Nanodrug delivery systems for ferroptosis-based cancer therapy

MOFs-Based Magnetic Nanozyme to Boost Cascade ROS Accumulation for Augmented Tumor Ferroptosis

The emerging cell death modality of ferroptosis has garnered increasing attention for antitumor treatment but still suffers from low therapeutic efficacy. A metal-organic frameworks (MOFs)-based magnetic nanozyme (PZFH) comprising porphyrin-based Zr-MOF (PCN) on zinc ferrite (ZF) nanoparticles modified with hyaluronic acid, delivering excellent magnetophotonic response for efficient ferroptosis, is reported here. PZFH shows multienzyme-like cascade activity encompassing a photon-triggered oxidase-like catalysis to generate O2 -, which is converted to H2O2 by superoxide dismutase-like activity and subsequent ·OH by magneto-promoted peroxidase (POD) behavior. Newly formed Fe─N coordination and increased Fe2+/Fe3+ levels in the PZFH contribute to the enhanced POD activity, which is further enhanced by accelerated surface electron transfer when exposure to alternated magnetic field. Accumulation of lipid peroxides is eventually accomplished through the conversion of ·OH radicals and singlet oxygen (1O2) produced through laser irradiation. When combined with the depletion of inhibition of glutathione and glutathione peroxidase 4, PZFH exhibits significantly enhanced ferroptosis in tumor-bearing mice, offering insights into nanomedicine for ferroptosis and holding great promise in clinical antitumor therapies.

Immune landscape of hepatocellular carcinoma: From dysregulation of the immune responses to the potential immunotherapies

Hepatocellular carcinoma (HCC) presents a considerable global health burden due to its late diagnosis and high morbidity. The liver's specific anatomical and physiological features expose it to various antigens, requiring precise immune regulation. To the best of our knowledge, this is the first time that a comprehensive overview of the interactions between the immune system and gut microbiota in the development of HCC, as well as the relevant therapeutic approaches are discussed. Dysregulation of immune compartments within the liver microenvironment drives HCC pathogenesis, characterized by elevated regulatory cells such as regulatory T cells (Tregs), myeloid-derived suppressor cells, and M2 macrophages as well as suppressive molecules, alongside reduced number of effector cells like T cells, natural killer cells, and M1 macrophages. Dysbiosis of gut microbiota also contributes to HCC by disrupting intestinal barrier integrity and triggering overactivated immune responses. Immunotherapy approaches, particularly immune checkpoint inhibitors, have exhibited promise in HCC management, yet adoptive cell therapy and cancer vaccination research are in the early steps with relatively less favorable outcomes. Further understanding of immune dysregulation, gut microbiota involvement, and therapeutic combination strategies are essential for advancing precision immunotherapy in HCC.

A platinum(IV)-artesunate complex triggers ferroptosis by boosting cytoplasmic and mitochondrial lipid peroxidation to enhance tumor immunotherapy

Ferroptosis is an iron-dependent cell death form that initiates lipid peroxidation (LPO) in tumors. In recent years, there has been growing interest on ferroptosis, but how to propel it forward translational medicine remains in mist. Although experimental ferroptosis inducers such as RSL3 and erastin have demonstrated bioactivity in vitro, the poor antitumor outcome in animal model limits their development. In this study, we reveal a novel ferroptosis inducer, oxaliplatin-artesunate (OART), which exhibits substantial bioactivity in vitro and vivo, and we verify its feasibility in cancer immunotherapy. For mechanism, OART induces cytoplasmic and mitochondrial LPO to promote tumor ferroptosis, via inhibiting glutathione-mediated ferroptosis defense system, enhancing iron-dependent Fenton reaction, and initiating mitochondrial LPO. The destroyed mitochondrial membrane potential, disturbed mitochondrial fusion and fission, as well as downregulation of dihydroorotate dehydrogenase mutually contribute to mitochondrial LPO. Consequently, OART enhances tumor immunogenicity by releasing damage associated molecular patterns and promoting antigen presenting cells maturation, thereby transforming tumor environment from immunosuppressive to immunosensitive. By establishing in vivo model of tumorigenesis and lung metastasis, we verified that OART improves the systematic immune response. In summary, OART has enormous clinical potential for ferroptosis-based cancer therapy in translational medicine.

