One-Step Integration of Tumor Microenvironment-Responsive Calcium and Copper Peroxides Nanocomposite for Enhanced Chemodynamic/Ion-Interference Therapy

Biomimetic copper-doped polypyrrole nanoparticles induce glutamine metabolism inhibition to enhance breast cancer cuproptosis and immunotherapy

Cuproptosis, a newly discovered mechanism of inducing tumor cell death, primarily relies on the intracellular accumulation of copper ions. The utilization of Cu-based nanomaterials to induce cuproptosis holds promising prospects in future biomedical applications. However, the presence of high levels of glutathione (GSH) within tumor cells hinders the efficacy of cuproptosis. In this study, we have developed a BPTES-loaded biomimetic Cu-doped polypyrrole nanoparticles (CuP) nanosystem (PCB) for enhanced cuproptosis and immune modulation. PCB comprises an internal BPTES and CuP core and an external platelet membrane (PM) that facilitates active targeting to tumor sites following intravenous administration. Subsequently, PCB effectively suppresses glutaminase (GLS1) activity, thereby reducing GSH content. Moreover, CuP catalyze intracellular H2O2, amplifying oxidative stress while simultaneously inducing dihydrolipoyl transacetylase (DLAT) oligomerization through released Cu2+, resulting in cuproptosis. PCB not only inhibits primary tumors but also exhibits inhibitory effects on abscopal tumors. This work represents the first instance where GLS inhibition has been employed to enhance cuproptosis and immunotherapy. It also provides valuable insights into further investigations on cuproptosis.

Vacancy-Rich Bismuth-Based Nanosheets for Mitochondrial Destruction via CO Poisoning, Ca2+ Dyshomeostasis, and Oxidative Damage

Mitochondria are core regulators of tumor cell homeostasis, and their damage has become an arresting therapeutic modality against cancer. Despite the development of many mitochondrial-targeted pharmaceutical agents, the exploration of more powerful and multifunctional medications is still underway. Herein, oxygen vacancy-rich BiO2-x wrapped with CaCO3 (named BiO2-x@CaCO3/PEG, BCP) is developed for full-fledged attack on mitochondrial function. After endocytosis of BCP by tumor cells, the CaCO3 shell can be decomposed in the acidic lysosomal compartment, leading to immediate Ca2+ release and CO2 production in the cytoplasm. Near-infrared irradiation enhances the adsorption of CO2 onto BiO2-x defects, which enables highly efficient photocatalysis of CO2-to-CO. Meanwhile, such BiO2-x nanosheets possess catalase-, peroxidase- and oxidase-like catalytic activities under acidic pH conditions, allowing hypoxia relief and the accumulation of diverse reactive oxygen species (ROS) in the tumor microenvironment. Ca2+ overload-induced ion dyshomeostasis, CO-mediated respiratory chain poisoning, ROS-triggered oxidative stress aggravation, and cytosolic hyperoxia can cause severe mitochondrial disorders, which further lead to type I cell death in carcinoma. Not only does BCP cause irreversible apoptosis, but immunogenic cell death is simultaneously triggered to activate antitumor immunity for metastasis inhibition. Collectively, this platform promises high benefits in malignant tumor therapy and may expand the medical applications of bismuth-based nanoagents.

Covalent organic frameworks-derived carbon nanospheres based nanoplatform for tumor specific synergistic therapy via oxidative stress amplification and calcium overload

Combinational therapy in cancer treatment that integrates the merits of different therapies is an effective approach to improve therapeutic outcomes. Herein, a simple nanoplatform (N-CNS-CaO2-HA/Ce6 NCs) that synergized chemodynamic therapy (CDT), photodynamic therapy (PDT), photothermal therapy (PTT), and Ca2+ interference therapy (CIT) has been developed to combat hypoxic tumors. With high photothermal effect, excellent peroxidase-like activity, and inherent mesoporous structure, N-doped carbon nanospheres (N-CNSs) were prepared via in situ pyrolysis of an established nanoscale covalent organic frameworks (COFs) precursor. These N-CNSs acted as PTT/CDT agents and carriers for the photosensitizer chlorin e6 (Ce6), thereby yielding a minimally invasive PDT/PTT/CDT synergistic therapy. Hyaluronic acid (HA)-modified CaO2 nanoparticles (CaO2-HA NPs) coated on the surface of the nanoplatform endowed the nanoplatform with O2/H2O2 self-supply capability to respond to and modulate the tumor microenvironment (TME), which greatly facilitated the tumor-specific performance of CDT and PDT. Moreover, the reactive oxygen species (ROS) produced during PDT and CDT enhanced the Ca2+ overloading due to CaO2 decomposition, amplifying the intracellular oxidative stress and leading to mitochondrial dysfunction. Notably, the HA molecules not only increased the cancer-targeting efficiency but also prevented CaO2 degradation during blood circulation, providing double insurance of tumor-selective CIT. Such a nanotherapeutic system possessed boosted antitumor efficacy with minimized systemic toxicity and showed great potential for treating hypoxic tumors.

New Ca2+ based anticancer nanomaterials trigger multiple cell death targeting Ca2+ homeostasis for cancer therapy

Calcium ion (Ca2+) is a necessary element for human and Ca2+ homeostasis plays important roles in various cellular process and functions. Recent reaches have targeted on inducing Ca2+ overload (both intracellular and transcellular) for tumor therapy. With the development of nanotechnology, nanoplatform-mediated Ca2+ overload has been safe theranostic model for cancer therapy, and defined a special calcium overload-induced tumor cell death as "calcicoptosis". However, the underlying mechanism of calcicoptosis in cancer cells remains further identification. In this review, we summarized multiple cell death types due to Ca2+ overload that induced by novel anticancer nanomaterials in tumor cells, including apoptosis, autophagy, pyroptosis, and ferroptosis. We reviewed the roles of these anticancer nanomaterials on Ca2+ homeostasis, including transcellular Ca2+ influx and efflux, and intracellular Ca2+ change in the cytosolic and organelles, and connection of Ca2+ overload with other metal ions. This review provides the knowledge of these nano-anticancer materials-triggered calcicoptosis accompanied with multiple cell death by regulating Ca2+ homeostasis, which could not only enhance their efficiency and specificity, but also enlighten to design new cancer therapeutic strategies and biomedical applications.

Unveiling the promising anticancer effect of copper-based compounds: a comprehensive review

Copper is a necessary micronutrient for maintaining the well-being of the human body. The biological activity of organic ligands, especially their anticancer activity, is often enhanced when they coordinate with copper(I) and (II) ions. Copper and its compounds are capable of inducing tumor cell death through various mechanisms of action, including activation of apoptosis signaling pathways by reactive oxygen species (ROS), inhibition of angiogenesis, induction of cuproptosis, and paraptosis. Some of the copper complexes are currently being evaluated in clinical trials for their ability to map tumor hypoxia in various cancers, including locally advanced rectal cancer and bulky tumors. Several studies have shown that copper nanoparticles can be used as effective agents in chemodynamic therapy, phototherapy, hyperthermia, and immunotherapy. Despite the promising anticancer activity of copper-based compounds, their use in clinical trials is subject to certain limitations. Elevated copper concentrations may promote tumor growth, angiogenesis, and metastasis by affecting cellular processes.

Bioinspired Tumor Calcification-Guided Early Diagnosis and Eradication of Hepatocellular Carcinoma

Tumor calcification is found to be associated with the benign prognostic, and which shows considerable promise as a somewhat predictive index of the tumor response clinically. However, calcification is still a missing area in clinical cancer treatment. A specific strategy is proposed for inducing tumor calcification through the synergy of calcium peroxide (CaO2)-based microspheres and transcatheter arterial embolization for the treatment of hepatocellular carcinoma (HCC). The persistent calcium stress in situ specifically leads to powerful tumor calcioptosis, resulting in diffuse calcification and a high-density shadow on computed tomography that enables clear localization of the in vivo tumor site and partial delineation of tumor margins in an orthotopic HCC rabbit model. This osmotic calcification can facilitate tumor clinical diagnosis, which is of great significance in differentiating tumor response during early follow-up periods. Proteome and phosphoproteome analysis identify that calreticulin (CALR) is a crucial target protein involved in tumor calcioptosis. Further fluorescence molecular imaging analysis also indicates that CALR can be used as a prodromal marker of calcification to predict tumor response at an earlier stage in different preclinical rodent models. These findings suggest that upregulated CALR in association with tumor calcification, which may be broadly useful for quick visualization of tumor response.

