Biomimetic Activator of Sonodynamic Ferroptosis Amplifies Inherent Peroxidation for Improving the Treatment of Breast Cancer

Bioconjugation and Reaction-Induced Tumor Therapy via Alkynamide-Based Thiol-Yne Click Reaction

Ferroptosis is associated with the occurrence and development of many diseases, which is the result of an imbalance in cellular metabolism and oxidation-reduction balance. Therefore, it is an effective therapeutic strategy that simultaneously regulating the intracellular oxidation-reduction system. Herein, a click reaction of alkynylamide with thiol groups in the presence of amine or in PBS (pH = 7.4) is developed, which can react efficiently with thiol substances, such as cysteine (Cys), glutathione (GSH), and bovine serum albumin (BSA). Notably, MBTB-PA, an aggregation-induced emission (AIE) photosensitizer with an alkynylamide unit, is synthesized and its intracellular behavior is visualized in situ by fluorescence imaging, demonstrating its excellent ability to target the endoplasmic reticulum. Furthermore, MBTB-PA reacted with proteins in tumor cells, consumed reducing substances, and triggered intracellular oxidative stress, resulting in cell death. Based on this reaction therapy strategy, click reaction is combined with photodynamic therapy to achieve effective killing of tumor cells by simultaneously raising the intracellular oxidative state and reducing the reductive state. This work not only develops an application of click reaction of alkynamide with thiol in bioconjugation and anti-tumor therapy, but also provides feasible ideas for organic reactions in the exploration of organisms.

Bimetallic Cu@Ru Core-Shell Structures with Ligand Effects for Endo-Exogenous Stimulation-Mediated Dynamic Oncotherapy

Dynamic therapies, which induce reactive oxygen species (ROS) production in situ through endogenous and exogenous stimulation, are emerging as attractive options for tumor treatment. However, the complexity of the tumor substantially limits the efficacy of individual stimulus-triggered dynamic therapy. Herein, bimetallic copper and ruthenium (Cu@Ru) core-shell nanoparticles are applied for endo-exogenous stimulation-triggered dynamic therapy. The electronic structure of Cu@Ru is regulated through the ligand effects to improve the adsorption level for small molecules, such as water and oxygen. The core-shell heterojunction interface can rapidly separate electron-hole pairs generated by ultrasound and light stimulation, which initiate reactions with adsorbed small molecules, thus enhancing ROS generation. This synergistically complements tumor treatment together with ROS from endogenous stimulation. In vitro and in vivo experiments demonstrate that Cu@Ru nanoparticles can induce tumor cell apoptosis and ferroptosis through generated ROS. This study provides a new paradigm for endo-exogenous stimulation-based synergistic tumor treatment.

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.

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.

Nanomedicine/materdicine-enabled sonocatalytic therapy

The advent of numerous treatment modalities with desirable therapeutic efficacy has been made possible by the fast development of nanomedicine and materdicine, among which the ultrasound (US)-triggered sonocatalytic process as minimal or non-invasive method has been frequently employed for diagnostic and therapeutic purposes. In comparison to phototherapeutic approaches with inherent penetration depth limitations, sonocatalytic therapy shatters the depth limit of photoactivation and offers numerous remarkable prospects and advantages, including mitigated side effects and appropriate tissue-penetration depth. Nevertheless, the optimization of sonosensitizers and therapies remains a significant issue in terms of precision, intelligence and efficiency. In light of the fact that nanomedicine and materdicine can effectively enhance the theranostic efficiency, we herein aim to furnish a cutting-edge review on the latest progress and development of nanomedicine/materdicine-enabled sonocatalytic therapy. The design methodologies and biological features of nanomedicine/materdicine-based sonosensitizers are initially introduced to reveal the underlying relationship between composition/structure, sonocatalytic function and biological effect, in accompany with a thorough discussion of nanomedicine/materdicine-enabled synergistic therapy. Ultimately, the facing challenges and future perspectives of this intriguing sonocatalytic therapy are highlighted and outlined to promote technological advancements and clinical translation in efficient disease treatment.

