygen production by modulating the single-component doping content. The efficiency of PDT was verified by in vivo and in vitro assays under NIR light. Our results revealed that NIR-II (1208 nm) light irradiation of ZnxFe3-xO4 NPs exerted a remarkable antitumor activity, superior to NIR-I light (808 nm). More importantly, the reported ZnxFe3-xO4 NPs strategy provides an opportunity for the success of comparison with light in the first and second near-infrared regions.

Application of nano-radiosensitizers in non-small cell lung cancer

Radiotherapy stands as a cornerstone in the treatment of numerous malignant tumors, including non-small cell lung cancer. However, the critical challenge of amplifying the tumoricidal effectiveness of radiotherapy while minimizing collateral damage to healthy tissues remains an area of significant research interest. Radiosensitizers, by methods such as amplifying DNA damage and fostering the creation of free radicals, play a pivotal role in enhancing the destructive impact of radiotherapy on tumors. Over recent decades, nano-dimensional radiosensitizers have emerged as a notable advancement. Their mechanisms include cell cycle arrest in the G2/M phase, combating tumor hypoxia, and others, thereby enhancing the efficacy of radiotherapy. This review delves into the evolving landscape of nanomaterials used for radiosensitization in non-small cell lung cancer. It provides insights into the current research progress and critically examines the challenges and future prospects within this burgeoning field.

A deep insight into ferroptosis in lung disease: facts and perspectives

In the last decade, ferroptosis has received much attention from the scientific research community. It differs from other modes of cell death at the morphological, biochemical, and genetic levels. Ferroptosis is mainly characterized by non-apoptotic iron-dependent cell death caused by iron-dependent lipid peroxide excess and is accompanied by abnormal iron metabolism and oxidative stress. In recent years, more and more studies have shown that ferroptosis is closely related to the occurrence and development of lung diseases. COPD, asthma, lung injury, lung fibrosis, lung cancer, lung infection and other respiratory diseases have become the third most common chronic diseases worldwide, bringing serious economic and psychological burden to people around the world. However, the exact mechanism by which ferroptosis is involved in the development and progression of lung diseases has not been fully revealed. In this manuscript, we describe the mechanism of ferroptosis, targeting of ferroptosis related signaling pathways and proteins, summarize the relationship between ferroptosis and respiratory diseases, and explore the intervention and targeted therapy of ferroptosis for respiratory diseases.

Ferroptosis in lung cancer: dual role, multi-level regulation, and new therapeutic strategies

Lung cancer is a highly prevalent malignant tumor worldwide, with high incidence and death rates. Recently, there has been increasing recognition of the role of ferroptosis, a unique cell death mechanism, in lung cancer. This review aims to summarize the current research progress on the relationship between ferroptosis and lung cancer. It also provides a comprehensive analysis of the regulatory processes of ferroptosis in various stages, including epigenetics, transcription, post-transcription, translation, and post-translation. Additionally, the review explores the dual nature of ferroptosis in lung cancer progression, which presents interesting therapeutic possibilities. On one hand, ferroptosis can promote the escape of immune surveillance and reduce the efficacy of treatment in the early stages of tumors. On the other hand, it can counter drug resistance, enhance radiosensitivity, and promote immunotherapy. The article also discusses various combination treatment strategies based on the mechanism of ferroptosis. Overall, this review offers a holistic perspective on the role of ferroptosis in the onset, progression, and treatment of lung cancer. It aims to contribute to future research and clinical interventions in this field.

A Lysosome-Targeted Magnetic Nanotorquer Mechanically Triggers Ferroptosis for Breast Cancer Treatment

Targeting ferroptosis has attracted exponential attention to eradicate cancer cells with high iron-dependent growth. Increasing the level of intracellular labile iron pool via small molecules and iron-containing nanomaterials is an effective approach to induce ferroptosis but often faces insufficient efficacy due to the fast drug metabolism and toxicity issues on normal tissues. Therefore, developing a long-acting and selective approach to regulate ferroptosis is highly demanded in cancer treatment. Herein, a lysosome-targeted magnetic nanotorquer (T7-MNT) is proposed as the mechanical tool to dynamically induce the endogenous Fe2+ pool outbreak for ferroptosis of breast cancer. T7-MNTs target lysosomes via the transferrin receptor-mediated endocytosis in breast cancer cells. Under the programmed rotating magnetic field, T7-MNTs generate torques to trigger endogenous Fe2+ release by disrupting the lysosomal membrane. This magneto-mechanical manipulation can induce oxidative damage and antioxidant defense imbalance to boost frequency- and time-dependent lipid peroxidization. Importantly, in vivo studies show that T7-MNTs can efficiently trigger ferroptosis under the magnetic field and play as a long-acting physical inducer to boost ferrotherapy efficacy in combination with RSL3. It is anticipated that this dynamic targeted strategy can be coupled with current ferroptosis inducers to achieve enhanced efficacy and inspire the design of mechanical-based ferroptosis inducers for cancer treatment.

Photonic control of image-guided ferroptosis cancer nanomedicine

Photonic nanomaterials, characterized by their remarkable photonic tunability, empower a diverse range of applications, including cutting-edge advances in cancer nanomedicine. Recently, ferroptosis has emerged as a promising alternative strategy for effectively killing cancer cells with minimizing therapeutic resistance. Novel design of photonic nanomaterials that can integrate photoresponsive-ferroptosis inducers, -diagnostic imaging, and -synergistic components provide significant benefits to effectively trigger local ferroptosis. This review provides a comprehensive overview of recent advancements in photonic nanomaterials for image-guided ferroptosis cancer nanomedicine, offering insights into their strengths, constraints, and their potential as a future paradigm in cancer treatment.

