A multifunctional cascade enzyme system for enhanced starvation/chemodynamic combination therapy against hypoxic tumors

Starvation therapy has shown promise as a cancer treatment, but its efficacy is often limited when used alone. In this work, a multifunctional nanoscale cascade enzyme system, named CaCO3@MnO2-NH2@GOx@PVP (CMGP), was fabricated for enhanced starvation/chemodynamic combination cancer therapy. CMGP is composed of CaCO3 nanoparticles wrapped in a MnO2 shell, with glucose oxidase (GOx) adsorbed and modified with polyvinylpyrrolidone (PVP). MnO2 decomposes H2O2 in cancer cells into O2, which enhances the efficiency of GOx-mediated starvation therapy. CaCO3 can be decomposed in the acidic cancer cell environment, causing Ca2+ overload in cancer cells and inhibiting mitochondrial metabolism. This synergizes with GOx to achieve more efficient starvation therapy. Additionally, the H2O2 and gluconic acid produced during glucose consumption by GOx are utilized by MnO2 with catalase-like activity to enhance O2 production and Mn2+ release. This process accelerates glucose consumption, reactive oxygen species (ROS) generation, and CaCO3 decomposition, promoting the Ca2+ release. CMGP can alleviate tumor hypoxia by cycling the enzymatic cascade reaction, which increases enzyme activity and combines with Ca2+ overload to achieve enhanced combined starvation/chemodynamic therapy. In vitro and in vivo studies demonstrate that CMGP has effective anticancer abilities and good biosafety. It represents a new strategy with great potential for combined cancer therapy.

Tumour microenvironment-responded Fe-doped carbon dots-sensitized cubic Cu2O for Z-scheme heterojunction-enhanced sono-chemodynamic synergistic tumor therapy

The efficacy of electron-hole separation in a single sonosensitizer and the complexities of the tumor microenvironment (TME) present significant challenges to the effectiveness of sonodynamic therapy (SDT). Designing efficient sonosensitizers to enhance electron-hole separation and alleviate TME resistance is crucial yet challenging. Herein, we introduce a novel Z-scheme heterojunctions (HJs) sonosensitizer using Fe-doped carbon dots (CDs) as auxiliary semiconductors to sensitize cubic Cu2O (Fe-CDs@Cu2O) for the first time. Fe-CDs@Cu2O demonstrated enhanced SDT effects due to improved electron-hole separation. Additionally, the introduction of Fe ions in CDs synergistically enhances Fenton-like reactions with Cu ions in Cu2O, resulting in enhanced chemodynamic therapy (CDT) effects. Moreover, Fe-CDs@Cu2O exhibited rapid glutathione (GSH) depletion, effectively mitigating TME resistance. With high rates of 1O2 and OH generated by Fe-CDs@Cu2O, coupled with strong GSH depletion, single drug injection and ultrasound (US) irradiation effectively eliminate tumors. This innovative heterojunction sonosensitizer offers a promising pathway for clinical anti-tumor treatment.

Zeolitic imidazole framework-derived rich-Zn-Co3O4/N-doped porous carbon with multiple enzyme-like activities for synergistic cancer therapy

Reactive oxygen species (ROS)-centered chemodynamic therapy (CDT) holds significant potential for tumor-specific treatment. However, insufficient endogenous H2O2 and extra glutathione within tumor microenvironment (TME) severely deteriorate the CDT's effectiveness. Herein, rich-Zn-Co3O4/N-doped porous carbon (Zn-Co3O4/NC) was fabricated by two-step pyrolysis, and applied to build high-efficiency nano-platform for synergistic cancer therapy upon combination with glucose oxidase (GOx), labeled Zn-Co3O4/NC-GOx for clarity. Specifically, the multiple enzyme-like activities of the Zn-Co3O4/NC were scrutinously investigated, including peroxidase-like activity to convert H2O2 to O2∙-, catalase-like activity to decompose H2O2 into O2, and oxidase-like activity to transform O2 to O2∙-, which achieved the CDT through the catalytic cascade reaction. Simultaneously, GOx reacted with intracellular glucose to produce gluconic acid and H2O2, realizing starvation therapy. In the acidic TME, the Zn-Co3O4/NC-GOx rapidly caused intracellular Zn2+ pool overload and disrupted cellular homeostasis for ion-intervention therapy. Additionally, the Zn-Co3O4/NC exhibited glutathione peroxidase-like activity, which consumed glutathione in tumor cells and reduced the ROS consumption for ferroptosis. The tumor treatments offer some constructive insights into the nanozyme-mediated catalytic medicine, coupled by avoiding the TME limitations.

Nanomedicine alleviates doxorubicin-induced cardiotoxicity and enhances chemotherapy synergistic chemodynamic therapy

Doxorubicin (DOX) is widely used in clinic as a broad-spectrum chemotherapy drug, which can enhance the efficacy of chemodynamic therapy (CDT) by interfering tumor-related metabolize to increase H2O2 content. However, DOX can induce serious cardiomyopathy (DIC) due to its oxidative stress in cardiomyocytes. Eliminating oxidative stress would create a significant opportunity for the clinical application of DOX combined with CDT. To address this issue, we introduced sodium ascorbate (AscNa), the main reason is that AscNa can be catalyzed to produce H2O2 by the abundant Fe3+ in the tumor site, thereby enhancing CDT. While the content of Fe3+ in heart tissue is relatively low, so the oxidation of AscNa had tumor specificity. Meanwhile, due to its inherent reducing properties, AscNa could also eliminate the oxidative stress generated by DOX, preventing cardiotoxicity. Due to the differences between myocardial tissue and tumor microenvironment, a novel nanomedicine was designed. MoS2 was employed as a carrier and CDT catalyst, loaded with DOX and AscNa, coating with homologous tumor cell membrane to construct an acid-responsive nanomedicine MoS2-DOX/AscNa@M (MDA@M). In tumor cells, AscNa enhances the synergistic therapy of DOX and MoS2. In cardiomyocytes, AscNa could effectively reduce the cardiomyopathy induced by DOX. Overall, this study enhanced the clinical potential of chemotherapy synergistic CDT.

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

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

EGCG-vanadium nanomedicine with neutral pH Fenton reaction activity inhibits heat shock proteins for enhanced photothermal/chemodynamic therapy

A burgeoning interest has recently focused on the development of nanomedicine to integrate noninvasive photothermal therapy (PTT) and chemodynamic therapy (CDT) for synergistic tumor treatments, owing to PTT's amplification effect on CDT. However, challenges emerge as hyperthermia often induces an unwarranted overexpression of cytoprotective heat shock proteins (HSPs), thereby curtailing PTT efficacy. Additionally, the nearly neutral tumor intracellular pH (pHi ≈ 7.2) that handicaps the Fenton reaction poses a leading limitation to CDT. Addressing these hurdles, we introduce EVP, a nanomedicine developed through the straightforward assembly of epigallocatechin gallate (EGCG), vanadium sulfate (VOSO4), and Pluronic F-127 (PF127). EVP comprehensively downregulates overexpressed HSPs (HSP 60, 70, 90) through the collaborative action of EGCG and vanadyl (VO2+). Moreover, the tumor intracellular pH-processed Fenton-like reaction by VO2+ ensures highly efficient hydroxyl radicals (OH) production in cytosols, overcoming the stringent acidity requirement for CDT. Additionally, the hyperthermia induced by PTT augments OH production, further enhancing CDT efficacy. In vitro and in vivo experiments validate EVP's excellent biocompatibility and potent tumor inhibition, highlighting its substantial potential in tumor therapy.