Ferroptosis resistance in cancer: recent advances and future perspectives

Ferroptosis is an iron-dependent, non-apoptotic form of regulated cell death and has been implicated in the occurrence and development of various diseases, including heart disease, nervous system diseases and cancer. Ferroptosis induction recently emerged as an attractive strategy for cancer therapy. Ferroptosis has become a potential target for intervention in these diseases or injuries in relevant preclinical models. This review summarizes recent progress on the mechanisms of ferroptosis resistance in cancer, highlights redox status and metabolism's role in it. Combination therapy for ferroptosis has great potential in cancer treatment, especially malignant tumors that are resistant to conventional therapies. This review will lead us to have a comprehensive understanding of the future exploration of ferroptosis and cancer therapy. A deeper understanding of the relationship between ferroptosis resistance and metabolism reprogramming may provide new strategies for tumor treatment and drug development based on ferroptosis.

Strategies to Reverse Hypoxic Tumor Microenvironment for Enhanced Sonodynamic Therapy

Sonodynamic therapy (SDT) has emerged as a highly effective modality for the treatment of malignant tumors owing to its powerful penetration ability, noninvasiveness, site-confined irradiation, and excellent therapeutic efficacy. However, the traditional SDT, which relies on oxygen availability, often fails to generate a satisfactory level of reactive oxygen species because of the widespread issue of hypoxia in the tumor microenvironment of solid tumors. To address this challenge, various approaches are developed to alleviate hypoxia and improve the efficiency of SDT. These strategies aim to either increase oxygen supply or prevent hypoxia exacerbation, thereby enhancing the effectiveness of SDT. In view of this, the current review provides an overview of these strategies and their underlying principles, focusing on the circulation of oxygen from consumption to external supply. The detailed research examples conducted using these strategies in combination with SDT are also discussed. Additionally, this review highlights the future prospects and challenges of the hypoxia-alleviated SDT, along with the key considerations for future clinical applications. These considerations include the development of efficient oxygen delivery systems, the accurate methods for hypoxia detection, and the exploration of combination therapies to optimize SDT outcomes.

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.

Nanomaterials-based precision sonodynamic therapy enhancing immune checkpoint blockade: A promising strategy targeting solid tumor

Burgeoning is an evolution from conventional photodynamic therapy (PDT). Thus, sonodynamic therapy (SDT) regulated by nanoparticles (NPs) possesses multiple advantages, including stronger penetration ability, better biological safety, and not reactive oxygen species (ROS)-dependent tumor-killing effect. However, the limitation to tumor inhibition instead of shrinkage and the incapability of eliminating metastatic tumors hinder the clinical potential for SDT. Fortunately, immune checkpoint blockade (ICB) can revive immunological function and induce a long-term immune memory against tumor rechallenges. Hence, synergizing NPs-based SDT with ICB can provide a promising therapeutic outcome for solid tumors. Herein, we briefly reviewed the progress in NPs-based SDT and ICB therapy. We highlighted the synergistic anti-tumor mechanisms and summarized the representative preclinical trials on SDT-assisted immunotherapy. Compared to other reviews, we provided comprehensive and unique perspectives on the innovative sonosensitizers in each trial. Moreover, we also discussed the current challenges and future corresponding solutions.

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.

Fe-doped carbon dots: a novel biocompatible nanoplatform for multi-level cancer therapy

BACKGROUND

Tumor treatment still remains a clinical challenge, requiring the development of biocompatible and efficient anti-tumor nanodrugs. Carbon dots (CDs) has become promising nanomedicines for cancer therapy due to its low cytotoxicity and easy customization.

RESULTS

Herein, we introduced a novel type of "green" nanodrug for multi-level cancer therapy utilizing Fe-doped carbon dots (Fe-CDs) derived from iron nutrient supplement. With no requirement for target moieties or external stimuli, the sole intravenous administration of Fe-CDs demonstrated unexpected anti-tumor activity, completely suppressing tumor growth in mice. Continuous administration of Fe-CDs for several weeks showed no toxic effects in vivo, highlighting its exceptional biocompatibility. The as-synthesized Fe-CDs could selectively induce tumor cells apoptosis by BAX/Caspase 9/Caspase 3/PARP signal pathways and activate antitumoral macrophages by inhibiting the IL-10/Arg-1 axis, contributing to its significant tumor immunotherapy effect. Additionally, the epithelial-mesenchymal transition (EMT) process was inhibited under the treatment of Fe-CDs by MAPK/Snail pathways, indicating the capacity of Fe-CDs to inhibit tumor recurrence and metastasis.

CONCLUSIONS

A three-level tumor treatment strategy from direct killing to activating immunity to inhibiting metastasis was achieved based on "green" Fe-CDs. Our findings reveal the broad clinical potential of Fe-CDs as a novel candidate for anti-tumor nanodrugs and nanoplatform.

