Amplification of Lipid Peroxidation by Regulating Cell Membrane Unsaturation To Enhance Chemodynamic Therapy

Copper Single-Atom-Based Metal-Organic Framework for Ultrasound-Enhanced Nanocatalytic Therapy

Chemodynamic therapy (CDT) is an emerging therapeutic modality triggered by endogenous substances in the tumor microenvironment (TME) to generate reactive oxygen species. However, the mild acid pH, low H2O2 concentration, and overexpressed glutathione can suppress the CDT efficiency. Herein, ultrasound (US)-triggered Cu2+-based single-atom nanoenzymes (FA-NH2-UiO-66-Cu, FNUC) are constructed with the performance of target and glutathione depletion. In the TME, the single-atom Cu sites of FNUC consume glutathione and the FNUC:Cu+ generates •OH via peroxidase-like activity. The US-activated FNUC exhibits a fast •OH generation rate, a low Michaelis constant, and a large •OH concentration, indicating the cavitation effect of US promotes the •OH generation. Meanwhile, the tumor target of FNUC is confirmed by NIR-II fluorescence imaging, in which it is modified with IR-1061. Combined with the antitumor performance of FNUC in vitro and in vivo, the novel Cu-based SAzymes can achieve efficient and precise cancer treatment.

A multifunctional nanoplatform for chemotherapy and nanocatalytic synergistic cancer therapy achieved by amplified lipid peroxidation

Traditional cancer chemotherapy suffers from low efficacy and severe side effects, limiting its use as a first-line treatment. To address this issue, we investigated a novel way to induce lipid peroxidation (LPO), which plays an essential role in ferroptosis and may be useful against cancer cells and tumors. In this study, a pH-responsive synergistic cancer therapy nanoplatform was prepared using CaCO3 co-loaded with oleanolic acid (OA) and lipoxygenase (LOX), resulting in the formation OLCaP NP. This nanoplatform exhibited good drug release properties in an acidic tumor environment owing to the presence of CaCO3. As a result of acidic stimulation at tumor sites, the OLCaP NP released OA and LOX. OA, a chemotherapeutic drug with anticancer activity, is already known to promote the apoptosis of cancer cells, and LOX is a natural enzyme that catalyzes the oxidation of polyunsaturated fatty acids, leading to the accumulation of lipid peroxides and promoting the apoptosis of cancer cells. More importantly, OA upregulated the expression of acyl-coenzyme A synthetase long-chain family member 4 (ACSL4), which promoted enzyme-mediated LPO. Based on our combined chemotherapy and nanocatalytic therapy, the OLCaP NP not only had remarkable antitumor ability but also upregulated ACSL4 expression, allowing further amplification of LPO to inhibit tumor growth. These findings demonstrate the potential of this nanoplatform to enhance the therapeutic efficacy against tumors by inducing oxidative stress and disrupting lipid metabolism, highlighting its clinical potential for improved cancer treatment. STATEMENT OF SIGNIFICANCE: This study presents a novel nanoplatform that combines oleanolic acid (OA), a chemotherapeutic drug, and lipoxygenase (LOX), which oxidizes polyunsaturated fatty acids to trigger apoptosis, for targeted cancer therapy. Unlike traditional treatments, our nanoplatform exhibits pH-responsive drug release, specifically in acidic tumor environments. This innovation enhances the therapeutic effects of OA and LOX, upregulating acyl-CoA synthetase long-chain family member 4 expression and amplifying lipid peroxidation to promote tumor cell apoptosis. Our findings significantly advance the existing literature by demonstrating a synergistic approach that combines chemotherapy and nanocatalytic therapy. The scientific impact of this work lies in its potential to improve cancer treatment efficacy and specificity, offering a promising strategy for clinical applications and future research in cancer therapy.

Metal-polyphenol self-assembled nanodots for NIR-II fluorescence imaging-guided chemodynamic/photodynamic therapy-amplified ferroptosis

The effectiveness of tumor treatment using reactive oxygen species as the primary therapeutic medium is hindered by limitations of tumor microenvironment (TME), such as intrinsic hypoxia in photodynamic therapy (PDT) and overproduction of reducing glutathione (GSH) in chemodynamic therapy (CDT). Herein, we fabricate metal-polyphenol self-assembled nanodots (Fe@BDP NDs) guided by second near-infrared (NIR-II) fluorescence imaging. The Fe@BDP NDs are designed for synergistic combination of type-I PDT and CDT-amplified ferroptosis. In a mildly acidic TME, Fe@BDP NDs demonstrate great Fenton activity, leading to the generation of highly toxic hydroxyl radicals from overproduced hydrogen peroxide in tumor cells. Furthermore, Fe@BDP NDs show favorable efficacy in type-I PDT, even in tolerating tumor hypoxia, generating active superoxide anion upon exposure to 808 nm laser irradiation. The significant efficiency in reactive oxygen species (ROS) products results in the oxidation of sensitive polyunsaturated fatty acids, accelerating lethal lipid peroxidation (LPO) bioprocess. Additionally, Fe@BDP NDs illustrate an outstanding capability for GSH depletion, causing the inactivation of glutathione peroxidase 4 and further promoting lethal LPO. The synergistic type-I photodynamic and chemodynamic cytotoxicity effectively trigger irreversible ferroptosis by disrupting the intracellular redox homeostasis. Moreover, Fe@BDP NDs demonstrate charming NIR-II fluorescence imaging capability and effectively accumulated at the tumor site, visualizing the distribution of Fe@BDP NDs and the treatment process. The chemo/photo-dynamic-amplified ferroptotic efficacy of Fe@BDP NDs was evidenced both in vitro and in vivo. This study presents a compelling approach to intensify ferroptosis via visualized CDT and PDT. STATEMENT OF SIGNIFICANCE: In this study, we detailed the fabrication of metal-polyphenol self-assembled nanodots (Fe@BDP NDs) guided by second near-infrared (NIR-II) fluorescence imaging, aiming to intensify ferroptosis via the synergistic combination of type-I PDT and CDT. In a mildly acidic TME, Fe@BDP NDs exhibited significant Fenton activity, resulting in the generation of highly toxic •OH from overproduced H2O2 in tumor cells. Fe@BDP NDs possessed a remarkable capability for GSH depletion, resulting in the inactivation of glutathione peroxidase 4 (GPX4) and further accelerating lethal LPO. This study presented a compelling approach to intensify ferroptosis via visualized CDT and PDT.