Chemo-photodynamic antitumour therapy based on Er-doped upconversion nanoparticles coated with hypocrellin B and MnO2

An antitumour chemo-photodynamic therapy nanoplatform was constructed based on phospholipid-coated NaYF4: Yb/Er upconversion nanoparticles (UCNPs). In this work, the amphiphilic block copolymer DSPE-PEG2000 was combined with the surface ligand oleic acid of the UCNPs through hydrophobic interaction to form liposomes with a dense hydrophobic layer in which the photosensitizer hypocrellin B (HB) was assembled. The coated HB formed J-aggregates, which caused a large redshift in the absorption spectrum and improved the quantum efficiency of energy transfer. Furthermore, MnO2 nanosheets grew in-situ on the liposomes through OMn coordination. Therefore, a multifunctional tumour microenvironment (TME)-responsive theranostic nanoplatform integrating photodynamic therapy (PDT) and chemodynamic therapy (CDT) was successfully developed. The results showed that this NIR-mediated chemo-photodynamic therapy nanoplatform was highly efficient for oncotherapy.

Oxygen vacancy-rich nickel oxide nanoplatforms for enhanced photothermal and chemodynamic therapy combat methicillin-resistant Staphylococcus aureus

Bacterial infections pose a global concern due to high fatality rates, particularly with the rise of drug-resistant bacteria and biofilm formation. There is an urgent need for innovative strategies to combat this issue. A study on chemodynamic therapy (CDT) using nanozymes in conjunction with photothermal therapy (PTT) has displayed potential in addressing drug-resistant bacterial infections. However, the effectiveness of this combined approach is limited by inadequate light absorption. This work suggests the NiOx nanoparticles enriched with oxygen vacancies enhance CDT and PTT to overcome this challenge. The presence of oxygen vacancies in NiOx can reduce the energy gap between its valence band and conduction band, facilitating oxygen adsorption. NiOx has exhibited notable antibacterial properties and complete eradication of biofilms in both laboratory and animal trials. In animal abscess models, NiOx demonstrated antibacterial and anti-inflammatory effects in the initial stages, while also promoting wound healing and tissue regeneration by influencing immune factors and encouraging collagen deposition and neovascularization. With positive biosafety and biocompatibility profiles, the oxygen vacancy-enhanced CDT and PTT therapy proposed in this article hold promise for effective sterilization, deep biofilm removal, and treatment of infections caused by drug-resistant bacteria. STATEMENT OF SIGNIFICANCE: This study constructs oxygen vacancies NiOx nanoparticles (NiOx NPs) to improve the efficacy of photothermal therapy and chemodynamic therapy. The presence of oxygen vacancies in NiOx NPs helps bridge the energy gap between its valence band and conduction band, facilitating oxygen adsorption and improving catalytic efficiency. In both in vivo and in vitro antibacterial experiments, NiOx NPs demonstrate effective antibacterial and anti-inflammatory properties. Furthermore, it aids in wound healing and tissue regeneration by modulating immune factors, collagen deposition, and angiogenesis. This approach presents a promising collaborative strategy for utilizing nickel-based defective nanomaterials in combating deep drug-resistant bacterial infections.

Cisplatin-activated and hemoglobin-mediated injectable hydrogel system for antitumor chemodynamic and chemotherapy

Low specificity and hypoxia-induced drug resistance are significant challenges in traditional cancer treatment. To enhance the anticancer efficacy, an injectable hydrogel system is developed through the formation of dynamic covalent bonds in hyaluronic acid, allowing for localized controlled release of drugs. This system also utilizes double-stranded DNA sequences for the intercalation delivery of the chemotherapeutic drug, enabling a multifaceted approach to therapy. Cisplatin not only serves as a chemotherapy drug but also acts as a catalyst for chemodynamic therapy (CDT) to initiate CDT cascades by creating hydrogen peroxide for the Fenton reaction. Hemoglobin, enclosed in PLGA nanoparticles, provides ferrous ions that react with hydrogen peroxide in an acidic environment, yielding hydroxyl radicals that induce cancer cell death. Additionally, oxygen released from hemoglobin mitigates hypoxia-induced chemoresistance, bolstering overall anticancer efficacy. Results demonstrate the shear-thinning properties and injectability of the hydrogel. Cisplatin elevates intracellular hydrogen peroxide levels in tumor cells, while hemoglobin efficiently releases ferrous ions and generates reactive oxygen species (ROS) in the presence of hydrogen peroxide. In in vitro and in vivo study, the combinational use of chemo- and chemodynamic therapies achieves a synergistic anticancer effect on combating glioblastoma. In summary, our CDT-based hydrogel, activated by endogenous cues and mediated by chemo drugs, spontaneously produces ROS and ameliorates the adverse tumor microenvironment with rational and selective antitumor strategies.

Cisplatin-loaded mesoporous polydopamine nanoparticles capped with MnO2 and coated with platelet membrane provide synergistic anti-tumor therapy

A multifunctional nanoplatform was constructed in this work, with the goal of ameliorating the challenges faced with traditional cancer chemotherapy. Cisplatin (CP) was loaded into mesoporous polydopamine (mPDA) nanoparticles (NPs) with a drug loading of 15.8 ± 0.1 %, and MnO2 used as pore sealing agent. Finally, the NPs were wrapped with platelet membrane (PLTM). P-selectin on the PLTM can bind to CD44, which is highly expressed on the tumor cell membrane, so as to improve the targeting performance of the NPs. In addition, the CD47 on the PLTM can prevent the NPs from being phagocytosed by macrophages, which is conducive to immune escape. The final PLTM-CP@mPDA/MnO2 NPs were found to have a particle size of approximately 198 nm. MnO2 is degraded into Mn2+ in the tumor microenvironment, leading to CP release from the pores in the mPDA. CP both acts as a chemotherapy agent and can also increase the concentration of H2O2 in cells. Mn2+ can catalyze the conversion of H2O2 to OH, resulting in oxidative damage and chemodynamic therapy. In addition, Mn2+ can be used as a contrast agent in magnetic resonance imaging (MRI). In vitro and in vivo experiments were performed to explore the therapeutic effect of the NPs. When the concentration of CP is 30 μg/mL, the NPs cause approximately 50 % cell death. It was found that the PLTM-CP@mPDA/MnO2 NPs are targeted to cancerous cells, and in the tumor site cause extensive apoptosis. Tumor growth is thereby repressed. No negative off-target side effects were noted. MRI could be used to confirm the presence of the NPs in the tumor site. Overall, the nano-platform developed here provides cooperative chemotherapy and chemodynamic therapy, and can potentially be used for effective cancer treatment which could be monitored by MRI.

A pH-sensitive imidazole grafted polymeric micelles nanoplatform based on ROS amplification for ferroptosis-enhanced chemodynamic therapy

Highly toxic reactive oxygen species (ROS), crucial in inducing apoptosis and ferroptosis, are pivotal for cell death pathways in cancer therapy. However, the effectiveness of ROS-related tumor therapy is impeded by the limited intracellular ROS and substrates, coupled with the presence of abundant ROS scavengers like glutathione (GSH). In this research, we developed acid-responsive, iron-coordinated polymer nanoparticles (PPA/TF) encapsulating a mitochondrial-targeting drug alpha-tocopheryl succinate (α-TOS) for enhanced synergistic tumor treatment. The imidazole grafted micelles exhibit prolonged blood circulation and improve the delivery efficiency of the hydrophobic drug α-TOS. Additionally, PPA's design aids in delivering Fe3+, supplying ample iron ions for chemodynamic therapy (CDT) and ferroptosis through the attachment of imidazole groups to Fe3+. In the tumor's weakly acidic intracellular environment, PPA/TF facilitates pH-responsive drug release. α-TOS specifically targets mitochondria, generating ROS and replenishing those depleted by the Fenton reaction. Moreover, the presence of Fe3+ in PPA/TF amplifies ROS upregulation, promotes GSH depletion, and induces oxidative damage and ferroptosis, effectively inhibiting tumor growth. This research presents an innovative ROS-triggered amplification platform that optimizes CDT and ferroptosis for effective cancer treatment.

