Cascade-Reaction-Based Nanodrug for Combined Chemo/Starvation/Chemodynamic Therapy against Multidrug-Resistant Tumors

Recent advances in chemodynamic nanotherapeutics to overcome multidrug resistance in cancers

Multidrug resistance (MDR) has become a major challenge in cancer therapy, it results in the failure of chemotherapy and anticancer drug development. Chemodynamic therapy (CDT), an emerging cancer treatment strategy, has been reported as a novel approach for cancer treatment characterized by low toxicity and minimal side effects. By generating robust cytotoxic hydroxyl radicals (·OH) via Fenton/Fenton-like reaction, CDT may cause cellular damage and oxidative stress-induced cell death. In recent years, many therapies based on CDT and/or combined with other treatment modalities are reported and exhibit exciting treatment efficacy in cancer treatment, such as photothermal therapy, photodynamic therapy, sonodynamic therapy, chemotherapy, starvation therapy and gas therapy etc. These combination therapies exhibit synergistic effects, significantly improving anticancer outcomes compared to CDT alone. Herein, we provide a comprehensive overview of CDT-based strategies in cancer treatment, highlighting developments of CDT and CDT-based combination strategies in tumor therapy, especially in overcoming MDR challenges. Finally, the opportunities and challenges of CDT and CDT-combination therapy in the clinical application are also addressed.

Focused starvation of tumor cells using glucose oxidase: A comprehensive review

Starvation therapy targets the high metabolic demand of tumor cells. It primarily leans over the consumption of intracellular glucose and simultaneous blockade of alternative metabolic pathways. The strategy involves the use of glucose oxidase (GOx) for catalyzing the conversion of glucose into gluconic acid and hydrogen peroxide. Under these conditions, metabolic re-programming of tumor cells enables the utilization of substrates such as amino acids, fatty acids and lipids. This can be overcome by co-administration of chemo-, photo- and immuno-therapeutics together with glucose oxidase. Targeted delivery of glucose oxidase at tumor site can be enabled with the use of nanoformulations. In this review, we highlight that the outcomes of starvation therapy can be improved using rationally developed nano-formulations. It is possible to load synergistically acting bioactives in these formulations and deliver in site-specific manner and hence achieve the elimination of tumors cells with greater efficacy.

A Combination of Biocatalysis and Fenton-Like Reaction Induced OH• Burst for Cascade Amplification of Cancer Chemodynamic Therapy

Chemodynamic therapy (CDT) is a novel antitumor strategy that employs Fenton or Fenton-like reactions to generate highly toxic hydroxyl radical (OH•) from hydrogen peroxide (H2O2) for inducing tumor cell death. However, the antitumor efficacy of the CDT strategy is harshly limited by the redox homeostasis of tumor cells; especially the OH • is easily scavenged by glutathione (GSH) and the intracellular H2O2 level is insufficient in the tumor cells. Herein, we propose the Mn2+-menadione (also known as vitamin K3, MK3) cascade biocatalysis strategy to disrupt the redox homeostasis of tumor cells and induce a OH• storm, resulting in enhanced CDT effect. A nanoliposome encapsulating Mn-MK3 (Mn-MK3@LP) was prepared for the treatment of hepatic tumors in this study. After Mn-MK3@LPs were taken up by tumor cells, menadione could facilitate the production of intracellular H2O2 via redox cycling, and further the cytotoxic OH • burst was induced by Mn2+-mediated Fenton-like reaction. Moreover, high-valent manganese ions were reduced by GSH and the depletion of GSH further disrupted the redox homeostasis of tumor cells, thus achieving synergistically enhanced CDT. Overall, both cellular and animal experiments confirmed that the Mn-MK3@LP cascade biocatalysis nanoliposome exhibited excellent biosafety and tumor suppression efficacy. This study may provide deep insights for developing novel CDT-based strategies for tumor therapy.

Cu2+-Citrate-Chitosan Complex Nanoparticles for the Chemodynamic Therapy of Lung Cancer

Lung cancer poses a significant threat to human health. Surgical intervention is the preferred treatment modality for lung cancer, but a large number of patients are deprived of the opportunity for surgery for various reasons and are compelled to undergo radiotherapy and chemotherapy, which entail systemic adverse reactions. In recent years, with the advancement of nanomedicine, chemodynamic therapy (CDT) based on free radicals has been extensively investigated. In this study, we fabricated copper-citrate-chitosan composite nanoparticles (CuCC NPs) by encapsulating copper-citrate complexes with natural chitosan polymers, resulting in a substantial reduction in the biotoxicity of copper ions. The CuCC NPs selectively accumulated in tumor tissues through the enhanced permeability and retention effect (EPR) and gradually degraded within the acidic and glutathione (GSH)-rich microenvironment of the tumor, thereby releasing the loaded copper ions. Through CDT, the copper ions converted the overexpressed hydrogen peroxide (H2O2) in the tumor tissue into hydroxyl radicals (•OH), leading to the eradication of tumor cells. In animal experiments, CuCC NPs exhibited remarkable efficacy in CDT. Further histopathological and hematological analyses demonstrated that CuCC NPs could induce substantial apoptosis in tumor tissues while maintaining an extremely high level of safety.

Rapid Synthesis of Trimetallic Nanozyme for Sustainable Cascaded Catalytic Therapy via Tumor Microenvironment Remodulation

Tumor microenvironment (TME)-responsive nanozyme-catalyzed cancer therapy shows great potential due to its specificity and efficiency. However, breaking the self-adaption of tumors and improving the sustainable remodeling TME ability remains a major challenge for developing novel nanozymes. Here, a rapid method is developed first to synthesize unprecedented trimetalic nanozyme (AuMnCu, AMC) with a targeting peptide (AMCc), which exhibits excellent peroxidase-like, catalase-like, and glucose oxidase-like activities. The released Cu and Mn ions in TME consume endogenous H2 O2 and produce O2 , while the AMCccatalyzes glucose oxidation reaction to generate H2 O2 and gluconic acid, which achieves the starvation therapy by depleting the energy and enhances the chemodynamic therapy effect by lowering the pH of the TME and producing extra H2 O2 . Meanwhile, the reactive oxygen species damage is amplified, as AMCc can constantly oxidize intracellular reductive glutathione through the cyclic valence alternation of Cu and Mn ions, and the generated Cu+ elevate the production of ·OH from H2 O2 . Further studies depict that the well-designed AMCc exhibits the excellent photothermal performance and achieves TME-responsive sustainable starvation/photothermal-enhanced chemodynamic synergistic effects in vitro and in vivo. Overall, a promising approach is demonstrated here to design "all-in-one" nanozyme for theranostics by remodeling the TME.