Metal-Coordinated NIR-II Nanoadjuvants with Nanobody Conjugation for Potentiating Immunotherapy by Tumor Metabolism Reprogramming

Immune checkpoint blockade (ICB) immunotherapy remains hampered by insufficient immunogenicity and a high-lactate immunosuppressive tumor microenvironment (TME). Herein, a nanobody-engineered NIR-II nanoadjuvant with targeting metabolic reprogramming capability is constructed for potentiating NIR-II photothermal-ferroptosis immunotherapy. Specifically, the nanoadjuvant (2DG@FS-Nb) is prepared by metallic iron ion-mediated coordination self-assembly of D-A-D type NIR-II molecules and loading of glycolysis inhibitor, 2-deoxy-D-glucose (2DG), followed by modification with aPD-L1 nanobody (Nb), which can effectively target the immunosuppressive TME and trigger in situ immune checkpoint blockade. The nanoadjuvants responsively release therapeutic components in the acidic TME, enabling the precise tumor location by NIR-II fluorescence/photoacoustic imaging while initiating NIR-II photothermal-ferroptosis therapy. The remarkable NIR-II photothermal efficiency and elevated glutathione (GSH) depletion further sensitize ferroptosis to induce severe lipid peroxidation, provoking robust immunogenic cell death (ICD) to trigger anti-tumor immune response. Importantly, the released 2DG markedly inhibits lactate generation through glycolysis obstruction. Decreased lactate efflux remodels the immunosuppressive TME by suppressing M2 macrophage proliferation and downregulating regulatory T cell levels. This work provides a new paradigm for the integration of NIR-II phototheranostics and lactate metabolism regulation into a single nanoplatform for amplified anti-tumor immunotherapy combined with ICB therapy.

Current progress in the regulation of endogenous molecules for enhanced chemodynamic therapy

Chemodynamic therapy (CDT) is a potential cancer treatment strategy, which relies on Fenton chemistry to transform hydrogen peroxide (H2O2) into highly cytotoxic reactive oxygen species (ROS) for tumor growth suppression. Although overproduced H2O2 in cancerous tissues makes CDT a feasible and specific tumor therapeutic modality, the treatment outcomes of traditional chemodynamic agents still fall short of expectations. Reprogramming cellular metabolism is one of the hallmarks of tumors, which not only supports unrestricted proliferative demands in cancer cells, but also mediates the resistance of tumor cells against many antitumor modalities. Recent discoveries have revealed that various cellular metabolites including H2O2, iron, lactate, glutathione, and lipids have distinct effects on CDT efficiency. In this perspective, we intend to provide a comprehensive summary of how different endogenous molecules impact Fenton chemistry for a deep understanding of mechanisms underlying endogenous regulation-enhanced CDT. Moreover, we point out the current challenges and offer our outlook on the future research directions in this field. We anticipate that exploring CDT through manipulating metabolism will yield significant advancements in tumor treatment.

Lipid Nanoparticular Codelivery System for Enhanced Antitumor Effects by Ferroptosis-Apoptosis Synergistic with Programmed Cell Death-Ligand 1 Downregulation

Intrinsic or acquired resistance to chemical drugs severely limits their therapeutic efficacy in cancer treatment. Various intracellular antioxidant molecules, particularly glutathione (GSH), play a crucial role in maintaining intracellular redox homeostasis by mitigating the overproduced reactive oxygen species (ROS) due to rapid cell proliferation. Notably, these antioxidants also eliminate chemical-drug-induced ROS, eventually diminishing their cytotoxicity and rendering them less effective. In this study, we combined erastin, a GSH biosynthesis inhibitor, with 2'-deoxy-5-fluorouridine 5'-monophosphate sodium salt (FdUMP), an ROS-based drug, to effectively disrupt intracellular redox homeostasis and reverse chemotherapy resistance. Therefore, efficient ferroptosis and apoptosis were simultaneously induced for enhanced antitumor effects. Additionally, we employed small interfering RNA targeting PD-L1 (siPD-L1) as a third agent to block immune-checkpoint recognition by CD8+ T cells. The highly immunogenic cell peroxidates or damage-associated molecular patterns (DAMPs) induced by erastin acted synergistically with downregulated PD-L1 to enhance the antitumor effects. To codeliver these three drugs simultaneously and efficiently, we designed GE11 peptide-modified lipid nanoparticles (LNPs) containing calcium phosphate cores to achieve high encapsulation efficiencies. In vitro studies verified its enhanced cytotoxicity, efficient intracellular ROS induction and GSH/GPX4 downregulation, substantial lipid peroxidation product accumulation, and mitochondrial depolarization. In vivo, this formulation effectively accumulated at tumor sites and achieved significant tumor inhibition in subcutaneous colon cancer (CRC) mouse models with a maximum tumor inhibition rate of 83.89% at a relatively low dose. Overall, a strategy to overcome clinical drug resistance was verified in this study by depleting GSH and activating adaptive immunity.