Lipid bilayer-based biological nanoplatforms for sonodynamic cancer therapy

Sonodynamic therapy (SDT) has been developed as a promising alternative therapeutic modality for cancer treatment, involving the synergetic application of sonosensitizers and low-intensity ultrasound. However, the antitumor efficacy of SDT is significantly limited due to the poor performance of conventional sonosensitizers in vivo and the constrained tumor microenvironment (TME). Recent breakthroughs in lipid bilayer-based nanovesicles (LBBNs), including multifunctional liposomes, exosomes, and isolated cellular membranes, have brought new insights into the advancement of SDT. Despite their distinct sources and preparation methods, the lipid bilayer structure in common allows them to be functionalized in many comparable ways to serve as ideal nanocarriers against challenges arising from the tumor-specific sonosensitizer delivery and the complicated TME. In this review, we provide a comprehensive summary of the recent advances in LBBN-based SDT, with particular attention on how LBBNs can be engineered to improve the delivery efficiency of sonosensitizers and overcome physical, biological, and immune barriers within the TME for enhanced sonodynamic cancer therapy. We anticipate that this review will offer valuable guidance in the construction of LBBN-based nanosonosensitizers and contribute to the development of advanced strategies for next-generation sonodynamic cancer therapy.

Light-Triggered Nitric Oxide Nanogenerator with High l-Arginine Loading for Synergistic Photodynamic/Gas/Photothermal Therapy

The development of nanomedicines that combine photothermal therapy (PTT) with photodynamic therapy (PDT) is considered promising for cancer treatment, but still faces the challenge of enhancing tumoricidal efficiency. Fortunately, apart from the well-acknowledged effect on direct tumor cell-killing, nitric oxide (NO) is also considered to be effective for the enhancement of both PTT and PDT. However, both the low loading efficiency of NO precursor and the short half-life time and diffusion distance of NO hamper the synergistic therapeutic efficacy of NO. Taking the aforementioned factors into account, a mitochondria-targeted nitric oxide nanogenerator, EArgFe@Ce6, is constructed to achieve high loading of the NO donor l-Arginine (l-Arg) for synergistic photodynamic/gas/photothermal therapy upon single 660 nm light irradiation. The coordination of epigallocatechin gallate (EGCG) and ferric ions (Fe3+ ) provides EArgFe@Ce6 supreme photothermal capability to perform low-temperature PTT (mPTT). EGCG endows EArgFe@Ce6 with mitochondria-targeting capability and meanwhile favors hypoxia alleviation for enhanced PDT. The PDT-produced massive reactive oxygen species (ROS) further catalyzes l-Arg to generate a considerable amount of NO to perform gas therapy and sensitize both mPTT and PDT. In vitro and in vivo studies demonstrate that the synergistic photodynamic/gas/photothermal therapy triggered by single 660 nm light irradiation is highly effective for tumor treatments.

Ultrasound-Triggered Cascade Amplification of Nanotherapy

Ultrasound (US)-triggered cascade amplification of nanotherapies has attracted considerable attention as an effective strategy for cancer treatment. With the remarkable advances in materials chemistry and nanotechnology, a large number of well-designed nanosystems have emerged that incorporate presupposed cascade amplification processes and can be activated to trigger therapies such as chemotherapy, immunotherapy, and ferroptosis, under exogenous US stimulation or specific substances generated by US actuation, to maximize antitumor efficacy and minimize detrimental effects. Therefore, summarizing the corresponding nanotherapies and applications based on US-triggered cascade amplification is essential. This review comprehensively summarizes and highlights the recent advances in the design of intelligent modalities, consisting of unique components, distinctive properties, and specific cascade processes. These ingenious strategies confer unparalleled potential to nanotherapies based on ultrasound-triggered cascade amplification and provide superior controllability, thus overcoming the unmet requirements of precision medicine and personalized treatment. Finally, the challenges and prospects of this emerging strategy are discussed and it is expected to encourage more innovative ideas and promote their further development.