Ferroptosis inducers: A new frontier in cancer therapy

Ferroptosis represents a non-apoptotic form of programmed cell death characterized by iron-dependent lipid peroxidation. This cell death modality not only facilitates the direct elimination of cancer cells, but also enhances their susceptibility to other pharmacological anti-cancer agents. The burgeoning interest in ferroptosis has been driven by a growing body of evidence that underscores the efficiency and minimal toxicity of ferroptosis inducers. Traditional inducers, such as erastin and RSL3 have shown substantial promise in clinical applications due to their potent therapeutic effects. Their significant potential of these inducers has spurred the development of a variety of small molecule ferroptosis inducers. These novel inducers boast an enhanced structural variety, improved metabolic stability, the capability to initiate ferroptosis without triggering apoptosis, making them well-suited for in vivo use. Despite these advancements, challenges still remain, particularly concerning the drug delivery, tumor specificity, and circulation duration of these small molecules in vivo. Addressing these challenges, contemporary research has pivoted towards innovative delivery systems tailored for ferroptosis inducers to facilitate precise, targeted, and synegestic therapeutic delivery. This review scrutinizes the latest progress in small molecule ferroptosis inducers and nano drug delivery systems geared towards ferroptosis sensitization. Furthermore, it delineated the prospective therapeutic advantages and the existing hurdles in the development of ferroptosis inducers for malignant tumor treatment.

Recent research progress based on ferroptosis-related signaling pathways and the tumor microenvironment on it effects

The existing therapies for cancer are not remote satisfactory due to drug-resistance in tumors that are malignant. There is a pressing necessity to take a step forward to develop innovative therapies that can complement current ones. Multiple investigations have demonstrated that ferroptosis therapy, a non-apoptotic modality of programmed cell death, has tremendous potential in face of multiple crucial events, such as drug resistance and toxicity in aggressive malignancies. Recently, ferroptosis at the crosswalk of chemotherapy, materials science, immunotherapy, tumor microenvironment, and bionanotechnology has been presented to elucidate its therapeutic feasibility. Given the burgeoning progression of ferroptosis-based nanomedicine, the newest advancements in this field at the confluence of ferroptosis-inducers, nanotherapeutics, along with tumor microenvironment are given an overview. Here, the signaling pathways of ferroptosis-related were first talked about briefly. The emphasis discussion was placed on the pharmacological mechanisms and the nanodrugs design of ferroptosis inducing agents based on multiple distinct metabolism pathways. Additionally, a comprehensive overview of the action mechanisms by which the tumor microenvironment influences ferroptosis was elaborately descripted. Finally, some limitations of current researches and future research directions were also deliberately discussed to provide details about therapeutic avenues for ferroptosis-related diseases along with the design of anti-drugs.

Intelligent Size-Switchable Iron Carbide-Based Nanocapsules with Cascade Delivery Capacity for Hyperthermia-Enhanced Deep Tumor Ferroptosis