Self-Reinforced Bimetallic Mito-Jammer for Ca2+ Overload-Mediated Cascade Mitochondrial Damage for Cancer Cuproptosis Sensitization

Overproduction of reactive oxygen species (ROS), metal ion accumulation, and tricarboxylic acid cycle collapse are crucial factors in mitochondria-mediated cell death. However, the highly adaptive nature and damage-repair capabilities of malignant tumors strongly limit the efficacy of treatments based on a single treatment mode. To address this challenge, a self-reinforced bimetallic Mito-Jammer is developed by incorporating doxorubicin (DOX) and calcium peroxide (CaO2) into hyaluronic acid (HA) -modified metal-organic frameworks (MOF). After cellular, Mito-Jammer dissociates into CaO2 and Cu2+ in the tumor microenvironment. The exposed CaO2 further yields hydrogen peroxide (H2O2) and Ca2+ in a weakly acidic environment to strengthen the Cu2+-based Fenton-like reaction. Furthermore, the combination of chemodynamic therapy and Ca2+ overload exacerbates ROS storms and mitochondrial damage, resulting in the downregulation of intracellular adenosine triphosphate (ATP) levels and blocking of Cu-ATPase to sensitize cuproptosis. This multilevel interaction strategy also activates robust immunogenic cell death and suppresses tumor metastasis simultaneously. This study presents a multivariate model for revolutionizing mitochondria damage, relying on the continuous retention of bimetallic ions to boost cuproptosis/immunotherapy in cancer.

Bacteria-responsive programmed self-activating antibacterial hydrogel to remodel regeneration microenvironment for infected wound healing

There is still an urgent need to develop hydrogels with intelligent antibacterial ability to achieve on-demand treatment of infected wounds and accelerate wound healing by improving the regeneration microenvironment. We proposed a strategy of hydrogel wound dressing with bacteria-responsive self-activating antibacterial property and multiple nanozyme activities to remodel the regeneration microenvironment in order to significantly promote infected wound healing. Specifically, pH-responsive H2O2 self-supplying composite nanozyme (MSCO) and pH/enzyme-sensitive bacteria-responsive triblock micelles encapsulated with lactate oxidase (PPEL) were prepared and encapsulated in hydrogels composed of L-arginine-modified chitosan (CA) and phenylboronic acid-modified oxidized dextran (ODP) to form a cascade bacteria-responsive self-activating antibacterial composite hydrogel platform. The hydrogels respond to multifactorial changes of the bacterial metabolic microenvironment to achieve on-demand antibacterial and biofilm eradication through transformation of bacterial metabolites, and chemodynamic therapy enhanced by nanozyme activity in conjunction with self-driven nitric oxide (NO) release. The composite hydrogel showed 'self-diagnostic' treatment for changes in the wound microenvironment. Through self-activating antibacterial therapy in the infection stage to self-adaptive oxidative stress relief and angiogenesis in the post-infection stage, it promotes wound closure, accelerates wound collagen deposition and angiogenesis, and completely improves the microenvironment of infected wound regeneration, which provides a new method for the design of intelligent wound dressings.

Coordination Self-Assembled AuTPyP-Cu Metal-Organic Framework Nanosheets with pH/Ultrasound Dual-Responsiveness for Synergistically Triggering Cuproptosis-Augmented Chemotherapy

Reactive oxygen species (ROS) mediated tumor cell death is a powerful anticancer strategy. Cuproptosis is a copper-dependent and ROS-mediated prospective tumor therapy strategy. However, the complex tumor microenvironment (TME), low tumor specificity, poor therapy efficiency, and lack of imaging capability impair the therapy output of current cuproptosis drugs. Herein, we designed a dual-responsive two-dimensional metal-organic framework (2D MOF) nanotheranostic via a coordination self-assembly strategy using Au(III) tetra-(4-pyridyl) porphine (AuTPyP) as the ligand and copper ions (Cu2+) as nodes. The dual-stimulus combined with the protonation of the pyridyl group in AuTPyP and deep-penetration ultrasound (US) together triggered the controlled release in an acidic TME. The ultrathin structure (3.0 nm) of nanotheranostics promoted the release process. The released Cu2+ was reduced to Cu+ by depleting the overexpressed glutathione (GSH) in the tumor, which not only activated the Ferredoxin 1 (FDX1)-mediated cuproptosis but also catalyzed the overexpressed hydrogen peroxide (H2O2) in the tumor into reactive oxygen species via Fenton-like reaction. Simultaneously, the released AuTPyP could specifically bind with thioredoxin reductase and activate the redox imbalance of tumor cells. These together selectively induced significant mitochondrial vacuoles and prominent tumor cell death but did not damage the normal cells. The fluorescence and magnetic resonance imaging (MRI) results verified this nanotheranostic could target the HeLa tumor to greatly promote the self-enhanced effect of chemotherapy/cuproptosis and tumor inhibition efficiency. The work helped to elucidate the controlled assembly of multiresponsive nanotheranostics and the high-specificity ROS regulation for application in anticancer therapy.

A cascade nanoplatform for intelligent response to tumor microenvironment and collaborative cancer therapy

Disulfiram (DSF), a new potential anticancer drug, has been shown to exhibit anticancer activity dependent on the formation of CuET, the chelation product of DSF with Cu2+. However, the poor stability of DSF and insufficient physiological concentration of Cu2+ hinder its practical application. To achieve the co-delivery of DSF and Cu2+ while overcoming the inefficiency of single chemotherapy, in this study, a cascade nanoplatform, DSF/Ce6@ZIF-8@CuO2, was constructed by encapsulating DSF and chlorin e6 (Ce6, a photosensitizer) in zeolite imidazole framework-8 (ZIF-8, a nanocarrier) and then loading CuO2, which self-supplied H2O2/O2, onto DSF/Ce6@ZIF-8. By triggering the response of DSF/Ce6@ZIF-8@CuO2 to the acidic tumor microenvironment, encapsulated DSF, Ce6 and CuO2 were released to achieve multimodal synergistic treatment with enhanced DSF chemotherapy and chemodynamic/photodynamic therapy (CDT/PDT). In vitro and animal studies indicated that the designed DSF/Ce6@ZIF-8@CuO2 has strong tumor-inhibitory effects and provides a promising paradigm for designing smart nanoplatforms.

Apoptosis and Paraptosis Induced by Disulfiram-Loaded Ca2+/Cu2+ Dual-Ions Nano Trap for Breast Cancer Treatment

Regarded as one of the hallmarks of tumorigenesis and tumor progression, the evasion of apoptotic cell death would also account for treatment resistance or failure during cancer therapy. In this study, a Ca2+/Cu2+ dual-ion "nano trap" to effectively avoid cell apoptosis evasion by synchronously inducing paraptosis together with apoptosis was successfully designed and fabricated for breast cancer treatment. In brief, disulfiram (DSF)-loaded amorphous calcium carbonate nanoparticles (NPs) were fabricated via a gas diffusion method. Further on, the Cu2+-tannic acid metal phenolic network was embedded onto the NPs surface by self-assembling, followed by mDSPE-PEG/lipid capping to form the DSF-loaded Ca2+/Cu2+ dual-ions "nano trap". The as-prepared nanotrap would undergo acid-triggered biodegradation upon being endocytosed by tumor cells within the lysosome for Ca2+, Cu2+, and DSF releasing simultaneously. The released Ca2+ could cause mitochondrial calcium overload and lead to hydrogen peroxide (H2O2) overexpression. Meanwhile, Ca2+/reactive oxygen species-associated mitochondrial dysfunction would lead to paraptosis cell death. Most importantly, cell paraptosis could be further induced and strengthened by the toxic dithiocarbamate (DTC)-copper complexes formed by the Cu2+ combined with the DTC, the metabolic products of DSF. Additionally, the released Cu2+ will be reduced by intracellular glutathione to generate Cu+, which can catalyze the H2O2 to produce a toxic hydroxyl radical by a Cu+-mediated Fenton-like reaction for inducing cell apoptosis. Both in vitro cellular assays and in vivo antitumor evaluations confirmed the cancer therapeutic efficiency by the dual ion nano trap. This study can broaden the cognition scope of dual-ion-mediated paraptosis together with apoptosis via a multifunctional nanoplatform.