Cisplatin-Based Combination Therapy for Enhanced Cancer Treatment

Cisplatin, a primary chemotherapeutic drug, is of great value in the realm of tumor treatment. However, its clinical efficacy is strictly hindered by issues, such as drug resistance, relapse, poor prognosis, and toxicity to normal tissue. Cisplatin-based combination therapy has garnered increasing attention in both preclinical and clinical cancer research for its ability to overcome resistance, reduce toxicity, and enhance anticancer effects. This review examines three primary co-administration strategies of cisplatin-based drug combinations and their respective advantages and disadvantages. Additionally, seven types of combination therapies involving cisplatin are discussed, focusing on their main therapeutic effects, mechanisms in preclinical research, and clinical applications. This review also discusses future prospects and challenges, aiming to offer guidance for the development of optimal cisplatin-based combination therapy regimens for improved cancer treatment.

Glucose-primed PEEK orthopedic implants for antibacterial therapy and safeguarding diabetic osseointegration

Diabetic infectious microenvironment (DIME) frequently leads to a critical failure of osseointegration by virtue of its main peculiarities including typical hyperglycemia and pathogenic infection around implants. To address the plaguing issue, we devise a glucose-primed orthopedic implant composed of polyetheretherketone (PEEK), Cu-chelated metal-polyphenol network (hauberk coating) and glucose oxidase (GOx) for boosting diabetic osseointegration. Upon DIME, GOx on implants sostenuto consumes glucose to generate H2O2, and Cu liberated from hauberk coating catalyzes the H2O2 to highly germicidal •OH, which massacres pathogenic bacteria through photo-augmented chemodynamic therapy. Intriguingly, the catalytic efficiency of the coating gets greatly improved with the turnover number (TON) of 0.284 s-1. Moreover, the engineered implants exhibit satisfactory cytocompatibility and facilitate osteogenicity due to the presence of Cu and osteopromotive polydopamine coating. RNA-seq analysis reveals that the implants enable to combat infections and suppress pro-inflammatory phenotype (M1). Besides, in vivo evaluations utilizing infected diabetic rat bone defect models at week 4 and 8 authenticate that the engineered implants considerably elevate osseointegration through pathogen elimination, inflammation dampening and osteogenesis promotion. Altogether, our present study puts forward a conceptually new tactic that arms orthopedic implants with glucose-primed antibacterial and osteogenic capacities for intractable diabetic osseointegration.

Current status and prospect of ZIF-based materials for breast cancer treatment

Breast cancer, one of the three most life-threatening cancers in modern times, must be explored for treatments with low side effects and practical efficacy. Metal organic framework materials (MOFs) is made by metal ions as the center for point and organic ligands as a bridge connecting a new type of porous nano-materials, among them, the zinc base zeolite imidazole skeleton material series (ZIFs) because of its excellent biocompatibility and pH slow controlled release ability, is widely used in the tumor microenvironment in basic research and achieved remarkable curative effect. Inspired by this, in this review, we focus on the recent research progress on the application of ZIFs in the treatment of breast cancer, mainly studying the structure of ZIFs such as ZIF-8, ZIF-90 and ZIF-67 and their application in novel therapies for breast cancer treatment, such as targeted drug delivery, photothermal therapy, immunotherapy and gene therapy.We will more fully demonstrate the potential of zif in breast cancer treatment, hoping to provide an avenue for exploring breast cancer treatment.

O2-Generation-Enhanced Responsive Starvation/Photothermal Synergistic Tumor Therapy Based on the AuNRs@MnO2@SiO2 Nanocarrier and Thermosensitive Biomimetic Camouflaging

Cancer starvation/photothermal combined tumor therapy (CST/PTT) has attracted great interest attributed to their mutual compensation and synergistically enhanced effect. However, the very low O2 supply in the tumor microenvironment (TME) greatly limits the CST efficiency of glucose oxidase (GOx). Additionally, the easy degradation in blood circulation and significant off-target effects are big challenges for clinical applications of the GOx-based CST. In this study, a drug delivery system (DDS) with specific tumor-targeted GOx delivery, near-infrared (NIR) light and TME responsive O2 generation, NIR-responsive glucose consumption, high GOx loading, and efficient NIR photothermia was developed. Positively charged AuNRs@MnO2@SiO2 nanoparticles (named AMS+ NPs) were synthesized. GOx was covalently loaded with a high loading ratio of 36.0%. Finally, a thermosensitive biomimetic hybrid membrane composed of a thermosensitive lipid (TSL) membrane, red blood cell membrane (RBCM), and 4T1 cancer cell membrane (CCM) was coated on the NPs through a double-layer strategy. The AMS+-G@TSL@[RBC-CC-TSL]M NPs consumed 32.7 times glucose at 50 °C as that at 37 °C and generated 4.9 times O2 upon NIR laser irradiation. The thermosensitive biomimetic NPs showed an efficient targeting capability to the homotypic 4T1 cancer cells/tumors accompanied by good biocompatibility, macrophage evading capability, high cancer cell cytotoxicity, and excellent antitumor efficacy. The tumor growth inhibition ratio with NIR laser irradiation reached 92.8%. The AMS+-GOx@TSL@[RBC-CC-TSL]M NPs provide a smart, efficient, safe, PTT/CST combined DDS for highly efficient tumor therapy.