The ferroptosis pathway is recognized as an essential strategy for tumor treatment. However, killing tumor cells in deep tumor regions with ferroptosis agents is still challenging because of distinct size requirements for intratumoral accumulation and deep tumor penetration. Herein, intelligent nanocapsules with size-switchable capability that responds to acid/hyperthermia stimulation to achieve deep tumor ferroptosis are developed. These nanocapsules are constructed using poly(lactic-co-glycolic) acid and Pluronic F127 as carrier materials, with Au-Fe2 C Janus nanoparticles serving as photothermal and ferroptosis agents, and sorafenib (SRF) as the ferroptosis enhancer. The PFP@Au-Fe2 C-SRF nanocapsules, designed with an appropriate size, exhibit superior intratumoral accumulation compared to free Au-Fe2 C nanoparticles, as evidenced by photoacoustic and magnetic resonance imaging. These nanocapsules can degrade within the acidic tumor microenvironment when subjected to laser irradiation, releasing free Au-Fe2 C nanoparticles. This enables them to penetrate deep into tumor regions and disrupt intracellular redox balance. Under the guidance of imaging, these PFP@Au-Fe2 C-SRF nanocapsules effectively inhibit tumor growth when exposed to laser irradiation, capitalizing on the synergistic photothermal and ferroptosis effects. This study presents an intelligent formulation based on iron carbide for achieving deep tumor ferroptosis through size-switchable cascade delivery, thereby advancing the comprehension of ferroptosis in the context of tumor theranostics.

Synthesis of Fe3O4core/MIL-100(Fe) shell nanocomposites for tumor chemo-ferroptosis combination therapy and MR imaging

The application of both chemotherapy and ferrotherapy together has shown great potential in increasing the effectiveness of cancer treatment. To achieve such a combination, we herein have synthesized Fe3O4core/MIL-100(Fe) shell nanocomposites (FM) that can be used for tumor chemo-ferroptosis combination therapy. In these nanocomposites, the anticancer drug 10-hydroxycamptothecin (HCPT) and iron ions could be co-delivered into tumors. On one hand, the released HCPT molecules can enter the cell nucleus and bind with DNA, resulting in induction of tumor cell apoptosis. On the other hand, the iron ions could react with H2O2leading to the production of ROS through the Fenton reaction, thereby triggering tumor cell ferroptosis. Consequently, a superior antitumor effect was achieved through the combination of the apoptosis and ferroptosis. Additionally, the Fe3O4core endowed FM with high performance for magnetic resonance imaging, which further provided novel avenues for imaging guidance therapy. Therefore, we anticipate that application of these nanocomposites could have great potential in the field of tumor therapy.

Recent progress in biomaterials-driven ferroptosis for cancer therapy

Ferroptosis, first suggested in 2012, is a type of non-apoptotic programmed cell death caused by the buildup of lipid peroxidation and marked by an overabundance of oxidized poly unsaturated fatty acids. During the last decade, researchers have uncovered the formation of ferroptosis and created multiple drugs aimed at it, but due to poor selectivity and pharmacokinetics, clinical application has been hindered. In recent years, biomedical discoveries and developments in nanotechnology have spurred the investigation of ferroptosis nanomaterials, providing new opportunities for the ferroptosis driven tumours treatment. Additionally, hydrogels have been widely studied in ferroptosis because of their unique 3D structure and excellent controllability. By using these biomaterials, it is possible to achieve controlled release and targeted delivery of drugs, thus increasing the potency of the drugs and minimizing adverse effects. Therefore, summarizing the biomedical nanomaterials, including hydrogels, used in ferroptosis for cancer therapy is a must. This article provides an overview of ferroptosis, detailing its properties and underlying mechanisms. It also categorizes and reviews the use of various nanomaterials in ferroptosis, along with relevant explanations and illustrations. In addition, we discuss the opportunities and challenges facing the application of nanomaterials in ferroptosis. Finally, the development prospects of this field are prospected. This review is intended to provide a foundation for the development and application of biomedical nanomaterials in ferroptosis.

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.