The application of nanoparticles based on ferroptosis in cancer therapy

Ferroptosis is a new form of non-apoptotic programmed cell death. Due to its effectiveness in cancer treatment, there are increasing studies on the application of nanoparticles based on ferroptosis in cancer therapy. In this paper, we present a summary of the latest progress in nanoparticles based on ferroptosis for effective tumor therapy. We also describe the combined treatment of ferroptosis with other therapies, including chemotherapy, radiotherapy, phototherapy, immunotherapy, and gene therapy. This summary of drug delivery systems based on ferroptosis aims to provide a basis and inspire opinions for researchers concentrating on exploring this field. Finally, we present some prospects and challenges for the application of nanotherapies to clinical treatment by promoting ferroptosis in cancer cells.

Pulmonary delivery of nano-particles for lung cancer diagnosis and therapy: Recent advances and future prospects

Although our understanding of lung cancer has significantly improved in the past decade, it is still a disease with a high incidence and mortality rate. The key reason is that the efficacy of the therapeutic drugs is limited, mainly due to insufficient doses of drugs delivered to the lungs. To achieve precise lung cancer diagnosis and treatment, nano-particles (NPs) pulmonary delivery techniques have attracted much attention and facilitate the exploration of the potential of those in inhalable NPs targeting tumor lesions. Since the therapeutic research focusing on pulmonary delivery NPs has rapidly developed and evolved substantially, this review will mainly discuss the current developments of pulmonary delivery NPs for precision lung cancer diagnosis and therapy. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Respiratory Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Nanomedicine targeting ferroptosis to overcome anticancer therapeutic resistance

A potential reason for the failure of tumor therapies is treatment resistance. Resistance to chemotherapy, radiotherapy, and immunotherapy continues to be a major obstacle in clinic, resulting in tumor recurrence and metastasis. The major mechanisms of therapy resistance are inhibitions of cell deaths, like apoptosis and necrosis, through drug inactivation and excretion, repair of DNA damage, tumor heterogeneity, or changes in tumor microenvironment, etc. Recent studies have shown that ferroptosis play a major role in therapies resistance by inducing phospholipid peroxidation and iron-dependent cell death. Some ferroptosis inducers in combination with clinical treatment techniques have been used to enhance the effect in tumor therapy. Notably, versatile ferroptosis nanoinducers exhibit an extensive range of functions in reversing therapy resistance, including directly triggering ferroptosis and feedback regulation. Herein, we provide a detailed description of the design, mechanism, and therapeutic application of ferroptosis-mediated synergistic tumor therapeutics. We also discuss the prospect and challenge of nanomedicine in tumor therapy resistance by regulating ferroptosis and combination therapy.

X-ray-controllable release of carbon monoxide potentiates radiotherapy by ultrastable hybrid nanoreservoirs

Carbon monoxide (CO) exhibits unique abilities in sensitizing cancer radiotherapy (RT). However, the development of a highly stable CO-delivery nanosystem with sustained CO release in tumor tissues and the prevention of CO leakage into normal tissues remains a challenge. Herein, an organic-inorganic hybrid strategy is proposed to create ultrastable CO nanoreservoirs by locking an unstable iron carbonyl (FeCO) prodrug in a stable mesoporous silica matrix. Different from traditional FeCO-loading nanoplatforms, FeCO-bridged nanoreservoirs not only tethered labile FeCO in the framework to prevent unwanted FeCO leakage, but also achieved sustained CO release in response to X-ray and endogenous H2O2. Importantly, FeCO-bridged nanoreservoirs exhibited the sequential release of CO and Fe2+, thereby performing highly efficient chemodynamic therapy. Such a powerful combination of RT, gas therapy, and chemodynamic therapy boosts robust immunogenic cell death, thus enabling the elimination of deeply metastatic colon tumors with minimal side effects. The proposed organic-inorganic hybrid strategy opens a new window for the development of stable nanoreservoirs for the on-demand delivery of unstable gases and provides a feasible approach for the sequential release of CO and metal ions from metal carbonyl complexes.

Emergence of magnetic nanoparticles in photothermal and ferroptotic therapies

With their distinctive physicochemical features, nanoparticles have gained recognition as effective multifunctional tools for biomedical applications, with designs and compositions tailored for specific uses. Notably, magnetic nanoparticles stand out as first-in-class examples of multiple modalities provided by the iron-based composition. They have long been exploited as contrast agents for magnetic resonance imaging (MRI) or as anti-cancer agents generating therapeutic hyperthermia through high-frequency magnetic field application, known as magnetic hyperthermia (MHT). This review focuses on two more recent applications in oncology using iron-based nanomaterials: photothermal therapy (PTT) and ferroptosis. In PTT, the iron oxide core responds to a near-infrared (NIR) excitation and generates heat in its surrounding area, rivaling the efficiency of plasmonic gold-standard nanoparticles. This opens up the possibility of a dual MHT + PTT approach using a single nanomaterial. Moreover, the iron composition of magnetic nanoparticles can be harnessed as a chemotherapeutic asset. Degradation in the intracellular environment triggers the release of iron ions, which can stimulate the production of reactive oxygen species (ROS) and induce cancer cell death through ferroptosis. Consequently, this review emphasizes these emerging physical and chemical approaches for anti-cancer therapy facilitated by magnetic nanoparticles, combining all-in-one functionalities.