A Metal-Polyphenol-Based Oxygen Economizer and Fenton Reaction Amplifier for Self-Enhanced Synergistic Photothermal/Chemodynamic/Chemotherapy

To overcome the limitations of doxorubicin (DOX) chemotherapy, nanomedicines that integrate additional photothermal therapy (PTT) and chemodynamic therapy (CDT) strategies are highlighted as promising alternatives for the treatment of malignant tumors. However, time-consuming preparation processes, biosafety concerns, and the bottlenecks of individual therapeutic modalities often limit the practical applications of this strategy. To address these issues, this work designs an oxygen economizer that additionally serves as a Fenton reaction amplifier through the simple assembly of epigallocatechin gallate (EGCG), pluronic F-127 (PF127), iron (III) ions, and doxorubicin (DOX) for the enhancement of synergistic PTT/CDT/chemotherapy. The resulting nanoformulation, EFPD, can target mitochondria and inhibit cell respiration to reduce O2 consumption, thus boosting DOX-mediated H2 O2 generation for enhanced CDT and simultaneously improving hypoxia-limited DOX chemotherapy efficacy. Moreover, the coordination between EGCG and Fe3+ provides EFPD with excellent photothermal conversion efficiencies (η = 34.7%) for PTT and photothermal-accelerated drug release. Experimental results indicate that EFPD-mediated synergistic enhancement of PTT/CDT/chemotherapy can achieve excellent therapeutic outcomes, including enhanced ablation of solid tumors, reduced metastasis and cardiotoxicity, and extended life spans.

An Intelligent Cell-Derived Nanorobot Bridges Synergistic Crosstalk Between Sonodynamic Therapy and Cuproptosis to Promote Cancer Treatment

Recent progress in cuproptosis sheds light on the development of treatment approaches for advancing sonodynamic therapy (SDT) due to its unique cell death mechanism. Herein, we elaborately developed an intelligent cell-derived nanorobot (SonoCu), composed of macrophage-membrane-camouflaged nanocarrier encapsulating copper-doped zeolitic imidazolate framework-8 (ZIF-8), perfluorocarbon, and sonosensitizer Ce6, for synergistically triggering cuproptosis-augmented SDT. SonoCu not only improved tumor accumulation and cancer-cell uptake through cell-membrane camouflaging but responded to ultrasound stimuli to enhance intratumor blood flow and oxygen supply, which consequently overcame treatment barriers and activated sonodynamic cuproptosis. Importantly, the SDT effectiveness could be further amplified by cuproptosis through multiple mechanisms, including reactive oxygen species accumulation, proteotoxic stress, and metabolic regulation, which synergistically sensitized cancer cell death. Particularly, SonoCu exhibited ultrasound-responsive cytotoxicity against cancer cells but not healthy cells, endowing it with good biosafety. Therefore, we present the first anticancer combination of SDT and cuproptosis, which may inspire studies pursuing a rational multimodal treatment strategy.

The Role of Ferroptosis in the Pathogenesis of Osteoarthritis

Osteoarthritis (OA) is the most common type of arthritis. Its high prevalence, especially in the elderly, and its negative impact on physical function make it a leading cause of disability in the elderly. Joint pain as well joint stiffness are the common classic signs of OA. Chondrocyte death together with loss of articular cartilage integrity are the main pathologic changes in OA. Non-steroidal anti-inflammatory drugs (NSAIDs) and glucocorticoids are commonly used for the management of OA; still, their effectiveness is limited, and no therapeutic strategy is able to fully stop OA progression. Ferroptosis is a kind of cell death, distinct from apoptosis and necroptosis, caused by iron-dependent peroxidation of membrane phospholipids that terminates cell life by disintegrating all plasma membranes. It has been suggested that ferroptosis has a critical role in decreased viability of chondrocytes in OA, and here, we review recent findings regarding the pathologic pathways that lead to chondrocyte ferroptosis, and discuss the possible therapeutic utility of ferroptosis inhibition in OA.

Titanium-Based Nanoarchitectures for Sonodynamic Therapy-Involved Multimodal Treatments

Sonodynamic therapy (SDT) has considerably revolutionized the healthcare sector as a viable noninvasive therapeutic procedure. It employs a combination of low-intensity ultrasound and chemical entities, known as a sonosensitizer, to produce cytotoxic reactive oxygen species (ROS) for cancer and antimicrobial therapies. With nanotechnology, several unique nanoplatforms are introduced as a sonosensitizers, including, titanium-based nanomaterials, thanks to their high biocompatibility, catalytic efficiency, and customizable physicochemical features. Additionally, developing titanium-based sonosensitizers facilitates the integration of SDT with other treatment modalities (for example, chemotherapy, chemodynamic therapy, photodynamic therapy, photothermal therapy, and immunotherapy), hence increasing overall therapeutic results. This review summarizes the most recent developments in cancer therapy and tissue engineering using titanium nanoplatforms mediated SDT. The synthesis strategies and biosafety aspects of Titanium-based nanoplatforms for SDT are also discussed. Finally, various challenges and prospects for its further development and potential clinical translation are highlighted.

