Covalent Organic Framework Nanobowls as Activatable Nanosensitizers for Tumor-Specific and Ferroptosis-Augmented Sonodynamic Therapy

Cationic porphyrin-based covalent organic frameworks for enhanced phototherapy and targeted chemotherapy of bacterial infections

Bacterial infections significantly impede wound healing and threaten global public health. Porphyrin covalent organic frameworks (COFs) have shown promise as phototherapy antibacterial materials. However, the inherent π-π stacking interactions between the monomers also lead to aggregation and quenching of photosensitizers, thereby reducing the production of singlet oxygen (1O2) and compromising their antibacterial efficacy. Herein, we designed and prepared a novel cationic porphyrin-based COFs nanoplatform (TAPP-VIO), utilizing photosensitive TAPP and cationic VIO as structural units. This multifunctional nanoplatform is specifically tailored for targeted phototherapy and chemotherapy against bacterial infections. Upon irradiation, TAPP unit in TAPP-VIO generates heat and 1O2, which effectively disrupt bacterial structure and cause cell death. The incorporation of VIO unit introduces electrostatic repulsion between layers, mitigating π-π stacking effects and enhancing 1O2 production. Additionally, the positive charge imparted by the VIO unit enables TAPP-VIO to bind efficiently to negatively charged bacterial surfaces, immobilizing the bacteria and reducing their motility, thereby improving the overall efficacy of phototherapy. Under identical experimental conditions and concentrations, TAPP-VIO exhibits a 1O2 generation capacity that is 179 % higher than that of nonionic porphyrin COF. Moreover, the temperature increase induced by TAPP-VIO is 85 % of that observed with nonionic porphyrin COF (TAPP-MMA-Da), which is conducive to enhancing the phototherapeutic effects while minimizing heat-induced damage to healthy tissues. In summary, our study presents a straightforward approach to developing non-antibiotic antibacterial nanoagents, and the as-prepared TAPP-VIO is a promising candidate drug suitable for clinical trials in the future.

Ultrasound-responsive nanoweapons: covalent organic frameworks for cancer sonodynamic therapy

Sonodynamic therapy (SDT), characterized by its non-invasiveness, low toxicity, and deep tissue penetration, has emerged as a promising therapeutic modality for anticancer treatments. Recently, covalent organic frameworks (COFs) have garnered significant attention in the SDT realm as a powerful and versatile toolbox. Notably, COF-based SDT has achieved many encouraging outcomes owing to the remarkable potential of COFs, and the volume of related research has experienced continuous growth. Therefore, we strive to provide a timely and comprehensive review that thoroughly summarizes the advancements in COF-based SDT. This review begins with a concise yet comprehensive summary of ultrasonic cavitation and sonodynamic effects, elucidating the fundamental principles and potential mechanisms of SDT. Subsequently, it delves into the chemistry of COFs, examining intricate structure designs, various types of linkages, and diverse synthetic methods. The primary focus of this review is to summarize COF-based sonosensitizers, including construction strategies and product properties. More importantly, the role of COFs in SDT combined therapies is described in detail, aiming to highlight the advantages of COF-enhanced SDT and synergistic treatments. Finally, the review points out the current challenges and future opportunities in this rapidly evolving research field. Overall, the deliberations and overviews of COF-based sonosensitizers and SDT strategies are expected to facilitate advancements, leading to early-stage clinical benefits for patients.

Programmatically Controllable Activation of Sonodynamic Therapeutics with Bioorthogonal-Based Mitochondria-Specific Exogenous Agents toward Accurate Tumor Elimination

Sonodynamic therapy (SDT) mediated by endogenous stimuli-activated sonosensitizing prodrugs is faced with problems such as low specificity, tumor heterogeneity, and uncontrollability. Utilizing bioorthogonal reactions as exogenous stimuli to programmatically activate the prodrugs has been identified as a potential solution to these problems. Herein, we present a mitochondria-specific sonosensitizing system for programmatically controllable activation of sonodynamic therapeutics based on the Staudinger reaction by rationally designing a mitochondrial-targeting bioorthogonal trigger (TP) and a mitochondria-targeting sonosensitizing nanoprodrug (MA-NPs). The MA-NPs is enriched inside the mitochondria of the tumor cell driven by the mitochondrial membrane potential. The enrichment of MA-NPs and the subsequently loaded TP within mitochondria initiate Staudinger reactions, which promote the disintegration of MA-NPs to release sonosenitizing methylene blue (MB). Then, under ultrasound irradiation, MB produces reactive oxygen species (ROS) to damage the mitochondria of tumor cells and induce apoptosis, which effectively inhibits tumor development and facilitates the effects of SDT. This research presents an innovative strategy for the advancement of exogenous activation agents capable of selectively and efficiently activating prosonosensitizers and achieving controllable and effective SDT.

Sonodynamic therapy-boosted biomimetic nanoplatform targets ferroptosis and CD47 as vulnerabilities for cancer immunotherapy

The efficacy of cancer immunotherapy is frequently hindered by the immunosuppressive "cold" tumor microenvironment. Inducing immunogenic cell death (ICD) may address this limitation. Ferroptosis, a form of ICD characterized by iron-dependent lipid peroxidation, has gained attention as a therapeutic target due to its inherent or therapy-induced susceptibility in refractory cancers and resistant tumor microenvironments. CD47, overexpressed on tumor cell membranes, enables immune evasion by suppressing macrophage-mediated surveillance, positioning it as a promising immune checkpoint target for macrophage-driven immunotherapy. Combining ferroptosis induction with CD47 blockade represents a strategic approach to enhance therapeutic outcomes. In this study, we developed a biomimetic nanoplatform-IR780/MnO2@PLGA@cell membrane-PEP20 nanoparticles-featuring a shell derived from 4T1 cell membranes conjugated with the CD47-inhibitory peptide PEP20. This design enables tumor-targeted delivery while enhancing macrophage phagocytosis of tumor cells. The MnO2 core depletes intra-tumoral glutathione, downregulating glutathione peroxidase 4 and accumulating lipid peroxides to trigger ferroptosis. Concurrently, the ultrasound-responsive agent IR780 generates singlet oxygen under ultrasound irradiation, amplifying ferroptosis via oxidative stress. The resultant reactive oxygen species drive M2-to-M1 macrophage repolarization. Ferroptosis-mediated ICD further stimulates dendritic cell antigen presentation, activates cytotoxic T-cell immunity, and establishes durable immune memory. By exploiting tumor defense mechanisms as therapeutic vulnerabilities, this nanoplatform offers an innovative strategy for refractory cancer treatment.