NIR Light-Activated and RGD-Conjugated Ultrasmall Fe/PPy Nanopolymers for Enhanced Tumor Photothermal Ferrotherapy and MR Imaging

Iron-based nanomaterials have shown great promise for tumor ferrotherapy in recent years. However, nanoparticle-induced ferroptosis has low therapeutic efficacy owing to unsatisfactory Fenton reaction activity in a typical tumor microenvironment. In this study, NIR light-activated Fe/PPy-RGD nanopolymers were developed to combine photothermal therapy and ferrotherapy and achieve enhanced antitumor activity. Importantly, Fe/PPy-RGD exhibited excellent therapeutic performance under NIR light activation both in vitro and in vivo. Under irradiation with NIR light, the heat generated by Fe/PPy-RGD not only induced a therapeutic photothermal effect but also enhanced the release of iron ions and the Fenton reaction by inducing ferroptosis. Additionally, by virtue of RGD conjugation and its ultrasmall size, Fe/PPy-RGD could effectively accumulate at tumor sites in living mice after systemic administration and could be monitored via MR imaging. Hence, this study provides a promising approach for integrating ferrotherapy with photothermal therapy to achieve enhanced tumor treatment.

Synergistic Amplification of Ferroptosis with Liposomal Oxidation Catalyst and Gpx4 Inhibitor for Enhanced Cancer Therapy

As a distinctly different way from apoptosis, ferroptosis can cause cell death through excessive accumulation of lipid peroxide (LPO) and show great potential for cancer therapy. However, efficient strategies for ferroptosis therapy are still facing great challenges, mainly due to insufficient endogenous H2 O2 or relatively high pH value for Fenton reaction-dependent ferroptosis, and the high redox level of tumor cells attenuates the oxidation therapy. Herein, an efficient lipid-based delivery system to load oxidation catalyst and glutathione peroxidase 4 (Gpx4) inhibitor is orchestrated, intending to amplify Fenton reaction-independent ferroptosis by bidirectional regulation of LPO accumulation. Ferric ammonium citrate (FAC), Gpx4 inhibitor sorafenib (SF), and unsaturated lipids are constructed into mPEG2K -DSPE-modified liposomes (Lip@SF&FAC). Influenced by the high level of intratumoral glutathione, FAC can be converted into Fe2+ , and subsequently the formed iron redox pair (Fe2+ /Fe3+ ) catalyzes unsaturated phospholipids of liposomes into LPO via a Fenton reaction-independent manner. Meanwhile, SF can downregulate LPO reduction by inhibiting Gpx4 activation. In vitro and in vivo antitumor experiments show that Lip@SF&FAC induces massive LPO accumulation in tumor cells and ultimately exhibits strong tumor-killing ability with negligible side effect. Consequently, this two-pronged approach provides a new ferroptosis strategy for predominant LPO accumulation and enhanced cancer therapy.

Iron, Ferroptosis, and Head and Neck Cancer

Ferroptosis is an iron-dependent regulatory form of cell death characterized by the accumulation of intracellular reactive oxygen species and lipid peroxidation. It plays a critical role not only in promoting drug resistance in tumors, but also in shaping therapeutic approaches for various malignancies. This review aims to elucidate the relationship between ferroptosis and head and neck cancer treatment by discussing its conceptual framework, mechanism of action, functional aspects, and implications for tumor therapy. In addition, this review consolidates strategies aimed at improving the efficacy of head and neck cancer treatment through modulation of ferroptosis, herein serving as a valuable reference for advancing the treatment landscape for this patient population.

Activatable Semiconducting Polymer Nanoinducers Amplify Oxidative Damage via Sono-Ferroptosis for Synergistic Therapy of Bone Metastasis

Bone metastases are secondary malignant tumors that commonly occur after the spread of advanced cancer cells. We herein report the activatable semiconducting polymer nanoinducers (ASPNFP) that can amplify oxidative damage via sono-ferroptosis for bone metastasis treatment. ASPNFP are constructed by encapsulating plasma amine oxidase-based semiconducting polymer nanoparticles (SPNP) and Fe3O4 nanoparticles into singlet oxygen (1O2)-responsive nanocarriers. ASPNFP generate 1O2 under ultrasound (US) irradiation via a sonodynamic effect to destroy the stability of 1O2-responsive nanocarriers, allowing US-triggered releases of SPNP and Fe3O4 nanoparticles. SPNP decompose polyamines in tumor cells to produce acrolein and hydrogen peroxide (H2O2), in which H2O2 promotes Fenton reaction mediated by Fe3O4 nanoparticles for inducing enhanced ferroptosis and generation of hydroxyl radicals (•OH). The generated acrolein, 1O2, and •OH can simultaneously amplify the oxidative damage. ASPNFP thus mediate an amplified sono-ferroptosis effect to inhibit the growth of bone metastasis and restrict tumor metastasis.

