Dual-Oxygenation/Dual-Fenton Synergistic Photothermal/Chemodynamic/Starvation Therapy for Tumor Treatment

Nanomaterials in cancer starvation therapy: pioneering advances, therapeutic potential, and clinical challenges

Gaining significant attention in recent years, starvation therapy based on the blocking nutrients supply to cancer cells via blood occlusion and metabolic interventions is a promisingly novel approach in cancer treatment. However, there are many crucial obstacles to overcome to achieve effective treatment, for example, poor-targeting delivery, cellular hypoxia, adverse effects, and ineffective monotherapy. The starvation-based multitherapy based on multifunctional nanomaterials can narrow these gaps and pave a promising way for future clinical translation. This review focuses on the progression in nanomaterials-mediated muti-therapeutic modalities based on starvation therapy in recent years and therapeutic limitations that prevent their clinical applications. Moreover, unlike previous reviews that focused on a single aspect of the field, this comprehensive review presents a broader perspective on starvation therapy by summarising advancements across its various therapeutic strategies.

Emerging glucose oxidase-delivering nanomedicines for enhanced tumor therapy

Abnormalities in glucose metabolism have been shown to characterize malignant tumors. Glucose depletion by glucose oxidase (GOD) has shown great potential in tumor therapy by causing tumor starvation. Since 2017, nanomedicines have been designed and utilized to deliver GOD for more precise and effective glucose modulation, which can overcome intrinsic limitations of different cancer therapeutic modalities by remodeling the tumor microenvironment to enhance antitumor therapy. To date, the topic of GOD-delivering nanomedicines for enhancing tumor therapy has not been comprehensively summarized. Herein, this review aims to provide an overview and discuss in detail recent advances in GOD delivery and directly involved starvation therapy strategies, GOD-sensitized various tumor therapy strategies, and GOD-mediated multimodal antitumor strategies. Finally, the challenges and outlooks for the future progress of the emerging tumor therapeutic nanomedicines are discussed. This review provides intuitive and specific insights to a broad audience in the fields of nanomedicines, biomaterials, and cancer therapy.

Orchestrated copper-loaded nanoreactor for simultaneous induction of cuproptosis and immunotherapeutic intervention in colorectal cancer

Ion interference, including intracellular copper (Cu) overload, disrupts cellular homeostasis, triggers mitochondrial dysfunction, and activates cell-specific death channels, highlighting its significant potential in cancer therapy. Nevertheless, the insufficient intracellular Cu ions transported by existing Cu ionophores, which are small molecules with short blood half-lives, inevitably hamper the effectiveness of cuproptosis. Herein, the ESCu@HM nanoreactor, self-assembled from the integration of H-MnO2 nanoparticles with the Cu ionophore elesclomol (ES) and Cu, was fabricated to facilitate cuproptosis and further induce relevant immune responses. Specifically, the systemic circulation and tumoral accumulation of Cu, causing irreversible cuproptosis, work in conjunction with Mn2+, resulting in the repolarization of tumor-associated macrophages (TAMs) and amplification of the activation of the cGAS-STING pathway by damaged DNA fragments in the nucleus and mitochondria. This further stimulates antitumor immunity and ultimately reprograms the tumor microenvironment (TME) to inhibit tumor growth. Overall, ESCu@HM as a nanoreactor for cuproptosis and immunotherapy, not only improves the dual antitumor mechanism of ES and provides potential optimization for its clinical application, but also paves the way for innovative strategies for cuproptosis-mediated colorectal cancer (CRC) treatment.

Self-supply of hydrogen peroxide by a bimetal-based nanocatalytic platform to enhance chemodynamic therapy for tumor treatment