Cascade strategy for glucose oxidase-based synergistic cancer therapy using nanomaterials

Nanomaterial-based cancer therapy faces significant limitations due to the complex nature of the tumor microenvironment (TME). Starvation therapy is an emerging therapeutic approach that targets tumor cell metabolism using glucose oxidase (GOx). Importantly, it can provide a material or environmental foundation for other diverse therapeutic methods by manipulating the properties of the TME, such as acidity, hydrogen peroxide (H2O2) levels, and hypoxia degree. In recent years, this cascade strategy has been extensively applied in nanoplatforms for ongoing synergetic therapy and still holds undeniable potential. However, only a few review articles comprehensively elucidate the rational designs of nanoplatforms for synergetic therapeutic regimens revolving around the conception of the cascade strategy. Therefore, this review focuses on innovative cascade strategies for GOx-based synergetic therapy from representative paradigms to state-of-the-art reports to provide an instructive, comprehensive, and insightful reference for readers. Thereafter, we discuss the remaining challenges and offer a critical perspective on the further advancement of GOx-facilitated cancer treatment toward clinical translation.

Nanodelivery systems: An efficient and target-specific approach for drug-resistant cancers

BACKGROUND

Cancer treatment is still a global health challenge. Nowadays, chemotherapy is widely applied for treating cancer and reducing its burden. However, its application might be in accordance with various adverse effects by exposing the healthy tissues and multidrug resistance (MDR), leading to disease relapse or metastasis. In addition, due to tumor heterogeneity and the varied pharmacokinetic features of prescribed drugs, combination therapy has only shown modestly improved results in MDR malignancies. Nanotechnology has been explored as a potential tool for cancer treatment, due to the efficiency of nanoparticles to function as a vehicle for drug delivery.

METHODS

With this viewpoint, functionalized nanosystems have been investigated as a potential strategy to overcome drug resistance.

RESULTS

This approach aims to improve the efficacy of anticancer medicines while decreasing their associated side effects through a range of mechanisms, such as bypassing drug efflux, controlling drug release, and disrupting metabolism. This review discusses the MDR mechanisms contributing to therapeutic failure, the most cutting-edge approaches used in nanomedicine to create and assess nanocarriers, and designed nanomedicine to counteract MDR with emphasis on recent developments, their potential, and limitations.

CONCLUSIONS

Studies have shown that nanoparticle-mediated drug delivery confers distinct benefits over traditional pharmaceuticals, including improved biocompatibility, stability, permeability, retention effect, and targeting capabilities.

Cuproptosis-Inducible Chemotherapeutic/Cascade Catalytic Reactor System for Combating with Breast Cancer

Cascade hydroxyl radical generating hydrogel reactor structures including a chemotherapeutic agent are invented for multiple treatment of breast cancer. Glucose oxidase (GOx) and cupric sulfate (Cu) are introduced for transforming accumulated glucose (in cancer cells) to hydroxyl radicals for starvation/chemodynamic therapy. Cu may also suppress cancer cell growth via cuproptosis-mediated cell death. Berberine hydrochloride (BER) is engaged as a chemotherapeutic agent in the hydrogel reactor for combining with starvation/chemodynamic/cuproptosis therapeutic modalities. Moreover, Cu is participated as a gel crosslinker by coordinating with catechol groups in hyaluronic acid-dopamine (HD) polymer. Controlling viscoelasticity of hydrogel reactor can extend the retention time following local injection and provide sustained drug release patterns. Low biodegradation rate of designed HD/BER/GOx/Cu hydrogel can reduce dosing frequency in local cancer therapy and avoid invasiveness-related inconveniences. Especially, it is anticipated that HD/BER/GOx/Cu hydrogel system can be applied for reducing size of breast cancer prior to surgery as well as tumor growth suppression in clinical application.

Mesoporous nanodrug delivery system: a powerful tool for a new paradigm of remodeling of the tumor microenvironment

Tumor microenvironment (TME) plays an important role in tumor progression, metastasis and therapy resistance. Remodeling the TME has recently been deemed an attractive tumor therapeutic strategy. Due to its complexity and heterogeneity, remodeling the TME still faces great challenges. With the great advantage of drug loading ability, tumor accumulation, multifactor controllability, and persistent guest molecule release ability, mesoporous nanodrug delivery systems (MNDDSs) have been widely used as effective antitumor drug delivery tools as well as remolding TME. This review summarizes the components and characteristics of the TME, as well as the crosstalk between the TME and cancer cells and focuses on the important role of drug delivery strategies based on MNDDSs in targeted remodeling TME metabolic and synergistic anticancer therapy.

Ultrasound-enhanced cascade chemodynamic tumor nanotherapy with lactic acid-enabled hydrogen peroxide self-production

Chemodynamic therapy (CDT) is an effective therapeutic modality for cancer treatment with the action of a catalytic Fenton-like chemoreactive process. To furnish sufficient hydrogen peroxide (H₂O₂) for CDT, catalysts similar to superoxide dismutase are designed to be in cooperation with nanoplatforms. In this work, we rationally integrate lactate oxidase (LOD) with ultrasmall superparamagnetic iron oxide nanoparticles (USPION) to achieve high efficiency of the cascade Fenton reaction for efficient tumor therapy. During the sequential reaction, LOD converts lactic acid into H₂O₂ and pyruvate (PA) in situ, and then USPION with peroxidase-like activity generates large amounts of toxic hydroxyl radicals (˙OH) under the action of H₂O₂. Moreover, the reaction effectively utilizes the excess lactic acid of the tumor microenvironment (TME) as a new target of cancer treatment. To further achieve high-performance tumor treatment, ultrasound has been introduced for augmenting this specific chemoreactive tumor therapy, which can affect cancer cells mainly through sonoporation, cavitation, and thermal effect. With the effects of ultrasound irradiation, this work has constructed an efficient oncology treatment system for tumors. Moreover, the presence of USPION is highly desirable for contrast-enhanced T₁-weighted MRI for monitoring the therapeutic process of cancer in real time.