A Multifunctional Covalent Organic Framework Nanozyme for Promoting Ferroptotic Radiotherapy against Esophageal Cancer

Radiotherapy is inevitably accompanied by some degree of radiation resistance, which leads to local recurrence and even therapeutic failure. To overcome this limitation, herein, we report the room-temperature synthesis of an iodine- and ferrocene-loaded covalent organic framework (COF) nanozyme, termed TADI-COF-Fc, for the enhancement of radiotherapeutic efficacy in the treatment of radioresistant esophageal cancer. The iodine atoms on the COF framework not only exerted a direct effect on radiotherapy, increasing its efficacy by increasing X-ray absorption, but also promoted the radiolysis of water, which increased the production of reactive oxygen species (ROS). In addition, the ferrocene surface decoration disrupted redox homeostasis by increasing the levels of hydroxyl and lipid peroxide radicals and depleting intracellular antioxidants. Both in vitro and in vivo experiments substantiated the excellent radiotherapeutic response of TADI-COF-Fc. This study demonstrates the potential of COF-based multinanozymes as radiosensitizers and suggests a possible treatment integration strategy for combination oncotherapy.

Immunotherapeutic treatment of lung cancer and bone metastasis with a mPLA/mRNA tumor vaccine

Malignant expansion and rapid metastasis are the main limiting factors to successful treatment of lung cancer. Messenger RNA (mRNA) tumor vaccines are a promising immunotherapeutic treatment for lung cancer as well as other metastatic cancers. Herein, we developed a mPLA/mRNA tumor vaccine (mLPR) to escort mRNA into the cytoplasm and improve immune response with the help of TLR4 agonist mPLA. After nasal administration, the mLPR vaccine stimulated the maturation of dendritic cells, reprogramed M2 macrophages into M1 macrophages, as well cross-activated innate and adaptive immune responses. The mLPR vaccine inhibited the development of lung cancer and reduced bone metastasis by means of immune cell activation, IFN-γ/IL-12 cytokine secretion, and natural killer cell-mediated antibody dependent cellular cytotoxicity. The mPLA/mRNA tumor vaccine will provide ideas and application prospects for the use of mRNA tumor vaccine in the treatment of lung cancer. STATEMENT OF SIGNIFICANCE: Lung cancer and bone metastasis seriously affect patient survival, and traditional treatment methods are inefficient and have many side effects. We have constructed an mRNA vaccine that simultaneously activates the innate immune and adaptive responses of the body, in order to achieve better immunotherapeutic effects. To sum up, we confirmed through vaccine design and in vitro and in vivo immunological studies that the mLPR vaccine stimulated the maturation of dendritic cells, reprogrammed M2 macrophages into M1 macrophages, as well cross activated in vivo and adaptive immune responses.

Mechanism underlying the effect of MnO2 nanosheets for A549 cell chemodynamic therapy

MnO2 nanosheets (MnO2NSs) were synthesized by one-step method, and MnO2NSs were applied to A549 cell chemodynamic Therapy (CDT). The cytotoxicity, redox ability, and reactive oxygen species production of MnO2NSs have been investigated, and differences in cell metabolism during CDT were determined using liquid chromatography-mass spectrometry (LC-MS/MS). In addition, the metabolites of A549 lung cancer cells affected by MnO2NSs treatment are identified; metabolite differences were identified by PCA, PLS-DA, orthogonal PLS-DA, and other methods; and these differences were analyzed using non-targeted metabolomics. We found that A549 cells which were treated by MnO2NSs have 17 different metabolites and 9 metabolic pathways that varied markedly. Owing to their unique composition, structure, and physicochemical properties, MnO2NSs and their composites have become a favored type of nanomaterial used for CDT in cancer therapy. This work provides insights into the mechanism underlying the effects of MnO2NSs on the tumor microenvironment of A549 lung cancer cells, effectively making up for the deficiency of the study on cellular mechanism of CDT-induced apoptosis of cancer cells. It could aid the development of cancer CDT treatment strategies and help improve the use of nanomaterials in the clinical field.

Current advances in nanoformulations of therapeutic agents targeting tumor microenvironment to overcome drug resistance

The tumor microenvironment (TME) plays a pivotal role in cancer development and progression. In this line, revealing the precise mechanisms of the TME and associated signaling pathways of tumor resistance could pave the road for cancer prevention and efficient treatment. The use of nanomedicine could be a step forward in overcoming the barriers in tumor-targeted therapy. Novel delivery systems benefit from enhanced permeability and retention effect, decreasing tumor resistance, reducing tumor hypoxia, and targeting tumor-associated factors, including immune cells, endothelial cells, and fibroblasts. Emerging evidence also indicates the engagement of multiple dysregulated mediators in the TME, such as matrix metalloproteinase, vascular endothelial growth factor, cytokines/chemokines, Wnt/β-catenin, Notch, Hedgehog, and related inflammatory and apoptotic pathways. Hence, investigating novel multitargeted agents using a novel delivery system could be a promising strategy for regulating TME and drug resistance. In recent years, small molecules from natural sources have shown favorable anticancer responses by targeting TME components. Nanoformulations of natural compounds are promising therapeutic agents in simultaneously targeting multiple dysregulated factors and mediators of TME, reducing tumor resistance mechanisms, overcoming interstitial fluid pressure and pericyte coverage, and involvement of basement membrane. The novel nanoformulations employ a vascular normalization strategy, stromal/matrix normalization, and stress alleviation mechanisms to exert higher efficacy and lower side effects. Accordingly, the nanoformulations of anticancer monoclonal antibodies and conventional chemotherapeutic agents also improved their efficacy and lessened the pharmacokinetic limitations. Additionally, the coadministration of nanoformulations of natural compounds along with conventional chemotherapeutic agents, monoclonal antibodies, and nanomedicine-based radiotherapy exhibits encouraging results. This critical review evaluates the current body of knowledge in targeting TME components by nanoformulation-based delivery systems of natural small molecules, monoclonal antibodies, conventional chemotherapeutic agents, and combination therapies in both preclinical and clinical settings. Current challenges, pitfalls, limitations, and future perspectives are also discussed.