H2S-driven chemotherapy and mild photothermal therapy induced mitochondrial reprogramming to promote cuproptosis

The elevated level of hydrogen sulfide (H2S) in colon cancer hinders complete cure with a single therapy. However, excessive H2S also offers a treatment target. A multifunctional cascade bioreactor based on the H2S-responsive mesoporous Cu2Cl(OH)3-loaded hypoxic prodrug tirapazamine (TPZ), in which the outer layer was coated with hyaluronic acid (HA) to form TPZ@Cu2Cl(OH)3-HA (TCuH) nanoparticles (NPs), demonstrated a synergistic antitumor effect through combining the H2S-driven cuproptosis and mild photothermal therapy. The HA coating endowed the NPs with targeting delivery to enhance drug accumulation in the tumor tissue. The presence of both the high level of H2S and the near-infrared II (NIR II) irradiation achieved the in situ generation of photothermic agent copper sulfide (Cu9S8) from the TCuH, followed with the release of TPZ. The depletion of H2S stimulated consumption of oxygen, resulting in hypoxic state and mitochondrial reprogramming. The hypoxic state activated prodrug TPZ to activated TPZ (TPZ-ed) for chemotherapy in turn. Furthermore, the exacerbated hypoxia inhibited the synthesis of adenosine triphosphate, decreasing expression of heat shock proteins and subsequently improving the photothermal therapy. The enriched Cu2+ induced not only cuproptosis by promoting lipoacylated dihydrolipoamide S-acetyltransferase (DLAT) heteromerization but also performed chemodynamic therapy though catalyzing H2O2 to produce highly toxic hydroxyl radicals ·OH. Therefore, the nanoparticles TCuH offer a versatile platform to exert copper-related synergistic antitumor therapy.

In situ generation of copper(Ⅱ)/diethyldithiocarbamate complex through tannic acid/copper(Ⅱ) network coated hollow mesoporous silica for enhanced cancer chemodynamic therapy

The Cu2+ complex formed by the coordination of disulfiram (DSF) metabolite diethyldithiocarbamate (DTC), Cu(DTC)2, can effectively inhibit tumor growth. However, insufficient Cu2+ levels in the tumor microenvironment can impact tumor-suppressive effects of DTC. In this study, we proposed a Cu2+ and DSF tumor microenvironment-targeted delivery system. This system utilizes hollow mesoporous silica (HMSN) as a carrier, after loading with DSF, encases it using a complex of tannic acid (TA) and Cu2+ on the outer layer. In the slightly acidic tumor microenvironment, TA/Cu undergoes hydrolysis, releasing Cu2+ and DSF, which further form Cu(DTC)2 to inhibit tumor growth. Additionally, Cu2+ can engage in a Fenton-like reaction with H2O2 in the tumor microenvironment to form OH, therefore, chemodynamic therapy (CDT) and Cu(DTC)2 are used in combination for tumor therapy. In vivo tumor treatment results demonstrated that AHD@TA/Cu could accumulate at the tumor site, achieving a tumor inhibition rate of up to 77.6 %. This study offers a novel approach, circumventing the use of traditional chemotherapy drugs, and provides valuable insights into the development of in situ tumor drug therapies.

High-performance pyrite nano-catalyst driven photothermal/chemodynamic synergistic therapy for Osteosarcoma

Osteosarcoma (OS) is an aggressive bone tumor with strong invasiveness, rapid metastasis, and dreadful mortality. Chemotherapy is a commonly used approach for OS treatment but is limited by the development of drug resistance and long-term adverse effects. To date, OS still lacks the curative treatment. Herein, we fabricated pyrite-based nanoparticles (FeS2@CP NPs) as synergetic therapeutic platform by integrating photothermal therapy (PTT) and chemo-dynamic therapy (CDT) into one system. The synthetic FeS2@CP NPs showed superior Fenton reaction catalytic activity. FeS2@CP NPs-based CDT efficaciously eradicated the tumor cells by initiating dual-effect of killing of apoptosis and ferroptosis. Furthermore, the generated heat from FeS2@CP under near-infrared region II (NIR-II) laser irradiation could not only inhibit tumor's growth, but also promote tumor cell apoptosis and ferroptosis by accelerating •OH production and GSH depletion. Finally, the photothermal/NIR II-enhanced CDT synergistic therapy showed excellent osteosarcoma treatment effects both in vitro and in vivo with negligible side effects. Overall, this work provided a high-performance and multifunctional Fenton catalyst for osteosarcoma synergistic therapy, which provided a pathway for the clinical application of PTT augmented CDT.

Tumor microenvironment-activatable nanocatalysts with chemodynamic therapy and enhanced autophagy for specific treatment of oral squamous cell carcinoma

Adjuvant therapy following surgery is imperative for enhancing the prognosis of patients with oral squamous cell carcinoma (OSCC) in the clinical setting. Nevertheless, challenges such as treatment resistance mediated by the tumor microenvironment (TME), systemic toxicity, and adverse side effects hinder the effectiveness of conventional adjuvant therapy. In this context, we introduce a novel nanocatalyst denoted as MnO2-x@HA-CCM (MnHA@CCM NC) designed specifically for treating OSCC. This nanocatalyst exerts targeted anti-tumor effects through TME-activatable chemodynamic therapy (CDT) and tumoricidal autophagy. The MnHA@CCM NCs exploit the biocompatibility of hyaluronic acid (HA) coating and the homologous targeting effect of cancer cell membrane (CCM) camouflage, ensuring safe in vivo delivery and specific accumulation at tumor sites. Following intracellular uptake, Fenton-like Mn2+ is generated by consuming glutathione (GSH) within the TME. Subsequently, Mn2+ catalyzes the overproduced H2O2 to generate reactive oxygen species (ROS), inducing cell apoptosis through mitochondrial damage. Additionally, phagocytized NCs and the resultant ROS accumulation in tumor cells elevate the autophagy flux, leading to autophagosome overload and consequent tumoricidal autophagy. Notably, normal cells without TME-catalytic CDT undergo mild protective autophagy to rebalance the stimulation of NCs. As a result, the TME-activatable MnHA@CCM NCs demonstrate a therapeutic efficacy in inhibiting cancer cell growth both in vitro and in vivo. This study presents a targeted treatment strategy for OSCC tumors while sparing normal cells, offering a potential alternative in the realm of adjuvant therapy.

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.