Advances in PD-1 signaling inhibition-based nano-delivery systems for tumor therapy

In recent years, cancer immunotherapy has emerged as an exciting cancer treatment. Immune checkpoint blockade brings new opportunities for more researchers and clinicians. Programmed cell death receptor-1 (PD-1) is a widely studied immune checkpoint, and PD-1 blockade therapy has shown promising results in a variety of tumors, including melanoma, non-small cell lung cancer and renal cell carcinoma, which greatly improves patient overall survival and becomes a promising tool for the eradication of metastatic or inoperable tumors. However, low responsiveness and immune-related adverse effects currently limit its clinical application. Overcoming these difficulties is a major challenge to improve PD-1 blockade therapies. Nanomaterials have unique properties that enable targeted drug delivery, combination therapy through multidrug co-delivery strategies, and controlled drug release through sensitive bonds construction. In recent years, combining nanomaterials with PD-1 blockade therapy to construct novel single-drug-based or combination therapy-based nano-delivery systems has become an effective mean to address the limitations of PD-1 blockade therapy. In this study, the application of nanomaterial carriers in individual delivery of PD-1 inhibitors, combined delivery of PD-1 inhibitors and other immunomodulators, chemotherapeutic drugs, photothermal reagents were reviewed, which provides effective references for designing new PD-1 blockade therapeutic strategies.

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.

Nanomaterials in tumor immunotherapy: new strategies and challenges

Tumor immunotherapy exerts its anti-tumor effects by stimulating and enhancing immune responses of the body. It has become another important modality of anti-tumor therapy with significant clinical efficacy and advantages compared to chemotherapy, radiotherapy and targeted therapy. Although various kinds of tumor immunotherapeutic drugs have emerged, the challenges faced in the delivery of these drugs, such as poor tumor permeability and low tumor cell uptake rate, had prevented their widespread application. Recently, nanomaterials had emerged as a means for treatment of different diseases due to their targeting properties, biocompatibility and functionalities. Moreover, nanomaterials possess various characteristics that overcome the defects of traditional tumor immunotherapy, such as large drug loading capacity, precise tumor targeting and easy modification, thus leading to their wide application in tumor immunotherapy. There are two main classes of novel nanoparticles mentioned in this review: organic (polymeric nanomaterials, liposomes and lipid nanoparticles) and inorganic (non-metallic nanomaterials and metallic nanomaterials). Besides, the fabrication method for nanoparticles, Nanoemulsions, was also introduced. In summary, this review article mainly discussed the research progress of tumor immunotherapy based on nanomaterials in the past few years and offers a theoretical basis for exploring novel tumor immunotherapy strategies in the future.

Multifunctional Fe3O4-PEI@HA nanoparticles in the ferroptosis treatment of hepatocellular carcinoma through modulating reactive oxygen species