The tumor microenvironment (TME) is characterized by low pH, hypoxia, and overexpression of glutathione (GSH). Owing to the complexity of tumor pathogenesis and the heterogeneity of the TME, achieving satisfactory efficacy with a single treatment method is difficult, which significantly impedes tumor treatment. In this study, composite nanoparticles of calcium-copper/alginate-hyaluronic acid (HA) (CaO2-CuO2@SA/HA NC) with pH and GSH responsiveness were prepared for the first time through a one-step synthesis using HA as a targeting ligand. Nanoparticles loaded with H2O2can enhance the chemodynamic therapy effects. Simultaneously, Cu2+can generate oxygen in the TME and alleviate hypoxia in tumor tissue. Cu2+and H2O2undergo the Fenton reaction to produce cytotoxic hydroxyl radicals and Ca2+ions, which enhance the localization and clearance of nanoparticles in tumor cells. Additionally, HA and sodium alginate (SA) were utilized to improve the targeting and biocompatibility of the nanoparticles. Fourier transform infrared, x-ray diffraction, dynamic light scattering, SEM, transmission electron microscope, and other analytical methods were used to investigate their physical and chemical properties. The results indicate that the CaO2-CuO2@SA/HA NC prepared using a one-step method had a particle size of 220 nm, a narrow particle size distribution, and a uniform morphology. The hydrogen peroxide self-supplied nanodrug delivery system exhibited excellent pH-responsive release performance and glutathione-responsive •OH release ability while also reducing the level of reactive oxide species quenching.In vitrocell experiments, no obvious side effects on normal tissues were observed; however, the inhibition rate of malignant tumors HepG2 and DU145 exceeded 50%. The preparation of CaO2-CuO2@SA/HA NC nanoparticles, which can achieve both chemokinetic therapy and ion interference therapy, has demonstrated significant potential for clinical applications in cancer therapy.

Biodegradable Cascade-Amplified Nanotheranostics for Photoacoustic-Guided Synergistic PTT/CDT/Starvation Antitumor in the NIR-II Window

The development of nanoassemblies, activated by the tumor microenvironment, capable of generating photothermal therapy (PTT) and amplifying the "ROS (·OH) storm," is essential for precise and effective synergistic tumor treatment. Herein, an innovative cascade-amplified nanotheranostics based on biodegradable Pd-BSA-GOx nanocomposite for NIR-II photoacoustic imaging (PAI) guides self-enhanced NIR-II PTT/chemodynamic therapy (CDT)/starvation synergistic therapy. The Pd-BSA-GOx demonstrates the ability to selectively convert overexpressed H2O2 into strongly toxic ·OH by a Pd/Pd2+-mediated Fenton-like reaction at a lower pH level. Simultaneously, the GOx generates H2O2 and gluconic acid, effectively disrupting nutrient supply and instigating tumor starvation therapy. More importantly, the heightened levels of H2O2 and increased acidity greatly enhance the Fenton-like reactivity, generating a significant "·OH storm," thereby achieving Pd2+-mediated cascade-amplifying CDT. The specific PTT facilitated by undegraded Pd accelerates the Fenton-like reaction, establishing a positive feedback process for self-enhancing synergetic PTT/CDT/starvation therapy via the NIR-II guided-PAI. Therefore, the multifunctional nanotheranostics presents a simple and versatile strategy for the precision diagnosis and treatment of tumors.

Multi-responsive cascade enzyme-like catalytic nanoassembly for ferroptosis amplification and nanozyme-assisted mild photothermal therapy

Ferroptosis is greatly restricted by low reactive oxygen species (ROS) generation efficiency, and the inherent self-protection mechanism originating in heat shock proteins (HSPs) seriously impedes the efficiency of photothermal therapy (PTT). Herein, we designed an intelligent strategy utilizing cascade catalytic nanoassemblies (Au@COF@MnO2) with triple-enzyme activity for amplifying ferroptosis therapy and improving the efficiency of PTT in tumor. Gold nanozyme was encapsulated within a hollow manganese dioxide (MnO2) shell with the help of covalent organic frameworks (COFs). The nanoassemblies possess the ability of photothermal conversion. Mechanism studies suggested that glutathione (GSH) depletion by Au@COF@MnO2 leads to the inactivation of glutathione peroxidase 4 (GPX4). This effect synergized with Mn2+-mediated reactive oxygen species (ROS) generation to enhance the accumulation of lipid peroxide (LPO), thereby inducing high-efficiency ferroptosis. Notably, gold nanozyme facilitated the conversion of glucose into gluconic acid and hydrogen peroxide (H2O2). This process augmented the endogenous H2O2 levels necessary for Fenton chemistry, which could effectively promote the generation of ROS. Simultaneously, glucose depletion downregulated the expression of HSPs induced by hyperthermia, consequently reducing cellular heat resistance for enhancing PTT. Therefore, the cascade catalytic nanoassembly not only exhibits high tumor inhibition and admirable biosafety, but also possesses trimodal imaging performance for imaging-guided tumor therapy in vivo, holding great potential for clinical application. STATEMENT OF SIGNIFICANCE: This study engineered multi-responsive cascade catalytic nanoassembly (Au@COF@MnO2) with triple enzymatic functions for amplifying ferroptosis therapy and improving the efficiency of PTT in tumor. The nanoassembly exhibited multi-responsive release and great photothermal conversion performance. Glucose consumption-evoked starvation downregulated the hyperthermia-induced expression of HSPs in tumor cells, thereby improving the efficacy of PTT. Mechanism studies suggested that GSH depletion by Au@COF@MnO2 lead to the inactivation of GPX4, which synergized with Mn2+-mediated ROS generation to bolster the accumulation of LPO, thereby inducing high-efficiency ferroptosis. Moreover, the nanoassembly demonstrated trimodal (PT, PA, and MR) imaging in vivo, enabling the visualization of the tumor treatment with nanoassembly. Such nanoassembly exhibited high tumor inhibition and admirable biosafety in tumor therapy in vivo, holding a great potential for clinical application.