Ruthenium Single-Atom Nanozyme Driven Sonosensitizer with Oxygen Vacancies Enhances Electron-Hole Separation Efficacy and Remodels Tumor Microenvironment for Sonodynamic-Amplified Ferroptosis

Sonodynamic therapy (SDT) has emerged as a promising noninvasive approach for tumor therapy. However, the effectiveness of traditional inorganic semiconductor sonosensitizers is hindered by rapid electron (e-) and hole (h+) recombination under ultrasonic (US) stimulation, as well as the hypoxic and reductive conditions of tumor microenvironment (TME), which limit the generation of reactive oxygen species (ROS). Herein, a ruthenium (Ru) single-atom nanozyme-driven superimposition-enhanced titanium dioxide-based sonosensitizer (Ru/TiO2-x SAE) is presented that features sufficient oxygen vacancies and high e-/h+ separation efficiency. Through synchrotron radiation-based X-ray absorption spectroscopy and extended X-ray absorption fine structure analysis it is confirmed that oxygen vacancies in TiO2-x nanoparticles promote the immobilization of single-atomic Ru, forming Ru-O₄ active sites. Density functional theory calculations demonstrate that oxygen vacancies alter the electronic structure of nanosensitizer, enhanced e-/h+ separation, increasing oxygen adsorption, and accelerating reaction kinetics under US stimulation, ultimately improving ROS production. Moreover, Ru/TiO2-x SAE boosts sonodynamic efficacy by mitigating the hypoxic and reductive TME. This is attributed to its catalase- and glutathione peroxidase 4-like activities, which facilitate the generation of ROS and trigger lipid peroxidation-mediated ferroptosis. These findings highlight the innovative role of single-atom Ru in optimizing sonosensitizers for SDT-induced ferroptosis, demonstrating its potential for advancing cancer therapy.

A cascaded amplification carrier-free nanoplatform for synergistic photothermal/ferroptosis therapy via dual antioxidant pathway disruption in cervical cancer

Cellular defense mechanisms against ferroptosis are primarily mediated by antiferroptotic regulators, particularly glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1). Notably, singlet oxygen (1O2) generated through photoactivation of organic small-molecule photosensitizers (PSs) has been demonstrated to deplete both glutathione (GSH) and nicotinamide adenine dinucleotide phosphate (NADPH). This dual depletion mechanism effectively disrupts the GSH/GPX4 redox axis and the NADPH/FSP1/ubiquinone (CoQ) antioxidant system, thereby potentiating ferroptosis. In this study, we engineered a tumor-targeting amphiphilic iridium-based photosensitizer nanoplatform (Ir-TCF3P-FA NPs) for synergistic photothermal-ferroptosis therapy. Specifically, GSH depletion and NADPH oxidation by 1O2 produced via Ir-TCF3P-FA NPs at 450 nm can suppress the expression of GPX4 and FSP1, amplifying ferroptosis. Additionally, TCF3P exhibited high photothermal conversion efficiency at 808 nm, which not only can enhance photothermal therapy (PTT) efficacy but also facilitated 1O2 generation. The Ir-TCF3P-FA NPs enable effective tumor-targeted delivery and fluorescence/photoacoustic imaging for in vivo distribution tracking. In vivo studies revealed that dual-laser irradiation of Ir-TCF3P-FA NPs provided potent therapeutic efficacy, significantly inhibiting human cervical cancer progression in murine models. This cascaded amplification carrier-free nanoplatform holds promise for clinical multimodal treatment of cervical cancer.

Reprogramming Lung Redox Homeostasis by NIR Driven Ultra-Small Pd Loaded Covalent Organic Framework Inhibits NF-κB Pathway for Acute Lung Injury Immunotherapy

Acute lung injury (ALI) refers to damage to lung related cells, typically caused by an uncontrollable inflammatory response, and over-generated reactive oxygen species (ROS). Increasing evidence suggests that reprogramming lung redox homeostasis holds significant potentials for the clinical treatment of ALI. Herein, the simple synthesis of ultra-small Pd loaded covalent organic framework (COF) (TP@Pd) is reported, which, when combined with near infrared (NIR) irradiation, exhibits nanozyme functionalities, including multiple enzyme mimicking activities and broad spectrum ROS scavenging, thereby promoting tissue repair for ALI immunotherapy. Mechanistically, through the therapeutic strategy of TP@Pd+NIR, the damaged cells and tissues are ameliorated by decreasing intracellular ROS levels (total ROS, ·OH and ·O2 -), downregulating inflammatory cytokines levels (IL-6, TNF-α and IL-1β), upregulating antioxidant factor level (SOD2), inducing macrophage M2 directional polarization (downregulation of iNOS and CD86, and upregulation of IL-10 and CD206), activating immunoregulation (CD4+/CD8+ ratio increase), promoting tissue repair factor levels (upregulation of HSP70 and CD31), and suppressing the NF-κB signaling pathway (downregulation of phosphorylated p65 and IκBα). Furthermore, following intravenous (IV) injection in rats, TP@Pd accumulated in lung tissue for 6 h, indicating the promising therapeutic efficacy via this administration route. Notably, the TP@Pd+NIR strategy demonstrated the excellent synergistic effects in alleviating lung inflammation storms, reducing diffuse alveolar damage, and accelerating lung tissue repair. Summarily, this work has designed a novel TP@Pd+NIR strategy for the synergistic enhancement of ALI amelioration, which may serve as a promising therapeutic approach for other ROS related diseases.

Preparation of La2(WO4)3/CuWO4 composite nanomaterials with enhanced sonodynamic anti-glioma activity

Introduction

Sonodynamic therapy (SDT) is an innovative way to treat tumors by activating sonosensitizers via ultrasound (US). The development of sonosensitizers with high sonodynamic activity is the key to promote the clinical application of SDT.

Methods

In this study, a novel sonosensitizer, La2(WO4)3/CuWO4 composite LC-10, was prepared by two-step hydrothermal method and characterized. In addition, the sonodynamic antitumor activity of La2(WO4)3/CuWO4 composite LC-10 was investigated using u251 glioma cells as a model.

Results and Discussion

The results showed that compared with La2(WO4)3 and CuWO4, La2(WO4)3/CuWO4 composite had better sonodynamic antitumor activity, and LC-10 had good biosafety at concentrations below 50 μg/mL. After La2(WO4)3 and CuWO4 formed La2(WO4)3/CuWO4 composite, the recombination of electron-hole (e --h +) pairs were effectively inhibited, and more strongly oxidizing ROS was produced, inducing apoptosis of u251 glioma cells. In which, singlet oxygen (1O2) and hydroxyl radical (·OH), especially the production of ⋅OH, played an important role in the La2(WO4)3/CuWO4 composite mediated SDT antitumor process. The results of this study would offer a foundation for the design of CuWO4 base nano-sonosensitizers and its further clinical application in SDT antitumor. In addition, it also provided a new strategy for the design and development of novel nano-sonosensitizers with excellent sonodynamic activity.

Sono-Piezo Dynamic Therapy: Utilizing Piezoelectric Materials as Sonosensitizer for Sonodynamic Therapy

Sonodynamic therapy (SDT) represents a promising approach for cancer treatment. Compared to photodynamic therapy, SDT offers increased penetration depth and higher precision. However, the practical application of SDT is constrained by the low water solubility, poor tumor specificity, and metabolic susceptibility of most sonosensitizers. Recent research has explored the use of piezoelectric materials as sonosensitizers in cancer treatment and inhibition of bacterial growth. Upon ultrasound excitation, the separation of electron-hole (e--h+) pairs occurs within the piezoelectric material. By improving the crystal structure of the material or incorporating other nanoparticles to prevent rapid recombination of e--h+ pairs, the piezoelectric material accumulates charges in the conduction band and valence band, achieving the redox potential of O2/·O2 -. This enables the piezoelectric material to serve as a sonosensitizer, leading to the concept termed Sono-Piezo Dynamic Therapy (SPDT). This review aims to define the concept of SPDT, provide a systematic overview of the historical development of piezoelectric materials in the application of SDT, and elucidate the potential mechanisms by which piezoelectric materials act as sonosensitizers. Importantly, various piezoelectric materials will be discussed in terms of their feasibility, advantages, and disadvantages as sonosensitizers, offering new perspectives for identifying potential sonosensitizers.