Utilizing endosomal capture for tumor therapy via membrane-lytic mechanism-based Pickering emulsion

Nanocarriers are easily captured by endosomes, where the abundant hydrolases inevitably destroy the nanocarriers and the drugs they carry, ultimately resulting in a compromised or lost therapeutic efficacy. Herein, we report a membrane-lytic mechanism-based Pickering emulsion that can in turn utilize this seemingly unfavorable endosomal capture behavior for tumor therapy. This Pickering emulsion is constructed as an oil-in-water (O/W) emulsion stabilized by the hybrid nanoparticles (HNPs) composed of two molecules with opposite charges, cetyl trimethylamine bromide (CTAB) and linoleic acid (LA), through electrostatic interaction (defined as HNPs@PE). After HNPs@PE enters the lysosomes through macropinocytosis-mediated endocytosis, LA can be protonated in response to the acidic stimulus, and causing the swelling or disintegration of HNPs due to the disrupted electrostatic interaction. The released CTAB holds strong membrane-lytic activity and can directly damage the lysosomal membranes. Under the acidic condition and the participation of excessive iron ions (II) in lysosomes, LA induces lipid peroxidation and the resulting lipid peroxides (LPO) will oxidize the lysosomal membranes, collectively causing the leakage of lysosome membranes and the release of contents into cytoplasm. Subsequently, the diffused CTAB and LPO will continue to attack the mitochondrial membranes and cell membranes, resulting in the death of different types of tumor cells both in vitro and in vivo due to membrane damage. This Pickering emulsion with membrane-lytic ability represents a potential self-anticancer nanocarrier.

A Multifunctional Cascade Bioreactor Based on a Layered Double Oxides Composite Hydrogel for Synergetic Tumor Chemodynamic/Starvation/Photothermal Therapy

The field of nanomedicine-catalyzed tumor therapy has achieved a lot of progress; however, overcoming the limitations of the tumor microenvironment (TME) to achieve the desired therapeutic effect remains a major challenge. In this study, a nanocomposite hydrogel (GH@LDO) platform combining the nanozyme CoMnFe-layered double oxides (CoMnFe-LDO) and natural enzyme glucose oxidase (GOX) was engineered to remodel the TME to enhance tumor catalytic therapy. The CoMnFe-LDO is a nanozyme that can convert endogenous H₂O₂ into reactive oxygen species (ROS) and O₂ to achieve chemodynamic therapy (CDT) and alleviate the hypoxic microenvironment. Meanwhile, GOX can catalyze the conversion of glucose and O₂ to gluconic acid and H₂O₂, which not only represses the ATP production of tumor cells to achieve starvation therapy (ST), but also decreases the pH value of TME and supplies extra H₂O₂ to enhance the CDT effect. Furthermore, this well-designed CoMnFe-LDO possessed a high photothermal conversion efficiency (66.63%), which could promote the generation of ROS to enhance the CDT effect and achieve photothermal therapy (PTT) under near-infrared light irradiation. The GH@LDO hydrogel cascade reaction overcomes the limitation of the TME and achieves satisfactory CDT/ST/PTT synergetic effects in vitro and in vivo. This work provides a new strategy for remodeling the TME using nanomedicine to achieve precise tumor cascaded catalytic therapy. STATEMENT OF SIGNIFICANCE: At present, the focus of tumor therapy has begun to shift from monotherapy to combination therapy for improving the overall therapeutic effect. In this study, we synthesized a CoMnFe-layered double oxide (CoMnFe-LDO) nanozyme composed of multiple transition metal oxides, which demonstrated improved peroxidase and oxidase activities as well as favorable photothermal conversion capability. The CoMnFe-LDO nanozyme was compounded with an injectable GH hydrogel crosslinked by glucose oxidase (GOX) and peroxidase (HRP). This nanocomposite hydrogel overcame the limitations of weak acidity, H₂O₂, and O₂ levels in the tumor microenvironment (TME) and achieved synergetic chemodynamic therapy (CDT), starvation therapy (ST), and photothermal therapy (PTT) effects based on the cascaded catalytic actions of CoMnFe-LDO and GOX to H₂O₂ and glucose.

Supramolecular Self-Assemblies with Self-Supplying H2O2 and Self-Consuming GSH Property for Amplified Chemodynamic Therapy

Fe-based chemodynamic therapy (CDT) has become one potential method for cancer therapy due to its lower side effect and tumor-specific property. During the process of CDT, the lack of active targeting and biodegradable ability, insufficient endogenous H₂O₂, and overexpressed GSH in the tumor were responsible for the unsatisfactory therapeutic performance. Hence, we report host-guest interaction-based supramolecular polymers (HGSPs) that were constructed with the biomacromolecule β-cyclodextrin-grafted hyaluronic acid (HA-CD) as the active targeting host unit and hydrophobic ROS-responsive ferrocene-(phenylboronic acid pinacol ester) (Fc-BE) as the guest unit. HGSPs can further self-assemble into self-assemblies (HGSAs) and encapsulate PA as the prooxidant. After CD44-receptor-mediated cellular internalization, HGSAs could disassemble and release PA to elevate the H₂O₂ level for the production of higher cytotoxic hydroxyl radicals (^•OH) through the Fc-induced Fenton reaction. Moreover, quinone methide (QM) was generated to downregulate antioxidant GSH. The enhancement of H₂O₂ and consumption of GSH were favorable for CDT due to the amplified oxidative stress. In vivo experimental results indicated that HGSAs@PA might be used as an active targeting amplified CDT agent.