Blocking the utilization of carbon sources via two pathways to induce tumor starvation for cancer treatment

Glucose oxidase (GOx) is often used to starvation therapy. However, only consuming glucose cannot completely block the energy metabolism of tumor cells. Lactate can support tumor cell survival in the absence of glucose. Here, we constructed a nanoplatform (Met@HMnO2-GOx/HA) that can deplete glucose while inhibiting the compensatory use of lactate by cells to enhance the effect of tumor starvation therapy. GOx can catalyze glucose into gluconic acid and H2O2, and then HMnO2 catalyzes H2O2 into O2 to compensate for the oxygen consumed by GOx, allowing the reaction to proceed sustainably. Furthermore, metformin (Met) can inhibit the conversion of lactate to pyruvate in a redox-dependent manner and reduce the utilization of lactate by tumor cells. Met@HMnO2-GOx/HA nanoparticles maximize the efficacy of tumor starvation therapy by simultaneously inhibiting cellular utilization of two carbon sources. Therefore, this platform is expected to provide new strategies for tumor treatment.

Nanozymes-Mediated Cascade Reaction System for Tumor-Specific Diagnosis and Targeted Therapy

Cascade reactions are described as efficient and versatile tools, and organized catalytic cascades can significantly improve the efficiency of chemical interworking between nanozymes. They have attracted great interest in many fields such as chromogenic detection, biosensing, tumor diagnosis, and therapy. However, how to selectively kill tumor cells by enzymatic reactions without harming normal cells, as well as exploring two or more enzyme-engineered nanoreactors for cascading catalytic reactions, remain great challenges in the field of targeted and specific cancer diagnostics and therapy. The latest research advances in nanozyme-catalyzed cascade processes for cancer diagnosis and therapy are described in this article. Here, various sensing strategies are summarized, for tumor-specific diagnostics. Targeting mechanisms for tumor treatment using cascade nanozymes are classified and analyzed, "elements" and "dimensions" of cascade nanozymes, types, designs of structure, and assembly modes of highly active and specific cascade nanozymes, as well as a variety of new strategies of tumor targeting based on the cascade reaction of nanozymes. Finally, the integrated application of the cascade nanozymes systems in tumor-targeted and specific diagnostic therapy is summarized, which will lay the foundation for the design of more rational, efficient, and specific tumor diagnostic and therapeutic modalities in the future.

Progress of Nanomaterials Based on Manganese Dioxide in the Field of Tumor Diagnosis and Therapy

As a pivotal transition metal oxide, manganese dioxide (MnO2) has garnered significant attention owing to its abundant reserves, diverse crystal structures and exceptional performance. Nanosizing MnO2 results in smaller particle sizes, larger specific surface areas, optimized material characteristics, and expanded application possibilities. With the burgeoning research efforts in this field, MnO2 has emerged as a promising nanomaterial for tumor diagnosis and therapy. The distinctive properties of MnO2 in regulating the tumor microenvironment (TME) have attracted considerable interest, leading to a rapid growth in research on MnO2-based nanomaterials for tumor diagnosis and treatment. Additionally, MnO2 nanomaterials are also gradually showing up in the regulation of chronic inflammatory diseases. In this review, we mainly summarized the recent advancements in various MnO2 nanomaterials for tumor diagnosis and therapy. Furthermore, we discuss the current challenges and future directions in the development of MnO2 nanomaterials, while also envisaging their potential for clinical translation.