Remodeling Microenvironment for Implant-Associated Osteomyelitis by Dual Metal Peroxide

Implant-associated osteomyelitis (IAOM) is characterized by bone infection and destruction; current therapy of antibiotic treatment and surgical debridement often results in drug resistance and bone defect. It is challenging to develop an antibiotic-free bactericidal and osteogenic-enhanced strategy for IAOM. Herein, an IAOM-tailored antibacterial and osteoinductive composite of copper (Cu)-strontium (Sr) peroxide nanoparticles (CSp NPs), encapsulated in polyethylene glycol diacrylate (PEGDA) (CSp@PEGDA), is designed. The dual functional CSp NPs display hydrogen peroxide (H2 O2 ) self-supplying and Fenton catalytic Cu2+ ions' release, generating plenty of hydroxyl radical (• OH) in a pH-responsive manner for bacterial killing, while the released Sr2+ promotes the in vitro osteogenicity regarding cell proliferation, alkaline phosphatase activity, extracellular matrix calcification, and osteo-associated genes expression. The integration of Cu2+ and Sr2+ in CSp NPs together with the coated PEGDA hydrogel ensures the stable and sustainable ion release during short- and long-term periods. Benefitted from the injectablity and photo-crosslink ability, CSp@PEGDA is able to thoroughly fill the infectious site and gelate in situ for bacterial elimination and bone regeneration, which is verified through in vivo evaluation using a clinical-simulating IAOM mouse model. These favorable abilities of CSp@PEGDA precisely meet the multiple therapeutic needs and pave a promising way for implant-associated osteomyelitis treatment.

Bimetallic nanoplatform for synergistic sonodynamic-calcium overload therapy utilizing self-supplied hydrogen peroxide and relieved hypoxia

Sonodynamic therapy (SDT) has emerged as a potential alternative to traditional cancer treatments as it offers deep cellular penetration and reduced invasivity. Sonosensitizers generate reactive oxygen species (ROS) under ultrasound activation, focusing the ultrasound energy on malignant sites located deep in tissues and causing cell apoptosis and necrosis. However, due to tumor hypoxia and the limited levels of intracellular endogenous hydrogen peroxide (H2O2 is a fundamental species for supplying oxygen via catalase activity), SDT efficacy is still insufficient. In this study, a bimetallic and multifunctional system (Fe3O4-TAPP@PVP-CaO2) was prepared by using ferrosoferric oxide (Fe3O4) as a carrier loaded with 5,10,15,20-tetrakis(4-aminophenyl), porphyrin (TAPP), that was then coated with polyvinyl pyrrolidone (PVP) and calcium peroxide (CaO2). The CaO2 layer elevated the levels of H2O2 and Ca2+ in the tumor microenvironment when exposed to intracellular acidity, providing essential elements for oxygen generation. Intracellular hypoxia was alleviated via the catalase-like activity of Fe3O4 inducing calcium overload. Under ultrasonic irradiation, SDT generated toxic reactive oxygen species (ROS, singlet oxygen) and activated calcium influx through acoustic cavitation. Meanwhile, calcium overload therapy efficiently induced cell apoptosis at the moment of uncontrollable cellular accumulation of Ca2+. In addition, we modified the PVP on the surface to make it more stable. This study presents a bimetallic nanoplatform that can efficiently induce cancer cell death by synergistic sonodynamic-calcium overload therapy via modulation of O2/ROS/Ca2+ species, indicating its potential for multi-modality cancer therapy.

Advances in Nanodelivery Systems Based on Metabolism Reprogramming Strategies for Enhanced Tumor Therapy

Tumor development and metastasis are closely related to the complexity of the metabolism network. Recently, metabolism reprogramming strategies have attracted much attention in tumor metabolism therapy. Although there is preliminary success of metabolism therapy agents, their therapeutic effects have been restricted by the effective reaching of the tumor sites of drugs. Nanodelivery systems with unique physical properties and elaborate designs can specifically deliver to the tumors. In this review, we first summarize the research progress of nanodelivery systems based on tumor metabolism reprogramming strategies to enhance therapies by depleting glucose, inhibiting glycolysis, depleting lactic acid, inhibiting lipid metabolism, depleting glutamine and glutathione, and disrupting metal metabolisms combined with other therapies, including chemotherapy, radiotherapy, photodynamic therapy, etc. We further discuss in detail the advantages of nanodelivery systems based on tumor metabolism reprogramming strategies for tumor therapy. As well as the opportunities and challenges for integrating nanodelivery systems into tumor metabolism therapy, we analyze the outlook for these emerging areas. This review is expected to improve our understanding of modulating tumor metabolisms for enhanced therapy.

A TME-activated nano-catalyst for triple synergistic therapy of colorectal cancer

Colorectal cancer cells are highly heterogeneous and exhibit various drug resistances, making personalized treatment necessary. This typically involves a combination of different treatment modalities such as surgery, radiation, and chemotherapy to increase patient survival. Inspired by this, synergistic therapy, which combines multiple modalities into a single nanotherapeutic drug, shows promise in treating cancer. In this study, a nano-catalyst based on calcium peroxide (CaO2) and the chemotherapeutic drug doxorubicin hydrochloride (DOX) co-loaded into HPB nanoparticles (HPB@CaO2/DOX-PAA) was developed to achieve synergistic cancer treatment through chemodynamic/chemo/photothermal (CDT/CT/PTT) mechanisms. After being endocytosed by cancer cells, the nano-catalyst decomposes, releasing cargo. During near-infrared light irradiation, HPB induces a photothermal effect, DOX exhibits significant RNA and DNA destruction capabilities, meanwhile CaO2 produces a large amount of H2O2 in the moderately acidic TME, which combines with Fe2+ ions derived from HPB to form the highly toxic •OH in a Fenton-like reaction, enhancing the chemodynamic treatment. Assays conducted ex vivo and in vivo have exhibited the efficacy of this triple synergistic therapeutic regimen, indicating its potential clinical application.

Hollow Cavity CaO2 @Polydopamine Nanocomposites for pH-Responsive Ca2+ -Enhanced Efficient Mild Hyperthermia in the NIR-II Region

Second near-infrared (NIR-II) mild photothermal therapy with higher tissue penetration depth and less damage to healthy tissues is emerging as an attractive antitumor modality, but its therapeutic efficiency is dramatically suppressed by the resistance of heat shock proteins (HSPs). As a widely explored photothermal agent, the application of polydopamine (PDA) in the NIR-II region is hampered by low photothermal conversion efficiency (PCE). Herein, its PCE in the NIR-II region is improved by developing novel hollow cavity CaO2 @PDA nanocomposites through chelation-induced diffusion of inner core Ca2+ to the shell PDA to facilitate multiple reflections of laser in the cavity. Upon pH-responsive degradation of CaO2 , its structure is transformed into a stacked "nano-mesh" with excellent light absorption and an enlarged effective irradiation area. Overloading of Ca2+ ions not only induces downregulation of HSPs but also enhances interference of light on membrane potential, which further aggravate mitochondrial dysfunction and reduce the thermotolerance of tumor cells, promoting efficient mild hyperthermia of PDA in the NIR-II region.

Tumor-Microenvironment-Activatable Nanoparticle Mediating Immunogene Therapy and M2 Macrophage-Targeted Inhibitor for Synergistic Cancer Immunotherapy

Immunotherapy has achieved prominent clinical efficacy in combating cancer and has recently become a mainstream treatment strategy. However, achieving broad efficacy with a single modality is challenging, and the heterogeneity of the tumor microenvironment (TME) restricts the accuracy and effectiveness of immunotherapy strategies for tumors. Herein, a TME-responsive targeted nanoparticle to enhance antitumor immunity and reverse immune escape by codelivering interleukin-12 (IL-12) expressing gene and colony-stimulating factor-1 receptor (CSF-1R) inhibitor PLX3397 (PLX) is presented. The introduction of disulfide bonds and cyclo(Arg-Gly-Asp-d-Phe-Lys) (cRGD) peptides conferred reduction reactivity and tumor targeting to the nanoparticles, respectively. It is hypothesized that activating host immunity by the local expression of IL-12, while modulating the tumor-associated macrophages (TAM) function through blocking CSF-1/CSF-1R signaling, could constitute a feasible approach for cancer immunotherapy. The fabricated functional nanoparticle successfully ameliorated the TME by stimulating the proliferation and activation of T lymphocytes, promoting the repolarization of TAMs, reducing myeloid-derived suppressor cells (MDSCs), and promoting the maturation of dendritic cells (DC) as well as the secretion of antitumor cytokines, which efficiently suppressed tumor growth and metastasis. Finally, substantial changes in the TME were deciphered by single-cell analysis including infiltration of different cells, transcriptional states, secretory signaling and cell-cell communications. These findings provide a promising combinatorial immunotherapy strategy through immunomodulatory nanoparticles.

Recent Progress in Anti-Tumor Nanodrugs Based on Tumor Microenvironment Redox Regulation

The growth state of tumor cells is strictly affected by the specific abnormal redox status of the tumor microenvironment (TME). Moreover, redox reactions at the biological level are also central and fundamental to essential energy metabolism reactions in tumors. Accordingly, anti-tumor nanodrugs targeting the disruption of this abnormal redox homeostasis have become one of the hot spots in the field of nanodrugs research due to the effectiveness of TME modulation and anti-tumor efficiency mediated by redox interference. This review discusses the latest research results of nanodrugs in anti-tumor therapy, which regulate the levels of oxidants or reductants in TME through a variety of therapeutic strategies, ultimately breaking the original "stable" redox state of the TME and promoting tumor cell death. With the gradual deepening of study on the redox state of TME and the vigorous development of nanomaterials, it is expected that more anti-tumor nano drugs based on tumor redox microenvironment regulation will be designed and even applied clinically.