Inhomogeneously distributed ferroptosis with a high peak-to-valley ratio may improve the antitumor immune response

Combined radiotherapy (RT) and mild hyperthermia have been used clinically for decades to increase local control. Both modalities tend to achieve a homogeneous dose distribution within treatment targets to induce immunogenic cell death. However, marked, and long-lasting abscopal effects have not usually been observed. We proposed a hypothesis to emphasize the importance of the peak-to-valley ratio of the dose distribution inside the tumor to induce immunogenic ferrroptosis in peak area while avoid nonimmunogenic ferroptosis in valley area. Although inhomogeneous distributed energy absorption has been noted in many anticancer medical fields, the idea of sedulously created dose inhomogeneity related to antitumor immunity has not been discussed. To scale up the peak-to-valley ratio, we proposed possible implications by the combination of nanoparticles (NP) with conventional RT or hyperthermia, or the use of a high modulation depth of extremely low frequency hyperthermia or high resolution spatially fractionated radiotherapy (SFRT) to enhance the antitumor immune reactions.

Inorganic nanoparticle agents for enhanced chemodynamic therapy of tumours

With the recent interest in the role of oxidative species/radicals in diseases, inorganic nanomaterials with redox activities have been extensively investigated for their potential use in nanomedicine. While many studies focusing on relieving oxidative stress to prevent pathogenesis and to suppress the progression of diseases have shown considerable success, another approach for increasing oxidative stress using nanomaterials to kill malignant cells has suffered from low efficiency despite its wide applicability to various targets. Chemodynamic therapy (CDT) is an emerging technique that can resolve such a problem by exploiting the characteristic tumour microenvironment to achieve high selectivity. In this review, we summarize the recent strategies and underlying mechanisms that have been used to improve the CDT performance using inorganic nanoparticles. In addition to the design of CDT agents, the effects of contributing factors, such as the acidity and the levels of hydrogen peroxide and antioxidants in the tumour microenvironment, together with their modulation and application in combination therapy, are presented. The challenges lying ahead of future clinical translation of this rapidly advancing technology are also discussed.

Intermittent dietary methionine deprivation facilitates tumoral ferroptosis and synergizes with checkpoint blockade

Dietary methionine interventions are beneficial to apoptosis-inducing chemotherapy and radiotherapy for cancer, while their effects on ferroptosis-targeting therapy and immunotherapy are unknown. Here we show the length of time methionine deprivation affects tumoral ferroptosis differently. Prolonged methionine deprivation prevents glutathione (GSH) depletion from exceeding the death threshold by blocking cation transport regulator homolog 1 (CHAC1) protein synthesis. Whereas, short-term methionine starvation accelerates ferroptosis by stimulating CHAC1 transcription. In vivo, dietary methionine with intermittent but not sustained deprivation augments tumoral ferroptosis. Intermittent methionine deprivation also sensitizes tumor cells against CD8+ T cell-mediated cytotoxicity and synergize checkpoint blockade therapy by CHAC1 upregulation. Clinically, tumor CHAC1 correlates with clinical benefits and improved survival in cancer patients treated with checkpoint blockades. Lastly, the triple combination of methionine intermittent deprivation, system xc- inhibitor and PD-1 blockade shows superior antitumor efficacy. Thus, intermittent methionine deprivation is a promising regimen to target ferroptosis and augment cancer immunotherapy.

Nanoparticle-mediated synergistic anticancer effect of ferroptosis and photodynamic therapy: Novel insights and perspectives

Current antitumor monotherapy has many limitations, highlighting the need for novel synergistic anticancer strategies. Ferroptosis is an iron-dependent form of nonapoptotic cell death that plays a pivotal regulatory role in tumorigenesis and treatment. Photodynamic therapy (PDT) causes irreversible chemical damage to target lesions and is widely used in antitumor therapy. However, PDT's effectiveness is usually hindered by several obstacles, such as hypoxia, excess glutathione (GSH), and tumor resistance. Ferroptosis improves the anticancer efficacy of PDT by increasing oxygen and reactive oxygen species (ROS) or reducing GSH levels, and PDT also enhances ferroptosis induction due to the ROS effect in the tumor microenvironment (TME). Strategies based on nanoparticles (NPs) can subtly exploit the potential synergy of ferroptosis and PDT. This review explores recent advances and current challenges in the landscape of the underlying mechanisms regulating ferroptosis and PDT, as well as nano delivery system-mediated synergistic anticancer activity. These include polymers, biomimetic materials, metal organic frameworks (MOFs), inorganics, and carrier-free NPs. Finally, we highlight future perspectives of this novel emerging paradigm in targeted cancer therapies.