Differentiated management of ROS level in tumor and kidney to alleviate Cis-platinum induced acute kidney injury with improved efficacy

Cisplatin (DDP) is a prevalent chemotherapeutic agent used in tumor therapy, yet DDP-induced acute kidney injury (AKI) severely limits its clinical application. Antioxidants as reactive oxygen species (ROS) scavengers can circumvent this adverse effect while leading to the decrease of efficacy to tumor. Herein, we report ultrasmall ruthenium nanoparticles (URNPs) as switchable ROS scavengers/generators to alleviate DDP-induced AKI and improve its therapeutic efficacy. In the physiological environment of the kidney, URNPs mimic multi-enzyme activities, such as superoxide dismutase and catalase, effectively protecting the renal cell and tissue by down-regulating the increased ROS level caused by DDP and alleviating AKI. Specifically, URNPs are oxidized by high levels of H2O2 in the tumor microenvironment (TME), resulting in the generation of oxygen vacancies and Ru3+/Ru4+ ions. This unique structure transformation endows URNPs to generate singlet oxygen (1O2) under laser irradiation and hydroxyl radicals (∙OH) through a Fenton-like reaction in tumor cell and tissue. The simultaneous generation of multifarious ROS effectively improves the efficacy of DDP in vitro and in vivo. This TME-responsive ROS scavenger/generator acts as an adjuvant therapeutic agent to minimize side effects and improve the efficacy of chemotherapy drugs, providing a new avenue to chemotherapy and facilitating clinical tumor therapy.

Dual biomarkers-activatable hollow MnO2-Based theranostic nanoplatform for efficient breast cancer-specific multisite fluorescence imaging and synergistic therapy

BACKGROUND

Theranostic nanoplatforms with integrated diagnostic imaging and multiple therapeutic functions play a vital role in precise diagnosis and efficient treatment for breast cancer, but unfortunately, these nanoplatforms are usually stuck in single-site imaging and single mode of treatment, causing unsatisfactory diagnostic and therapeutic efficiency. Herein, a dual biomarkers-activatable facile hollow mesoporous MnO2 (H-MnO2)-based theranostic nanoplatform, DNAzyme@H-MnO2-MUC1 aptamer (DHMM), was constructed for the simultaneous multi-site diagnosis and multiple treatment of breast cancer.

RESULTS

The DHMM acted as an integrated diagnostic and therapeutic nanoplatform that realizes multi-site fluorescence imaging-guided high-efficient photothermal/chemodynamic/gene synergistic therapy (PTT/CDT/GT) for breast cancer. The H-MnO2 exhibits high loading capacity for Cy5-MUC1 aptamer (3.05 pmoL μg-1) and FAM-DNAzyme (3.37 pmoL μg-1), and excellent quenching for the probes. In the presence of MUC1 on the cell membrane and GSH in the cytoplasm, Cy5-MUC1 aptamer and FAM-DNAzyme was activated triggering dual-channel fluorescence imaging at different sites. Moreover, the self-supplied Mn2+ was further supplied as DNAzyme cofactors to catalytic cleavage intracellular EGR-1 mRNA for high-efficient GT and stimulated the Fenton-like reaction for CDT. The H-MnO2 also showcases a favorable photothermal performance with a photothermal conversion efficiency of 44.16%, which ultimately contributes to multi-site fluorescence imaging-guided synergistic treatment with an apoptosis rate of 71.82%.

SIGNIFICANCE

This dual biomarker-activatable multiple therapeutic nanoplatform was realized multi-site fluorescence imaging-guided PTT/CDT/GT combination therapy for breast cancer with higher specificity and efficiency, which provides a promising theranostic nanoplatform for the precision and efficiency of breast cancer treatment.

Dual-Responsive hollow mesoporous organosilicon nanocarriers for photodynamic therapy

HYPOTHESIS

The nano-delivery platform, -SS-HMONs@MB@MnO2 nanoparticles (SMM NPs) loaded with methylene blue (MB) as photosensitizer have excellent photodynamic therapy (PDT) effect. The disulfide bond and MnO2 give the shell redox-responsive properties. SMM NPs consume glutathione (GSH) in tumor cells, reducing the scavenging of reactive oxygen species (ROS) by GSH and enhancing the PDT effect of MB.

EXPERIMENTS

The GSH dual-responsive nano-delivery platform, was designed and constructed by using disulfide-doped hollow mesoporous organosilicon nanoparticles (-SS-HMONs) as intermediate responsive layer, loaded with MB as photosensitizer and coated with MnO2 as shells. The MB photosensitizer release and GSH response were characterized. The PDT effect of nanoparticles was evaluated.

FINDINGS

The SMM NPs were uniform in size and well dispersed. The nanoparticles could react with GSH, leading to the decomposition of MnO2 shells and the breakage of disulfide bonds in -SS-HMONs, resulted in the release of MB photosensitizer. The cell experiment showed that SMM NPs had good ROS generating ability and PDT effect after being sucked by tumor cells, which could effectively kill tumor cells. However, in vivo experiments demonstrated that SMM NPs showed slight inhibition on tumor growth. The actual effect in animals was different from the effect in cells.