Covalent organic frameworks in cancer theranostics: advancing biomarker detection and tumor-targeted therapy

In recent years, covalent organic frameworks (COFs) have garnered considerable attention in the field of onco-nanotechnology as a new type of nanoporous construct due to their promising physicochemical properties, ease of modification, and ability to be coupled with several moieties and therapeutic molecules. They can not only be used as biocompatible nanocarriers to deliver therapeutic payloads to the tumor zone selectively but can also be combined with a variety of therapeutic modalities to achieve the desired treatments. This review comprehensively presented recent achievements and progress in COF-based cancer diagnosis, detection, and cancer therapy to provide a better prospect for further research. Herein our primary emphasis lies on exploring the application of COFs as potential sensors for cancer-derived biomarkers that have received comparatively less attention in previous discussions. While the utilization of COFs in solid tumor therapy has faced significant challenges in scientific research and clinical applications, we reviewed the most promising features that underscore their potential in cancer theranostics.

Mechanisms and Applications of Manganese-Based Nanomaterials in Tumor Diagnosis and Therapy

Tumors are the second most common cause of mortality globally, ranking just below heart disease. With continuous advances in diagnostic technology and treatment approaches, the survival rates of some cancers have increased. Nevertheless, due to the complexity of the mechanisms underlying tumors, cancer remains a serious public health issue that threatens the health of the population globally. Manganese (Mn) is an essential trace element for the human body. Its regulatory role in tumor biology has received much attention in recent years. Developments in nanotechnology have led to the emergence of Mn-based nanoparticles that have great potential for use in the diagnosis and treatment of cancers. Mn-based nanomaterials can be integrated with conventional techniques, including chemotherapy, radiation therapy, and gene therapy, to augment their therapeutic effectiveness. Further, Mn-based nanomaterials can play a synergistic role in emerging treatment strategies for tumors, such as immunotherapy, photothermal and photodynamic therapy, electromagnetic hyperthermia, sonodynamic therapy, chemodynamic therapy, and intervention therapy. Moreover, Mn-based nanomaterials can enhance both the precision of tumor diagnostics and the capability for combined diagnosis and treatment. This article examines the roles and associated mechanisms of Mn in the field of physiology and tumor biology, with a focus on the application prospects of Mn-based nanomaterials in tumor diagnosis and treatment.

Nanomaterials Enhanced Sonodynamic Therapy for Multiple Tumor Treatment

Sonodynamic therapy (SDT) as an emerging modality for malignant tumors mainly involves in sonosensitizers and low-intensity ultrasound (US), which can safely penetrate the tissue without significant attenuation. SDT not only has the advantages including high precision, non-invasiveness, and minimal side effects, but also overcomes the limitation of low penetration of light to deep tumors. The cytotoxic reactive oxygen species can be produced by the utilization of sonosensitizers combined with US and kill tumor cells. However, the underlying mechanism of SDT has not been elucidated, and its unsatisfactory efficiency retards its further clinical application. Herein, we shed light on the main mechanisms of SDT and the types of sonosensitizers, including organic sonosensitizers and inorganic sonosensitizers. Due to the development of nanotechnology, many novel nanoplatforms are utilized in this arisen field to solve the barriers of sonosensitizers and enable continuous innovation. This review also highlights the potential advantages of nanosonosensitizers and focus on the enhanced efficiency of SDT based on nanosonosensitizers with monotherapy or synergistic therapy for deep tumors that are difficult to reach by traditional treatment, especially orthotopic cancers.

Single-atom-doped piezocatalyst induces copper-free cuproptosis in tumor therapy

Cuproptosis, a distinct cell death pathway, has been integrated into nanomedicine for disease theranostics. However, current nanosystems inducing cuproptosis rely on exogenous toxic copper ions, limiting the scope of biomaterials. Developing nanoplatforms that induce cuproptosis without exogenous copper holds substantial promise. Here, we engineered a two-dimensional iron (Fe) single-atom-doped molybdenum disulfide (MoS2) piezocatalyst (Fe-MoS2) for tumor therapy. Incorporating single Fe atoms enhances MoS2 piezoelectric polarization via charge redistribution and modulates Fe and Mo oxidation states, enabling multifaceted enzymatic activities, including peroxidase-, glutathione oxidase-, oxidase-, and catalase-like activities. Upon ultrasound stimulation, the Fe-MoS2 nanocatalyst generates reactive oxygen species and depletes glutathione via synergistic piezocatalytic and enzyocatalytic effects, disrupting copper ion homeostasis and inducing cuproptosis, concurrently triggering ferroptosis and ferritinophagy, which collectively enhances tumor suppression. This study represents the first paradigm to introduce a copper-free piezocatalyst for initiating cuproptosis, substantially advancing the applications of cuproptosis in tumor therapy.

Modulating Pore Wall Chemistry Empowers Sonodynamic Activity of Two-Dimensional Covalent Organic Framework Heterojunctions for Pro-Oxidative Nanotherapy

Covalent organic frameworks (COFs) have garnered growing interest in the field of biomedicine; however, their application in sonodynamic therapy remains underexplored due to limited understanding of their intrinsic activity and structure-property relationships. Here, we present a pore wall chemistry modulation strategy for empowering sonodynamic activity to two-dimensional (2D) COF heterojunctions through in situ growth of COFs on bismuth oxycarbonate nanosheets (B NSs). Compared to the negligible sonodynamic effects observed in the pristine B NSs, the 2D heterojunction with vinyl-decorated COF pore walls demonstrates a 3.6-fold enhancement in sonocatalytic singlet oxygen generation. This performance also significantly outperforms that of isoreticular COFs functionalized with methoxy or non-substituted groups. Mechanistic studies reveal that the vinyl groups in the B@COF (BC) heterojunction facilitate the separation and transfer of charge carriers while also enhancing the adsorption of oxygen molecules. Furthermore, peroxymonosulfate (PMS) loading into the porous COFs boosts the therapeutic efficacy of antitumor nanotherapy via sonocatalytic dual oxidative species generation. These findings underscore the critical role of pore wall chemistry in modulating the sonocatalytic properties of COFs, and advance the development of COF-based sonosensitizers for pro-oxidative applications.

Facile Synthesis of Fe-Based Metal-Quinone Networks for Mutually Enhanced Mild Photothermal Therapy and Ferroptosis

Mild photothermal therapy (MPTT) has emerged as a promising therapeutic modality for attenuating thermal damage to the normal tissues surrounding tumors, while the heat-induced upregulation of heat shock proteins (HSPs) greatly compromises the curative efficacy of MPTT by increasing cellular thermo-tolerance. Ferroptosis has been identified to suppress the overexpression of HSPs by the accumulation of lipid peroxides and reactive oxygen species (ROS), but is greatly restricted by overexpressed glutathione (GSH) in tumor microenvironment and undesirable ROS generation efficiency. Herein, a synergistic strategy based on the mutual enhancement of MPTT and ferroptosis is proposed for cleaving HSPs to recover tumor cell sensitivity. A facile method for fabricating a series of Fe-based metal-quinone networks (MQNs) by coordinated assembly is proposed and the representative FTP MQNs possess high photothermal conversion efficiency (69.3 %). Upon 808 nm laser irradiation, FTP MQNs not only trigger effective MPTT to induce apoptosis but more significantly, potentiate Fenton reaction and marked GSH consumption to boost ferroptosis, and the reinforced ferroptosis effect in turn can alleviate the thermal resistance by declining the HSP70 defense and reducing ATP levels. This study provides a valuable rationale for constructing a large library of MQNs for achieving mutual enhancement of MPTT and ferroptosis.