Ferroptosis is a novel form of regulated cell death induced by iron-dependent lipid peroxidation imbalance. It has emerged as a promising antitumor therapeutic strategy in recent years. In this work, we successfully synthesized a complex magnetic nanocube Fe₃O₄ modified with PEI and HA by the thermal decomposition method. While loading a ferroptosis inducer RSL3 inhibited cancer cells through the ferroptosis signal transduction pathway. The drug delivery system could actively target tumor cells through an external magnetic field and HA-CD44 binding. Zeta potential analysis showed that Fe₃O₄-PEI@HA-RSL3 nanoparticles were more stable and uniformly dispersed in tumor acidic environment. Moreover, cellular experiments demonstrated that Fe₃O₄-PEI@HA-RSL3 nanoparticles could significantly inhibit the proliferation of hepatoma cells without a cytotoxic effect on normal hepatic cells. In addition, Fe₃O₄-PEI@HA-RSL3 played a vital role in ferroptosis by accelerating ROS production. The expression of ferroptosis-related genes Lactoferrin, FACL 4, GPX 4 and Ferritin was significantly suppressed with increasing treatment of Fe₃O₄-PEI@HA-RSL3 nanocubes. Therefore, this ferroptosis nanomaterial has great potential in Hepatocellular carcinoma (HCC) therapy.

Mesoporous silica nanoparticles with chiral pattern topological structure function as “antiskid tires” on the intestinal mucosa to facilitate oral drugs delivery

The weak adhesion between nanocarriers and the intestinal mucosa was one of the main reasons caused the failure in oral delivery. Inspired by the "antiskid tires" with complex chiral patterns, mesoporous silica nanoparticles AT-R@CMSN exhibiting geometrical chiral structure were designed to improve the surface/interface roughness in nanoscale, and employed as the hosting system for insoluble drugs nimesulide (NMS) and ibuprofen (IBU). Once performing the delivery tasks, AT-R@CMSN with rigid skeleton protected the loaded drug and reduced the irritation of drug on gastrointestinal tract (GIT), while their porous structure deprived drug crystal and improved drug release. More importantly, AT-R@CMSN functioned as "antiskid tire" to produce higher friction on intestinal mucosa and substantively influenced multiple biological processes, including "contact", "adhesion", "retention", "permeation" and "uptake", compared to the achiral S@MSN, thereby improving the oral adsorption effectiveness of such drug delivery systems. By engineering AT-R@CMSN to overcome the stability, solubility and permeability bottlenecks of drugs, orally administered NMS or IBU loaded AT-R@CMSN could achieve higher relative bioavailability (705.95% and 444.42%, respectively) and stronger anti-inflammation effect. In addition, AT-R@CMSN displayed favorable biocompatibility and biodegradability. Undoubtedly, the present finding helped to understand the oral adsorption process of nanocarriers, and provided novel insights into the rational design of nanocarriers.

Ferroptosis-Related Metabolic Mechanism and Nanoparticulate Anticancer Drug Delivery Systems Based on Ferroptosis

Ferroptosis is a new type of cell death discovered in recent years that distinguishes from apoptosis and necrosis, mainly caused by the imbalance between the production and degradation of lipid reactive oxygen species in cells. Although the mechanism of ferroptosis is not yet clear, the phenomenon of ferroptosis has attracted widespread attention from researchers and has become a new hotspot in anti-tumor research. Studies have shown that ferroptosis is involved in the occurrence and development of a variety of diseases such as nervous system diseases, cardiovascular diseases and cancer. And inhibiting or inducing the occurrence of ferroptosis can effectively intervene in related diseases. At the same time, nanotechnology, by virtue of its distinct advantages, has been widely used in the development of nanodrug delivery systems. This review outlines current the advance on the intersection of ferroptosis and biomedical nanotechnology. In this review, the discovery and characteristics of ferroptosis, the mechanism of occurrence and the relationship with disease are summarized. More importantly, we summarized the strategies for inducing ferroptosis based on nanoparticulate drug delivery systems for cancer treatment.