Radiotherapy-induced ferroptosis for cancer treatment

Ferroptosis is a regulated cell death mechanism controlled by iron, amino acid and reactive oxygen species metabolisms, which is very relevant for cancer therapy. Radiotherapy-induced ferroptosis is critical for tumor suppression and several preclinical studies have demonstrated that the combination of ionizing radiation with small molecules or nano-systems is effective in combating cancer growth and overcoming drug or ionizing radiation resistance. Here, we briefly overview the mechanisms of ferroptosis and the cross-talk existing between the cellular pathways activated by ferroptosis and those induced by radiotherapy. Lastly, we discuss the recently reported combinational studies involving radiotherapy, small molecules as well as nano-systems and report the recent findings achieved in this field for the treatment of tumors.

Activatable Graphene Quantum-Dot-Based Nanotransformers for Long-Period Tumor Imaging and Repeated Photodynamic Therapy

Photodynamic therapy (PDT) is considered as an emerging therapeutic modality against cancer with high spatiotemporal selectivity because the utilized photosensitizers (PSs) are only active and toxic upon light irradiation. To maximize its effectiveness, PDT is usually applied repetitively for ablating various tumors. However, the total overdose of PSs from repeated administrations causes severe side effects. Herein, acidity-activated graphene quantum dots-based nanotransformers (GQD NT) are developed as PS vehicles for long-period tumor imaging and repeated PDT. Under the guidance of Arg-Gly-Asp peptide, GQD NT targets to tumor tissues actively, and then loosens and enlarges in tumor acidity, thus promising long tumor retention. Afterwards, GQD NT transforms into small pieces for better penetration in tumor. Upon laser irradiation, GQD NT generates mild hyperthermia that enhances cell membrane permeability and further promotes the PSs uptake. Most intriguingly, the as-prepared GQD NT not only "turns-on" fluorescence/magnetic resonance signals, but also achieves efficient repeated PDT. Notably, the total PSs dose is reduced to 3.5 µmol kg^-1 , which is 10-30 times lower than that of other reported works. Overall, this study exploits a smart vehicle to enhance accumulation, retention, and release of PSs in tumors through programmed deformation, thus overcoming the overdose obstacle in repeated PDT.

Bioinspired Structure Regulation of Apyrase-Like Nanozyme with Intracellular-Generated H2O2 for Tumor Catalytic Therapy

Adenosine triphosphate (ATP) is the major resource of energy supply in tumor activity. Therefore, improving ATP consumption efficiencies is a promising approach for cancer therapy. Herein, inspired by the H₂O₂-involved structure regulation effect during the catalysis of natural protein enzymes, we developed an artificial H₂O₂-driven ATP catalysis-promoting system, the Ce-based metal-organic framework (Ce-MOF), for catalytic cancer therapy. In the presence of H₂O₂, the hydrolysis ATP activity of Ce-MOF(H₂O₂) was enhanced by around 1.6 times. Taking advantage of the endogenous H₂O₂ in cancerous cells, catalytic hydrolysis for intracellular ATP of the Ce-MOF achieves the inhibition of cancerous cell growth, which involves damaged mitochondrial function and autophagy-associated cell death. Furthermore, in vivo studies suggest that the Ce-MOF has a good tumor inhibition effect. The artificial H₂O₂-driven ATP catalysis-promoting system not only demonstrates high catalytic ATP consumption efficiencies for cancer therapy but also highlights a bioinspired strategy to expedite nanozyme research in both design and applied sciences.

Alveolar Macrophages-Mediated Translocation of Intratracheally Delivered Perfluorocarbon Nanoparticles to Achieve Lung Cancer 19F-MR Imaging

Recent advances in intratracheal delivery strategies have sparked considerable biomedical interest in developing this promising approach for lung cancer diagnosis and treatment. However, there are very few relevant studies on the behavior and mechanism of imaging nanoparticles (NPs) after intratracheal delivery. Here, we found that nanosized perfluoro-15-crown-5-ether (PFCE NPs, ∼200 nm) exhibite significant ¹⁹F-MRI signal-to-noise ratio (SNR) enhancement than perfluorooctyl bromide (PFOB NPs) up to day 7 after intratracheal delivery. Alveolar macrophages (AMs) engulf PFCE NPs, become PFCE NPs-laden AMs, and then migrate into the tumor margin, resulting in increased tumor PFCE concentration and ¹⁹F-MRI signals. AMs-mediated translocation of PFCE NPs to lung draning lymph nodes (dLNs) decreases the background PFCE concentration. Our results shed light on the dynamic AMs-mediated translocation of intratracheally delivered PFC NPs for effective lung tumor visualization and reveal a pathway to develop and promote the clinical translation of an intratracheal delivery-based imaging strategy.

Lessons from the history of inorganic nanoparticles for inhalable diagnostics and therapeutics