In Situ Synthesis of Ru/TiO2- x @TiCN Ternary Heterojunctions for Enhanced Sonodynamic and Nanocatalytic Cancer Therapy

Albeit nanozymes-based tumor catalytic therapy (NCT) relies on endogenous chemical reactions that could achieve tumor microenvironment (TME)-specialized reactive oxygen species (ROS) production, the unsatisfactory catalytic activity of nanozymes accompanied by complex TME poses a barrier to the therapeutic effect of NCT. Herein, a one-step in situ synthesis strategy is reported to construct ternary Ru/TiO2- x @TiCN heterojunctions through oxidative conversion of TiCN nanosheets (NSs) to TiO2- x NSs and reductive deposition of Ru3+ to Ru nanoparticles. The narrow bandgap and existence of heterojunctions enhance the ultrasound-activated ROS generation of Ru/TiO2- x @TiCN because of the accelerated electron transfer and inhibits electron-hole pair recombination. The augmented ROS production efficiency is achieved by Ru/TiO2- x @TiCN with triple enzyme-like activities, which amplifies the ROS levels in a cascade manner through the catalytic decomposition of endogenous H2 O2 to relieve hypoxia and heterojunction-mediated NCT, as well as depletion of overexpressed glutathione. The satisfactory therapeutic effects of Ru/TiO2- x @TiCN heterojunctions are achieved through synergetic sonodynamic therapy and NCT, which achieve the complete elimination of tumors without recurrence. This strategy highlights the potential of in situ synthesis of semiconductor heterojunctions as enhanced sonosensitizers and nanozymes for efficient tumor therapy.

GSH/pH Dual Activatable Cross-linked and Fluorinated PEI for Cancer Gene Therapy Through Endogenous Iron De-Hijacking and in Situ ROS Amplification

Ferroptosis-related cancer therapy is limited by insufficient Fe2+ /Fe3+ redox pair and hydrogen peroxide (H2 O2 ) for producing lethal hydroxyl radicals (·OH). Although exogenous iron or ROS-producing drugs can enhance ferroptosis, exploiting endogenous iron (labile iron pool, LIP) stored in ferritin and promoting ROS generation may be safer. Herein, a metal/drug-free nanomedicine is developed for responsive LIP release and H2 O2 generation on the mitochondria membranes, amplifying hydroxyl radical production to enhance ferroptosis-mediated antitumor effects. A glutathione(GSH)/pH dual activatable fluorinated and cross-linked polyethyleneimine (PEI) with dialdehyde polyethylene glycol layer nanocomplex loaded with MTS-KR-SOD (Mitochondria-targeting-sequence-KillerRed-Superoxide Dismutase) and CRISPR/Cas9-CA IX (Carbonic anhydrase IX (CA IX)) plasmids (FP@MC) are developed for enhanced ferroptosis through endogenous iron de-hijacking and in situ ROS amplification. Two plasmids are constructed to knockdown CA IX and translate KillerRed-SOD recombinant protein specifically on mitochondria membranes, respectively. The CA IX knockdown acidifies the intracellular environment, leading the release of LIP from ferritin as a "flare" to initiate endogenous chemodynamic therapy. Meanwhile, MTS-KR-SOD generates H2 O2 when irradiated by a 590 nm laser to assist chemodynamic therapy, leading to ROS amplification for mitochondria damage and lipid peroxide accumulation. The combined therapeutic effects aggravate cancer ferroptosis and suppress tumor growth, providing a new paradigm for amplifying ROS and iron ions to promote ferroptosis-related cancer therapy.

Guiding the Path to Healing: CuO2 -Laden Nanocomposite Membrane for Diabetic Wound Treatment

Diabetic chronic wounds pose significant clinical challenges due to their characteristic features of impaired extracellular matrix (ECM) function, diminished angiogenesis, chronic inflammation, and increased susceptibility to infection. To tackle these challenges and provide a comprehensive therapeutic approach for diabetic wounds, the first coaxial electrospun nanocomposite membrane is developed that incorporates multifunctional copper peroxide nanoparticles (n-CuO2 ). The membrane's nanofiber possesses a unique "core/sheath" structure consisting of n-CuO2 +PVP (Polyvinylpyrrolidone)/PCL (Polycaprolactone) composite sheath and a PCL core. When exposed to the wound's moist environment, PVP within the sheath gradually disintegrates, releasing the embedded n-CuO2 . Under a weakly acidic microenvironment (typically diabetic and infected wounds), n-CuO2 decomposes to release H2 O2 and Cu2+ ions and subsequently produce ·OH through chemodynamic reactions. This enables the anti-bacterial activity mediated by reactive oxygen species (ROS), suppressing the inflammation while enhancing angiogenesis. At the same time, the dissolution of PVP unveils unique nano-grooved surface patterns on the nanofibers, providing desirable cell-guiding function required for accelerated skin regeneration. Through meticulous material selection and design, this study pioneers the development of functional nanocomposites for multi-modal wound therapy, which holds great promise in guiding the path to healing for diabetic wounds.

pH-Responsive Multifunctional Nanoplatforms with Reactive Oxygen Species-Controlled Release of CO for Enhanced Oncotherapy

Recently, various nanomaterials have drawn increasing attention for enhanced tumor therapy. However, a lack of tumor uptake and insufficient generation of cytotoxic agents have largely limited the antitumor efficacy in vivo. Herein, a multifunctional nanoplatform (IL@CPPor(CO)) was constructed with pH-responsive copper peroxide nanoparticles (CPNP) that are capable of self-supplying H2O2, a radical-sensitive carbonic oxide (CO) donor (Fe3(CO)12), photosensitizer Iridium(III) meso-tetra (N-methyl-4-pyridyl)porphyrin pentachloride (IrPor), and ionic liquid (IL) for enhanced oncotherapy. Under acidic conditions, the CPNP could decompose to release H2O2 and Cu2+. The concomitant generation of H2O2 could efficiently trigger Fe3(CO)12 to release the CO in situ. On the other hand, Cu2+ possesses both glutathione depletion and Fenton-like properties. In addition, IrPor has both peroxidase-like activity and photosensitizer properties to produce reactive oxygen species (ROS) in tumors. The released ROS could trigger the rapid intracellular release of CO. More importantly, released CO and ROS could promote cell apoptosis and improve the therapeutic efficacy. Moreover, due to the pH-dependent ROS generation property, the IL@CPPor(CO) exhibited high tumor accumulation, low toxicity, and good biocompatibility, which enabled effective tumor growth inhibition with minimal side effects in vivo. This work provides a novel multifunctional nanoplatform that combined photodynamic therapy with CDT and CO to improve therapeutic efficacy.

Fe/Cu-AuNP nanocomposites as enzyme-like catalysts to modulate the tumor microenvironment for enhanced synergistic cancer therapy

The intensive investigation of chemodynamic therapy (CDT) for tumor eradication revealed that the therapeutic effects of this ROS-mediated therapy are limited by endogenous reductants and inefficient Fenton-like reactions. In this study, we developed a new Fe/Cu-AuNP-PEG nanocomposite to enhance CDT and provide a synergistic treatment for tumors. The Fe/Cu-AuNP-PEG nanocomposite demonstrated effective ˙OH production and high photothermal conversion efficiency under 808 nm illumination, which promoted the ˙OH production, thereby enhancing the CDT efficacy and exhibiting a synergistic treatment for cancer. More importantly, the Fe/Cu-AuNP-PEG nanocomposite showed the ability to deplete GSH and catalyze glucose to generate H2O2, which facilitated the Fenton-like reaction and reduced the antioxidant properties of tumors, further improving the efficacy of CDT. Therefore, the Fe/Cu-AuNP-PEG nanocomposite, with horseradish peroxidase-like, glutathione peroxidase-like, and glucose oxidase-like activities, is a promising anti-tumor agent for integrating enhanced CDT and photothermal therapy (PTT) with the enhancement of synergistic therapeutic effects.