Construction and evaluation of a nanosystem that combines acidification promoted chemodynamic therapy and intracellular drug release monitoring

Triple-negative breast cancer (TNBC) is a highly invasive subtype of breast cancer that seriously affects women's physical and mental health. Chemodynamic therapy (CDT) induces cell death by specifically generating Fenton/Fenton-like reactions within tumor cells. However, the weak acidity of the tumor microenvironment (TME) greatly weakens the effectiveness of CDT. This work constructed a kind of P-CAIDF/PT nanoparticles (NPs), composed of two Pluronic F127 (PF127) based polymers: one was PF127-CAI (P-CAI), composed by connecting PF127 with the carbonic anhydrase IX (CA IX) inhibitor (CAI); the other was PF127-SS-TPE (PT), composed of PF127 and the aggregation-induced emission molecule, tetraphenylethylene (TPE), via the linkage of disulfide bonds. The two polymers were employed to construct the doxorubicin (DOX) and ferrocene (Fc) co-loaded P-CAIDF/PT NPs through the film dispersion method. After being administrated via i.v., P-CAIDF/PT could be accumulated in the TME by the enhanced permeability and retention (EPR) effect and engulfed by tumor cells. P-CAI induced intracellular acidification by inhibiting the overexpressed CA IX, thus promoting CDT by enhancing the Fc-mediated Fenton reaction. The acidification-enhanced CDT combined with the DOX-mediated chemotherapy could improve the therapeutic effect on TNBC. Moreover, P-CAIDF/PT also monitored the intracellular drug release processes through the fluorescence resonance energy transfer (FRET) effect depending on the inherent DOX/TPE pair. In conclusion, the P-CAIDF/PT nanosystem can achieve the combination therapy of acidification-enhanced CDT and chemotherapy as well as therapy monitoring, thus providing new ideas for the design and development of TNBC therapeutic agents.

Tumor acidification and GSH depletion by bimetallic composite nanoparticles for enhanced chemodynamic therapy of TNBC

Chemodynamic therapy (CDT) based on intracellular Fenton reaction to produce highly cytotoxic reactive oxygen species (ROS) has played an essential role in tumor therapy. However, this therapy still needs to be improved by weakly acidic pH and over-expression of glutathione (GSH) in tumor microenvironment (TEM), which hinders its future application. Herein, we reported a multifunctional bimetallic composite nanoparticle MnO2@GA-Fe@CAI based on a metal polyphenol network (MPN) structure, which could reduce intracellular pH and endogenous GSH by remodeling tumor microenvironment to improve Fenton activity. MnO2 nanoparticles were prepared first and MnO2@GA-Fe nanoparticles with Fe3+ as central ion and gallic acid (GA) as surface ligands were prepared by the chelation reaction. Then, carbonic anhydrase inhibitor (CAI) was coupled with GA to form MnO2@GA-Fe@CAI. The properties of the bimetallic composite nanoparticles were studied, and the results showed that CAI could reduce intracellular pH. At the same time, MnO2 could deplete intracellular GSH and produce Mn2+ via redox reactions, which re-established the TME with low pH and GSH. In addition, GA reduced Fe3+ to Fe2+. Mn2+ and Fe2+ catalyzed the endogenous H2O2 to produce high-lever ROS to kill tumor cells. Compared with MnO2, MnO2@GA-Fe@CAI could reduce the tumor weight and volume for the xenograft MDA-MB-231 tumor-bearing mice and the final tumor inhibition rate of 58.09 ± 5.77%, showing the improved therapeutic effect as well as the biological safety. Therefore, this study achieved the high-efficiency CDT effect catalyzed by bimetallic through reshaping the tumor microenvironment.

Accelerated cascade melanoma therapy using enzyme-nanozyme-integrated dissolvable polymeric microneedles

Dissolvable polymeric microneedles (DPMNs) have emerged as a powerful technology for the localized treatment of diseases, such as melanoma. Herein, we fabricated a DPMN patch containing a potent enzyme-nanozyme composite that transforms the upregulated glucose consumption of cancerous cells into lethal reactive oxygen species via a cascade reaction accelerated by endogenous chloride ions and external near-infrared (NIR) irradiation. This was accomplished by combining glucose oxidase (Gox) with a NIR-responsive chloroperoxidase-like copper sulfide (CuS) nanozyme. In contrast with subcutaneous injection, the microneedle system highly localizes the treatment, enhancing nanomedicine uptake by the tumor and reducing its systemic exposure to the kidneys and spleen. NIR irradiation further controls the potency and toxicity of the formulation by thermally disabling Gox. In a mouse melanoma model, this unique combination of photothermal, starvation, and chemodynamic therapies resulted in complete tumor eradication (99.2 ± 0.8 % reduction in tumor volume within 10 d) without producing signs of systemic toxicity. By comparison, other treatment combinations only resulted in a 42-76.5 % reduction in tumor growth. The microneedle patch design is therefore not only highly potent but also with regulated toxicity and improved safety.

Near-infrared-guided NO generator for combined NO/photothermal/chemodynamic therapy of bacterial infections

Nitric oxide (NO)-based gas therapy approaches are promising in the treatment of infections; however, these strategies are hindered by poor delivery to the target site, which leads to unsatisfactory effects. In this study, we developed a NO-controlled platform (SCM@HA) via NO-generating mesoporous silica nanoparticles co-doped with sodium nitroprusside and copper sulphide to control NO production under near-infrared (NIR)-laser irradiation. Irradiation with an 808 nm NIR laser rapidly triggered the release of NO from the particles to actualise gas therapy. Photothermal therapy (PTT) also increased the local microenvironment temperature, and the close relationship between chemodynamic therapy (CDT) and temperature suggests that the increasing temperature facilitates in its working. The hydroxyl radicals generated by CDT can destroy the structure of bacteria in acidic environments. The germicidal activity of the nanoparticles was determined by the combined action of PTT, CDT, and NO-based gas therapy. The nanoparticles showed bactericidal activity in vitro against bacterial strains Staphylococcus aureus (S. aureus) and Salmonella typhimurium (S. typhimurium). Finally, the anti-infective efficacy in vivo in S. aureus-infected mouse model was demonstrated. Thus, the synergistic antimicrobial effects of NO-generating silica nanoparticles have good potential for the non-antibiotic treatment of bacterial infections in wounds. STATEMENT OF SIGNIFICANCE: Bacterial infections and resistance are challenging health threats. Therefore, the development of an antibiotic-independent method is essential for the treatment of wound bacterial infections. In this study, NO-generating nanoparticles loaded with sodium nitroprusside in copper sulphide-doped mesoporous silica were prepared to control the long-term release of NO using near-infrared laser, which has good efficacy of PTT and CDT. The bactericidal effects of as-prepared nanoparticles against S. aureus and S. typhimurium have been well elucidated. This study proposes a feasible method in the field of NO-based therapy, thus paving the way that will benefit for the treatment of bacterial infections in wounds.

A ferroptosis-reinforced nanocatalyst enhances chemodynamic therapy through dual H2O2 production and oxidative stress amplification

The existence of a delicate redox balance in tumors usually leads to cancer treatment failure. Breaking redox homeostasis by amplifying oxidative stress and reducing glutathione (GSH) can accelerate cancer cell death. Herein, we construct a ferroptosis-reinforced nanocatalyst (denoted as HBGL) to amplify intracellular oxidative stress via dual H2O2 production-assisted chemodynamic therapy (CDT). Specifically, a long-circulating liposome is employed to deliver hemin (a natural iron-containing substrate for Fenton reaction and ferroptosis), β-lapachone (a DNA topoisomerase inhibitor with H2O2 generation capacity for chemotherapy), and glucose oxidase (which can consume glucose for starvation therapy and generate H2O2). HBGL can achieve rapid, continuous, and massive H2O2 and •OH production and GSH depletion in cancer cells, resulting in increased intracellular oxidative stress. Additionally, hemin can reinforce the ferroptosis-inducing ability of HBGL, which is reflected in the downregulation of glutathione peroxidase-4 and the accumulation of lipid peroxide. Notably, HBGL can disrupt endo/lysosomes and impair mitochondrial function in cancer cells. HBGL exhibits effective tumor-killing ability without eliciting obvious side effects, indicating its clinical translation potential for synergistic starvation therapy, chemotherapy, ferroptosis therapy, and CDT. Overall, this nanocatalytic liposome may be a promising candidate for achieving potentiated cancer treatment.