Fluorocarbon-Functionalized Polymerization-Induced Self-Assembly Nanoparticles Alleviate Hypoxia to Enhance Sonodynamic Cancer Therapy

Sonodynamic therapy (SDT) is an ultrasound-based, noninvasive cancer treatment that targets tumor cells by triggering reactive oxygen species production. However, the limited accumulation of sonosensitizers and the insufficient supply of O2 to the hypoxic environment at the tumor site greatly limit the effectiveness of SDT. To address these issues, positively charged porphyrin-containing nanoparticles (NPs) from self-assembling of fluorocarbon/polyethylene glycol amphiphilic block copolymer, which is synthesized through reversible addition-fragmentation chain transfer polymerization, are constructed. The NPs with fluorocarbon core and positively charged hydrophilic shells not only stabilize the sonosensitizer and improve its cellular uptake, but also act as an O2 carrier alleviating the hypoxic tumor environment. In vitro and in vivo experiments demonstrate that the NPs effectively deliver O2 to the tumor and supply sufficient O2 to Renca cells after ultrasound treatment. Consequently, the NPs inhibit hypoxia-induced resistance to SDT and significantly produce reactive oxygen species by activated porphyrin moieties, inducing apoptosis in cancer cells. These oxygen-enhanced sonosensitizer NPs hold promise for cancer therapies such as photodynamic therapy, radiotherapy, and chemotherapy by overcoming hypoxia-induced resistance.

Reticular Chemistry for Enhancing Bioentity Stability and Functional Performance

Addressing the fragility of bioentities that results in instability and compromised performance during storage and applications, reticular chemistry, specifically through metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), offers versatile platforms for stabilization and enhancement of bioentities. These highly porous frameworks facilitate efficient loading and mass transfer, offer confined environments and selective permeability for stabilization and protection, and enable finely tunable biointerfacial interactions and microenvironments for function optimization, significantly broadening the applications of various bioentities, including enzymes, nucleic acids, cells, etc. This Perspective outlines strategies for integrating bioentities with reticular frameworks, highlighting new design ideas for existing issues within these strategies. It emphasizes the crucial roles of these frameworks for bioentities in enhancing stability, boosting activity, imparting non-native functions, and synergizing bioentity systems. Concluding with a discussion of the challenges and prospects in the design, characterization, and practical applications of these biocomposites, this Perspective aims to inspire further development of high-performance biocomposites in this promising field.

Engineering Sonosensitizer-Derived Nanotheranostics for Augmented Sonodynamic Therapy

Sonodynamic therapy (SDT), featuring noninvasive, deeper penetration, low cost, and repeatability, is a promising therapy approach for deep-seated tumors. However, the general or only utilization of SDT shows low efficiency and unsatisfactory treatment outcomes due to the complicated tumor microenvironment (TME) and SDT process. To circumvent the issues, three feasible approaches for enhancing SDT-based therapeutic effects, including sonosensitizer optimization, strategies for conquering hypoxia TME, and combinational therapy are summarized, with a particular focus on the combination therapy of SDT with other therapy modalities, including chemodynamic therapy, photodynamic therapy, photothermal therapy, chemotherapy, starvation therapy, gas therapy, and immunotherapy. In the end, the current challenges in SDT-based therapy on tumors are discussed and feasible approaches for enhanced therapeutic effects are provided. It is envisioned that this review will provide new insight into the strategic design of high-efficiency sonosensitizer-derived nanotheranostics, thereby augmenting SDT and accelerating the potential clinical transformation.

Nanosonosensitizer Optimization for Enhanced Sonodynamic Disease Treatment

Low-intensity ultrasound-mediated sonodynamic therapy (SDT), which, by design, integrates sonosensitizers and molecular oxygen to generate therapeutic substances (e.g., toxic hydroxyl radicals, superoxide anions, or singlet oxygen) at disease sites, has shown enormous potential for the effective treatment of a variety of diseases. Nanoscale sonosensitizers play a crucial role in the SDT process because their structural, compositional, physicochemical, and biological characteristics are key determinants of therapeutic efficacy. In particular, advances in materials science and nanotechnology have invigorated a series of optimization strategies for augmenting the therapeutic efficacy of nanosonosensitizers. This comprehensive review systematically summarizes, discusses, and highlights state-of-the-art studies on the current achievements of nanosonosensitizer optimization in enhanced sonodynamic disease treatment, with an emphasis on the general design principles of nanosonosensitizers and their optimization strategies, mainly including organic and inorganic nanosonosensitizers. Additionally, recent advancements in optimized nanosonosensitizers for therapeutic applications aimed at treating various diseases, such as cancer, bacterial infections, atherosclerosis, and autoimmune diseases, are clarified in detail. Furthermore, the biological effects of the improved nanosonosensitizers for versatile SDT applications are thoroughly discussed. The review concludes by highlighting the current challenges and future opportunities in this rapidly evolving research field to expedite its practical clinical translation and application.

Albumin-based co-loaded sonosensitizer and STING agonist nanodelivery system for enhanced sonodynamic and immune combination antitumor therapy

STING agonists can activate natural and adaptive immune responses, and are expected to become a new type of immunotherapy drug for tumor therapy. However, how to target deliver STING agonists to tumor tissues is a key factor affecting the efficacy of tumor treatment. Sonodynamic therapy (SDT) has become a research hotspot in the field of cancer treatment due to its non-invasive, spatiotemporally controllable, and high tissue penetration capabilities. Therefore, how to choose the appropriate drug delivery strategy, build a suitable drug delivery system to co-deliver photosensitizers and STING agonists, is a challenge faced in the tumor treatment. In this study, we developed an albumin-based nanodelivery system named FA-ICG&MnOx@HSA that co-loaded the sonosensitizers indocyanine green (ICG) and manganese oxide (MnOx). This approach achieved folate receptor-targeting mediated tumor delivery and tumor microenvironment (TME)-responsive release facilitated by high levels of glutathione (GSH) and hydrogen peroxide (H2O2), which catalyze oxygen generation to potentiate SDT efficacy in killing tumors and inducing immunogenic cell death (ICD). Simultaneously, the released Mn2+ acted as a STING agonist promoting dendritic cell maturation, IFN-β production, and proliferation of T cells. Ultimately, this albumin based co-loaded sonosensitizer and STING agonist demonstrated promising potential for advancing tumor treatment.

Immunomodulatory microneedle patch for enhanced Ferroptosis and immunogenic cell death in postoperative tumor therapy

Microneedle technologies have emerged as a promising transdermal drug delivery platform for postoperative tumor therapy. Despite their potential, enhancing intracellular drug delivery to tumor cells and boosting the therapeutic efficiency of microneedles pose significant challenges. Herein, we develop a nanomedicine-loaded microneedle to enhance the induction of ferroptosis and immunogenic cell death for postoperative tumor therapy. This advancement is achieved by pre-formulating small molecule drugs with transition metal and protein templates into nanomedicine. Upon insertion into the tumors, the microneedle rapidly dissolves, facilitating the release and subsequent cellular uptake of the nanomedicine by tumor cells. Notably, the nanomedicine can release Mn ions and ferroptosis-inducer sulfasalazine (SAS) under acidic conditions. Furthermore, the released Mn ions can produce reactive oxygen species, which decrease the levels of glutathione (GSH) and glutathione peroxidase 4 (GPX4) with increased lipid peroxidation and enhanced induction of ferroptosis. Besides, the treatment stimulates immunogenic cell death through the cell surface exposure of calreticulin (CRT) and release of high-mobility group box 1 (HMGB1), which further stimulates dendric cell maturation, T cell infiltration, and macrophage polarization towards the M1 phenotype. Consequently, this strategy significantly inhibits postoperative tumor regrowth and extends overall survival. Our study indicates the potential of the combination of nanomedicine and microneedle to improve postoperative therapeutic efficiency.