The respiratory tract is one of the most accessible ones to exogenous nanoparticles, yet drug delivery by their means to it is made extraordinarily challenging because of the plexus of aerodynamic, hemodynamic and biomolecular factors at cellular and extracellular levels that synergistically define the safety and efficacy of this process. Here, the use of inorganic nanoparticles (INPs) for inhalable diagnostics and therapies of the lung is viewed through the prism of the history of studies on the interaction of INPs with the lower respiratory tract. The most conceptually and methodologically innovative and illuminative studies are referred to in the chronological order, as they were reported in the literature, and the trends in the progress of understanding this interaction of immense therapeutic and toxicological significance are being deduced from it. The most outstanding actual trends delineated include the diminishment of toxicity via surface functionalization, cell targeting, tagging and tracking via controlled binding and uptake, hybrid INP treatments, magnetic guidance, combined drug and gene delivery, use as adjuvants in inhalable vaccines, and other. Many of the understudied research directions, which have been accomplished by the nanostructured organic polymers in the pulmonary niche, are discussed. The progress in the use of INPs as inhalable diagnostics or therapeutics has been hampered by their well-recognized inflammatory potential and toxicity in the respiratory tract. However, the annual numbers of methodologically innovative studies have been on the rise throughout the past two decades, suggesting that this is a prolific direction of research, its comparatively poor commercial takings notwithstanding. Still, the lack of consensus on the effects of many INP compositions at low but therapeutically effective doses, the plethora of contradictory reports on ostensibly identical chemical compositions and NP properties, and the many cases of antagonism in combinatorial NP treatments imply that the rational design of inhalable medical devices based on INPs must rely on qualitative principles for the most part and embrace a partially stochastic approach as well. At the same time, the fact that the most studied INPs for pulmonary applications have been those with some of the thickest records of pulmonary toxicity, e.g., carbon, silver, gold, silica and iron oxide, is a silent call for the expansion of the search for new inorganic compositions for use in inhalable therapies to new territories.

Iron-doped cross-linked lipoic acid nano-aggregates for ferroptosis-mediated cancer treatment

Recently, Fenton reaction-mediated ferroptosis has attracted great attention in cancer treatment while the metabolism loss of iron and the limited endogenous H₂O₂ level imped its clinical application. Here, a new ferroptosis inducer (Fe@cLANAs) constructed only by Fe(II) and (R)-(+)-lipoic acid (LA) was developed for tumor ablation. After entering the tumor cells, the Fe@cLANAs dissociated into disdihydrolipoic acid (DHLA) and released iron, which would regenerate each other to continuously provide iron and H₂O₂ to enhance ferroptosis. The Fe@cLANAs demonstrated the IC₅₀^Fe below 10 μM against various tumor cells, an anti-tumor effect comparable to many chemotherapy drugs. In vivo antitumor evaluation based on the tumor cell-derived xenograft model showed a tumor inhibitory rate (TIR) of 97.4% at the iron usage of 1.53 mg/kg, the lowest iron usage reported so far in ferrotherapy using iron as the main agent to treat tumors. Notably, the good anti-tumor effect of Fe@cLANAs was further achieved in the glioma patient-derived xenograft (PDX) model. This strategy utilizing the reciprocal circulation of metal iron and LA to delay the metabolism loss of iron and increase the H₂O₂ level in the tumor cells holds a great potential for ferroptosis-mediated cancer treatment. STATEMENT OF SIGNIFICANCE: The metabolism loss of iron and the limited endogenous H₂O₂ level are key factors to impede the clinical application of ferroptosis-mediated cancer treatment. Herein, a new ferroptosis inducer constructed only by lipoic acid and iron is developed to delay the metabolism loss of iron and increase the level of endogenous H₂O₂ by causing a cyclic regeneration of Fe(II)/Fe(III) and LA/DHLA in the tumor cells. According to the previous reports, at least 75 mg/kg of iron dosage was needed to achieve effective antitumor efficacy, here, the use of only 1.53 mg/kg iron in Fe@cLANAs achieved the TIR of 97.4% and 62.8% in the U251 CDX and glioma PDX models, showing the good prospect of Fe@cLANAs in clinic.

Nanomedicine-mediated ferroptosis targeting strategies for synergistic cancer therapy

Apoptosis-based treatment plays an important role in regulating the death of tumor cells (e.g., chemotherapy, radiotherapy, and immunotherapy). Nevertheless, cancer cells can escape surveillance from apoptosis-associated signaling by bypassing other biological pathways and thus result in considerable resistance to therapies. Significantly, ferroptosis, a newly identified type of regulated cell death that is characterized by iron-dependent and lipid peroxidation accumulation, has aroused great research interest in cancer therapy. Increasing approaches have been developed to induce ferroptosis of tumor cells, including using clinically approved drugs, experimentally used compounds, and nanomedicine formulations. More importantly, the emerging nanomedicine-based strategy has made great advances in tumor treatment because of the promising targeting efficacy and enhanced therapeutic effects. In this review, we mainly overview state-of-the-art research on nanomedicine-mediated ferroptosis targeting strategies for synergistic cancer therapies, such as immunotherapy, chemotherapy, radiotherapy, and photothermal therapy. The potential targeting mechanism of nanomedicine for ferroptosis induction was also included. Finally, the future development of nanomedicine in the field of ferroptosis-based cell death in tumor treatment will be envisioned, aiming to provide new insight for tumor treatment in the clinic.

Harnessing nanobiotechnology for cerebral ischemic stroke management

Cerebral ischemic stroke remains one of the most serious neurological disorders that pose threats to human health, causing a large amount of long-term disability or even death throughout the world. Based on its physiologic and pathological features, there are limited available therapeutic options for effective ischemic stroke management. Encouragingly, a rapid advancement of nanobiotechnology is bringing new insights into exploring more alternative strategies against cerebral ischemic stroke, which can cleverly overcome the limitations related to conventional treatment methods. Therefore, this review focuses on the recent achievements of nanobiotechnology for ischemic stroke management, which emphasizes diverse targeted delivery strategies using various nanoplatforms including liposomes, micelles, polymeric nanoparticles, nanogels, inorganic nanomaterials, and cell-derived nano-vectors based on the pathophysiological features of ischemic stroke. Moreover, different therapeutic approaches against ischemic stroke such as neuroprotection, anti-inflammation, thrombolysis, increased blood-brain barrier penetration and reactive oxygen species scavenging are highlighted. Meanwhile, this review discusses how these versatile nanoplatforms were designed to assist in the treatment of ischemic stroke. Based on this, challenges, opportunities, and future perspectives using nanobiotechnology through rational design for effective ischemic stroke management are revealed.