Rational Design of Guanidinium-Based Bio-MCOF as a Multifunctional Nanocatalyst in Tumor Cells for Enhanced Chemodynamic Therapy

Chemodynamic therapy (CDT) has emerged as a promising approach to cancer treatment, which can break the intracellular redox state balance and result in severe oxidative damage to biomolecules and organelles with the advantages of being less dependent on external stimulation, having deep tissue-healing abilities, and being resistant to drug resistance. There is considerable interest in developing CDT drugs with high efficiency and low toxicity. In this study, a new guanidinium-based biological metal covalent organic framework (Bio-MCOF), GZHMU-1@Mo, is rationally designed and synthesized as a multifunctional nanocatalyst in tumor cells for enhanced CDT. The DFT calculation and experimental results showed that due to the ability of MoO42- ion to promote electron transfer and increase the redox active site, Cu3 clusters and MoO42- ions in GZHMU-1@Mo can synergistically catalyze the production of reactive oxygen species (ROS) from oxygen and H2O2 in tumor cells, as well as degrade intracellular reducing substances, GSH and NADH, so as to disrupt the redox balance in tumor cells. Moreover, GZHMU-1@Mo exhibits a potent killing effect on tumor cells under both normal oxygen and anaerobic conditions. Further in vitro and in vivo antiproliferation studies revealed that the GZHMU-1@Mo nanoagent displays a remarkable antiproliferation effect and effectively inhibits tumor growth. Taken together, our study provides an insightful reference benchmark for the rational design of Bio-MCOF-based nanoagents with efficient CDT.

H2O2 Self-Supply and Glutathione Depletion Engineering Nanoassemblies for NIR-II Photoacoustic Imaging of Tumor Tissues and Photothermal-Enhanced Gas Starvation-Primed Chemodynamic Therapy

The development of tumor microenvironment (TME)-activated nanoassemblies which can produce a photoacoustic (PA) signal and enhance the H2O2 level is critical to achieve accurate diagnosis and highly efficient chemodynamic therapy (CDT). In this study, we developed nanoassemblies consisting of oxygen vacancy titanium dioxide (TiO2-x) surface-constructed copper, sulfur-doped mesoporous organosilica and glucose oxidase (TiO2-x@Cu,S-MONs@GOx, hereafter TMG). We found that highly abundant glutathione (GSH) in the TME nanoassemblies can reduce tetrasulfide bonds and Cu2+ to sulfur ions and Cu+ in the TMG nanoassemblies, respectively, causing the breakage of the tetrasulfide bond and the mesoporous structure collapse, releasing Cu+ ions and TiO2-x nanoparticles, and producing hydrogen sulfide gas, thereby achieving synergistic multimodal tumor treatment through TME-activated NIR-II PA imaging and photothermal-enhanced gas starvation-primed CDT. Therefore, the TMG nanoassemblies form a smart nanoplatform that can serve as an excellent tumor diagnosis-treatment agent by playing an important role in imaging-guided precision diagnosis of cancer and efficient targeting treatment.

A Glucose Metabolic Intervention Nanoplatform for Enhanced Chemodynamic Therapy and Sensitized Photothermal Therapy of Hepatocellular Carcinoma

Traditional treatments for hepatocellular carcinoma (HCC) still lack effectiveness. Recently, the combined mode of chemodynamic therapy (CDT) and photothermal therapy (PTT) has shown great potential against HCC. However, insufficient Fenton reaction rates and hyperthermia-induced heat shock responses greatly impair their efficiency, hindering their further clinical application. Here, we constructed a cascade-amplified PTT/CDT nanoplatform by coating an IR780-embedded red blood cell membrane on glucose oxidase (GOx)-loaded Fe₃O₄ nanoparticles for effective HCC treatment. On the one hand, the nanoplatform interfered with glucose metabolism through the action of GOx to reduce the synthesis of ATP, which reduced the expression of heat shock proteins, thereby sensitizing the IR780-mediated PTT. On the other hand, hydrogen peroxide generated during GOx catalysis and the thermal effect of PTT accelerated the Fe₃O₄-mediated Fenton reaction, realizing enhanced CDT. Consequently, the sensitized PTT and enhanced CDT for HCC management could be simultaneously achieved by interfering with glucose metabolism, providing an alternative strategy for the effective treatment of tumors.