Multifunctional Tumor-Targeting Carbon Dots for Tumor Microenvironment Activated Ferroptosis and Immunotherapy in Cancer Treatment

As an emerging cancer treatment strategy, ferroptosis is distinguished by the perturbation of lipid metabolism equilibrium and the accumulation of lipid peroxidation. However, the efficacy is consistently hindered by excessive GSH in the tumor microenvironment (TME). Here, this work designed and prepared multifunctional tumor-targeting carbon dots (FG-CDs@Cu) for ferroptosis and immunotherapy. Cu2+ in FG-CDs@Cu rapidly depletes high concentrations of GSH and inhibits glutathione peroxidase 4 (GPX4) expression in an acidic TME. Meanwhile, the generated Cu+ produced reactive oxygen species (ROS) through Fenton-like reaction. Due to the high efficiency of ROS production and GSH depletion, ferroptosis mediated by oxidative stress is significantly enhanced by FG-CDs@Cu in vivo, which can induce immunogenic cell death and promote CD8+ T cell infiltration. Meanwhile, the generated O2 effectively improves the hypoxic environment of the cells and leads to the reduction of hypoxia factor-1α (HIF-1α) expression, which activates the transformation of tumor-promoting M2-type tumor-associated macrophages (TAMs) to tumor-inhibiting M1-type TAMs, further enhancing the immune response and ferroptosis. The in vivo tests suggested that FG-CDs@Cu could efficiently suppress tumor growth in the mouse model and did not cause obvious toxicity. The combination with antiprogrammed death-ligand 1 (αPD-L1) synergy immune therapy could effectively restrain the growth of distal tumors, suggesting the significant potential of FG-CDs@Cu in augmenting ferroptosis and immunotherapy for efficacious cancer treatment.

Rationally designed multifunctional nanoparticles as GSH-responsive anticancer drug delivery systems based on host-guest polymers derived from dextran and β-cyclodextrin

Tumor proliferation and metastasis rely on energy provided by mitochondria. The hexokinase inhibitor lonidamine (LND) could suppress the activities in mitochondria, being a potential antitumor drug. However, limited water-solubility of LND may hinder its biomedical applications. Besides, the cancer-killing effect of LND is compromised by the high level of glutathione (GSH) in cancer cells. Therefore, it is urgent to find a proper method to simultaneously deliver LND and deplete GSH as well as monitor GSH level in cancer cells. Herein, a host polymer β-cyclodextrin-polyethylenimine (β-CD-PEI) and a guest polymer dextran-5-dithio-(2-nitrobenzoic acid) (Dextran-SS-TNB) were synthesized and allowed to form LND-loaded GSH-responsive nanoparticles through host-guest inclusion complexation between β-CD and TNB as host and guest molecular moieties, respectively, which functioned as a system for simultaneous delivery of LND and -SS-TNB species into cancer cells. As a result, the delivery system could deplete GSH and elevate reactive oxygen species (ROS) level in cancer cells, further induce LND-based mitochondrial dysfunction and ROS-based immunogenic cell death (ICD), leading to a synergistic and efficient anticancer effect. In addition, -SS-TNB reacted with GSH to release TNB2-, which could be a probe with visible light absorption at 410 nm for monitoring the GSH level in the cells.

CDKN2A was a cuproptosis-related gene in regulating chemotherapy resistance by the MAGE-A family in breast cancer: based on artificial intelligence (AI)-constructed pan-cancer risk model

BACKGROUND

Before the discovery of cuproptosis, copper-loaded nanoparticle is a wildly applied strategy for enhancing the tumor-cell-killing effect of chemotherapy. Although copper(ii)-related researches are wide, details of cuproptosis-related bioprocess in pan-cancer are not clear yet now, especially for prognosis and drug sensitivity prediction yet now.

METHODS

In this study, VOSviewer is used for the literature review, and R4.2.0 is used for data analysis. Public data are collected from TCGA and GEO, local breast cancer cohort is collected to verify the expression level of CDKN2A.

RESULTS

7036 published articles exhibited a time-dependent linear relationship (R=0.9781, p<0.0001), and breast cancer (33.4%) is the most researched topic. Cuproptosis-related-genes (CRGs)-based unsupervised clustering divides pan-cancer subgroups into four groups (CRG subgroup) with differences in prognosis and tumor immunity. 44 tumor-driver-genes (TDGs)-based prediction model of drug sensitivity and prognosis is constructed by artificial intelligence (AI). Based on TDGs and clinical features, a nomogram is (C- index: 0.7, p= 6.958e- 12) constructed to predict the prognosis of breast cancer. Importance analysis identifies CDKN2A has a pivotal role in AI modeling, whose higher expression indicates worse prognosis in breast cancer. Furthermore, inhibition of CDKN2A down-regulates decreases Snail1, Twist1, Zeb1, vimentin and MMP9, while E-cadherin is increased. Besides, inhibition of CDKN2A also decreases the expression of MEGEA4, phosphorylated STAT3, PD-L1, and caspase3, while cleaved-caspase3 is increased. Finally, we find down-regulation of CDKN2A or MAGEA inhibits cell migration and wound healing, respectively.

CONCLUSIONS

AI identified CRG subgroups in pan-cancer based on CRGs-related TDGs, and 44-gene-based AI modeling is a novel tool to identify chemotherapy sensitivity in breast cancer, in which CDKN2A/MAGEA4 pathway played the most important role.

S100P as a potential biomarker for immunosuppressive microenvironment in pancreatic cancer: a bioinformatics analysis and in vitro study

BACKGROUND

Immunosuppression is a significant factor contributing to the poor prognosis of cancer. S100P, a member of the S100 protein family, has been implicated in various cancers. However, its role in the tumor microenvironment (TME) of pancreatic cancer remains unclear. This study aimed to investigate the potential impact of S100P on TME characteristics in patients with pancreatic cancer.

METHODS

Multiple data (including microarray, RNA-Seq, and scRNA-Seq) were obtained from public databases. The expression pattern of S100P was comprehensively evaluated in RNA-Seq data and validated in four different microarray datasets. Prognostic value was assessed through Kaplan-Meier plotter and Cox regression analyses. Immune infiltration levels were determined using the ESTIMATE and ssGSEA algorithms and validated at the single-cell level. Spearman correlation test was used to examine the correlation between S100P expression and immune checkpoint genes, and tumor mutation burden (TMB). DNA methylation analysis was performed to investigate the change in mRNA expression. Reverse transcription PCR (RT-PCR) and immunohistochemical (IHC) were utilized to validate the expression using five cell lines and 60 pancreatic cancer tissues.

RESULTS

This study found that S100P was differentially expressed in pancreatic cancer and was associated with poor prognosis (P < 0.05). Notably, S100P exhibited a significant negative-correlation with immune cell infiltration, particularly CD8 + T cells. Furthermore, a close association between S100P and immunotherapy was observed, as it strongly correlated with TMB and the expression levels of TIGIT, HAVCR2, CTLA4, and BTLA (P < 0.05). Intriguingly, higher S100P expression demonstrated a negative correlation with methylation levels (cg14323984, cg27027375, cg14900031, cg14140379, cg25083732, cg07210669, cg26233331, and cg22266967), which were associated with CD8 + T cells. In vitro RT-PCR validated upregulated S100P expression across all five pancreatic cancer cell lines, and IHC confirmed high S100P levels in pancreatic cancer tissues (P < 0.05).

CONCLUSION

These findings suggest that S100P could serve as a promising biomarker for immunosuppressive microenvironment, which may provide a novel therapeutic way for pancreatic cancer.

Recent progress of metal-based nanomaterials with anti-tumor biological effects for enhanced cancer therapy

Metal-based nanomaterials have attracted broad attention recently due to their unique biological physical and chemical properties after entering tumor cells, namely biological effects. In particular, the abilities of Ca2+ to modulate T cell receptors activation, K+ to regulate stem cell differentiation, Mn2+ to activate the STING pathway, and Fe2+/3+ to induce tumor ferroptosis and enhance catalytic therapy, make the metal ions and metal-based nanomaterials play crucial roles in the cancer treatments. Therefore, due to the superior advantages of metal-based nanomaterials and the characteristics of the tumor microenvironment, we will summarize the recent progress of the anti-tumor biological effects of metal-based nanomaterials. Based on the different effects of metal-based nanomaterials on tumor cells, this review mainly focuses on the following five aspects: (1) metal-enhanced radiotherapy sensitization, (2) metal-enhanced catalytic therapy, (3) metal-enhanced ferroptosis, (4) metal-enhanced pyroptosis, and (5) metal-enhanced immunotherapy. At the same time, the shortcomings of the biological effects of metal-based nanomaterials on tumor therapy are also discussed, and the future research directions have been prospected. The highlights of promising biosafety, potent efficacy on biological effects for tumor therapy, and the in-depth various biological effects mechanism studies of metal-based nanomaterials provide novel ideas for the future biological application of the nanomaterials.