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

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

A Versatile Nanozyme-Based NADH Circulating Oxidation Reactor for Tumor Therapy through Triple Cellular Metabolism Disruption

Nanozyme-based metabolic regulation triggered by tumor-specific endogenous stimuli has emerged as a promising therapeutic strategy for tumors. The current efficacy, however, is constrained by the limited concentration of endogenous substrates and the metabolic plasticity of tumors. Consequently, the implementation of efficient metabolic regulation in tumor therapy is urgently needed. Herein, a versatile nanozyme-based nicotinamide adenine dinucleotide (NADH) circulating oxidation nanoreactor is reported. First, the synthesized cobalt-doped hollow carbon spheres (Co-HCS) possess NADH oxidase (NOX)-mimicking activity for the NADH oxidation to disrupt oxidative phosphorylation (OXPHOS) pathway of tumor cells. Second, the substrate-cycle manner of Co-HCS can be used for NADH circulating oxidation to overcome the limitation of substrate deficiency. Finally, 2-Deoxy-D-glucose (2-DG) and 6-aminonicotinamide (6-AN) are introduced to block glycolysis and pentose phosphate pathway (PPP), thus creating a versatile nanozyme-based NADH circulating oxidation nanoreactor (Co-HCS/D/A) for tumor therapy through triple cellular metabolism disruption. In vitro and in vivo results demonstrate that the designed nanoreactor not only enhances the catalytic efficiency but also disrupts the tumor metabolic homeostasis, leading to efficient therapy outcome. This study develops a novel NADH circulating oxidation nanoreactor for tumor therapy through triple cellular metabolism disruption, which addresses the limitations of current nanozyme-based metabolism regulation for tumor therapy.

Chemodynamic PtMn Nanocubes for Effective Photothermal ROS Storm a Key Anti-Tumor Therapy in-vivo

Background

Chemodynamic therapy (CDT) is a new treatment approach that is triggered by endogenous stimuli in specific intracellular conditions for generating hydroxyl radicals. However, the efficiency of CDT is severely limited by Fenton reaction agents and harsh reaction conditions.

Methods

Bimetallic PtMn nanocubes were rationally designed and simply synthesized through a one-step high-temperature pyrolysis process by controlling both the nucleation process and the subsequent crystal growth stage. The polyethylene glycol was modified to enhance biocompatibility.

Results

Benefiting from the alloying of Pt nanocubes with Mn doping, the structure of the electron cloud has changed, resulting in different degrees of the shift in electron binding energy, resulting in the increasing of Fenton reaction activity. The PtMn nanocubes could catalyze endogenous hydrogen peroxide to toxic hydroxyl radicals in mild acid. Meanwhile, the intrinsic glutathione (GSH) depletion activity of PtMn nanocubes consumed GSH with the assistance of Mn3+/Mn2+. Upon 808 nm laser irradiation, mild temperature due to the surface plasmon resonance effect of Pt metal can also enhance the Fenton reaction.

Conclusion

PtMn nanocubes can not only destroy the antioxidant system via efficient reactive oxygen species generation and continuous GSH consumption but also propose the photothermal effect of noble metal for enhanced Fenton reaction activity.

Cr(VI) induces ferroptosis in DF-1 cells by simultaneously perturbing iron homeostasis of ferritinophagy and mitophagy

Hexavalent chromium [Cr(VI)] is an environmental pollutant known for its strong oxidizing and carcinogenic effects. However, its potential to induce ferroptosis in poultry remains poorly understood. This study aims to investigate the induction of ferroptosis by Cr(VI) in DF-1 cells and elucidate the underlying mechanisms. DF-1 cells exposed to Cr(VI) showed increased lipid reactive oxygen species and changes in ferroptosis marker genes (decreased expression of GPX4 and increased expression of COX2). Notably, the addition of the ferroptosis-specific inhibitor ferrostatin-1 (Fer-1) can reverse this effect. During the cell death process, Cr(VI) induced ferritinophagy, disrupting iron homeostasis and releasing labile iron ions. We predicted by docking that these iron ions would bind to mitochondrial membrane proteins through virtual docking. This binding was validated through colocalization analysis. In addition, Cr(VI) caused mitophagy, which releases additional ferrous ions. Therefore, Cr(VI) can induce the simultaneous release of ferrous ions through these pathways, thereby exacerbating lipid peroxidation and ultimately triggering ferroptosis in DF-1 cells. This study demonstrates that Cr(VI) can induce ferroptosis in DF-1 cells by disrupting intracellular iron homeostasis and providing valuable insights into the toxic effects of Cr(VI) in poultry and potentially other organisms.

A Functional "Key" Amplified Piezoelectric Effect Modulates ROS Storm with an Open Source for Multimodal Synergistic Cancer Therapy

Chemodynamic therapy (CDT) is a non-invasive strategy for generating reactive oxygen species (ROS) and is promising for cancer treatment. However, increasing ROS in tumor therapy remains challenging. Therefore, exogenous excitation and inhibition of electron-hole pair recombination are attractive for modulating ROS storms in tumors. Herein, a Ce-doped BiFeO3 (CBFO) piezoelectric sonosensitizer to modulate ROS generation and realize a synergistic mechanism of CDT/sonodynamic therapy and piezodynamic therapy (PzDT) is proposed. The mixed Fe2+ and Ce3+ can implement a circular Fenton/Fenton-like reaction in the tumor microenvironment. Abundant ·OH can be generated by ultrasound (US) stimulation to enhance CDT efficacy. As a typical piezoelectric sonosensitizer, CBFO can produce O2 - owing to the enhanced polarization by the US, resulting in the motion of charge carriers. In addition, CBFO can produce a piezoresponse irradiated upon US, which accelerates the migration rate of electrons/holes in opposite directions and results in energy band bending, further achieving toxic ROS production and realizing PzDT. Density functional theory calculations confirmed that Ce doping shortens the diffusion of electrons and improves the conductivity and catalytic activity of CBFO. This distinct US-enhanced strategy emphasizes the effects of doping engineering and piezoelectric-optimized therapy and shows great potential for the treatment of malignant tumors.