Ultrasound-pretreatment combined with Ti3C2-TiO2-AuNPs enhancing the electrogenerated chemiluminescence of the air-saturated luminol for exosomes detection

It is still a great challenge to develop effective strategies to improve the low electrogenerated chemiluminescence (ECL) of air-saturated luminol. Herein, the synergistic effects of Ti₃C₂-TiO₂-AuNPs nano hybrid and high-intensity focused ultrasound pretreatment (ultrasound-pretreatment) were used to significantly improve the ECL emission of the air-saturated luminol, and the mechanism was proposed. The ultrasound-pretreatment as a green method with the cavitation effect could form O₂^-• and H₂O₂ in situ as an initiator. TiO₂ and Au nanoparticles (AuNPs) were in situ decorated on the Ti₃C₂ surface to form Ti₃C₂-TiO₂-AuNPs, and it was proved as a highly efficient booster which could catalyze and aggregate H₂O₂ to the O₂^-•. The utilization rate of intermediates has been greatly improved. Exosomes as model targets can be sensitively detected by the ECL sensor. The detection limit was 195 particles μL^-1. The detection results of exosomes in actual samples are satisfactory. We believe that the ultrasound-pretreatment strategy could be extended to the sensitive detection in the biological sample.

Smart Metabolism Nanovalve Reprograms Cancer Energy Homeostasis for Maximizing Photometabolism Therapy

Better understanding of important roles of metabolic reprogramming in therapeutic resistance provides insights into advancing cancer treatment. Herein, we present a photoactive metabolic reprogramming strategy (termed as photometabolism therapy, PMT), in which photoregulation of mitochondria leads to cancer cell metabolic crisis, and consequently overcomes therapeutic resistance while improving treatment efficacy. In specific, a stimuli-responsive metabolism NanoValve is developed for improving cascade cancer therapy through blocking mitochondrial energy supply. NanoValve is composed of an onion-like architecture with a gold nanorod core, a mesoporous silica shell encapsulating photosensitizer chlorin e6 and oxygen-saturated perfluorocarbon, and cationic liposomal coating with MMP2-cleavable polyethylene glycol corona, which together initiate mitochondria-specific PMT. NanoValve selectively responds to tumor-overexpressed MMP2 and achieves size decrease and charge reversal, which consequently enhances tumor penetration, cancer cell uptake, endosome escape, and most critically, mitochondrial accumulation. Importantly, NanoValve-mediated phototherapy can strongly destruct mitochondrial energy metabolism, thereby minimizing therapy resistance. Particularly, perfluorocarbon supplies oxygen to further overcome the tumor hypoxia-associated therapeutic barrier and maximizes synergistic anticancer effects. In vivo studies show that NanoValve can effectively eliminate tumors without side effects, thereby dramatically prolonging the survival of tumor-bearing mice. Thus, NanoValve provides a modular PMT approach and has the potential of advancing the treatment of malignancy.

Ferroptosis: challenges and opportunities for nanomaterials in cancer therapy

Ferroptosis, a completely new form of regulated cell death, is mainly caused by an imbalance between oxidative damage and reductive protection and has shown great anti-cancer potential. However, existing small-molecule ferroptosis inducers have various limitations, such as poor water solubility, drug resistance and low targeting ability, hindering their clinical applications. Nanotechnology provides new opportunities for ferroptosis-driven tumor therapy. Especially, stimuli-responsive nanomaterials stand out among others and have been widely researched because of their unique spatiotemporal control advantages. Therefore, it's necessary to summarize the application of those stimuli-responsive nanomaterials in ferroptosis. Here, we describe the physiological feature of ferroptosis and illustrate the current challenges to induce ferroptosis for cancer therapy. Then, nanomaterials that induce ferroptosis are classified and elaborated according to the external and internal stimuli. Finally, the future perspectives in the field are proposed. We hope this review facilitates paving the way for the design of intelligent nano-ferroptosis inducers.