Biodegradable covalent organic frameworks achieving tumor micro-environment responsive drug release and antitumor treatment

The emergence of nanocarriers has greatly improved the therapeutic efficacy of chemotherapeutic drugs. As emerging nanocarriers, covalent organic frameworks (COFs) have been increasingly used in biomedicine in recent years. However, due to their inherent chemical stability, existing COF nanocarriers hardly undergo in vivo degradation, which brings potential safety hazards to further applications. In this work, we introduce the azo bond into COFs. When the nanocarrier enters the cell, ˙OH generated by the coordinated Fe response to the H2O2 in the cell will break the azo bond and cause the degradation of the framework structure, accelerating the release of internally loaded DOX to effectively realize tumor treatment. We verified the degradation ability of the materials by constructing model compounds, in vitro drug release, MTT assay and antitumor experiments. Compared with the control groups, the degradable COF accelerates the release of DOX and shows a stronger killing effect on 4T1 cells. Serum biochemical analysis and H&E sections of organs show good biocompatibility for both COFs and degradation products. This work provides a new idea for the design of biodegradable COFs in vivo, and greatly explores the potential application of COF materials in the biomedical field.

CaO2nanomedicines: a review of their emerging roles in cancer therapy

Metal peroxide-based nanomedicines have emerged as promising theranostic agents for cancer due to their multifunctional properties, including the generation of bioactive small molecules such as metal ions, H2O2, O2, and OH-. Among these metal peroxides, calcium peroxide (CaO2) nanomedicines have attracted significant attention due to their facile synthesis and good biocompatibility. CaO2nanoparticles have been explored for cancer treatment through three main mechanisms: (1) the release of O2, which helps alleviate tumor hypoxia and enhances oxygen-dependent therapies such as chemotherapy, photodynamic therapy, and immunotherapy; (2) the generation of H2O2, a precursor for ·OH generation, which enables cancer chemodynamic therapy; and (3) the release of Ca2+ions, which induce calcium overload and promote cell apoptosis (called ion-interference therapy). This review provides a comprehensive summary of recent examples of CaO2nanoparticle-based cancer therapeutic strategies, as well as discusses the challenges and future directions in the development of CaO2nanomedicines for cancer treatment.

Research progress on carbon materials in tumor photothermal therapy

At present, cancer remains one of the leading causes of human death worldwide, and surgery, radiotherapy and chemotherapy are still the main methods of cancer treatment. However, these treatments have their drawbacks. Surgical treatment often struggles with the complete removal of tumor tissue, leading to a high risk of cancer recurrence. Additionally, chemotherapy drugs have a significant impact on overall health and can easily result in drug resistance. The high risk and mortality of cancer and other reasons promote scientific researchers to unremittingly develop and find a more accurate and faster diagnosis strategy and effective cancer treatment method. Photothermal therapy, which utilizes near-infrared light, offers deeper tissue penetration and minimal damage to surrounding healthy tissues. Compared to conventional radiotherapy and other treatment methods, photothermal therapy boasts several advantages, including high efficiency, non-invasiveness, simplicity, minimal toxicity, and fewer side effects. Photothermal nanomaterials can be categorized as either organic or inorganic materials. This review primarily focuses on the behavior of carbon materials as inorganic materials and their role in tumor photothermal treatment. Furthermore, the challenges faced by carbon materials in photothermal treatment are discussed.

Multifaceted Roles of Copper Ions in Anticancer Nanomedicine

The significantly increased copper level in tumor tissues and serum indicates the close association of copper ions with tumor development, making copper ions attractive targets in the development of novel tumor treatment methods. The advanced nanotechnology developed in the past decades provides great potential for tumor therapy, among which Cu-based nanotherapeutic systems have received greater attention. Herein, the multifaceted roles of copper ions in cancer progression are summarized and the recent advances in the copper-based nanostructures or nanomedicines for different kinds of tumor therapies including copper depletion therapy, copper-based cytotoxins, copper-ion-based chemodynamic therapy and its combination with other treatments, and copper-ion-induced ferroptosis and cuproptosis activation are discussed. Furthermore, the perspectives for the further development of copper-ion-based nanomedicines for tumor therapy and clinic translation are presented by the authors.

Multifunctional Calcium-Manganese Nanomodulator Provides Antitumor Treatment and Improved Immunotherapy via Reprogramming of the Tumor Microenvironment

Ions play a vital role in regulating various biological processes, including metabolic and immune homeostasis, which involves tumorigenesis and therapy. Thus, the perturbation of ion homeostasis can induce tumor cell death and evoke immune responses, providing specific antitumor effects. However, antitumor strategies that exploit the effects of multiion perturbation are rare. We herein prepared a pH-responsive nanomodulator by coloading curcumin (CU, a Ca2+ enhancer) with CaCO3 and MnO2 into nanoparticles coated with a cancer cell membrane. This nanoplatform was aimed at reprogramming the tumor microenvironment (TME) and providing an antitumor treatment through ion fluctuation. The obtained nanoplatform, called CM NPs, could neutralize protons by decomposing CaCO3 and attenuating cellular acidity, they could generate Ca2+ and release CU, elevating Ca2+ levels and promoting ROS generation in the mitochondria and endoplasmic reticulum, thus, inducing immunogenic cell death. Mn2+ could decompose the endogenous H2O2 into O2 to relieve hypoxia and enhance the sensitivity of cGAS, activating the cGAS-STING signaling pathway. In addition, this strategy allowed the reprogramming of the immune TME, inducing macrophage polarization and dendritic cell maturation via antigen cross-presentation, thereby increasing the immune system's ability to combat the tumor effectively. Moreover, the as-prepared nanoparticles enhanced the antitumor responses of the αPD1 treatment. This study proposes an effective strategy to combat tumors via the reprogramming of the tumor TME and the alteration of essential ions concentrations. Thus, it shows great potential for future clinical applications as a complementary approach along with other multimodal treatment strategies.

Tumor Therapy Strategies Based on Microenvironment-Specific Responsive Nanomaterials

The tumor microenvironment (TME) is a complex and variable region characterized by hypoxia, low pH, high redox status, overexpression of enzymes, and high-adenosine triphosphate concentrations. In recent years, with the continuous in-depth study of nanomaterials, more and more TME-specific response nanomaterials are used for tumor treatment. However, the complexity of the TME causes different types of responses with various strategies and mechanisms of action. Aiming to systematically demonstrate the recent advances in research on TME-responsive nanomaterials, this work summarizes the characteristics of TME and outlines the strategies of different TME responses. Representative reaction types are illustrated and their merits and demerits are analyzed. Finally, forward-looking views on TME-response strategies for nanomaterials are presented. It is envisaged that such emerging strategies for the treatment of cancer are expected to exhibit dramatic trans-clinical capabilities, demonstrating the extensive potential for the diagnosis and therapy of cancer.

Self-Assembled Copper-Based Nanoparticles for Glutathione Activated and Enzymatic Cascade-Enhanced Ferroptosis and Immunotherapy in Cancer Treatment

As an emerging cancer treatment strategy, ferroptosis is greatly restricted by excessive glutathione (GSH) in tumor microenvironment (TME) and low reactive oxygen species (ROS) generation efficiency. Here, this work designs self-assembled copper-alanine nanoparticles (CACG) loaded with glucose oxidase (GOx) and cinnamaldehyde (Cin) for in situ glutathione activated and enzymatic cascade-enhanced ferroptosis and immunotherapy. In response to GSH-rich and acidic TME, CACG allows to effectively co-deliver Cu2+ , Cin, and GOx into tumors. Released Cin consumes GSH through Michael addition, accompanying with the reduction of Cu2+ into Cu+ for further GSH depletion. With the cascade of Cu+ -catalyzed Fenton reactions and enzyme-catalyzed reactions by GOx, CACG could get rid of the restriction of insufficient hydrogen peroxide in TME, leading to a robust and constant generation of ROS. With the high efficiency of GSH depletion and ROS production, ferroptosis is significantly enhanced by CACG in vivo. Moreover, elevated oxidative stress triggers robust immune responses by promoting dendritic cells maturation and T cell infiltration. The in vivo results prove that CACG could efficiently inhibit tumor growth in 4T1 tumor-bearing mouse model without causing obvious systemic toxicity, suggesting the great potential of CACG in enhancing ferroptosis and immunotherapy for effective cancer treatment.