Anti-osteosarcoma trimodal synergistic therapy using NiFe-LDH and MXene nanocomposite for enhanced biocompatibility and efficacy

Osteosarcoma is usually resistant to immunotherapy and, thus primarily relies on surgical resection and high-dosage chemotherapy. Unfortunately, less invasive or toxic therapies such as photothermal therapy (PTT) and chemodynamic therapy (CDT) generally failed to show satisfactory outcomes. Adequate multimodal therapies with proper safety profiles may provide better solutions for osteosarcoma. Herein, a simple nanocomposite that synergistically combines CDT, PTT, and chemotherapy for osteosarcoma treatment was fabricated. In this composite, small 2D NiFe-LDH flakes were processed into 3D hollow nanospheres via template methods to encapsulate 5-Fluorouracil (5-FU) with high loading capacity. The nanospheres were then adsorbed onto larger 2D Ti3C2 MXene monolayers and finally shielded by bovine serum albumin (BSA) to form 5-FU@NiFe-LDH/Ti3C2/BSA nanoplatforms (5NiTiB). Both in vitro and in vivo data demonstrated that the 5-FU induced chemotherapy, NiFe-LDH driven chemodynamic effects, and MXene-based photothermal killing collectively exhibited a synergistic "all-in-one" anti-tumor effect. 5NiTiB improved tumor suppression rate from <5% by 5-FU alone to ∼80.1%. This nanotherapeutic platform achieved higher therapeutic efficacy with a lower agent dose, thereby minimizing side effects. Moreover, the composite is simple to produce, enabling the fine-tuning of dosages to suit different requirements. Thus, the platform is versatile and efficient, with potential for further development.

Different Valence States of Copper Ion Delivery against Triple-Negative Breast Cancer

Different valence states of copper (Cu) ions are involved in complicated redox reactions in vivo, which are closely related to tumor proliferation and death pathways, such as cuproptosis and chemodynamic therapy (CDT). Cu ion mediated Fenton-like reagents induced tumor cell death which presents compelling attention for the CDT of tumors. However, the superiority of different valence states of Cu ions in the antitumor effect is unknown. In this study, we investigated different valence states of Cu ions in modulating tumor cell death by Cu-chelated cyanine dye against triple-negative breast cancer. The cuprous ion (Cu+) and copper ion (Cu2+) were chelated with four nitrogen atoms of dipicolylethylenediamine-modified cyanine for the construction of Cu+ and Cu2+ chelated cyanine dyes (denoted as CC1 and CC2, respectively). Upon 660 nm laser irradiation, the CC1 or CC2 can generate reactive oxygen species, which could disrupt the cyanine structure, achieving the rapid release of Cu ions and initiating the Fenton-like reaction for CDT. Compared with Cu2+-based Fenton-like reagent, the CC1 with Cu+ exhibited a better therapeutic outcome for the tumor due to there being no need for a reduction by glutathione and a shorter route to generate more hydroxyl radicals. Our findings suggest the precision delivery of Cu+ could achieve highly efficient antitumor therapy.

Synergistic effect of photothermal and magnetic hyperthermia for in situ activation of Fenton reaction in tumor microenvironment for chemodynamic therapy

Traditional cancer treatments are ineffective and cause severe adverse effects. Thus, the development of chemodynamic therapy (CDT) has the potential for in situ catalysis of endogenous molecules into highly toxic species, which would then effectively destroy cancer cells. However, the shortage of high-performance nanomaterials hinders the broad clinical application of this approach. In present study, an effective therapeutic platform was developed using a simple hydrothermal method for the in-situ activation of the Fenton reaction within the tumor microenvironment (TME) to generate substantial quantities of •OH and ultimately destroy cancer cells, which could be further synergistically increased by photothermal therapy (PHT) and magnetic hyperthermia (MHT) aided by FeMoO4 nanorods (NRs). The produced FeMoO4 NRs were used as MHT/PHT and Fenton catalysts. The photothermal conversion efficiency of the FeMoO4 NRs was 31.75 %. In vitro and \ experiments demonstrated that the synergistic combination of MHT/PHT/CDT notably improved anticancer efficacy. This work reveals the significant efficacy of CDT aided by both photothermal and magnetic hyperthermia and offers a feasible strategy for the use of iron-based nanoparticles in the field of biomedical applications.

Two-dimensional multifunctional nanosheets as radiosensitizers for chemodynamic/radio-therapy

The hypoxia tumor microenvironment and low radiation attenuation coefficient of tumor tissue usually limit the efficiency of radiotherapy. In this study, a two-dimensional multifunctional nano-sensitizer, CuNS@Pt, was prepared to function as a radiosensitizer, enhancing radiotherapy through multiple mechanisms. Numerous active sites were provided for the deposition of X-ray radiation energy by the in-situ chemical reduction of Pt to create functional hybrids on Cu-based nanosheets. CuNS@Pt catalyzed high concentration of endogenous hydrogen peroxide to generate oxygen in tumor microenvironment, alleviating the physiological environment of hypoxic tumors. Additionally, CuNS could reduce the content of intrinsic glutathione (GSH) and catalyze hydrogen peroxide to form hydroxyl radicals (·OH). The generated ·OH could damage mitochondria and destroy redox homeostasis due to the functional inclusion of Cu species, thereby achieving chemodynamic therapy and further improving the radiation effect. Both in vivo and in vitro experiments showed that the nano sensitizer effectively improved the therapeutic efficiency of radiotherapy and had good biological safety. All in all, this study provides a pragmatic and doable platform for maximizing the efficacy of RT in cancer. This study also highlights the future research value of two-dimensional nanomaterials.

Self-sufficient nanoparticles with dual-enzyme activity trigger radical storms and activate cascade-amplified antitumor immunologic responses

Radiotherapy (RT) can potentially induce systemic immune responses by initiating immunogenic cell death (ICD) of tumor cells. However, RT-induced antitumor immunologic responses are sporadic and insufficient against cancer metastases. Herein, we construct multifunctional self-sufficient nanoparticles (MARS) with dual-enzyme activity (GOx and peroxidase-like) to trigger radical storms and activate the cascade-amplified systemic immune responses to suppress both local tumors and metastatic relapse. In addition to limiting the Warburg effect to actualize starvation therapy, MARS catalyzes glucose to produce hydrogen peroxide (H2O2), which is then used in the Cu+-mediated Fenton-like reaction and RT sensitization. RT and chemodynamic therapy produce reactive oxygen species in the form of radical storms, which have a robust ICD impact on mobilizing the immune system. Thus, when MARS is combined with RT, potent systemic antitumor immunity can be generated by activating antigen-presenting cells, promoting dendritic cells maturation, increasing the infiltration of cytotoxic T lymphocytes, and reprogramming the immunosuppressive tumor microenvironment. Furthermore, the synergistic therapy of RT and MARS effectively suppresses local tumor growth, increases mouse longevity, and results in a 90% reduction in lung metastasis and postoperative recurrence. Overall, we provide a viable approach to treating cancer by inducing radical storms and activating cascade-amplified systemic immunity.