Ferroptosis-based drug delivery system as a new therapeutic opportunity for brain tumors

The brain tumor is a kind of malignant tumor with brutal treatment, high recurrence rate, and poor prognosis, and the incidence and death rate is increasing yearly. Surgery is often used to remove the primary tumor, supplemented by radiotherapy and chemotherapy, which have highly toxic side effects. Therefore, there is an urgent need to explore new strategies, methods, and technologies that can genuinely improve the treatment of brain tumors. Ferroptosis differs from traditional apoptosis's morphological and biochemical characteristics, and ferroptosis possesses its unique characteristics and mechanisms, opening up a new field of ferroptosis treatment for cancer. It has been found that there is a close relationship between ferroptosis and brain tumors, and a novel nano-drug delivery system based on ferroptosis has been used for the ferroptosis treatment of brain tumors with remarkable effects. This review firstly analyzes the characteristics of ferroptosis, summarizes the mechanism of its occurrence and some factors that can be involved in the regulation of ferroptosis, introduces the potential link between ferroptosis and brain tumors, and clarifies the feasibility of ferroptosis in the treatment of brain tumors. It then presents the ferroptosis nano drug delivery systems developed under different metabolic pathways for ferroptosis treatment of brain tumors. Finally, it summarizes the current problems and solutions of ferroptosis nano drugs for brain tumor treatment, aiming to provide a reference for developing ferroptosis nano drugs against brain tumors.

Tumor Microenvironment-Adaptive Nanoplatform Synergistically Enhances Cascaded Chemodynamic Therapy

Chemodynamic therapy (CDT), a noninvasive strategy, has emerged as a promising alternative to conventional chemotherapy for treating tumors. However, its therapeutic effect is limited by the amount of H₂O₂, pH value, the hypoxic environment of tumors, and it has suboptimal tumor-targeting ability. In this study, tumor cell membrane-camouflaged mesoporous Fe₃O₄ nanoparticles loaded with perfluoropentane (PFP) and glucose oxidase (GOx) are used as a tumor microenvironment-adaptive nanoplatform (M-mFeP@O₂-G), which synergistically enhances the antitumor effect of CDT. Mesoporous Fe₃O₄ nanoparticles are selected as inducers for photothermal and Fenton reactions and as nanocarriers. GOx depletes glucose within tumor cells for starving the cells, while producing H₂O₂ for subsequent ·OH generation. Moreover, PFP, which can carry O₂, relieves hypoxia in tumor cells and provides O₂ for the cascade reaction. Finally, the nanoparticles are camouflaged with osteosarcoma cell membranes, endowing the nanoparticles with homologous targeting and immune escape abilities. Both in vivo and in vitro evaluations reveal high synergistic therapeutic efficacy of M-mFeP@O₂-G, with a desirable tumor-inhibition rate (90.50%), which indicates the great potential of this platform for clinical treating cancer.

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GOx and PFP were loaded in mFe₃O₄ to form a TME-adaptive nanoplatform and synergistically enhance the cascaded reactions.

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Tumor cell membranes, endowing the nanoparticles with homologous targeting and immune escape abilities.

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The nanoparticles had excellent combined chemodynamic therapy, starvation therapy and photothermal tumor therapy effect.

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Tumor cell membranes coated nanoparticles improved cell uptake and had a desirable tumor-inhibition rate.

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.

A glutathione-responsive sulfur dioxide polymer prodrug selectively induces ferroptosis in gastric cancer therapy

Nanoparticle-induced ferroptosis has been proven to be an appealing strategy in cancer treatment. Previously, we reported the synthesis of an amphiphilic polymer prodrug of SO₂, mPEG-PLG(DNs), which could self-assemble to formulate nanoparticles (NP-DNs) and trigger cancer cell death by GSH consumption and SO₂ release. In the current study, the potential mechanism of NP-DNs-induced cell death was further investigated. We demonstrated that NP-DNs exhibited efficient antitumor activity against gastric cancer via ferroptosis. NP-DNs could selectively accelerate lipid peroxidation through GSH depletion and SO₂ generation in gastric cancer cells. In addition, the NP-DNs-induced GPX4 reduction played a collaborative role in ferroptosis. Concurrently, in vivo evaluations revealed that NP-DNs not only exhibited excellent antitumor efficiency via ferroptosis but also caused little systemic toxicity in mice. All the results showed that NP-DNs would be a promising prodrug in precision-targeted ferroptosis therapy.

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.