Radially Electrospun Fibrous Membrane Incorporated with Copper Peroxide Nanodots Capable of Self-Catalyzed Chemodynamic Therapy for Angiogenesis and Healing Acceleration of Diabetic Wounds

Vascular dysfunction severely hinders the healing process of diabetic wounds. Therefore, a radially structured fibrous membrane was fabricated through electrospinning by using a polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) mixed solution containing copper peroxide nanoparticles (CPs) as the chemodynamic therapy (CDT) agents, aiming to simultaneously accelerate tissue regeneration and angiogenesis. The fabricated membrane allowed for the in situ H₂O₂ generation activated by the acidic diabetic microenvironment and the subsequent Fenton-type reactions to realize 99.4% elimination against Staphylococcus aureus. Besides, the released Cu²⁺ ions significantly enhanced the expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in human umbilical vein endothelial cells (HUVECs), and they showed enhanced in vitro angiogenesis. Interestingly, the CP-embedded membrane also guided cell spreading and orientated migration of L929 fibroblasts along the fiber distribution through the radially aligned topology. The in vivo implantation indicated that the raidally structured membrane modified by CPs not only dramatically accelerated wound healing of diabetic Sprague-Dawley (SD) rats in 14 days but also promoted angiogenesis in wound sites. The combination of the in situ CDT with the radially structured morphology of the functional membrane is highly promising in applications to promote diabetic wound healing through anti-infection and revascularization.

pH-Activated Ce-Doped Molybdenum Oxide Nanoclusters for Tumor Microenvironment Responsive Photothermal and Chemodynamic Therapy

Molybdenum-based nanomaterials have shown promise for anticancer treatment due to their strong photothermal and redox-activated capabilities. Herein, we have fabricated cerium-doped MoO_x (Ce-MoO_v) with tunable Mo/Ce molar ratios by a one-pot method and investigated their effect on chemodynamic therapy (CDT) and photothermal therapy (PTT). It is found that Ce-MoO_v can self-assemble into nanoclusters in acidic conditions and the increasing Ce amount will generate oxygen vacancy defects and induce the valence change of Mo⁶⁺/Mo⁵⁺ and Ce⁴⁺/Ce³⁺, which leads to strong near-infrared absorption with high photothermal conversion efficiency of 71.31 and 49.86% for 808 and 1064 nm. Other than photothermal conversion, the materials demonstrate pH-/glutathione (GSH)-activated photoacoustic (PA) imaging capability in vitro. In addition, Ce-MoO_v acts as a CDT reagent capable of converting endogenous H₂O₂ to two types of reactive oxygen species (^•OH, ¹O₂) while depleting GSH. Ce-MoO_v demonstrates an excellent therapeutic effect against HCT116 cells and effectively reduces the intracellular GSH level and significantly increases the number of reactive radicals under 1064 nm laser irradiation as compared with the no-laser group in vitro. This work provides a new paradigm using lanthanide-doped polymetallic oxides for pH-/GSH-responsive photothermal/chemodynamic therapy with PA imaging ability.

A Strategy of Fenton Reaction Cycloacceleration for High-Performance Ferroptosis Therapy Initiated by Tumor Microenvironment Remodeling

The emerging tumor ferroptosis therapy confronts impediments of the tumor microenvironment (TME) with weak intrinsic acidity, inadequate endogenous H2 O2 , and a powerful intracellular redox balance system that eliminates toxic reactive oxygen species (ROS). Herein, a strategy of Fenton reaction cycloacceleration initiated by remodeling the TME for magnetic resonance imaging (MRI)-guided high-performance ferroptosis therapy of tumors is proposed. The synthesized nanocomplex exhibits enhanced accumulation at carbonic anhydrase IX (CAIX)-positive tumors based on the CAIX-mediated active targeting, and increased acidification via the inhibition of CAIX by 4-(2-aminoethyl) benzene sulfonamide (ABS) (remodeling TME). This accumulated H+ and abundant glutathione in TME synergistically trigger biodegradation of the nanocomplex to release the loaded cuprous oxide nanodots (CON), β-lapachon (LAP), Fe3+ , and gallic acid-ferric ions coordination networks (GF). The Fenton and Fenton-like reactions are cycloaccelerated via the catalytic loop of Fe-Cu, and the LAP-triggered and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase1-mediated redox cycle, generating robust ROS and plenitudinous lipid peroxides accumulation for ferroptosis of tumor cells. The detached GF network has improved relaxivities in response to the TME. Therefore, the strategy of Fenton reaction cycloacceleration initiated by remodeling the TME is promising for MRI-guided high-performance ferroptosis therapy of tumors.

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.

Mild-Temperature Responsive Nanocatalyst for Controlled Drug Release and Enhanced Catalytic Therapy

Owing to the advantages of the in situ production of toxic agents through catalytic reactions, nanocatalytic therapy has arisen as a highly potential strategy for cancer therapeutics in recent years. However, the insufficient amount of endogenous hydrogen peroxide (H₂O₂) in the tumor microenvironment commonly limits their catalytic efficacy. Here, we employed carbon vesicle nanoparticles (CV NPs) with high near-infrared (NIR, 808 nm) photothermal conversion efficiency as carriers. Ultrafine platinum iron alloy nanoparticles (PtFe NPs) were grown in situ on the CV NPs, where the highly porous nature of the resultant CV@PtFe NPs was employed to encapsulate a drug, β-lapachone (La), and phase-change material (PCM). As a multifunctional nanocatalyst CV@PtFe/(La-PCM) NPs can exhibit a NIR-triggered photothermal effect and activate cellular heat shock response, which upregulates the downstream NQO1 via HSP70/NQO1 axis to facilitate bio-reduction of the concurrently melted and released La. Moreover, sufficient oxygen (O₂) is supplied by CV@PtFe/(La-PCM) NPs catalyzed at the tumor site to reinforce the La cyclic reaction with abundant H₂O₂ generation. This promotes the bimetallic PtFe-based nanocatalysis, which breaks H₂O₂ down into highly toxic hydroxyl radicals (•OH) for catalytic therapy. Our results show that this multifunctional nanocatalyst can be used as a versatile synergistic therapeutic agent with NIR-enhanced nanocatalytic tumor therapy by tumor-specific H₂O₂ amplification and mild-temperature photothermal therapy, which holds promising potential for targeted cancer treatment. STATEMENT OF SIGNIFICANCE: We present a multifunctional nanoplatform with mild-temperature responsive nanocatalyst for controlled drug release and enhanced catalytic therapy. This work aimed at not only reduce the damage to normal tissues caused by photothermal therapy, but also improves the efficiency of nanocatalytic therapy by stimulating endogenous H₂O₂ production through photothermal heat. In vitro and in vivo confirmed that CV@PtFe/(La-PCM) NPs exhibited powerful and overall antitumor effects. This formulation may provide an alternative strategy for the development of the mild- photothermal enhanced nanocatalytic therapy effect in solid tumor.

H2O2/O2 self-supply and Ca2+ overloading MOF-based nanoplatform for cascade-amplified chemodynamic and photodynamic therapy

Introduction: Reactive oxygen species (ROS)-mediated therapies have typically been considered as noninvasive tumor treatments owing to their high selectivity and efficiency. However, the harsh tumor microenvironment severely impairs their efficiency. Methods: Herein, the biodegradable Cu-doped zeolitic imidazolate framework-8 (ZIF-8) was synthesized for loading photosensitizer Chlorin e6 (Ce6) and CaO₂ nanoparticles, followed by surface decoration by hyaluronic acid (HA), obtaining HA/CaO₂-Ce6@Cu-ZIF nano platform. Results and Discussion: Once HA/CaO₂-Ce6@Cu-ZIF targets tumor sites, the degradation of Ce6 and CaO₂ release from the HA/CaO₂-Ce6@Cu-ZIF in response to the acid environment, while the Cu²⁺ active sites on Cu-ZIF are exposed. The released CaO₂ decompose to generate hydrogen peroxide (H₂O₂) and oxygen (O₂), which alleviate the insufficiency of intracellular H₂O₂ and hypoxia in tumor microenvironment (TME), effectively enhancing the production of hydroxyl radical (•OH) and singlet oxygen (¹O₂) in Cu²⁺-mediated chemodynamic therapy (CDT) and Ce6-induced photodynamic therapy (PDT), respectively. Importantly, Ca²⁺ originating from CaO₂ could further enhance oxidative stress and result in mitochondrial dysfunction induced by Ca²⁺ overloading. Conclusion: Thus, the H₂O₂/O₂ self-supplying and Ca²⁺ overloading ZIF-based nanoplatform for cascade-amplified CDT/PDT synergistic strategy is promising for highly efficient anticancer therapy.