Fe-HCOF-PEG2000 as a Hypoxia-Tolerant Photosensitizer to Trigger Ferroptosis and Enhance ROS-Based Cancer Therapy

Background

The hypoxic tumor microenvironment and single mechanisms severely limit the photodynamic therapy (PDT) efficiency of covalent organic framework (COF) nanoparticles in cancer treatment.

Purpose

Here, we propose an iron-loaded, hydrophilic 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG2000)-modified hollow covalent organic framework (HCOF), Fe-HCOF-PEG2000, for use in hypoxic PDT and ferroptosis therapy owing to its type I and II photodynamic ability and iron nanoparticle loading property.

Results

Fe-HCOF-PEG2000 nanoparticles (Fe-HCOFs-PEG2000) with semiconducting polymers and microporous skeletons allow efficient photophysical properties. Moreover, the iron nanoparticles on Fe-HCOF-PEG2000 caused ferroptosis and further enhanced tumor elimination under normoxic and hypoxic conditions. DSPE-PEG2000 endowed Fe-HCOF-PEG2000 with hydrophilicity, allowing it to circulate and accumulate in organs rich in blood supply, especially tumors. 808 nm NIR activated Fe-HCOF-PEG2000 aggregated in tumors and significantly inhibited tumor growth under hypoxia.

Conclusion

To our knowledge, Fe-HCOF-PEG2000 is the leading combination of type I/II PDT and ferroptosis. The strong antitumor effects of this nanomaterial suggest prospects for clinical translation as a tumor nanotherapy drug.

NIR-triggered and Thermoresponsive Core-shell nanoparticles for synergistic anticancer therapy

Recent advancements in cancer treatment have underscored the inadequacy of conventional monotherapies in addressing complex malignant tumors. Consequently, there is a growing interest in synergistic therapies capable of overcoming the limitations of monotherapies, leading to more personalized and effective approaches. Among these, the combination of photothermal therapy (PTT) and chemotherapy has emerged as a promising avenue for tumor management. In this study, we present a novel approach utilizing thermoresponsive mesoporous silica nanoparticles (MSN) as a delivery system for the chemotherapeutic drug doxorubicin. By incorporating photothermal agent copper sulfide (CuS) nanoparticles into the MSN, the resulting composite material exhibits potent photothermal properties. Furthermore, the integration of an upper critical solution temperature (UCST) polymer within the silica outer layer serves as a "gatekeeper", enabling precise control over drug release kinetics. This innovative nanomaterial effectively merges thermoresponsive behavior with PTT, thereby minimizing the collateral damage associated with traditional chemotherapy on healthy tissues. Moreover, in both in vitro studies using mouse breast carcinoma cells (4 T1) and in vivo experiments utilizing a 4 T1 tumor-bearing mouse model, our nanomaterials demonstrated synergistic effects, enhancing the anti-tumor efficacy of combined PTT and chemotherapy. With its remarkable photothermal conversion efficiency, robust stability, and biocompatibility, the UCST-responsive nanoplatform holds immense potential for clinical applications.

Double-shelled, rattle-architecture covalent organic framework: harnessing morphological manipulation for enhanced synergistic multi-drug chemo-photothermal cancer therapy

Morphological modulation in covalent organic frameworks (COFs) with particular emphasis on the correlation between structure and target applications in biomedical fields, is currently in its early stage of evolution. Herein, a multifunctional rattle-architecture imine-based COF with a mobile core of gold nanoparticles (Au NPs) and an outer polydopamine (PDA) shell, tailored for cancer treatment, has been developed to effectively integrate dual responsive release capabilities with the potential for multiple therapeutic applications. The engineered COF displays outstanding crystallinity, a suitable size and precisely controlled morphological characteristics. By leveraging COF and PDA attributes, the successful co-delivery of hydrophilic doxorubicin (DOX) and hydrophobic docetaxel (DTX) within discrete compartments is achieved responsive to both pH and near-infrared triggers. Designed nanocarrier outperforms prior COFs with a superior 83.7% DOX loading capacity, thanks to its expansive internal space and porous shell. Taking advantage of the inclusion of Au core and the concurrent presence of COF and PDA outer shells, the nanocarrier exhibits a significant photothermal-conversion capability. The rattle-architecture double-shelled Au@RCOF@PDA were functionalized with poly(ethylene glycol)-folic acid (PEG-FA) to confer the system with active-targeting capability and enhanced biocompatibility. Through in vitro and in vivo evaluations, the designed system demonstrates an exceptional synergistic anti-tumor effect, along with favorable biosafety and histocompatibility. This study not only sheds light on the remarkable merits offered by regulating the morphology of COF-based systems in cancer therapy but also highlights the potential for synergistic therapeutic approaches in advancing cancer treatment strategies.

Ultrasound-Based Micro-/Nanosystems for Biomedical Applications

Due to the intrinsic non-invasive nature, cost-effectiveness, high safety, and real-time capabilities, besides diagnostic imaging, ultrasound as a typical mechanical wave has been extensively developed as a physical tool for versatile biomedical applications. Especially, the prosperity of nanotechnology and nanomedicine invigorates the landscape of ultrasound-based medicine. The unprecedented surge in research enthusiasm and dedicated efforts have led to a mass of multifunctional micro-/nanosystems being applied in ultrasound biomedicine, facilitating precise diagnosis, effective treatment, and personalized theranostics. The effective deployment of versatile ultrasound-based micro-/nanosystems in biomedical applications is rooted in a profound understanding of the relationship among composition, structure, property, bioactivity, application, and performance. In this comprehensive review, we elaborate on the general principles regarding the design, synthesis, functionalization, and optimization of ultrasound-based micro-/nanosystems for abundant biomedical applications. In particular, recent advancements in ultrasound-based micro-/nanosystems for diagnostic imaging are meticulously summarized. Furthermore, we systematically elucidate state-of-the-art studies concerning recent progress in ultrasound-based micro-/nanosystems for therapeutic applications targeting various pathological abnormalities including cancer, bacterial infection, brain diseases, cardiovascular diseases, and metabolic diseases. Finally, we conclude and provide an outlook on this research field with an in-depth discussion of the challenges faced and future developments for further extensive clinical translation and application.

Ferroptosis resistance in cancer cells: nanoparticles for combination therapy as a solution

Ferroptosis is a form of regulated cell death (RCD) characterized by iron-dependent lipid peroxidation. Ferroptosis is currently proposed as one of the most promising means of combating tumor resistance. Nevertheless, the problem of ferroptosis resistance in certain cancer cells has been identified. This review first, investigates the mechanisms of ferroptosis induction in cancer cells. Next, the problem of cancer cell resistance to ferroptosis, as well as the underlying mechanisms is discussed. Recently discovered ferroptosis-suppressing biomarkers have been described. The various types of nanoparticles that can induce ferroptosis are also discussed. Given the ability of nanoparticles to combine multiple agents, this review proposes nanoparticle-based ferroptosis cell death as a viable method of circumventing this resistance. This review suggests combining ferroptosis with other forms of cell death, such as apoptosis, cuproptosis and autophagy. It also suggests combining ferroptosis with immunotherapy.