Human Serum Albumin Mediated Controllable Synthesis of Defect-Rich Copper Hydroxide Nanowire for Cuproptosis-Based Anti-Tumor Therapy

Cuproptosis, as a newly identified form of programmed cell death, shows great promise in cancer treatment. Efficient Cu+ delivery while avoiding systemic toxicity and elimination of the resistance from over-expressed intracellular copper chelator glutathione (GSH) are critical for cuproptosis. Herein, this work innovatively constructs a biocompatible and defect-rich copper hydroxide nanowire (HCu nanowire) through a human serum albumin (HSA) mediated biomineralization method. This work finds that the morphology and size of HCu nanowires can be controlled adjusted by the feed ratio of HSA and Cu2+. Remarkably, except for outstanding biocompatibility, HSA coordination endows HCu nanowires abundant oxygen vacancies (OVs), and the defect-rich HCu nanowire possesses excellent GSH consumption efficiency. Density functional theory studies indicate that OVs change GSH absorption energy on defective HCu nanowires. In cancer cells, HCu nanowires deplete GSH and simultaneously produce sufficient free Cu+ for enhanced cuproptosis. Meanwhile, Cu+ can catalyze endogenous H2O2 into hydroxyl radicals (·OH) via a Fenton-like reaction. Thus, synergetic cuproptosis and ROS mediated apoptosis against tumor are achieved. The experimental results show that HCu nanowires have a better performance in both antitumor efficiency and safety compared with chemotherapeutic drug Dox at the same dose, demonstrating its great potential in clinical applications.

Multienzyme-Like Polyoxometalate-Based Single-Atom Enzymes for Cancer-Specific Therapy Through Acid-Triggered Nontoxicity-to-Toxicity Transition

Single-atom enzymes (SAzymes) exhibit great potential for chemodynamic therapy (CDT); while, general application is still challenged by their instability and unavoidable side effects during delivery. Herein, a manganese-based polyoxometalate single-atom enzyme (Mn-POM SAE) is first introduced into tumor-specific CDT, which exhibits tumor microenvironment (TME)-activated transition of nontoxicity-to-toxicity. Different from traditional POM materials, the aggregates of low-toxic Mn-POM SAE nanospheres are obtained at neutral conditions, facilitating efficient delivery and avoiding toxicity problems in normal tissues. Under acid TME conditions, these nanospheres are degraded into smaller units of toxic Mn(II)-PW11; thus, initiating cancer cell-specific therapy. The released active units of Mn(II)-PW11 exhibit excellent multienzyme-like activities (including peroxidase (POD)-like, oxidase (OXD)-like, catalase (CAT)-like, and glutathione peroxidase (Gpx)-like activities) for the synergistic cancer therapy due to the stabilized high valence Mn species (MnIII/MnIV). As demonstrated by both intracellular evaluations and in vivo experiments, ROS is generated to cause damage to lysosome membranes, further facilitating acidification and impaired autophagy to enhance cancer therapy. This study provides a detailed investigation on the acid-triggered releasing of active units and the electron transfer in multienzyme-mimic-like therapy, further enlarging the application of POMs from catalytical engineering into cancer therapy.

A non-metal single atom nanozyme for cutting off the energy and reducing power of tumors

Enzymes are considered safe and effective therapeutic tools for various diseases. With the increasing integration of biomedicine and nanotechnology, artificial nanozymes offer advanced controllability and functionality in medical design. However, several notable gaps, such as catalytic diversity, specificity and biosafety, still exist between nanozymes and their native counterparts. Here we report a non-metal single-selenium (Se)-atom nanozyme (SeSAE), which exhibits potent nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-mimetic activity. This novel single atom nanozyme provides a safe alternative to conventional metal-based catalysts and effectively cuts off the cellular energy and reduction equivalents through its distinctive catalytic function in tumors. In this study, we have demonstrated the substantial efficacy of SeSAE as an antitumor nanomedicine across diverse mouse models without discernible systemic adverse effects. The mechanism of the NADPH oxidase-like activity of the non-metal SeSAE was rationalized by density functional theory calculations. Furthermore, comprehensive elucidation of the biological functions, cell death pathways, and metabolic remodeling effects of the nanozyme was conducted, aiming to provide valuable insights into the development of single atom nanozymes with clinical translation potential.

Cascade-Catalyzed Nanogel for Amplifying Starvation Therapy by Nitric Oxide-Mediated Hypoxia Alleviation

Glucose oxidase (Gox)-mediated starvation therapy offers a prospective advantage for malignancy treatment by interrupting the glucose supply to neoplastic cells. However, the negative charge of the Gox surface hinders its enrichment in tumor tissues. Furthermore, Gox-mediated starvation therapy infiltrates large amounts of hydrogen peroxide (H2O2) to surround normal tissues and exacerbate intracellular hypoxia. In this study, a cascade-catalyzed nanogel (A-NE) was developed to boost the antitumor effects of starvation therapy by glucose consumption and cascade reactive release of nitric oxide (NO) to relieve hypoxia. First, the surface cross-linking structure of A-NE can serve as a bioimmobilization for Gox, ensuring Gox stability while improving the encapsulation efficiency. Then, Gox-mediated starvation therapy efficiently inhibited the proliferation of tumor cells while generating large amounts of H2O2. In addition, covalent l-arginine (l-Arg) in A-NE consumed H2O2 derived from glucose decomposition to generate NO, which augmented starvation therapy on metastatic tumors by alleviating tumor hypoxia. Eventually, both in vivo and in vitro studies indicated that nanogels remarkably inhibited in situ tumor growth and hindered metastatic tumor recurrence, offering an alternative possibility for clinical intervention.