Fe(III)-Naphthazarin Metal-Phenolic Networks for Glutathione-Depleting Enhanced Ferroptosis-Apoptosis Combined Cancer Therapy

Nowadays, Fenton chemistry-based chemodynamic therapy (CDT) is an emerging approach to killing tumor cells by converting endogenous H₂ O₂ into cytotoxic hydroxyl radicals (·OH). However, the elimination of ·OH by intracellular overexpressed glutathione (GSH) results in unsatisfactory antitumor efficiency. In addition, the single mode of consuming GSH and undesirable drug loading efficiency cannot guarantee the efficient cancer cells killing effect. Herein, a simple one-step strategy for the construction of Fe³⁺ -naphthazarin metal-phenolic networks (FNP MPNs) with ultrahigh loading capacity, followed by the modification of NH₂ -PEG-NH₂ , is developed. The carrier-free FNP MPNs can be triggered by acid and GSH, and rapidly release naphthazarin and Fe³⁺ , which is further reduced to Fe²⁺ that exerts Fenton catalytic activity to produce abundant ·OH. Meanwhile, the Michael addition between naphthazarin and GSH can lead to GSH depletion and thus achieve tumor microenvironment (TME)-triggered enhanced CDT, followed by activating ferroptosis and apoptosis. In addition, the reduced Fe²⁺ as a T₁ -weighted contrast agent endows the FNP MPNs with magnetic resonance imaging (MRI) functionality. Overall, this work is the debut of naphthazarin as ligands to fabricate functional MPNs for effectively depleting GSH, disrupting intracellular redox homeostasis, and enhancing CDT effects, which opens new perspectives on multifunctional MPNs for tumor synergistic therapy.

Intelligent Pd1.7Bi@CeO2 Nanosystem with Dual-Enzyme-Mimetic Activities for Cancer Hypoxia Relief and Synergistic Photothermal/Photodynamic/Chemodynamic Therapy

Reactive oxygen species-mediated therapeutic strategies, including chemodynamic therapy (CDT) and photodynamic therapy (PDT), have exhibited translational promise for effective cancer management. However, monotherapy often ends up with the incomplete elimination of the entire tumor due to inherent limitations. Herein, we report a core-shell-structured Pd_1.7Bi@CeO₂-ICG (PBCI) nanoplatform constructed by a facile and effective strategy for synergistic CDT, PDT, and photothermal therapy. In the system, both Pd_1.7Bi and CeO₂ constituents exhibit peroxidase- and catalase-like characteristics, which not only generate cytotoxic hydroxyl radicals (^•OH) for CDT but also produce O₂ in situ and relieve tumor hypoxia for enhanced PDT. Furthermore, upon 808 nm laser irradiation, Pd_1.7Bi@CeO₂ and indocyanine green (ICG) coordinately prompt favorable photothermia, resulting in thermodynamically amplified catalytic activities. Meanwhile, PBCI is a contrast agent for near-infrared fluorescence imaging to determine the optimal laser therapeutic window in vivo. Consequently, effective tumor elimination was realized through the above-combined functions. The as-synthesized unitary PBCI theranostic nanoplatform represents a potential one-size-fits-all approach in multimodal synergistic therapy of hypoxic tumors.

Tantalum-Zirconium Co-Doped Metal-Organic Frameworks Sequentially Sensitize Radio-Radiodynamic-Immunotherapy for Metastatic Osteosarcoma

Due to radiation resistance and the immunosuppressive microenvironment of metastatic osteosarcoma, novel radiosensitizers that can sensitize radiotherapy (RT) and antitumor immunity synchronously urgently needed. Here, the authors developed a nanoscale metal-organic framework (MOF, named TZM) by co-doping high-atomic elements Ta and Zr as metal nodes and porphyrinic molecules (tetrakis(4-carboxyphenyl)porphyrin (TCPP)) as a photosensitizing ligand. Given the 3D arrays of ultra-small heavy metals, porous TZM serves as an efficient attenuator absorbing X-ray energy and sensitizing hydroxyl radical generation for RT. Ta-Zr co-doping narrowed the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energy gap and exhibited close energy levels between the singlet and triplet photoexcited states, facilitating TZM transfer energy to the photosensitizer TCPP to sensitize singlet oxygen (¹ O₂ ) generation for radiodynamic therapy (RDT). The sensitized RT-RDT effects of TZM elicit a robust antitumor immune response by inducing immunogenic cell death, promoting dendritic cell maturation, and upregulating programmed cell death protein 1 (PD-L1) expression via the cGAS-STING pathway. Furthermore, a combination of TZM, X-ray, and anti-PD-L1 treatments amplify antitumor immunotherapy and efficiently arrest osteosarcoma growth and metastasis. These results indicate that TZM is a promising radiosensitizer for the synergistic RT and immunotherapy of metastatic osteosarcoma.

Enzyme functionalized PEOz modified magnetic polydopamine with enhanced penetration for cascade-augmented synergistic tumor therapy

In recent years, reactive oxygen species (ROS)-mediated cancer therapies have been widely recognized for their high selectivity and good biological safety. However, due to the difficulties of endogenous tumor microenvironment (TME), penetration of tumor tissues and integration of multimodal tumor ablation, the treatment with traditional therapies could not achieve satisfactory tumor inhibition effects. Here, a doxorubicin (DOX)-glucose oxidase (GOx) dual-loaded and poly (2-ethyl-2-oxazoline) (PEOz) decorated magnetic polydopamine nanoparticles (Fe₃O₄-DOX@PDA-GOx@PEOz, FDPGP) were constructed for tumor ablation. GOx-mediated cascade enzyme reactions could amplify oxidative stress damage and further synergistically inhibit breast cancer. Its pH-responsive charge reversal, drug-controlled release, photothermal, and cascade reactions were evaluated through extracellular experiments. Cellular uptake, cell cytotoxicity, tumor penetration and therapeutic efficacy of FDPGP were investigated through intracellular experiments. Finally, in vivo distribution, photothermal, synergistic antitumor therapeutic effect and biosafety were evaluated comprehensively by in vivo experiments. Excitingly, outstanding tumor enrichment and penetration, superior anticancer effects and biosafety were achieved by the combination of photothermal therapy (PTT)/starvation therapy (ST)/chemodynamic therapy (CDT)/chemotherapy (CT). As such, the FDPGP nanoplatform provides a new insight into the development of collaboratively multimodal enhanced tumor therapy.

Calcination-controlled performance optimization of iron-vanadium bimetallic oxide nanoparticles for synergistic tumor therapy

Calcination has been widely demonstrated as a favorable protocol for producing various inorganic nanomaterials for tumor therapy. However, little attention has been paid to its effect on the biotherapeutic efficacy of inorganic nanomaterials. Herein, we compare the effects of different calcination atmospheres on the therapeutic efficacy of Fe-V-O (FVO) nanomaterials. We find that compared with FVO nanomaterials synthesized by calcination in air, those prepared by argon calcination have a lower metallic valence state and a higher near-infrared light absorption capacity, hence resulting in significantly better biosafety and higher chemodynamic therapy (CDT)/photothermal therapy (PTT) efficacy. This study demonstrates that the therapeutic efficacy of inorganic nanomaterials can be optimized by employing different thermal treatment atmospheres, which provides new insights into the development of efficient anti-tumor agents.

Sustained-release behavior and the antitumor effect of charge-convertible poly(amino acid)s drug-loaded nanoparticles

Enhancing tissue permeability and achieving drug aggregation is the key to targeted tumor therapy. A series triblock copolymers of poly(ethylene glycol)-poly(L-lysine)-poly(L-glutamine) were synthesized by ring-opening polymerization, and charge-convertible nano-delivery system was constructed by loading doxorubicin (DOX) with 2-(hexaethylimide) ethanol on side chain. In normal environment (pH = 7.4), the zeta potential of the drug-loaded nanoparticle solution is negative, which is conducive to avoiding the identification and clearance of nanoparticles by the reticulo-endothelial system, while potential-reversal can be achieved in the tumor microenvironment, which effectively promotes cellular uptake. Nanoparticles could effectively reduce the distribution of DOX in normal tissues and achieve targeted aggregation at tumor sites, which can effectively improve the antitumor effect, while would not causing toxicity and damage to normal body.

Recent Advances in Cancer Therapeutic Copper-Based Nanomaterials for Antitumor Therapy

Copper serves as a vital microelement which is widely present in the biosystem, functioning as multi-enzyme active site, including oxidative stress, lipid oxidation and energy metabolism, where oxidation and reduction characteristics are both beneficial and lethal to cells. Since tumor tissue has a higher demand for copper and is more susceptible to copper homeostasis, copper may modulate cancer cell survival through reactive oxygen species (ROS) excessive accumulation, proteasome inhibition and anti-angiogenesis. Therefore, intracellular copper has attracted great interest that multifunctional copper-based nanomaterials can be exploited in cancer diagnostics and antitumor therapy. Therefore, this review explains the potential mechanisms of copper-associated cell death and investigates the effectiveness of multifunctional copper-based biomaterials in the field of antitumor therapy.