Remodeling the Tumor Microenvironment with Core-Shell Nanosensitizer Featuring Dual-Modal Imaging and Multimodal Therapy for Breast Cancer

To improve the efficiency of radiation therapy (RT) for breast cancer, a designable multifunctional core-shell nanocomposite of FeP@Pt is constructed using Fe(III)-polydopamine (denoted as FeP) as the core and platinum particles (Pt) as the shell. The hybrid structure is further covered with hyaluronic acid (HA) to give the final nanoplatform of FeP@Pt@HA (denoted as FPH). FPH exhibits good biological stability, prolongs blood circulation time, and is simultaneously endowed with tumor-targeting ability. With CD44-mediated endocytosis of HA, FPH can be internalized by cancer cells and activated by the tumor microenvironment (TME). The redox reaction between Fe³⁺ in FPH and endogenous glutathione (GSH) or/and hydrogen peroxide (H₂O₂) initiates ferroptosis therapy by promoting GSH exhaustion and •OH generation. Moreover, FPH has excellent photothermal conversion efficiency and can absorb near-infrared laser energy to promote the above catalytic reaction as well as to achieve photothermal therapy (PTT). Ferroptosis therapy and PTT are further accompanied by the catalase activity of Pt nanoshells to accelerate O₂ production and the high X-ray attenuation coefficient of Pt for enhanced radiotherapy (RT). Apart from the therapeutic modalities, FPH exhibits dual-modal contrast enhancement in infrared (IR) thermal imaging and computed tomography (CT) imaging, offering potential in imaging-guided cancer therapy. In this article, the nanoplatform can remodel the TME through the production of O₂, GSH- and H₂O₂-depletion, coenhanced PTT, ferroptosis, and RT. This multimodal nanoplatform is anticipated to shed light on the design of TME-activatable materials to enhance the synergism of treatment results and enable the establishment of efficient nanomedicine.

Synergistic Functional Nanomedicine Enhances Ferroptosis Therapy for Breast Tumors by a Blocking Defensive Redox System

The upregulation of dihydroorotate dehydrogenase (DHODH) redox systems inside tumor cells provides a powerful shelter against lipid peroxidation (LPO), impeding ferroptosis-induced antitumor responses. To solve this issue, we report a strategy to block redox systems and enhance ferroptotic cancer cell death based on a layered double hydroxide (LDH) nanoplatform (siR/IONs@LDH) co-loaded with ferroptosis agent iron oxide nanoparticles (IONs) and the DHODH inhibitor (siR). siR/IONs@LDH is able to simultaneously release IONs and siR in a pH-responsive manner, efficiently generate toxic reactive oxygen species (ROS) via an Fe²⁺-mediated Fenton reaction, and synergistically induce cancer cell death upon the acceleration of LPO accumulation. In vivo therapeutic evaluations demonstrate that this nanomedicine has excellent performance for tumor growth inhibition without any detectable side effects. This work thus provides a new insight into nanomaterial-mediated tumor ferroptosis therapy.

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

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

Enhanced natural killer cell anti-tumor activity with nanoparticles mediated ferroptosis and potential therapeutic application in prostate cancer

Ferroptosis provides an opportunity to overcome the cancer cell therapeutic resistance and modulate the immune system. Here an interaction between ferroptosis of cancer cells and natural killer (NK) cells was investigated with a clinical grade iron oxide nanoparticle (ferumoxytol) for potential synergistic anti-cancer effect of ferroptosis and NK cell therapy in prostate cancer. When ferumoxytol mediated ferroptosis of cancer cells was combined with NK cells, the NK cells' cytotoxic function was increased. Observed ferroptosis mediated NK cell activation was also confirmed with IFN-γ secretion and lytic degranulation. Upregulation of ULBPs, which is one of the ligands for NK cell activating receptor NKG2D, was observed in the co-treatment of ferumoxytol mediated ferroptosis and NK cells. Additionally, HMGB1 and PD-L1 expression of cancer cells were observed in the treatment of ferroptosis + NK cells. Finally, in vivo therapeutic efficacy of ferumoxytol mediated ferroptosis and NK cell therapy was observed with significant tumor volume regression in a prostate cancer mice model. These results suggest that the NK cells' function can be enhanced with ferumoxytol mediated ferroptosis.

Interface-Engineered Mesoporous with Programmed Drug Release for Synergistic Cancer Theranostics

The pursuit of mesoporous Fe-based nanoagents addresses the field of developing alternative Fe-bearing nanoagents for synergistic cancer therapy with the expectation that the use of an essential element may avoid the issues raised by the exogenous administration of other metal element-based nanoagents. Herein, we highlight the interface-engineered mesoporous FeB (mFeB) where the core mFeB is interfacially oxidized into an FeOOH nanosheet loaded with the chemotherapeutic drug doxorubicin (DOX) and further encapsuled within the double-sulfide-bonded SiO₂ outer layer, denoted as mFeB@DOX-ss-SiO₂, which can realize programmed drug release for synergistic cancer theranostics. When only in a tumor microenvironment, the nanoagent can be activated to release DOX from the mFeB and FeOOH nanosheets as well as expose the easily oxidized mFeB to spontaneously transform to FeOOH nanosheets with Fenton activity to facilitate chemodynamic therapy (CDT). In addition, the high photothermal conversion efficiency of mFeB@DOX-ss-SiO₂ would promote CDT. Also, owing to the inherent nature of ferromagnetism and red fluorescence of DOX, mFeB@DOX-ss-SiO₂ can realize T2-weighted magnetic resonance imaging and fluorescence imaging. In vivo mouse model experiments demonstrate that mFeB@DOX-ss-SiO₂ with good biocompatibility realizing CDT/photothermal therapy/chemotherapy achieved complete tumor suppression. This study opens up a new way to explore theranostic nanoagents.