Facile Synthesis of a Multifunctional Porous Organic Polymer Nanosonosensitizer (mHM@HMME) for Enhanced Cancer Sonodynamic Therapy

Sonodynamic therapy (SDT), which involves the activation of sonosensitizers to generate cytotoxic reactive oxygen species under ultrasound irradiation, is a promising noninvasive modality for cancer treatment. However, the clinical translational application of SDT is impeded by the lack of efficient sonosensitizers, the inefficient accumulation of sonosensitizers at tumor sites, and the complicated immunosuppressive tumor microenvironment. Herein, we developed a facilely synthesized multifunctional porous organic polymer nanosonosensitizer (mHM@HMME) for enhanced SDT. Specifically, mHM@HMME nanosonosensitizers were prepared by incorporating chemotherapeutic mitoxantrone into the one-step synthesis process of disulfide bond containing porous organic polymers, followed by loading with organic sonosensitizer (HMME) and camouflaging with a cancer cell membrane. Due to the cancer cell membrane camouflage, this multifunctional mHM@HMME nanosonosensitizer showed prolonged blood circulation and tumor targeting aggregation. Under ultrasound irradiation, the mHM@HMME nanosonosensitizer exhibited a satisfactory SDT performance both in vitro and in vivo. Moreover, the potent SDT combined with glutathione-responsive drug release in tumor cells induced robust immunogenic cell death to enhance the antitumor effect of SDT in turn. Overall, this facilely synthesized multifunctional mHM@HMME nanosonosensitizer shows great potential application in enhanced SDT.

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

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

Carrier-Free Self-Assembly Nano-Sonosensitizers for Sonodynamic-Amplified Cuproptosis-Ferroptosis in Glioblastoma Therapy

Cuproptosis is a newly discovered form of programmed cell death significantly depending on the transport efficacy of copper (Cu) ionophores. However, existing Cu ionophores, primarily small molecules with a short blood half-life, face challenges in transporting enough amounts of Cu ions into tumor cells. This work describes the construction of carrier-free nanoparticles (Ce6@Cu NPs), which self-assembled by the coordination of Cu2+ with the sonosensitizer chlorin e6 (Ce6), facilitating sonodynamic-triggered combination of cuproptosis and ferroptosis. Ce6@Cu NPs internalized by U87MG cells induce a sonodynamic effect and glutathione (GSH) depletion capability, promoting lipid peroxidation and eventually inducing ferroptosis. Furthermore, Cu+ concentration in tumor cells significantly increases as Cu2+ reacts with reductive GSH, resulting in the downregulation of ferredoxin-1 and lipoyl synthase. This induces the oligomerization of lipoylated dihydrolipoamide S-acetyltransferase, causing proteotoxic stress and irreversible cuproptosis. Ce6@Cu NPs possess a satisfactory ability to penetrate the blood-brain barrier, resulting in significant accumulation in orthotopic U87MG-Luc glioblastoma. The sonodynamic-triggered combination of ferroptosis and cuproptosis in the tumor by Ce6@Cu NPs is evidenced both in vitro and in vivo with minimal side effects. This work represents a promising tumor therapeutic strategy combining ferroptosis and cuproptosis, potentially inspiring further research in developing logical and effective cancer therapies based on cuproptosis.

Integrin αvβ3-targeted self-assembled polypeptide nanomicelles for efficacious sonodynamic therapy against breast cancer

Sonodynamic therapy (SDT) is an advanced non-invasive cancer treatment strategy with moderate tissue penetration, less invasiveness and a reliable curative effect. However, due to the low stability, potential bio-toxicity and lack of tumor targeting capability of most sonosensitizers, the vast clinical application of SDT has been challenging and limited. Therefore, it is desirable to develop a novel approach to implement sonosensitizers to SDT for cancer treatments. In this study, an amphiphilic polypeptide was designed to effectively encapsulate rose bengal (RB) as a model sonosensitizer to form peptido-nanomicelles (REPNs). The as-fabricated REPNs demonstrated satisfactory tumor targeting and fluorescence performances, which made them superb imaging tracers in vivo. In the meantime, they generated considerable amounts of reactive oxygen species (ROS) to promote tumor cell apoptosis under ultrasound irradiation and showed excellent anti-tumor performance without obvious side effects. These engineered nanomicelles in combination with medical ultrasound may be used to achieve integrin αvβ3-targeted sonodynamic therapy against breast cancer, and it is also a promising non-invasive cancer treatment strategy for clinical translations.

Hypoxia-triggered degradable porphyrinic covalent organic framework for synergetic photodynamic and photothermal therapy of cancer

Nanomedicines receive great attention in cancer treatment. Nevertheless, nonbiodegradable and long-term retention still limit their clinical translation. Herein, we successfully synthesize a hypoxia-triggered degradable porphyrinic covalent organic framework (HPCOF) for antitumor therapy in vivo. HPCOF possesses wide absorption in near infrared region (NIR) which endows HPCOF excellent photothermal conversion efficiency and photoacoustic (PA) imaging ability. Moreover, HPCOF exhibits excellent photodynamic and photothermal effect under special-wavelength laser irradiation. For the first time, the in vitro and in vivo tests demonstrate that HPCOF shows effective therapeutic effect for the combination of PDT and PTT under the monitoring of PA imaging. Importantly, in tumor region, HPCOF could be triggered by hypoxia microenvironment and collapsed gradually, then cleared from the body after treatment. This work fabricates a novel COF for cancer treatment and testifies great potential of HPCOF in clinical application with reducing long-term toxicity.

Strategies for utilizing covalent organic frameworks as host materials for the integration and delivery of bioactives

Covalent organic frameworks (COFs), a new and developing class of porous framework materials, are considered a type of promising carrier for the integration and delivery of bioactives, which have diverse fascinating merits, such as a large specific surface area, designable and specific porosity, stable and orderly framework structure, and various active sites. However, owing to the significant differences among bioactives (including drugs, proteins, nucleic acid, and exosomes), such as size, structure, and physicochemical properties, the interaction between COFs and bioactives also varies. In this review, we firstly summarize three strategies for the construction of single or hybrid COF-based matrices for the delivery of cargos, including encapsulation, covalent binding, and coordination bonding. Besides, their smart response release behaviors are also categorized. Subsequently, the applications of cargo@COF biocomposites in biomedicine are comprehensively summarized, including tumor therapy, central nervous system (CNS) modulation, biomarker analysis, bioimaging, and anti-bacterial therapy. Finally, the challenges and opportunities in this field are briefly discussed.

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.