Hollow CoP@N-Carbon Nanospheres: Heterostructure and Glucose-Enhanced Charge Separation for Sonodynamic/Starvation Therapy

Sonodynamic therapy (SDT) can be described as ultrasonic (US) catalysis. Adequate charge separation is considered as effective means to promote reactive oxygen species (ROS). Here, hollow CoP@N-carbon@PEG (CPCs@PEG) nanospheres (∼60 nm) are prepared as sonosensitizers, showing greater ROS generation than pure CoP@PEG under US irradiation. Both ¹O₂ and ·O₂^- are activation species that are determined by O₂ and electrons. The great SDT performance of CPCs@PEG is ascribed to the heterostructure which promotes the separation and transfer for US-generated electrons and holes. In addition, holes can be further captured by endogenous glucose that is in favor of electron aggregation and ROS generation. Moreover, the consumption of glucose would decrease intracellular ATP for starvation therapy. Given the higher oxidation ability of Co³⁺, CPCs@PEG nanospheres possess catalase (CAT) activity to convert H₂O₂ into O₂ for assisting ROS generation. Moreover, they also can oxidize glutathione (GSH) as a mimic GSH oxidase to break intratumor redox balance, facilitating oxidative stress. More importantly, the nanocomposites reveal good degradation ability dominated by the oxidation from insoluble phosphide into soluble phosphate, accelerating elimination via urine and feces within 14 days. CPCs@PEG nanospheres integrate the above effects not only to reveal great tumor inhibition ability but also to excite immune activation for anticancer.

Iron-Containing Protein-Mimic Supramolecular Iron Delivery Systems for Ferroptosis Tumor Therapy

Ferroptosis provides an innovative theoretical basis and method for tumor therapy but is limited by the low efficiency of conventional iron delivery systems. Herein, an efficient supramolecular iron delivery system (SIDS) is demonstrated upon the hydrolysis of FeCl₃, condensation of amino acids, and self-assembly of iron-containing components. The as-assembled SIDS possesses a shuttle-like core/shell structure with β-FeOOH as the core and Fe³⁺/polyamino acid coordinated networks as shells. The iron content of SIDS is up to 42 wt %, which is greatly higher than that of ferritin. The iron-containing protein-mimic structure and shuttle-like morphology of SIDS facilitate tumor accumulation and cell internalization. Once exposed to the tumor microenvironment with overexpressed glutathione (GSH), the SIDS will disassemble, accompanied by the depletion of GSH and the release of Fe²⁺, leading to dual amplified ferroptosis. Primary studies indicate that SIDS exhibits outstanding antitumor efficacy on bladder cancer.

Mechanical stimuli-driven cancer therapeutics

Mechanical stimulation utilizing deep tissue-penetrating and focusable energy sources, such as ultrasound and magnetic fields, is regarded as an emerging patient-friendly and effective therapeutic strategy to overcome the limitations of conventional cancer therapies based on fundamental external stimuli such as light, heat, electricity, radiation, or microwaves. Recent efforts have suggested that mechanical stimuli-driven cancer therapy (henceforth referred to as "mechanical cancer therapy") could provide a direct therapeutic effect and intelligent control to augment other anti-cancer systems as a synergistic combinational cancer treatment. This review article highlights the latest advances in mechanical cancer therapy to present a novel perspective on the fundamental principles of ultrasound- and magnetic field-mediated mechanical forces, including compression, tension, shear force, and torque, that can be generated in a cellular microenvironment using mechanical stimuli-activated functional materials. Additionally, this article will shed light on mechanical cancer therapy and inspire future research to pursue the development of ultrasound- and magnetic-field-activated materials and their applications in this field.

Newly developed gas-assisted sonodynamic therapy in cancer treatment

Sonodynamic therapy (SDT) is an emerging noninvasive treatment modality that utilizes low-frequency and low-intensity ultrasound (US) to trigger sensitizers to kill tumor cells with reactive oxygen species (ROS). Although SDT has attracted much attention for its properties including high tumor specificity and deep tissue penetration, its anticancer efficacy is still far from satisfactory. As a result, new strategies such as gas-assisted therapy have been proposed to further promote the effectiveness of SDT. In this review, the mechanisms of SDT and gas-assisted SDT are first summarized. Then, the applications of gas-assisted SDT for cancer therapy are introduced and categorized by gas types. Next, therapeutic systems for SDT that can realize real-time imaging are further presented. Finally, the challenges and perspectives of gas-assisted SDT for future clinical applications are discussed.