Mitochondria-Targeted Prodrug Nanoassemblies for Efficient Ferroptosis-Based Therapy via Devastating Ferroptosis Defense Systems

Ferroptosis is a form of regulated cell death accompanied by lipid reactive oxygen species (ROS) accumulation in an iron-dependent manner. However, the efficiency of tumorous ferroptosis was seriously restricted by intracellular ferroptosis defense systems, the glutathione peroxidase 4 (GPX4) system, and the ubiquinol (CoQH2) system. Inspired by the crucial role of mitochondria in the ferroptosis process, we reported a prodrug nanoassembly capable of unleashing potent mitochondrial lipid peroxidation and ferroptotic cell death. Dihydroorotate dehydrogenase (DHODH) inhibitor (QA) was combined with triphenylphosphonium moiety through a disulfide-containing linker to engineer well-defined nanoassemblies (QSSP) within a single-molecular framework. After being trapped in cancer cells, the acidic condition provoked the structural disassembly of QSSP to liberate free prodrug molecules. The mitochondrial membrane-potential-driven accumulation of the lipophilic cation prodrug was delivered explicitly into the mitochondria. Afterward, the thiol-disulfide exchange would occur accompanied by downregulation of reduced glutathione levels, thus resulting in mitochondria-localized GPX4 inactivation for ferroptosis. Simultaneously, the released QA from the hydrolysis reaction of the adjacent ester bond could further devastate mitochondrial defense and evoke robust ferroptosis via the DHODH-CoQH2 system. This subcellular targeted nanoassembly provides a reference for designing ferroptosis-based strategy for efficient cancer therapy through interfering antiferroptosis systems.

Enhancing lipid peroxidation via radical chain transfer reaction for MRI guided and effective cancer therapy in mice

Lipid peroxidation (LPO), the process of membrane lipid oxidation, is a potential new form of cell death for cancer treatment. However, the radical chain reaction involved in LPO is comprised of the initiation, propagation (the slowest step), and termination stages, limiting its effectiveness in vivo. To address this limitation, we introduce the radical chain transfer reaction into the LPO process to target the propagation step and overcome the sluggish rate of lipid peroxidation, thereby promoting endogenous lipid peroxidation and enhancing therapeutic outcomes. Firstly, radical chain transfer agent (CTA-1)/Fe nanoparticles (CTA-Fe NPs-1) was synthesized. Notably, CTA-1 convert low activity peroxyl radicals (ROO·) into high activity alkoxyl radicals (RO·), creating the cycle of free radical oxidation and increasing the propagation of lipid peroxidation. Additionally, CTA-1/Fe ions enhance reactive oxygen species (ROS) generation, consume glutathione (GSH), and thereby inactivate GPX-4, promoting the initiation stage and reducing termination of free radical reaction. CTA-Fe NPs-1 induce a higher level of peroxidation of polyunsaturated fatty acids in lipid membranes, leading to highly effective treatment in cancer cells. In addition, CTA-Fe NPs-1 could be enriched in tumors inducing potent tumor inhibition and exhibit activatable T1-MRI contrast of magnetic resonance imaging (MRI). In summary, CTA-Fe NPs-1 can enhance intracellular lipid peroxidation by accelerating initiation, propagation, and inhibiting termination step, promoting the cycle of free radical reaction, resulting in effective anticancer outcomes in tumor-bearing mice.

Redox-Active Ferrocene Quencher-Based Supramolecular Nanomedicine for NIR-II Fluorescence-Monitored Chemodynamic Therapy

Real-time monitoring of hydroxyl radical (⋅OH) generation is crucial for both the efficacy and safety of chemodynamic therapy (CDT). Although ⋅OH probe-integrated CDT agents can track ⋅OH production by themselves, they often require complicated synthetic procedures and suffer from self-consumption of ⋅OH. Here, we report the facile fabrication of a self-monitored chemodynamic agent (denoted as Fc-CD-AuNCs) by incorporating ferrocene (Fc) into β-cyclodextrin (CD)-functionalized gold nanoclusters (AuNCs) via host-guest molecular recognition. The water-soluble CD served not only as a capping agent to protect AuNCs but also as a macrocyclic host to encapsulate and solubilize hydrophobic Fc guest with high Fenton reactivity for in vivo CDT applications. Importantly, the encapsulated Fc inside CD possessed strong electron-donating ability to effectively quench the second near-infrared (NIR-II) fluorescence of AuNCs through photoinduced electron transfer. After internalization of Fc-CD-AuNCs by cancer cells, Fenton reaction between redox-active Fc quencher and endogenous hydrogen peroxide (H2 O2 ) caused Fc oxidation and subsequent NIR-II fluorescence recovery, which was accompanied by the formation of cytotoxic ⋅OH and therefore allowed Fc-CD-AuNCs to in situ self-report ⋅OH generation without undesired ⋅OH consumption. Such a NIR-II fluorescence-monitored CDT enabled the use of renal-clearable Fc-CD-AuNCs for efficient tumor growth inhibition with minimal side effects in vivo.

Bioinspired BSA@polydopamine@Fe Nanoprobe with Self-Purification Capacity for Targeted Magnetic Resonance Imaging of Acute Kidney Injury

Contrast-enhanced magnetic resonance imaging (CE-MRI) of acute kidney injury (AKI) is severely hindered by the poor targeting capacity and potential toxicity of current contrast agents. Herein, we propose one-step fabrication of a bovine serum albumin@polydopamine@Fe (BSA@PDA@Fe, BPFe) nanoprobe with self-purification capacity for targeted CE-MRI of AKI. BSA endows the BPFe nanoprobe with renal tubule-targeting ability, and PDA is capable of completely inhibiting the intrinsic metal-induced reactive oxygen species (ROS), which are always involved in Fe/Mn-based agents. The as-prepared nanoprobe owns a tiny size of 2.7 nm, excellent solubility, good T1 MRI ability, superior biocompatibility, and powerful antioxidant capacity. In vivo CE-MRI shows that the BPFe nanoprobe can accumulate in the renal cortex due to the reabsorption effect toward the serum albumin. In the AKI model, impaired renal reabsorption function can be effortlessly detected via the diminishment of renal cortical signal enhancement. More importantly, the administration of the BPFe nanoprobe would not aggravate renal damage of AKI due to the outstanding self-purification capacity. Besides, the BPFe nanoprobe is employed for CE-MR angiography to visualize fine vessel structures. This work provides an MRI contrast agent with good biosafety and targeting ability for CE-MRI of kidney diseases.