Dye-augmented bandgap engineering of a degradable cascade nanoreactor for tumor immune microenvironment-enhanced dynamic phototherapy of breast cancer

Non-invasive precision tumor dynamic phototherapy has broad application prospects. Traditional semiconductor materials have low photocatalytic activity and low reactive oxygen species (ROS) production rate due to their wide band gap, resulting in unsatisfactory phototherapy efficacy for tumor treatment. Employing the dye-sensitization mechanism can significantly enhance the catalytic activity of the materials. We develop a multifunctional nanoplatform (BZP) by leveraging the benefits of bismuth-based semiconductor nanomaterials. BZP possesses robust ROS generation and remarkable near-infrared photothermal conversion capabilities for improving tumor immune microenvironment and achieving superior phototherapy sensitization. BZP produces highly cytotoxic ROS species via the photocatalytic process and cascade reaction, amplifying the photocatalytic therapy effect. Moreover, the simultaneous photothermal effect during the photocatalytic process facilitates the improvement of therapeutic efficacy. Additionally, BZP-mediated phototherapy can trigger the programmed death of tumor cells, stimulate dendritic cell maturation and T cell activation, modulate the tumor immune microenvironment, and augment the therapeutic effect. Hence, this study demonstrates a promising research paradigm for tumor immune microenvironment-improved phototherapy. STATEMENT OF SIGNIFICANCE: Through the utilization of dye sensitization and rare earth doping techniques, we have successfully developed a biodegradable bismuth-based semiconductor nanocatalyst (BZP). Upon optical excitation, the near-infrared dye incorporated within BZP promptly generates free electrons, which, under the influence of the Fermi energy level, undergo transfer to BiF3 within BZP, thereby facilitating the effective separation of electron-hole pairs and augmenting the catalytic capability for reactive oxygen species (ROS) generation. Furthermore, a cascade reaction mechanism generates highly cytotoxic ROS, which synergistically depletes intracellular glutathione, thereby intensifying oxidative stress. Ultimately, this dual activation strategy, combining oxidative and thermal damage, holds significant potential for tumor immunotherapy.

Covalent Organic Frameworks: Opportunities for Rational Materials Design in Cancer Therapy

Nanomedicines are extensively used in cancer therapy. Covalent organic frameworks (COFs) are crystalline organic porous materials with several benefits for cancer therapy, including porosity, design flexibility, functionalizability, and biocompatibility. This review examines the use of COFs in cancer therapy from the perspective of reticular chemistry and function-oriented materials design. First, the modification sites and functionalization methods of COFs are discussed, followed by their potential as multifunctional nanoplatforms for tumor targeting, imaging, and therapy by integrating functional components. Finally, some challenges in the clinical translation of COFs are presented with the hope of promoting the development of COF-based anticancer nanomedicines and bringing COFs closer to clinical trials.

Spatially Asymmetric Nanoparticles for Boosting Ferroptosis in Tumor Therapy

Despite its effectiveness in eliminating cancer cells, ferroptosis is hindered by the high natural antioxidant glutathione (GSH) levels in the tumor microenvironment. Herein, we developed a spatially asymmetric nanoparticle, Fe3O4@DMS&PDA@MnO2-SRF, for enhanced ferroptosis. It consists of two subunits: Fe3O4 nanoparticles coated with dendritic mesoporous silica (DMS) and PDA@MnO2 (PDA: polydopamine) loaded with sorafenib (SRF). The spatial isolation of the Fe3O4@DMS and PDA@MnO2-SRF subunits enhances the synergistic effect between the GSH-scavengers and ferroptosis-related components. First, the increased exposure of the Fe3O4 subunit enhances the Fenton reaction, leading to increased production of reactive oxygen species. Furthermore, the PDA@MnO2-SRF subunit effectively depletes GSH, thereby inducing ferroptosis by the inactivation of glutathione-dependent peroxidases 4. Moreover, the SRF blocks Xc- transport in tumor cells, augmenting GSH depletion capabilities. The dual GSH depletion of the Fe3O4@DMS&PDA@MnO2-SRF significantly weakens the antioxidative system, boosting the chemodynamic performance and leading to increased ferroptosis of tumor cells.

Chemical Sensors Based on Covalent Organic Frameworks

Covalent organic frameworks (COFs) are a type of crystalline porous polymer composed of light elements through strong covalent bonds. COFs have attracted considerable attention due to their unique designable structures and excellent material properties. Currently, COFs have shown outstanding potential in various fields, including gas storage, pollutant removal, catalysis, adsorption, optoelectronics, and their research in the sensing field is also increasingly flourishing. In this review, we focus on COF-based sensors. Firstly, we elucidate the fundamental principles of COF-based sensors. Then, we present the primary application areas of COF-based sensors and their recent advancements, encompassing gas, ions, organic compounds, and biomolecules sensing. Finally, we discuss the future trends and challenges faced by COF-based sensors, outlining their promising prospects in the field of sensing.

Boosting Reactive Oxygen Species Generation with a Dual-Catalytic Nanomedicine for Enhanced Tumor Nanocatalytic Therapy

Generating lethal reactive oxygen species (ROS) within tumors by nanocatalytic medicines is an advanced strategy for tumor-specific therapy in recent years. Nevertheless, the low yield of ROS restrains its therapeutic efficiency. Herein, a dual-catalytic nanomedicine based on tumor microenvironment (TME)-responsive liposomal nanosystem co-delivering CuO2 and dihydroartemisinin (DHA) (LIPSe@CuO2&DHA) is developed to boost ROS generation against tumor. The liposomal nanosystem can degrade in the ROS-overexpressed TME and liberate CuO2 and DHA to initiate Cu-based dual-catalytic ROS generation. Serving as generators of H2O2 and Cu2+, CuO2 can self-produce plenty of toxic hydroxyl radicals via Fenton-like reaction in the acidic TME. Meanwhile, the released Cu2+ can catalyze DHA to generate cytotoxic C-centered radicals. Together, the self-supplied H2O2 and Cu-based dual-catalytic reaction greatly increase the intratumoral level of lethal ROS. Importantly, Cu2+ can decrease the GSH-mediated scavenging effect on the produced ROS via a redox reaction and undergo a Cu2+-to-Cu+ conversion to enhance the Fenton-like reaction, further guaranteeing the high efficiency of ROS generation. Resultantly, LIPSe@CuO2&DHA induces remarkable cancer cell death and tumor growth inhibition, which may present a promising nanocatalytic medicine for cancer therapy.

Ultrasmall PtMn nanoparticles as sensitive manganese release modulator for specificity cancer theranostics

Manganese-based nanomaterials (Mn-nanomaterials) hold immense potential in cancer diagnosis and therapies. However, most Mn-nanomaterials are limited by the low sensitivity and low efficiency toward mild weak acidity (pH 6.4-6.8) of the tumor microenvironment, resulting in unsatisfactory therapeutic effect and poor magnetic resonance imaging (MRI) performance. This study introduces pH-ultrasensitive PtMn nanoparticles as a novel platform for enhanced ferroptosis-based cancer theranostics. The PtMn nanoparticles were synthesized with different diameters from 5.3 to 2.7 nm with size-dominant catalytic activity and magnetic relaxation, and modified with an acidity-responsive polymer to create pH-sensitive agents. Importantly, R-PtMn-1 (3 nm core) presents "turn-on" oxidase-like activity, affording a significant enhancement ratio (pH 6.0/pH 7.4) in catalytic activity (6.7 folds), compared with R-PtMn-2 (4.2 nm core, 3.7 folds) or R-PtMn-3 (5.3 nm core, 2.1 folds), respectively. Moreover, R-PtMn-1 exhibits dual-mode contrast in high-field MRI. R-PtMn-1 possesses a good enhancement ratio (pH 6.4/pH 7.4) that is 3 or 3.2 folds for T1- or T2-MRI, respectively, which is higher than that of R-PtMn-2 (1.4 or 1.5 folds) or R-PtMn-3 (1.1 or 1.2 folds). Moreover, their pH-ultrasensitivity enabled activation specifically within the tumor microenvironment, avoiding off-target toxicity in normal tissues during delivery. In vitro studies demonstrated elevated intracellular reactive oxygen species production, lipid peroxidation, mitochondrial membrane potential changes, malondialdehyde content, and glutathione depletion, leading to enhanced ferroptosis in cancer cells. Meanwhile, normal cells remained unaffected by the nanoparticles. Overall, the pH-ultrasensitive PtMn nanoparticles offer a promising strategy for accurate cancer diagnosis and ferroptosis-based therapy.