Targeting ferroptosis, the achilles' heel of breast cancer: A review

Ferroptosis is referred as a novel type of cell death discovered in recent years with the feature of the accumulation of iron-dependent lipid reactive oxygen species. Breast cancer is one of the most common malignant cancers in women. There is increasing evidence that ferroptosis can inhibit breast cancer cell growth, improve the sensitivity of chemotherapy and radiotherapy and inhibit distant metastases. Therefore, ferroptosis can be regarded a new target for tumor suppression and may expand the landscape of clinical treatment of breast cancer. This review highlights the ferroptosis mechanism and its potential role in breast cancer treatment to explore new therapeutic strategies of breast cancer.

Boosting the electrochemiluminescence of luminol-O2 system by high-intensity focused ultrasound

Electrochemiluminescence (ECL) of luminol is a well-established methodology in analytical chemistry and bioimaging. Developing novel strategies to enhance the ECL signal of this model emitter is a challenging but rewarding task. In this work, we introduced the high-intensity focused ultrasound (HIFU), as a pretreatment means and a non-invasive way to trigger and boost the ECL signal with a 40-fold significant enhancement in the luminol-O₂ system without the addition of exogenous co-reactants. The superoxide anion (O₂^-•) generated in situ by HIFU was the key initiator for boosting the ECL emission as demonstrated in this study for the first time. This promising co-reactant-free strategy could find potential applications for ultrasensitive ECL detection in the analysis of complex biological entities.

Oral Nanomotor-Enabled Mucus Traverse and Tumor Penetration for Targeted Chemo-Sono-Immunotherapy against Colon Cancer

The therapeutic outcomes of oral nanomedicines against colon cancer are heavily compromised by their lack of specific penetration into the internal tumor, favorable anti-tumor activity, and activation of anti-tumor immunity. Herein, hydrogen peroxide (H₂ O₂ )/ultrasound (US)-driven mesoporous manganese oxide (MnO_x )-based nanomotors are constructed by loading mitochondrial sonosensitizers into their mesoporous channels and orderly dual-functionalizing their surface with silk fibroin and chondroitin sulfate. The locomotory activities and tumor-targeting capacities of the resultant nanomotors (CS-ID@NMs) are greatly improved in the presence of H₂ O₂ and US irradiation, inducing efficient mucus-traversing and deep tumor penetration. The excess H₂ O₂ in the tumor microenvironment (TME) is decomposed into hydroxyl radicals and oxygen by an Mn²⁺ -mediated Fenton-like reaction, and the produced oxygen participates in sonodynamic therapy (SDT), yielding abundant singlet oxygen. The combined Mn²⁺ -mediated chemodynamic therapy and SDT cause effective ferropotosis of tumor cells and accelerate the release of tumor antigens. Importantly, animal experiments reveal that the treatment of combining oral hydrogel (chitosan/alginate)-embedding CS-ID@NMs and immune checkpoint inhibitors can simultaneously suppress the growth of primary and distal tumors through direct killing, reversion of immunosuppressive TME, and potentiation of systemic anti-tumor immunity, demonstrating that the CS-ID@NM-based platform is a robust oral system for synergistic treatment of colon cancer.

The promising interplay between sonodynamic therapy and nanomedicine

Sonodynamic therapy (SDT) is a non-invasive approach for cancer treatment in which chemical compounds, named sonosensitizers, are activated by non-thermal ultrasound (US), able to deeply penetrate into the tissues. Despite increasing interest, the underlying mechanisms by which US triggers the sonosensitizer therapeutic activity are not yet clearly elucidate, slowing down SDT clinical application. In this review we will discuss the main mechanisms involved in SDT with particular attention to the sonosensitizers involved for each described mechanism, in order to highlight how much important are the physicochemical properties of the sonosensitizers and their cellular localization to predict their bioeffects. Moreover, we will also focus our attention on the pivotal role of nanomedicine providing the sonodynamic anticancer approach with the ability to shape US-responsive agents to enhance specific sonodynamic effects as the sonoluminescence-mediated anticancer effects. Indeed, SDT is one of the biomedical fields that has significantly improved in recent years due to the increased knowledge of nanosized materials. The shift of the nanosystem from a delivery system for a therapeutic agent to a therapeutic agent in itself represents a real breakthrough in the development of SDT. In doing so, we have also highlighted potential areas in this field, where substantial improvements may provide a valid SDT implementation as a cancer therapy.