Rational designed Fe-ZIFs@CoP nanoplatforms for photothermal-enhanced ROS-mediated tumor therapy

Metal-organic frameworks (MOFs), with biocompatible and bio-friendly properties, exhibit intriguing potential for the drug delivery system and imaging-guided synergistic cancer theranostics. Even though tremendous attention has been attracted on MOFs-based therapeutics, which play a crucial role in therapeutic drugs, gene, and biomedical agents delivery of cancer therapy, they are often explored as simple nanocarriers without further "intelligent" functions. Herein, Fe-doped MOFs with CoP nanoparticles loading were rationally designed and synthesized for photothermal enhanced reactive oxygen species (ROS)-mediated treatment. Fe-ZIFs@CoP could generate efficient ROS through the Fenton reaction while depleting glutathione for amplifying oxidative stress. Particularly, due to the photothermal effect of Fe-ZIFs@CoP, the hyperthermia generated by as-synthesized Fe-ZIFs@CoP facilitated the advanced performance of the Fenton effect for a high amount of ROS generation. The promising "all-in-one" synergistic MOFs platform herein reported provides some prospects for future directions in this area.

Impact of ferroptosis-related risk genes on macrophage M1/M2 polarization and prognosis in glioblastoma

Objective

To explore the effect impact of ferroptosis on macrophage polarization and patient prognosis in glioblastoma.

Methods

We screened ferroptosis-related risk from the public datasets of primary and recurrent glioblastoma, combined with reported ferroptosis genes, calculated the risk genes among the ferroptosis-related genes using the LASSO Cox regression model, and investigated the relationship between these ferroptosis-related risk genes in the tumor and the spectrum of infiltrating M1/M2 macrophages. Macrophages were analyzed using the CIBERSORTx deconvolution algorithm. Samples from The Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA) and a single-cell RNA sequencing dataset (GSE84465) were included. The expression levels of ferroptosis-related risk genes and molecular markers of M1 and M2 macrophages were detected by qPCR and western blot.

Results

A total of fourteen ferroptosis-related risk genes were obtained and the patients' risk scores were calculated. Compared with patients in the low-risk group, patients in the high-risk group had worse prognosis. The M1/M2 macrophage ratio and risk score were negatively correlated, indicating that the tumor microenvironment of glioblastoma in the high-risk group contained more M2 than M1 macrophages. In the single-cell RNA sequencing dataset, the risk score of ferroptosis-related genes in tumor cells was positively correlated with the proportion of high M2 macrophages. The expression of eight ferroptosis-related risk genes was increased in glioblastoma cell, which promoted the polarization of M1 macrophages to M2.

Conclusion

We investigated the fourteen ferroptosis-related risk genes in glioblastoma for the first time, and clarified the impact of ferroptosis-related risk genes on M1/M2 macrophage polarization and patient prognosis.

High spatial-resolved heat manipulating membrane heterogeneity alters cellular migration and signaling

Plasma membrane heterogeneity is a key biophysical regulatory principle of membrane protein dynamics, which further influences downstream signal transduction. Although extensive biophysical and cell biology studies have proven membrane heterogeneity is essential to cell fate, the direct link between membrane heterogeneity regulation to cellular function remains unclear. Heterogeneous structures on plasma membranes, such as lipid rafts, are transiently assembled, thus hard to study via regular techniques. Indeed, it is nearly impossible to perturb membrane heterogeneity without changing plasma membrane compositions. In this study, we developed a high-spatial resolved DNA-origami-based nanoheater system with specific lipid heterogeneity targeting to manipulate the local lipid environmental temperature under near-infrared (NIR) laser illumination. Our results showed that the targeted heating of the local lipid environment influences the membrane thermodynamic properties, which further triggers an integrin-associated cell migration change. Therefore, the nanoheater system was further applied as an optimized therapeutic agent for wound healing. Our strategy provides a powerful tool to dynamically manipulate membrane heterogeneity and has the potential to explore cellular function through changes in plasma membrane biophysical properties.

Stepwise formation of a chemodynamic therapy agent of {Cu8} macrocyclic complex recognized by iodide ions

An atomically precise Cu(I) macrocyclic complex Cu8I was developed for chemodynamic therapy (CDT) research. The {Cu8} macrocyclic skeleton gradually forms with the selective recognition of iodide ions, and the monitoring of intermediate fragments during Cu8I formation using time-dependent electrospray ionization mass spectrometry indicates the following possible formation process: [Cu1] → [Cu2] → [Cu3] → [Cu4] → [Cu5I] → [Cu6I] → [Cu7I] → [Cu8I] when recognized by iodide ions. Furthermore, the Cu(I)-mediated Fenton-like reaction in Cu8I catalyzes the production of toxic ˙OH from H2O2, which results in efficient tumor suppression.

Stimuli-Responsive Nanoadjuvant Rejuvenates Robust Immune Responses to Sensitize Cancer Immunotherapy

Despite their immense therapeutic potential, cancer immunotherapies such as immune checkpoint blockers (ICBs) benefit only a small subset of patients. Toll-like receptor agonists reverse the immunosuppressive tumor microenvironment (TME) to enhance antitumor immunity, but their systemic administration induces side effects. This work describes a TME-responsive nanotherapeutic platform for the site-specific release of drug candidates in tumors with a significant antitumor efficacy. Imidazoquinoline (IMQ)-derived liposomal nanovesicles (LN-IMQ) triggered the antitumor ability of macrophages, mobilized T-cell immunity, and promoted the secretion of antitumor cytokines, explaining the synergistic effect of LN-IMQ with ICBs. LN-IMQ monotherapy observed complete tumor regression in 6/8 of 4T1-bearing mouse, and cured mice resisted secondary tumor challenge. Besides, LN-IMQ decreased the occurrence of lung metastases, being effective against advanced metastases. On the other hand, neoantigen-based cancer vaccine has very low immune responses. Here, we also verified that LN-IMQ can serve as an ideal tumor antigen delivery vector. Cancer cells in vitro treated with chemotherapeutic drugs included multiple neoantigens and high levels of damage-associated molecular patterns, which were then successfully encapsulated in LN-IMQ to obtain a "personalized nanovaccine" with artificially amplified antigenicity and adjuvant properties. This study developed an attractive potential personalized nanovaccine for chemotherapeutic-drug-induced tumor neoantigens and immunotherapy.