Ionizing Radiation-Induced Ferroptosis Based on Nanomaterials

Ferroptosis is an iron-dependent form of regulated cell death (RCD), that is associated with peroxidative damage to cellular membranes. A promising therapeutic method is to target ferroptosis. Nanomaterial-induced ferroptosis attracts enormous attention. Nevertheless, there are still certain shortcomings in ferroptosis, such as inadequate triggered immunogenic cell death to suit clinical demands. Various investigations have indicated that ionizing radiation (IR) can further induce ferroptosis. Consequently, it is a potential strategy for cancer therapy that combines nanomaterials and IR to induce ferroptosis. Initially, we discuss various ferroptosis inducers based on nanomaterials in this review. Furthermore, mechanisms of IR-induced ferroptosis are briefly introduced. Ultimately, we assess the feasibility of combining nanomaterials with IR to induce ferroptosis, paving the way for future research.

Targeting ferroptosis as a vulnerability in pulmonary diseases

Ferroptosis is an iron-dependent regulated cell death marked by excessive oxidative phospholipids (PLs). The polyunsaturated fatty acids-containing phospholipids (PUFA-PLs) are highly susceptible to lipid peroxidation under oxidative stress. Numerous pulmonary diseases occurrences and degenerative pathologies are driven by ferroptosis. This review discusses the role of ferroptosis in the pathogenesis of pulmonary diseases including asthma, lung injury, lung cancer, fibrotic lung diseases, and pulmonary infection. Additionally, it is proposed that targeting ferroptosis is a potential treatment for pulmonary diseases, particularly drug-resistant lung cancer or antibiotic-resistant pulmonary infection, and reduces treatment-related adverse events.

Ferroptosis, necroptosis, and pyroptosis in the occurrence and development of ovarian cancer

Ovarian cancer (OC) is one of the most common malignancies that causes death in women and is a heterogeneous disease with complex molecular and genetic changes. Because of the relatively high recurrence rate of OC, it is crucial to understand the associated mechanisms of drug resistance and to discover potential target for rational targeted therapy. Cell death is a genetically determined process. Active and orderly cell death is prevalent during the development of living organisms and plays a critical role in regulating life homeostasis. Ferroptosis, a novel type of cell death discovered in recent years, is distinct from apoptosis and necrosis and is mainly caused by the imbalance between the production and degradation of intracellular lipid reactive oxygen species triggered by increased iron content. Necroptosis is a regulated non-cysteine protease–dependent programmed cell necrosis, morphologically exhibiting the same features as necrosis and occurring via a unique mechanism of programmed cell death different from the apoptotic signaling pathway. Pyroptosis is a form of programmed cell death that is characterized by the formation of membrane pores and subsequent cell lysis as well as release of pro-inflammatory cell contents mediated by the abscisin family. Studies have shown that ferroptosis, necroptosis, and pyroptosis are involved in the development and progression of a variety of diseases, including tumors. In this review, we summarized the recent advances in ferroptosis, necroptosis, and pyroptosis in the occurrence, development, and therapeutic potential of OC.

Ambient synthesis of an iminium-linked covalent organic framework for synergetic RNA interference and metabolic therapy of fibrosarcoma

Small interfering RNA (siRNA)-mediated gene silencing is a promising therapeutic approach. Herein, we report the ambient synthesis of a positively charged iminium-linked covalent organic framework by a three-component one-pot reaction. Through anion exchange and siRNA adsorption, the resulting multifunctional siRNA@ABMBP-COF, which possesses both the HK2 inhibitor 3-bromopyruvate and SLC7A11 siRNA, exhibits powerful synergistic antitumor activity against fibrosarcoma via the ferroptosis and apoptosis pathways.

Metabolic Adaptation-Mediated Cancer Survival and Progression in Oxidative Stress

Undue elevation of ROS levels commonly occurs during cancer evolution as a result of various antitumor therapeutics and/or endogenous immune response. Overwhelming ROS levels induced cancer cell death through the dysregulation of ROS-sensitive glycolytic enzymes, leading to the catastrophic depression of glycolysis and oxidative phosphorylation (OXPHOS), which are critical for cancer survival and progression. However, cancer cells also adapt to such catastrophic oxidative and metabolic stresses by metabolic reprograming, resulting in cancer residuality, progression, and relapse. This adaptation is highly dependent on NADPH and GSH syntheses for ROS scavenging and the upregulation of lipolysis and glutaminolysis, which fuel tricarboxylic acid cycle-coupled OXPHOS and biosynthesis. The underlying mechanism remains poorly understood, thus presenting a promising field with opportunities to manipulate metabolic adaptations for cancer prevention and therapy. In this review, we provide a summary of the mechanisms of metabolic regulation in the adaptation of cancer cells to oxidative stress and the current understanding of its regulatory role in cancer survival and progression.