Enzyme-loaded glycogen nanoparticles with tumor-targeting Activatable host-guest supramolecule for augmented chemodynamic therapy

Chemodynamic therapy (CDT) has advantages in site-specific killing tumor and avoiding systemically side effect. Although numerous nano-systems have been developed to enhance the intracellular hydrogen peroxide (H₂O₂) for improving CDT effect, the biocompatibility of the materials limits their further biomedical applications. Herein glycogen, as a natural biological macromolecule, was used to construct a new targeted separable GOx@GF/HC nanoparticle system to deliver glucose oxidase (GOx) for CDT/starvation tumor therapy. Amination glycogen-ferrocene (GF) as a guest core and hyaluronic acid-β-cyclodextrin (HC) as a host shell were synthesized and self-assembled through host-guest interactions to deliver GOx. After being entered into tumor cells, GOx were released to catalyze glucose to produce gluconic acid and H₂O₂, which in turn cut off the nutrition of tumor cells for starvation therapy and enhanced the generation of OH with ferrous ion through Fenton reaction. Furthermore, GOx@GF/HC also exhibited remarkable tumor-targeting and tumor-suppression in vivo. Therefore, the GOx@GF/HC system can exert excellent synergistic effect of CDT and starvation therapy on cancer treatment through a cascade reaction, which have some potential application for the development of CDT tumor-treatment.

Ferrocene and glucose oxidase-installed multifunctional hydrogel reactors for local cancer therapy

A hyaluronic acid (HA)-based one-pot hydrogel reactor with single syringe injection and immediate gelation was developed for starvation therapy (ST), chemodynamic therapy (CDT), ferroptosis, and photothermal therapy (PTT) against breast cancer. A rheologically tuned hydrogel network, composed of HA-phenylboronic acid (HP) and HA-dopamine (HD), was designed by introducing a boronate ester linkage (phenylboronic acid-dopamine interaction) and polydopamine bond (pH control). Ferrocene (Fc)-conjugated HP (Fc-HP) was synthesized to achieve ferroptosis, Fenton reaction-involved toxic hydroxyl radical (^•OH) generation, and photothermal ablation in cancer therapy. Glucose oxidase (GOx) was entrapped in the pH-modulated Fc-HP (Fc-HP°)/HD hydrogel network for converting intracellular glucose to H₂O₂ to enable its own supply. The GOx/Fc combination-installed hydrogel reactor system can provide sustained ST/CDT/PTT functions along with ferroptosis. Injection of Fc-HP°/HD/GOx hydrogel with single-syringe injectability, shear-thinning feature, and self-healing capability offered a slow biodegradation rate and high safety profiles. Peritumorally injected Fc-HP°/HD/GOx hydrogel also efficiently suppressed the growth of breast cancer based on multifunctional therapeutic approaches with reduced dosing frequency. Hyperthermia induced by near-infrared (NIR) laser absorption may amplify the therapeutic effects of free radicals. It is expected that this Fc-HP°/HD/GOx hydrogel system can be applied to local cancer therapy with high efficacy and safety profiles.

Copper-based metal-organic framework impedes triple-negative breast cancer metastasis via local estrogen deprivation and platelets blockade

Metastasis is one of the main causes of failure in the treatment of triple-negative breast cancer (TNBC). Abnormally estrogen level and activated platelets are the key driving forces for TNBC metastasis. Herein, an "ion/gas" bioactive nanogenerator (termed as IGBN), comprising a copper-based MOF and loaded cisplatin-arginine (Pt-Arg) prodrug is developed for metastasis-promoting tumor microenvironment reprogramming and TNBC therapy. The copper-based MOF not only serves as a drug carrier, but also specifically produces Cu2+ in tumors, which catalytic oxidizing estrogen to reduce estrogen levels in situ. Meanwhile, the rationally designed Pt-Arg prodrug reduced into cisplatin to significantly promote the generation of H2O2 in the tumor, then permitting self-augmented cascade NO gas generation by oxidizing Arg through a H2O2 self-supplied way, thus blocking platelet activation in tumor. We clarified that IGBN inhibited TNBC metastasis through local estrogen deprivation and platelets blockade, affording 88.4% inhibition of pulmonary metastasis in a 4T1 mammary adenocarcinoma model. Notably, the locally copper ion interference, NO gas therapy and cisplatin chemotherapy together resulted in an enhanced therapeutic efficacy in primary tumor ablation without significant toxicity. This "ion/gas" bioactive nanogenerator offers a robust and safe strategy for TNBC therapy.

Cyclodextrin-Based Nanoplatforms for Tumor Phototherapy: An Update

Tumor phototherapies are light-mediated tumor treatment modalities, which usually refer to tumor photothermal therapy (PTT) and photodynamic therapy (PDT). Due to the outstanding spatial-temporal control over treatment through light irradiation, tumor phototherapies display extremely low side effects during treatment and are believed to be a tumor treatment method with a clinical translation potential. However, current tumor phototherapy nanoplatforms face obstacles, including light irradiation-induced skin burning, tumor hypoxia microenvironments, limited light penetration depth, et al. Therefore, one important research direction is developing a tumor phototherapy nanoplatform with multifunctionality and enhanced pharmacological effects to overcome the complexity of tumor treatment. On the other hand, cyclodextrins (CDs) are starch-originated circular oligosaccharides with negligible toxicity and have been used to form supermolecular nanostructures through a host-guest interaction between the inner cavity of CDs and functional biomolecules. In the past few years, numerous studies have focused on CD-based multifunctional tumor phototherapy nanoplatforms with an enhanced photoeffect, responsive morphological transformation, and elevated drug bioavailability. This review focuses on the preparation methods of CD-based tumor phototherapy nanoplatforms and their unique physiochemical properties for improving anti-tumor pharmacological efficacy.