Cu3-xP nanocrystals filled halloysite nanotubes for chemodynamic therapy of breast cancer

Copper-based Fenton-like agents have the ability to convert weakly oxidizing H2O2 into highly oxidizing hydroxyl radicals (·OH) at tumor sites during chemodynamic therapy (CDT). In this study, the interfacial attraction properties between the negatively charged OCP- in sodium phosphathynolate (NaOCP) and the positively charged environment inside the lumen of halloysite nanotubes (HNTs) were utilized to synthesize Cu3-xP nanoparticles in situ within the HNTs. The study investigated the chemical composition, morphology, and structure of Cu3-x P@HNTs. The results indicated uniform distribution of Cu3-xP particles measuring 3-5 nm within HNTs' lumen. Experiments conducted internally and externally to cells confirmed the catalytic capability of Cu3-xP@HNTs to oxidize H2O2 to ·OH. Furthermore, CP@H-CM was synthesized by enclosing Cu3-xP@HNTs in a cancer cell membrane, which selectively targets cancer cells. The experiments revealed the cytotoxicity of CP@H-CM on 4T1 cells. Additionally, the antitumor efficacy of CP@H-CM was evaluated in vivo through tumor recurrence experiments in mice. Moreover, the efficacy of CP@H-CM in repressing tumor growth was enhanced by incorporating infrared laser, indicating a synergistic photodynamic treatment for breast cancer. This study presents an efficacious and viable therapeutic approach to inhibit postoperative tumor reappearance. The implications of this approach are promising, particularly in the domain of tumor treatment and metastasis.

Dual chemodynamic/photothermal therapeutic nanoplatform based on DNA-functionalized prussian blue

The combination of chemodynamic therapy and photothermal therapy has a promising application owing to its impressive anti-cancer effects. However, the degradability of the material and the lack of targeting severely limit its further clinical application. Herein, DNAs containing nucleolin aptamer (AS1411) and different bases sequences were used to functionalize PB NPs for the targeted treatment. Compared to prussian blue, DNA-functionalized prussian blue does not reduce the photothermal properties of prussian blue. Moreover, DNA confers DNA-functionalized prussian blue targeting and higher enzymatic activity, thereby achieving a more effective combination of chemodynamic and photothermal treatment. The therapeutic efficacy of this nanoplatform was evaluated in vivo and in vitro experiments, exhibiting that DNA-functionalized prussian blue nanozyme can maximize the precise control of the therapeutic effect, reduce the toxic and side effects caused by non-specific accumulation on other normal cells, and effectively achieve targeted killing of cancer cells. This work demonstrates that DNA-functionalized prussian blue can improve the efficiency of combined tumor treatment and enhance the application value of prussian blue in tumor treatment, which is expected to provide theoretical support for clinical application.

Copper(II) complexes with plumbagin and bipyridines target mitochondria for enhanced chemodynamic cancer therapy

The combination of mitochondrial targeting and chemodynamic therapy is a promising anti-cancer strategy. Three mitochondria targeting copper(II) complexes (Cu1-Cu3) with plumbagin and bipyridine ligands for enhanced chemodynamic therapy were synthesized and characterized. Their anti-proliferative activity to HeLa cells was higher than that of cisplatin, and their toxicity to normal cells was low. Cellular uptake and distribution studies indicated that Cu1 and Cu3 were mainly accumulated in mitochondria. The mechanism studies showed that Cu1 and Cu3 converted intracellular H2O2 into toxic hydroxyl radicals by consuming glutathione, leading to mitochondrial dysfunction. Treatment with the copper complex caused ER stress and cell arrest in the S phase which resulted in apoptosis. In vivo, Cu1 and Cu3 effectively inhibited the growth of HeLa xenograft tumors without obvious toxic and side effects.

Bioactive VS4-based sonosensitizer for robust chemodynamic, sonodynamic and osteogenic therapy of infected bone defects

BACKGROUND

Most bone defects caused by bone disease or trauma are accompanied by infection, and there is a high risk of infection spread and defect expansion. Traditional clinical treatment plans often fail due to issues like antibiotic resistance and non-union of bones. Therefore, the treatment of infected bone defects requires a strategy that simultaneously achieves high antibacterial efficiency and promotes bone regeneration.

RESULTS

In this study, an ultrasound responsive vanadium tetrasulfide-loaded MXene (VSM) Schottky junction is constructed for rapid methicillin-resistant staphylococcus aureus (MRSA) clearance and bone regeneration. Due to the peroxidase (POD)-like activity of VS4 and the abundant Schottky junctions, VSM has high electron-hole separation efficiency and a decreased band gap, exhibiting a strong chemodynamic and sonodynamic antibacterial efficiency of 94.03%. Under the stimulation of medical dose ultrasound, the steady release of vanadium element promotes the osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). The in vivo application of VSM in infected tibial plateau bone defects of rats also has a great therapeutic effect, eliminating MRSA infection, then inhibiting inflammation and improving bone regeneration.

CONCLUSION

The present work successfully develops an ultrasound responsive VS4-based versatile sonosensitizer for robust effective antibacterial and osteogenic therapy of infected bone defects.

A double-gain theranostic nanoplatform based on self-supplying H2O2 nanocomposites for synergistic chemodynamic/gas therapy

Chemodynamic therapy (CDT) based on hydroxyl radicals (•OH) to suppress tumor cells is a promising strategy due to its efficacy and safety. Nevertheless, in tumor cells, CDT still faces challenges such as insufficient •OH and weak killing effect of tumor cells under physiological conditions due to inadequate amounts of endogenous hydrogen peroxide (H2O2) and heightened glutathione expression. These challenges limit the therapeutic potential of CDT. To improve the effects of CDT, combination treatment strategies have been developed. Here, we report a rationally designed nanocomposite (CaO2@Cu-LA) with self-supplying H2O2 ability from calcium peroxide, and nitric oxide (NO) generation ability from l-arginine. NO molecules not only exhibit a strong killing effect, but also have the potential to transfer into the more cytotoxic substance peroxynitrite anion by reacting with reactive oxygen species. The results showed that CaO2@Cu-LA could significantly suppress tumor growth by increasing •OH radicals and NO molecules. Taken together, the strategy developed here provides a good application foreground to yield a remarkable synergistic antitumor effect of CDT and NO gas therapy.

Sulfonated vitamin K3 mediated bimetallic metal-organic framework for multistage augmented cancer therapy

Chemodynamic therapy (CDT) relying on Fenton reaction has emerged as a promising strategy for tumor treatment. However, its clinical efficacy is hindered by the inadequate reactive oxygen species (ROS) and the potential cytotoxicity towards normal cells. To address these challenges, we have successfully developed a multistage augmented cancer therapy system based on bimetallic metal-organic framework (BMOF) that amplifies ROS and facilitates tumor-specific therapeutic effects. By employing a simple one-pot self-assembly approach, we synthesized SVK3@ZnCo-ZIF in which sulfonated vitamin K3 (SVK3) was encapsulated within ZnCo-ZIF BMOF. The results revealed that the incorporation of Zn atoms significantly diluted the Fenton activity of Co atoms towards normal cells. Notably, SVK3@ZnCo-ZIF underwent pH-controlled decomposition triggered by the tumor microenvironment (TME), thus releasing SVK3, Co2+ and Zn2+. Specifically, the H2O2 levels in tumors was effectively elevated by the interaction of SVK3 with NAD(P)H quinone oxidoreductase-1 (NQO-1). It thus enhanced the Fenton activity of Co2+. Moreover, the release of Zn2+ ions can induce cellular dysfunction and mitochondrial damage, thereby promoting the generation of ROS and subsequent cell death. The synergistic combination of CDT, SVK3 chemotherapy, and Zn2+-interfered therapy greatly facilitated apoptosis of tumor cells. Collectively, our investigations demonstrate the efficacy of such system in selectively inducing toxicity in cancer cells while minimizing detrimental effects on normal cells.