Nanotechnology-integrated ferroptosis inducers: a sharp sword against tumor drug resistance

Presently, the biggest hurdle to cancer therapy is the inevitable emergence of drug resistance. Since conventional therapeutic schedules fall short of the expectations in curbing drug resistance, the development of novel drug resistance management strategies is critical. Extensive research over the last decade has revealed that the process of ferroptosis is correlated with cancer resistance; moreover, it has been demonstrated that ferroptosis inducers reverse drug resistance. To elucidate the development and promote the clinical transformation of ferroptosis strategies in cancer therapy, we first analyzed the roles of key ferroptosis-regulating molecules in the progression of drug resistance in-depth and then reviewed the design of ferroptosis-inducing strategies based on nanotechnology for overcoming drug resistance, including glutathione depletion, reactive oxygen species generation, iron donation, lipid peroxidation aggregation, and multiple-drug resistance-associated tumor cell destruction. Finally, the prospects and challenges of regulating ferroptosis as a therapeutic strategy for reversing cancer therapy resistance were evaluated. This review aimed to provide a comprehensive understanding for researchers to develop ferroptosis-inducing nanoplatforms that can overcome drug resistance.

The Regulatory Role of Ferroptosis in Bone Homeostasis

Ferroptosis is an iron-dependent form of programmed cell death and an important type of biological catabolism. Through the action of divalent iron or ester oxygenase, ferroptosis can induce lipid peroxidation and cell death, regulating a variety of physiological processes. The role of ferroptosis in the modulation of bone homeostasis is a significant topic of interest. Herein, we review and discuss recent studies exploring the mechanisms and functions of ferroptosis in different bone-related cells, including mesenchymal stem cells, osteoblasts, osteoclasts, and osteocytes. The association between ferroptosis and disorders of bone homeostasis is also explored in this review. Overall, we aim to provide a detailed overview of ferroptosis, summarizing recent understanding on its role in regulation of bone physiology and bone disease pathogenesis.

A Novel Prognostic Signature Based on Glioma Essential Ferroptosis-Related Genes Predicts Clinical Outcomes and Indicates Treatment in Glioma

Background

Ferroptosis is a form of programmed cell death (PCD) that has been implicated in cancer progression, although the specific mechanism is not known. Here, we used the latest DepMap release CRISPR data to identify the essential ferroptosis-related genes (FRGs) in glioma and their role in patient outcomes.

Methods

RNA-seq and clinical information on glioma cases were obtained from the Chinese Glioma Genome Atlas (CGGA) and The Cancer Genome Atlas (TCGA). FRGs were obtained from the FerrDb database. CRISPR-screened essential genes (CSEGs) in glioma cell lines were downloaded from the DepMap portal. A series of bioinformatic and machine learning approaches were combined to establish FRG signatures to predict overall survival (OS) in glioma patients. In addition, pathways analysis was used to identify the functional roles of FRGs. Somatic mutation, immune cell infiltration, and immune checkpoint gene expression were analyzed within the risk subgroups. Finally, compounds for reversing high-risk gene signatures were predicted using the GDSC and L1000 datasets.

Results

Seven FRGs (ISCU, NFS1, MTOR, EIF2S1, HSPA5, AURKA, RPL8) were included in the model and the model was found to have good prognostic value (p < 0.001) in both training and validation groups. The risk score was found to be an independent prognostic factor and the model had good efficacy. Subgroup analysis using clinical parameters demonstrated the general applicability of the model. The nomogram indicated that the model could effectively predict 12-, 36-, and 60-months OS and progression-free interval (PFI). The results showed the presence of more aggressive phenotypes (lower numbers of IDH mutations, higher numbers of EGFR and PTEN mutations, greater infiltration of immune suppressive cells, and higher expression of immune checkpoint inhibitors) in the high-risk group. The signaling pathways enriched closely related to the cell cycle and DNA damage repair. Drug predictions showed that patients with higher risk scores may benefit from treatment with RTK pathway inhibitors, including compounds that inhibit RTKs directly or indirectly by targeting downstream PI3K or MAPK pathways.

Conclusion

In summary, the proposed cancer essential FRG signature predicts survival and treatment response in glioma.

Synergistic therapy for orthotopic glioma via biomimetic nanosonosensitizer mediated sonodynamic therapy and ferroptosis

Ferroptosis is an emerging form of programmed cell death, and its combination with sonodynamic therapy (SDT) for antitumor is gradually attracting attention. However, their application in against glioma has not...