Glucose Metabolism Intervention-Facilitated Nanomedicine Therapy

Ordinarily, cancer cells possess features of abnormally increased nutrient intake and metabolic pathways. The disorder of glucose metabolism is the most important among them. Therefore, starvation therapy targeting glucose metabolism specifically, which results in metabolic disorders, restricted synthesis, and inhibition of tumor growth, has been developed for cancer therapy. However, issues such as inadequate targeting effectiveness and drug tolerance impede their clinical transformation. In recent years, nanomaterial-assisted starvation treatment has made significant progress in addressing these challenges, whether as a monotherapy or in combination with other medications. Herein, representative researches on the construction of nanosystems conducting starvation therapy are introduced. Elaborate designs and interactions between different treatment mechanisms are meticulously mentioned. Not only are traditional treatments based on glucose oxidase involved, but also newly sprung small molecule agents targeting glucose metabolism. The obstacles and potential for advancing these anticancer therapies were also highlighted in this review.

pH-Responsive Hyaluronic Acid Nanoparticles for Enhanced Triple Negative Breast Cancer Therapy

Purpose

Methods

Results

Conclusion

High-dose VitC plus oncolytic adenoviruses enhance immunogenic tumor cell death and reprogram tumor immune microenvironment

Preclinical and clinical studies have validated the antitumor effects of several oncolytic viruses (OVs). However, the efficacy of OVs is limited when they are administered as monotherapies. Combination therapy is a promising direction for oncolytic virotherapy in the future. A high dose of vitamin C (VitC) exerts anticancer effects by triggering the accretion of substantial amounts of reactive oxygen species (ROS). OVs can induce immunogenic tumor cell death and elicit an antitumor immune response. ROS play an important role in immunogenic cell death (ICD). This study aimed to explore whether high-dose VitC in combination with oncolytic adenoviruses (oAds) exhibited a synergistic antitumor effect. High-dose VitC synergized with oAds against tumor by enhancing immunogenic tumor cell death. Combination therapy with high-dose VitC and oAds significantly increased the number of T cells in the tumor microenvironment (TME) and promoted the activation of T cells. Furthermore, the antitumor effect of the combination therapy was CD8⁺ T cell dependent. In addition, combination therapy with high-dose VitC and oAds reprogramed the immunosuppressive TME. Our study provides a new strategy for combination therapy of OVs.

Chemodynamic Therapy via Fenton and Fenton-Like Nanomaterials: Strategies and Recent Advances

Chemodynamic therapy (CDT), a novel cancer therapeutic strategy defined as the treatment using Fenton or Fenton-like reaction to produce •OH in the tumor region, was first proposed by Bu, Shi, and co-workers in 2016. Recently, with the rapid development of Fenton and Fenton-like nanomaterials, CDT has attracted tremendous attention because of its unique advantages: 1) It is tumor-selective with low side effects; 2) the CDT process does not depend on external field stimulation; 3) it can modulate the hypoxic and immunosuppressive tumor microenvironment; 4) the treatment cost of CDT is low. In addition to the Fe-involved CDT strategies, the Fenton-like reaction-mediated CDT strategies have also been proposed, which are based on many other metal elements including copper, manganese, cobalt, titanium, vanadium, palladium, silver, molybdenum, ruthenium, tungsten, cerium, and zinc. Moreover, CDT has been combined with other therapies like chemotherapy, radiotherapy, phototherapy, sonodynamic therapy, and immunotherapy for achieving enhanced anticancer effects. Besides, there have also been studies that extend the application of CDT to the antibacterial field. This review introduces the latest advancements in the nanomaterials-involved CDT from 2018 to the present and proposes the current limitations as well as future research directions in the related field.

Manipulating Intratumoral Fenton Chemistry for Enhanced Chemodynamic and Chemodynamic-Synergized Multimodal Therapy

Chemodynamic therapy (CDT) uses the tumor microenvironment-assisted intratumoral Fenton reaction for generating highly toxic hydroxyl free radicals (•OH) to achieve selective tumor treatment. However, the limited intratumoral Fenton reaction efficiency restricts the therapeutic efficacy of CDT. Recent years have witnessed the impressive development of various strategies to increase the efficiency of intratumoral Fenton reaction. The introduction of these reinforcement strategies can dramatically improve the treatment efficiency of CDT and further promote the development of enhanced CDT (ECDT)-based multimodal anticancer treatments. In this review, the authors systematically introduce these reinforcement strategies, from their basic working principles, reinforcement mechanisms to their representative clinical applications. Then, ECDT-based multimodal anticancer therapy is discussed, including how to integrate these emerging Fenton reinforcement strategies for accelerating the development of multimodal anticancer therapy, as well as the synergistic mechanisms of ECDT and other treatment methods. Eventually, future direction and challenges of ECDT and ECDT-based multimodal synergistic therapies are elaborated, highlighting the key scientific problems and unsolved technical bottlenecks to facilitate clinical translation.

One-Pot Synthesis of Multifunctional Carbon-Based Nanoparticle-Supported Dispersed Cu2+ Disrupts Redox Homeostasis to Enhance CDT

In chemodynamic therapy (CDT), the levels of reactive oxygen species (ROS) production plays an important role for evaluating the therapeutic efficacy. However, the high levels of glutathione (GSH) in tumor cells consume the ROS, directly reducing the therapeutic efficiency. Herein, we synthesized carbon-based nanoparticle (Cu-cys CBNPs) using one-pot strategy, which consume GSH via redox reactions to produce Cu⁺ that catalyze H₂ O₂ to produce ^. OH, thus the ROS level was observably increased through this synergistic effect. In vivo experiments further revealed that Cu-cys CBNPs could effectively inhibit tumor growth. Additionally, Cu-cys CBNPs can affect the activity of some protein sulfhydryl groups in cells, which was assessed by rdTOP-ABPP assay. In general, this study not only provides a potential CDT drug, but also provides a strategy for one-pot synthesis of multifunctional nanomaterials.