Multifunctional Fe-based coordination polymer nano-bomb modified with β-lapachone and CaO2 for targeted tumor dual chemodynamic therapy with enhanced ferroptosis and H2O2 self-supply

Chemodynamic therapy (CDT) is seriously limited by the inadequacy of exogenous catalytic ions and endogenous H2O2 in tumors. Herein, a multifunction nano-bomb integrated with calcium peroxide (CaO2) and β-lapachone as donors of H2O2 and GSH-sensitive Fe-based coordination polymer as provider of catalytic ions was constructed for dual cascade-amplified tumor CDT. This hyaluronic acid (HA)-modified nano-bomb could be specially endocytosed by breast cancer cells through a targeting pathway, degraded and released cargoes in response to the GSH-rich cytoplasm. Furthermore, the released CaO2 and β-lapachone could significantly self-generated sufficient H2O2, which could dual-cascade amplify CDT and induce severe oxidative to tumors via cooperating with the delivered iron ions from nano-bombs. Moreover, the unloaded iron and calcium ions could further accelerate tumor damage by overloading Ca2+ and ferroptosis, as accompanied by good magnetic resonance imaging (MRI). In vitro and in vivo studies collectively reveal that this nano-bomb not only self-initiates double cascade-amplified CDT via self-generation of H2O2, but also efficiently activates ferroptosis and initiates Ca2+ overloading, consequently significantly tumor growth suppression. This study offers a novel tumor-initiated nano-bomb for dual cascade-amplified CDT and bioimaging with activated ferroptosis and self-supplying H2O2.

Metal-polyphenol "prison" attenuated bacterial outer membrane vesicle for chemodynamics promoted in situ tumor vaccines

As natural adjuvants, the bacterial outer membrane vesicles (OMV) hold great potential in cancer vaccines. However, the inherent immunotoxicity of OMV and the rarity of tumor-specific antigens seriously hamper the clinical translation of OMV-based cancer vaccines. Herein, metal-phenolic networks (MPNs) are used to attenuate the toxicity of OMV, meanwhile, provide tumor antigens via the chemodynamic effect induced immunogenic cell death (ICD). Specifically, MPNs are assembled on the OMV surface through the coordination reaction between ferric ions and tannic acid. The iron-based "prison" is locally collapsed in the tumor microenvironment (TME) with both low pH and high ATP features, and thus the systemic toxicity of OMV is significantly attenuated. The released ferric ions in TME promote the ICD of cancer cells through Fenton reaction and then the generation of abundant tumor antigens, which can be used to fabricate in-situ vaccines by converging with OMV. Together with the immunomodulatory effect of OMV, potent tumor repression on a bilateral tumor model is achieved with good biosafety.

Tumor microenvironment-activated, immunomodulatory nanosheets loaded with copper(II) and 5-FU for synergistic chemodynamic therapy and chemotherapy

The tumor microenvironment (TME) has a redox state that differs greatly from normal tissues, as characterized by the overexpression of H2O2 and glutathione (GSH). To address the GSH-related restrictions on chemodynamic therapy (CDT) efficacy, we have developed a Cu(II)-based CDT strategy. In this study, a novel organic-inorganic hybrid drug delivery system (LDH/HA/5-FU) was conceived and prepared by the intercalation of 5-FU into the interlayer of copper-aluminum layered double hydroxide (CuAl-LDH) via ion exchange strategy and the adsorption of hyaluronic acid (HA) on the surface of CuAl-LDH. Taking advantage of the pH-degradable property of CuAl-LDH and the CD44-targeting property of HA, the formed LDH/HA/5-FU nanosheets could specifically target tumor cells' overexpressing CD44 receptor, rapidly release Cu(II) and 5-FU in tumor cells, inducing tumor cell apoptosis and cuproptosis, and long-term intracellular GSH depletion and toxic hydroxyl radicals (·OH) generation could be achieved through the cyclic catalytic reaction of Cu(I)/Cu(II). Meanwhile, peritumoral injection of LDH/HA/5-FU nanosheets might function as an adjuvant to increase the levels of antitumor tumor-associated macrophages (TAMs) and T cells. In vivo experiments further verified that the intelligently designed LDH/HA/5-FU nanosheets successfully promoted the immune systems, with an excellent inhibition efficacy towards tumors by combining Cu-based CDT and chemotherapy, showing promising potential for solid tumor treatments.

Immobilization of horseradish peroxidase on metal-organic framework to imporve enzyme activity for enhanced chemodynamic therapy

Bio-enzymes have the advantages of strong substrate specificity, high catalytic efficiency, and minimal toxic side effects, making them promising drugs in cancer therapy. However, the poor stability and cellular penetrability of uncoated protein in the physiological environment severely restricts the direct application of Bio-enzyme. To address it, we report a metal-organic framework (MOF), Hf-DBA (H2DBA, biphenyl carboxylic acid ligands). The morphology of the Hf-DBA was revealed by TEM and the diameter was in the range of 200 to 350 nm. Hf-DBA acted a carrier for intracellular delivery and protection of horseradish peroxidase (HRP). The prepared HRP@Hf-DBA can catalyze the excess H2O2 in the tumor cells to generation of •OH for chemodynamic therapy (CDT). Compared with free HRP, the catalytic activity of HRP@Hf-DBA is significantly improved, and the optimal catalytic conditions are explored. The catalytic stability of HRP@Hf-DBA remained above 70% after 12 cycles of catalysis. After treatment with HRP@Hf-DBA, the apoptosis rates of A549 and Hela cells was 71.64%, and 76.86%. The results in vitro show that HRP@Hf-DBA can effectively inhibit the growth of tumor cells through enhanced CDT.

Hierarchically decorated magnetic nanoparticles amplify the oxidative stress and promote the chemodynamic/magnetic hyperthermia/immune therapy

Magnetic nanoparticles (MNPs) are promising in tumor treatments due to their capacity for magnetic hyperthermia therapy (MHT), chemodynamic therapy (CDT), and immuno-related therapies, but still suffer from unsatisfactory tumor inhibition in the clinic. Insufficient hydrogen peroxide supply, glutathione-induced resistance, and high-density extracellular matrix (ECM) are the barriers. Herein, we hierarchically decorated MNPs with disulfide bonds (S-S), dendritic L-arginine (R), and glucose oxidase (GOx) to form a nanosystem (MNPs-SS-R-GOx). Its outer GOx layer not only enhanced the H2O2 supply to produce .OH by Fenton reaction, but also generated stronger oxidants (ONOO-) together with the interfaced R layer. The inner S-S layer consumed glutathione to interdict its reaction with oxidants, thus enhancing CDT effects. Importantly, the generated ONOO- tripled the MMP-9 expression to induce ECM degradation, enabling much deeper penetration of MNPs and benefiting CDT, MHT, and immunotherapy. Finally, the MNPs-SS-R-GOx demonstrated a remarkable 91.7% tumor inhibition in vivo. STATEMENT OF SIGNIFICANCE: Magnetic nanoparticles (MNPs) are a promising tumor therapeutic agent but with limited effectiveness. Our hierarchical MNP design features disulfide bonds (S-S), dendritic L-arginine (R), and glucose oxidase (GOx), which boosts H2O2 supply for ·OH generation in Fenton reactions, produces potent ONOO-, and enhances chemodynamic therapy via glutathione consumption. Moreover, the ONOO- facilitates the upregulation of matrix metalloprotein expression beneficial for extracellular matrix degradation, which in turn enhances the penetration of MNPs and benefits the antitumor CDT/MHT/immuno-related therapy. In vivo experiments have demonstrated an impressive 91.7% inhibition of tumor growth. This hierarchical design offers groundbreaking insights for further advancements in MNP-based tumor therapy. Its implications extend to a broader audience, encompassing those interested in material science, biology, oncology, and beyond.