Recent advances of ferroptosis in tumor: From biological function to clinical application

Ferroptosis is a recently recognized form of cell death with distinct features in terms of morphology, biochemistry, and molecular mechanisms. Unlike other types of cell death, ferroptosis is characterized by iron dependence, reactive oxygen species accumulation and lipid peroxidation. Recent studies have demonstrated that selective autophagy plays a vital role in the induction of ferroptosis, including ferritinophagy, lipophagy, clockophagy, and chaperone-mediated autophagy. Emerging evidence has indicated the involvement of ferroptosis in tumorigenesis through regulating various biological processes, including tumor growth, metastasis, stemness, drug resistance, and recurrence. Clinical and preclinical studies have found that novel therapies targeting ferroptosis exert great potential in the treatment of tumors. This review provides a comprehensive overview of the molecular mechanisms in ferroptosis, especially in autophagy-driven ferroptosis, discusses the recent advances in the biological roles of ferroptosis in tumorigenesis, and highlights the application of novel ferroptosis-targeted therapies in the clinical treatment of tumors.

Polymeric Bowl-Shaped Nanoparticles: Hollow Structures with a Large Opening on the Surface

Polymeric bowl-shaped nanoparticles (BNPs) are anisotropic hollow structures with large openings on the surface, which have shown advantages such as high specific area and efficient encapsulation, delivery and release of large-sized cargoes on demand compared to solid nanoparticles or closed hollow structures. Several strategies have been developed to prepare BNPs based on either template or template-free methods. For instance, despite the widely used self-assembly strategy, alternative methods including emulsion polymerization, swelling and freeze-drying of polymeric spheres, and template-assisted approaches have also been developed. It is attractive but still challenging to fabricate BNPs due to their unique structural features. However, there is still no comprehensive summary of BNPs up to now, which significantly hinders the further development of this field. In this review, the recent progress of BNPs will be highlighted from the perspectives of design strategies, preparation methods, formation mechanisms, and emerging applications. Moreover, the future perspectives of BNPs will also be proposed.

Stimuli responsive nanosonosensitizers for sonodynamic therapy

Sonodynamic therapy (SDT) has gained significant attention in the treatment of deep tumors and multidrug-resistant (MDR) bacterial infections due to its high tissue penetration depth, high spatiotemporal selectivity, and noninvasive therapeutic method. SDT combines low-intensity ultrasound (US) and sonosensitizers to produce lethal reactive oxygen species (ROS) and external damage, which is the main mechanism behind this therapy. However, traditional organic small-molecule sonosensitizers display poor water solubility, strong phototoxicity, and insufficient targeting ability. Inorganic sonosensitizers, on the other hand, have low ROS yield and poor biocompatibility. These drawbacks have hindered SDT's clinical transformation and application. Hence, designing stimuli-responsive nano-sonosensitizers that make use of the lesion's local microenvironment characteristics and US stimulation is an excellent alternative for achieving efficient, specific, and safe treatment. In this review, we provide a comprehensive overview of the currently accepted mechanisms in SDT and discuss the application of responsive nano-sonosensitizers in the treatment of tumor and bacterial infections. Additionally, we emphasize the significance of the principle and process of response, based on the classification of response patterns. Finally, this review emphasizes the potential limitations and future perspectives of SDT that need to be addressed to promote its clinical transformation.

Doxorubicin-Fe(III)-Gossypol Infinite Coordination Polymer@PDA:CuO2 Composite Nanoparticles for Cost-Effective Programmed Photothermal-Chemodynamic-Coordinated Dual Drug Chemotherapy Trimodal Synergistic Tumor Therapy

To achieve the maximum therapeutic effects and minimize adverse effects of trimodal synergistic tumor therapies, a cost-effective programmed photothermal (PTT)-chemodynamic (CDT)-coordinated dual drug chemotherapy (CT) trimodal synergistic therapy strategy in chronological order is proposed. According to the status or volumes of the tumors, the intensity and time of each therapeutic modality are optimized, and three modalities are combined programmatically and work in chronological order. The optimal synergistic therapy begins with high-intensity PTT for 10 min to ablate larger tumors, followed by medium-intensity CDT for several hours to eliminate medium-sized tumors, and then low-intensity coordinated dual drugs CT lasts over 48 h to clear smaller residual tumors. Composite nanoparticles, made of Fe-coordinated polydopamine mixed with copper peroxide as the cores and their surface dotted with lots of doxorubicin-Fe(III)-gossypol infinite coordination polymers (ICPs), have been developed to implement the strategy. These composite nanoparticles show excellent synergistic effects with the minimum dose of therapeutic agents and result in nearly 100% tumor inhibition for mice bearing PC-3 tumors and no observed recurrence within 60 days of treatment. The ratios of the different therapeutic agents in the composite nanoparticles can be adjusted to accommodate different types of tumors with this cost-effective programmed trimodal therapy strategy.

Recent progress in covalent organic frameworks for cancer therapy

Covalent organic frameworks (COFs) have gained tremendous interest in cancer therapy owing to their multifunctional properties, such as biocompatibility, tunable cavities, excellent crystallinity, ease of modification/functionalization, and high flexibility. These unique properties offer multiple benefits, such as high loading capacity, prevention from premature leakage, targeted delivery to the tumor microenvironment (TME), and release of therapeutic agents in a controlled manner, which makes them effective and excellent nanoplatforms for cancer therapeutics. In this review, we outline recent advances in using COFs as delivery system for chemotherapeutic agents, photodynamic therapy (PDT), photothermal therapy (PTT), sonodynamic therapy (SDT), cancer diagnostics, and combinatorial therapy for cancer therapeutics. We also summarize current challenges and future directions of this unique research field. Teaser: This review highlights recent advances in covalent organic frameworks as multifaceted nanoplatform with recent case studies for improving therapeutic outcomes for cancer therapeutics.

An iodide-containing covalent organic framework for enhanced radiotherapy

Metal-free radiosensitizers, particularly iodine, have shown promise in enhancing radiotherapy due to their suitable X-ray absorption capacities and negligible biotoxicities. However, conventional iodine compounds have very short circulating half-lives and are not retained in tumors very well, which significantly limits their applications. Covalent organic frameworks (COFs) are highly biocompatible crystalline organic porous materials that are flourishing in nanomedicine but have not been developed for radiosensitization applications. Herein, we report the room-temperature synthesis of an iodide-containing cationic COF by the three-component one-pot reaction. The obtained TDI-COF can be a tumor radiosensitizer for enhanced radiotherapy by radiation-induced DNA double-strand breakage and lipid peroxidation and inhibits colorectal tumor growth by inducing ferroptosis. Our results highlight the excellent potential of metal-free COFs as radiotherapy sensitizers.