Plasmonic enhanced enzyme activity by catalytic cascade induced mutual benefit tumor starvation/immune/photothermal therapy

Single tumor starvation therapy can activate other signaling pathways in tumor cells and easily induce tumor cell metastasis. This research proposes an intelligent nanoparticle, which is effectively combined with plasmonic and immunotherapy to realize a new strategy of "upstream consumption and downstream blocking" of nutrients in tumor sites. The intelligent nanoparticle (Ag-G/C@M) was composed of Ag NCs loaded with glucose oxidase (GOx), catalase (CAT) and coated with the tumor cytomembrane (M). Homologous targeting of tumor cytomembrane facilitated more delivery of Ag-G/C@M to tumor sites and then the plasmonic excited from Ag-G/C@M can increase the catalytic efficiency of the enzymatic reaction. Hydrogen peroxide (H₂O₂) produced by Ag-G/C@M through the consumption of glucose is further catalyzed by CAT to produce oxygen (O₂). This self-reinforcing cascade reaction not only consumes the nutrients of tumor cells, but also the plasmonic-induced photothermal therapy can further stimulate the immune system to produce interferon-γ (IFN-γ), blocking angiogenesis and restricting the nutrient supply of tumor cells. This strategy takes the nutrition necessary for cell survival as the entry point, through endogenous continuous consumption of intracellular nutrients and containment of exogenous supplementation, combined with plasmonic thermal effect and immunotherapy to kill tumor cells, which provides a new way of treating cancer safely and effectively.

A nanoselenium-coating biomimetic cytomembrane nanoplatform for mitochondrial targeted chemotherapy- and chemodynamic therapy through manganese and doxorubicin codelivery

The cell membrane is widely considered as a promising delivery nanocarrier due to its excellent properties. In this study, self-assembled Pseudomonas geniculate cell membranes were prepared with high yield as drug nanocarriers, and named BMMPs. BMMPs showed excellent biosafety, and could be more efficiently internalized by cancer cells than traditional red cell membrane nanocarriers, indicating that BMMPs could deliver more drug into cancer cells. Subsequently, the BMMPs were coated with nanoselenium (Se), and subsequently loaded with Mn²⁺ ions and doxorubicin (DOX) to fabricate a functional nanoplatform (BMMP-Mn²⁺/Se/DOX). Notably, in this nanoplatform, Se nanoparticles activated superoxide dismutase-1 (SOD-1) expression and subsequently up-regulated downstream H₂O₂ levels. Next, the released Mn²⁺ ions catalyzed H₂O₂ to highly toxic hydroxyl radicals (·OH), inducing mitochondrial damage. In addition, the BMMP-Mn²⁺/Se nanoplatform inhibited glutathione peroxidase 4 (GPX4) expression and further accelerated intracellular reactive oxygen species (ROS) generation. Notably, the BMMP-Mn²⁺/Se/DOX nanoplatform exhibited increased effectiveness in inducing cancer cell death through mitochondrial and nuclear targeting dual-mode therapeutic pathways and showed negligible toxicity to normal organs. Therefore, this nanoplatform may represent a promising drug delivery system for achieving a safe, effective, and accurate cancer therapeutic plan.

Chemodynamic nanomaterials for cancer theranostics

It is of utmost urgency to achieve effective and safe anticancer treatment with the increasing mortality rate of cancer. Novel anticancer drugs and strategies need to be designed for enhanced therapeutic efficacy. Fenton- and Fenton-like reaction-based chemodynamic therapy (CDT) are new strategies to enhance anticancer efficacy due to their capacity to generate reactive oxygen species (ROS) and oxygen (O2). On the one hand, the generated ROS can damage the cancer cells directly. On the other hand, the generated O2 can relieve the hypoxic condition in the tumor microenvironment (TME) which hinders efficient photodynamic therapy, radiotherapy, etc. Therefore, CDT can be used together with many other therapeutic strategies for synergistically enhanced combination therapy. The antitumor applications of Fenton- and Fenton-like reaction-based nanomaterials will be discussed in this review, including: (iþ) producing abundant ROS in-situ to kill cancer cells directly, (ii) enhancing therapeutic efficiency indirectly by Fenton reaction-mediated combination therapy, (iii) diagnosis and monitoring of cancer therapy. These strategies exhibit the potential of CDT-based nanomaterials for efficient cancer therapy.

The reversal of chemotherapy-induced multidrug resistance by nanomedicine for cancer therapy

Multidrug resistance (MDR) of cancer is a persistent problem in chemotherapy. Scientists have considered the overexpressed efflux transporters responsible for MDR and chemotherapy failure. MDR extremely limits the therapeutic effect of chemotherapy in cancer treatment. Many strategies have been applied to solve this problem. Multifunctional nanoparticles may be one of the most promising approaches to reverse MDR of tumor. These nanoparticles can keep stability in the blood circulation and selectively accumulated in the tumor microenvironment (TME) either by passive or active targeting. The stimuli-sensitive or organelle-targeting nanoparticles can release the drug at the targeted-site without exposure to normal tissues. In order to better understand reversal of MDR, three main strategies are concluded in this review. First strategy is the synergistic effect of chemotherapeutic drugs and ABC transporter inhibitors. Through directly inhibiting overexpressed ABC transporters, chemotherapeutic drugs can enter into resistant cells without being efflux. Second strategy is based on nanoparticles circumventing over-expressed efflux transporters and directly targeting resistance-related organelles. Third approach is the combination of multiple therapy modes overcoming cancer resistance. At last, numerous researches demonstrated cancer stem-like cells (CSCs) had a deep relation with drug resistance. Here, we discuss two different drug delivery approaches of nanomedicine based on CSC therapy.