An Immunomodulatory Biomimetic Single-Atomic Nanozyme for Biofilm Wound Healing Management

Nanozyme-driven catalytic antibacterial therapy has become a promising modality for bacterial biofilm infections. However, current catalytic therapy of biofilm wounds is severely limited by insufficient catalytic efficiency, excessive inflammation, and deep tissue infection. Drawing from the homing mechanism of natural macrophages, herein, a hollow mesoporous biomimetic single-atomic nanozyme (SAN) is fabricated to actively target inflamed parts, suppress inflammatory factors, and eliminate deeply organized bacteria for enhance biofilm eradication. In the formulation, this biomimetic nanozyme (Co@SAHSs@IL-4@RCM) consists of IL-4-loaded cobalt SANs-embedded hollow sphere encapsulate by RAW 264.7 cell membrane (RCM). Upon accumulation at the infected sites through the specific receptors of RCM, Co@SAHS catalyze the conversion of hydrogen peroxide into hydroxyl radicals and are further amplify by NIR-II photothermal effect and glutathione depletion to permeate and destroy biofilm structure. This behavior subsequently causes the dissociation of RCM shell and the ensuing release of IL-4 that can reprogram macrophages, enabling suppression of oxidative injury and tissue inflammation. The work paves the way to engineer alternative "all-in-one" SANs with an immunomodulatory ability and offers novel insights into the design of bioinspired materials.

Multi-Bioinspired MOF Delivery Systems from Microfluidics for Tumor Multimodal Therapy

Metal-organic framework (MOF)-based drug delivery systems have demonstrated values in oncotherapy. Current research endeavors are centralized on the functionality enrichment of featured MOF materials with designed versatility for synergistic multimodal treatments. Here, inspired by the multifarious biological functions including ferroptosis pattern, porphyrins, and cancer cell membrane (CCM) camouflage technique, novel multi-biomimetic MOF nanocarriers from microfluidics are prepared. The Fe3+ , meso-tetra(4-carboxyphenyl)porphine and oxaliplatin prodrug are incorporated into one MOF nano-system (named FeTPt), which is further cloaked by CCM to obtain a "Trojan Horse"-like vehicle (FeTPt@CCM). Owing to the functionalization with CCM, FeTPt@CCM can target and accumulate at the tumor site via homologous binding. After being internalized by cancer cells, FeTPt@CCM can be activated by a Fenton-like reaction as well as a redox reaction between Fe3+ and glutathione and hydrogen peroxide to generate hydroxyl radical and oxygen. Thus, the nano-platform effectively initiates ferroptosis and improves photodynamic therapy performance. Along with the Pt-drug chemotherapy, the nano-platform exhibits synergistic multimodal actions for inhibiting cancer cell proliferation in vitro and suppressing tumor growth in vivo. These features indicate that such a versatile biomimetic MOF delivery system from microfluidics has great potential for synergistic cancer treatment.

Synergistically remodulating H+/Ca2+ gradients to induce mitochondrial depolarization for enhanced synergistic cancer therapy

The remodulation of H+/Ca2+ gradients in the mitochondria matrix could be effective to induce mitochondria depolarization for the enhancement of cancer therapy. However, it is still challenged by H+ homeostasis, insufficient Ca2+, uncoordinated regulations, and inefficient loading/delivery strategies. Herein, a supramolecular DNA nanocomplex (Ca@DNA-MF) was prepared to synergistically remodulate H+/Ca2+ gradients for mitochondrial depolarization. Upon targeted functionalization and TME-triggered delivery, multiple reagents were released in cancer cells for synergistic three-channel mitochondrial depolarization: the gene reagent of siMCT4 blocked the LA metabolism to induce mitochondrial acidification by downregulating monocarboxylate transporter 4 (MCT4); released Ca2+ disrupted Ca2+ homeostasis to facilitate Ca2+-based mitochondrial depolarization; specifically, TME-activated glutathione (GSH) depletion facilitated efficient generation of hydroxyl radicals (˙OH), further enhancing the mitochondrial depolarization. The remodulation not only triggered apoptosis but also led to ferroptosis to generate abundant ROS for efficient LPO-based apoptosis, providing a synergistic strategy for enhanced synergistic cancer therapy.

Iron-chelated semiconducting oligomer nanoparticles for NIR-II fluorescence imaging-guided enhanced chemodynamic/photothermal combination therapy

Chemodynamic therapy (CDT) has attracted increasing attention owing to its high tumor specificity and low number of side effects. However, the low absolute concentration of reactive oxygen species (ROS) within tumor cells restricts the CDT efficacy. Herein, we use dihydroartemisinin (DHA) to enhance the CDT efficacy and combine photothermal therapy (PTT) to further improve the anticancer effect. To achieve such a goal, an iron-containing semiconducting oligomer nanoparticle (DHA@FePSOD) is prepared by loading DHA into a Fe3+-chelated NIR-II fluorescent semiconducting oligomer (FePSOD). The Fe3+ ion within DHA@FePSOD can be reduced to the Fe2+ ion by glutathione (GSH) and subsequently catalyze the decomposition of hydrogen peroxide (H2O2) into the highly toxic hydroxyl radical (˙OH) for CDT. The loaded DHA may be further reduced by Fe2+ and generate a DHA radical to enhance the CDT efficacy. In addition, DHA@FePSOD shows a good photothermal effect and intense NIR-II fluorescence signal under 808 nm laser irradiation. Both in vitro and in vivo studies prove the better anticancer effect of DHA@FePSOD than FePSOD, which is attributed to the loaded DHA. Furthermore, DHA@FePSOD can effectively accumulate into a tumor and delineate the tumor via NIR-II fluorescence imaging. This study thus provides an efficient approach for developing a NIR-II fluorescence imaging-guided enhanced chemodynamic/photothermal combination therapeutic nanoplatform.

Nanohole-Array Induced Metallic Molybdenum Selenide Nanozyme for Photoenhanced Tumor-Specific Therapy

Deficient catalytic sensitivity to the tumor microenvironment is a major obstacle to nanozyme-mediated tumor therapy. Electron transfer is the intrinsic essence for a nanozyme-catalyzed redox reaction. Here, we developed a nanohole-array-induced metallic molybdenum selenide (n-MoSe2) that is enriched with Se vacancies and can serve as an electronic transfer station for cycling electrons between H2O2 decomposition and glutathione (GSH) depletion. In a MoSe2 nanohole array, the metallic phase reaches up to 84.5%, which has been experimentally and theoretically demonstrated to exhibit ultrasensitive H2O2 responses and enhanced peroxidase (POD)-like activities for H2O2 thermodynamic heterolysis. More intriguingly, plenty of delocalized electrons appear due to phase- and vacancy-facilitated band structure reconstruction. Combined with the limited characteristic sizes of nanoholes, the surface plasmon resonance effect can be excited, leading to the broad absorption spectrum spanning of n-MoSe2 from the visible to near-infrared region (NIR) for photothermal conversion. Under NIR laser irradiation, metallic MoSe2 is able to induce out-of-balance redox and metabolism homeostasis in the tumor region, thus significantly improving therapeutic effects. This study that takes advantage of phase and defect engineering offers inspiring insights into the development of high-efficiency photothermal nanozymes.

Inorganic nanoparticle agents for enhanced chemodynamic therapy of tumours

With the recent interest in the role of oxidative species/radicals in diseases, inorganic nanomaterials with redox activities have been extensively investigated for their potential use in nanomedicine. While many studies focusing on relieving oxidative stress to prevent pathogenesis and to suppress the progression of diseases have shown considerable success, another approach for increasing oxidative stress using nanomaterials to kill malignant cells has suffered from low efficiency despite its wide applicability to various targets. Chemodynamic therapy (CDT) is an emerging technique that can resolve such a problem by exploiting the characteristic tumour microenvironment to achieve high selectivity. In this review, we summarize the recent strategies and underlying mechanisms that have been used to improve the CDT performance using inorganic nanoparticles. In addition to the design of CDT agents, the effects of contributing factors, such as the acidity and the levels of hydrogen peroxide and antioxidants in the tumour microenvironment, together with their modulation and application in combination therapy, are presented. The challenges lying ahead of future clinical translation of this rapidly advancing technology are also discussed.

Copper-instigated modulatory cell mortality mechanisms and progress in oncological treatment investigations

Copper, a transition metal, serves as an essential co-factor in numerous enzymatic active sites and constitutes a vital trace element in the human body, participating in crucial life-sustaining activities such as energy metabolism, antioxidation, coagulation, neurotransmitter synthesis, iron metabolism, and tetramer deposition. Maintaining the equilibrium of copper ions within biological systems is of paramount importance in the prevention of atherosclerosis and associated cardiovascular diseases. Copper induces cellular demise through diverse mechanisms, encompassing reactive oxygen species responses, apoptosis, necrosis, pyroptosis, and mitochondrial dysfunction. Recent research has identified and dubbed a novel regulatory cell death modality-"cuprotosis"-wherein copper ions bind to acylated proteins in the tricarboxylic acid cycle of mitochondrial respiration, resulting in protein aggregation, subsequent downregulation of iron-sulfur cluster protein expression, induction of proteotoxic stress, and eventual cell death. Scholars have synthesized copper complexes by combining copper ions with various ligands, exploring their significance and applications in cancer therapy. This review comprehensively examines the multiple pathways of copper metabolism, copper-induced regulatory cell death, and the current status of copper complexes in cancer treatment.

Cu-doped polypyrrole hydrogel with tumor catalyst activity for NIR-II thermo-radiotherapy

Introduction: Radiotherapy (RT) is one of the key methods for treating breast cancer. However, the effect of single RT is often poor because of insufficient deposition of X-rays in tumor sites and radiation resistance induced by the abnormal tumor microenvironment (overexpression of glutathione (GSH)). The development of multifunctional RT sensitizers and synergetic therapeutic strategies is, therefore, a promising area for enhancing the anticancer effect of RT. Methods: In this study, a multifunctional nanozyme hydrogel based on Cu-doped polypyrrole (CuP) was designed to work concertedly with a second near-infrared thermal RT. The CuP-based hydrogel (CH) reached the tumor site when injected in-situ and achieved long-term storage. Results: Once stimulated with 1064-nm laser irradiation, the heated and softened hydrogel system released CuP nanozyme to provide photothermal therapy, thereby inhibiting the repair of DNA damage caused by RT. In addition, CuP with dual nanozyme activity depleted the intracellular GSH to reduce the antioxidant capacity of the tumor. Moreover, CuP converted H₂O₂ to produce ·OH to directly kill the tumor cells, thus enhancing the capability of low-dose RT to inhibit tumor growth. In vivo experiments showed that the CH system used in combination with a low-power 1064-nm laser and low-dose RT (4 Gy) exhibited good synergistic anticancer effects and biological safety. Discussion: As a new light-responsive hydrogel system, CH holds immense potential for radio-sensitization.