Nanomedicines for combating multidrug resistance of cancer

Chemotherapy typically involves the use of specific chemodrugs to inhibit the proliferation of cancer cells, but the frequent emergence of a variety of multidrug-resistant cancer cells poses a tremendous threat to our combat against cancer. The fundamental causes of multidrug resistance (MDR) have been studied for decades, and can be generally classified into two types: one is associated with the activation of diverse drug efflux pumps, which are responsible for translocating intracellular drug molecules out of the cells; the other is linked with some non-efflux pump-related mechanisms, such as antiapoptotic defense, enhanced DNA repair ability, and powerful antioxidant systems. To overcome MDR, intense efforts have been made to develop synergistic therapeutic strategies by introducing MDR inhibitors or combining chemotherapy with other therapeutic modalities, such as phototherapy, gene therapy, and gas therapy, in the hope that the drug-resistant cells can be sensitized toward chemotherapeutics. In particular, nanotechnology-based drug delivery platforms have shown the potential to integrate multiple therapeutic agents into one system. In this review, the focus was on the recent development of nanostrategies aiming to enhance the efficiency of chemotherapy and overcome the MDR of cancer in a synergistic manner. Different combinatorial strategies are introduced in detail and the advantages as well as underlying mechanisms of why these strategies can counteract MDR are discussed. This review is expected to shed new light on the design of advanced nanomedicines from the angle of materials and to deepen our understanding of MDR for the development of more effective anticancer strategies. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Deep Drug Penetration of Nanodrug Aggregates at Tumor Tissues by Fast Extracellular Drug Release

Herein, a new nanodrug of azobenzene-functionalized interfacial cross-linked reverse micelles (AICRM) with 5-fluorouracil loading (5-FU@AICRM) is reported. Upon irradiation with 530 nm light in water, the surface azobenzenes of the nanoparticles change from polar cis-conformation to nonpolar trans-conformation, resulting in the aggregation of 5-FU@AICRM within minutes. Simultaneously, the conformation change unlocks hydrophilic 5-FU with a strong water immigration propensity, allowing them to spray out from the AICRM quickly. This fast release ensures a thorough release of the drug, before the aggregates are internalized by adjacent cells, making it possible to achieve deep tissue penetration. A study of in vivo anticancer activity in A549 tumor-bearing nude mice shows that the tumor inhibition rate (TIR) of 5-FU@AICRM is up to ≈86.2%, 31.6% higher than that of group without green light irradiation and 20.7% higher than that of carmofur (CF, a hydrophobic analog of 5-FU)-loaded AICRM (CF@AICRM), in which CF is released slowly under light irradiation because of its hydrophobicity. Fast drug release upon nanodrug aggregation provides a good solution for balancing the contradiction of "aggregation and penetration" in tumor treatment with nanodrugs.

Novel carboxylated ferrocene polymer nanocapsule with high reactive oxygen species sensitivity and on-demand drug release for effective cancer therapy

Multidrug resistance (MDR) is a major clinical issue leading to substantial reductions in the intracellular levels of anticancer drugs. To overcome MDR, stimulus-responsive polymeric nanotherapeutics that facilitate drug release and cellular uptake at target sites have emerged as promising tools for safe and effective cancer treatment. Among these nanotherapeutics, reactive oxygen species (ROS)-responsive nanocapsules are ideal carriers, as abnormally increased ROS levels can drive controlled drug release at target sites. In this study, we developed novel, high ROS-responsive carboxylated ferrocene nanocapsules (CFNCs) using solvents of different polarities for effective multidrug-resistant cancer therapy. The CFNCs were prepared via the self-assembly of an amphiphilic carboxylated ferrocene polymer composed of a hydrophilic COOH segment and a hydrophobic ferrocenylmethyl methacrylate segment possessing a ROS-responsive group. The size and ROS sensitivity of self-assembled CFNCs could be controlled by using solvents of different polarities during the simple nanoprecipitation process. The CFNCs showed a high loading content (approximately 30 wt%) and on-demand release of paclitaxel under both normal and tumor-mimicking conditions, and exhibited synergistic anticancer effects in multidrug-resistant colorectal cancer cells (HCT-15). Our findings suggest that CFNCs can be applied as carriers for effective cancer therapy.

Nanomedicine-driven molecular targeting, drug delivery, and therapeutic approaches to cancer chemoresistance

Cancer cell resistance to chemotherapeutics (chemoresistance) poses a significant clinical challenge that oncology research seeks to understand and overcome. Multiple anticancer drugs and targeting agents can be incorporated in nanomedicines, in addition to different treatment modalities, forming a single nanoplatform that can be used to address tumor chemoresistance. Nanomedicine-driven molecular assemblies using nucleic acids, small interfering (si)RNAs, miRNAs, and aptamers in combination with stimuli-responsive therapy improve the pharmacokinetic (PK) profile of the drugs and enhance their accumulation in tumors and, thus, therapeutic outcomes. In this review, we highlight nanomedicine-driven molecular targeting and therapy combination used to improve the 3Rs (right place, right time, and right dose) for chemoresistant tumor therapies.

NIR-Driven Water Splitting H2 Production Nanoplatform for H2-Mediated Cascade-Amplifying Synergetic Cancer Therapy

As a newly emerging treatment strategy for many diseases, hydrogen therapy has attracted a lot of attention because of its excellent biosafety. However, the high diffusivity and low solubility of hydrogen make it difficult to accumulate in local lesions. Herein, we develop a H₂ self-generation nanoplatform by in situ water splitting driven by near-infrared (NIR) laser. In this work, core-shell nanoparticles (CSNPs) of NaGdF₄:Yb,Tm/g-C₃N₄/Cu₃P (UCC) nanocomposites as core encapsulated with zeolitic imidazolate framework-8 (ZIF-8) modified with folic acid as shell are designed and synthesized. Due to the acid-responsive ZIF-8 shell, enhanced permeability and retention (EPR) effect, and folate receptor-mediated endocytosis, CSNPs are selectively captured by tumor cells. Upon 980 nm laser irradiation, CSNPs exhibit a high production capacity of H₂ and active oxygen species (ROS), as well as an appropriate photothermal conversion temperature. Furthermore, rising temperature increases the Fenton reaction rate of Cu(I) with H₂O₂ and strengthens the curative effect of chemodynamic therapy (CDT). The excess glutathione (GSH) in tumor microenvironment (TME) can deplete positive holes produced in the valence band of g-C₃N₄ in the g-C₃N₄/Cu₃P Z-scheme heterojunction. GSH also can reduce Cu(II) to Cu(I), ensuring a continuous Fenton reaction. Thus, a NIR-driven H₂ production nanoplatform is constructed for H₂-mediated cascade-amplifying multimodal synergetic therapy.