A multivalent polyphenol-metal-nanoplatform for cascade amplified chemo-chemodynamic therapy

Chemodynamic therapy (CDT), as an emerging therapeutic strategy, kills cancer cells by converting intracellular hydrogen peroxide (H2O2) into cytotoxic oxidizing hydroxyl radicals (⋅OH). However, the therapeutic efficiency of CDT is compromised due to the insufficient endogenous H2O2 and metal catalysts in tumor cells. The use of multivalent polyphenols with multiple hydroxyl functions provides a facile yet robust means for efficient CDT augmentation. For this purpose, we reported herein the construction of polyphenol-metal nanoparticles (NPs) via a phenol-metal coordination strategy. The uniqueness of this study is the preparation of only one polymer construct with multivalency that can afford various supramolecular interactions for simultaneous "one-pot" loading of different therapeutic species, i.e., doxorubicin (DOX), glucose oxidases (GOD), and Fe3+ and further co-self-assembly into a stabilized nanomedicine for cascade amplified chemo-chemodynamic therapy. Specifically, the tumor intracellular acidic pH-triggered DOX release could serve for chemotherapy as well as enhance the intracellular H2O2 level. Together with the extra H2O2 and gluconic acid produced by the GOD-triggered glucose consumption, DOX@POAD-Fe@GOD NPs promoted Fe3+participation in the Fe-mediated Fenton reaction for cascade amplified chemo-chemodynamic therapy. Notably, this formulation displayed a greater anti-tumor effect with a tumor inhibition ratio 1.6-fold higher than that of free DOX in a BALB/c mice model bearing 4T1 tumors. Overall, the multivalent polyphenol-metal nanoplatform developed herein integrates chemotherapy, starvation therapy, and CDT for synergistic enhanced anticancer efficiency, which shows great potential for clinical translations. STATEMENT OF SIGNIFICANCE: Chemodynamic therapy (CDT) generally suffers from compromised therapeutic efficiency due to insufficient endogenous H2O2 and metal catalysts in tumor cells. To develop a facile yet robust strategy for efficient CDT augmentation, we reported herein construction of a multivalent polyphenol-metal nanoplatform, DOX@POAD-Fe@GOD nanoparticles (NPs) via a phenol-metal coordination strategy. This nanoplatform integrates multiple supramolecular dynamic interactions not only for simultaneously safe encapsulation of doxorubicin (DOX), Fe3+, and glucose oxidases (GOD), but also for cascade amplified chemo-chemodynamic therapy. Specifically, the intracellular acidic pH-triggered dissociation of DOX@POAD-Fe@GOD NPs promoted the release of Fe3+, DOX, and GOD for significantly increased ROS levels that can accelerate Fenton reactions for cascaded chemotherapy, starvation therapy, and CDT with amplified antitumor efficiency in vivo.

Phytic acid-Cu2+ framework/Cu2-xS nanocomposites with heat-shock protein down-modulation ability for enhanced multimodal combination therapy

Mild-temperature photothermal therapy (mPTT) has shown some advantages over traditional photothermal therapy, such as reducing the damage to surrounding healthy tissues and minimizing side effects. Nevertheless, cancer cells can easily repair damage caused by mild hyperthermia due to heat shock proteins (HSPs). Thus, it is imperative to maximize the mPTT efficiency by down-regulating HSPs overexpression and combining other cancer treatments. Herein, we report the synthesis of phytic acid (PA)-Cu2+ framework/copper sulfide (Cu2-xS) nanocomposites (abbreviated as PA-Cu/Cu2-xS NPs) as the novel therapeutic platform that can down-regulate HSPs overexpression for enhanced multimodal mPTT/chemodynamic therapy (CDT)/chemotherapy. PA-Cu/Cu2-xS NPs were prepared through self-assembly and in-situ vulcanization strategy, resulting in irregular-shaped particles with an approximate size of 100 nm. PA-Cu/Cu2-xS NPs display a plasmon effect from Cu2-xS, which enhances near-infrared (NIR) absorption and possesses excellent photothermal conversion efficiency (41.7%). Moreover, PA-Cu/Cu2-xS NPs exhibit Fenton-like reaction activity resulting from the Cu ions for CDT, and the reaction activity can be further improved 1.3 times due to mild hyperthermia during mPTT. Furthermore, the generated hydroxyl radical (•OH) can effectively decrease HSPs level to enhance mPTT. PA-Cu/Cu2-xS NPs can also serve as a drug delivery system, and they are capable of loading doxorubicin (DOX) with a loading ability (20.7%). Combining mPTT/CDT/chemotherapy exhibits significant inhibition of tumor growth. This approach can serve as a basis for designing more exquisite platforms that combine mPTT with other therapies to achieve more effective cancer treatment.

Glutathione/pH-responsive copper-based nanoplatform for amplified chemodynamic therapy through synergistic cycling regeneration of reactive oxygen species and dual glutathione depletion

The rapid scavenging of reactive oxygen species (ROS) by glutathione (GSH) and insufficient endogenous hydrogen peroxide (H2O2) in tumor cells are the major factors greatly restricting the efficacy of chemodynamic therapy (CDT). Herein, we developed a tumor microenvironment (TME)-responsive Cu-based metal-mesoporous organosilica nanoplatform integrating vitamin k3 (VK3), which could deplete GSH and specifically regenerate H2O2 for amplified CDT of cancer. Once the CuO@MON-PEG/VK3 nanoparticles entered into the tumor cells through enhanced permeability and retention (EPR) effect, the organosilicon shell and CuO core would be successively degraded upon the triggering of GSH and endo/lysosomal acidity. Subsequently, the enriched tetrasulfide bridges and released Cu2+ could consume GSH substantially, thus triggering Fenton-like reaction for CDT. Furthermore, the released VK3 could be catalyzed by the highly expressed quinone oxidoreductase-1 (NQO1) inside tumor cells to generate sufficient H2O2 through a "reversible" redox cycle, which in turn promoted Cu+-mediated Fenton-like reaction. Both in vitro and in vivo studies demonstrated that this nanoplatform could achieve synergistic CDT against tumor through synergistic cycling regeneration of ROS and dual GSH exhaustion with excellent biosafety. Our finding highlight the promising potential of CuO@MON-PEG/VK3 nanoplatform with multiple oxidative stress amplification for highly efficient tumor therapy.

Camouflaged Nanoreactors Mediated Radiotherapy-Adjuvant Chemodynamic Synergistic Therapy

Chemodynamic therapy based on the Fenton-like catalysis ability of Fe3O4 has the advantages of no involvement of chemical drugs and minimal adverse effects as well as the limitation of depletable efficacy. Radiotherapy based on high-energy radiation offers the convenience of treatment and cost-effectiveness but lacks precision and cellular adaptation of tumor cells. Approaching such dilemmas from a nanoscale materials perspective, we aim to bridge the weaknesses of both treatment methods by combining the principles of two therapeutics reciprocally. We have designed a camouflaged Fe3O4@HfO2 composite nanoreactor (FHCM), which combines a chemodynamic therapeutic agent Fe3O4 and a radiosensitizer HfO2 that both has passed clinical trials and was inspired by a cell membrane biomimetic technique. FHCM is employed as conceived radiotherapy-adjuvant chemodynamic synergistic therapy of malignant tumors, which has undergone dual scrutiny from both the physical and biological aspects. Experimental results obtained at different levels, including theory, material characterizations, and in vitro and in vivo verifications, suggest that FHCM effectively impaired tumor cells through physical and molecular biological mechanisms involving a HfO2-Fe3O4 photoelectron-electron transfer chain and DNA damage-ferroptosis-immunity chain. It is worth noting that compared to single therapies such as only chemodynamic therapy or radiotherapy, FHCM-mediated radiotherapy-adjuvant chemodynamic synergistic therapy exhibits stronger tumor inhibition efficacy. It significantly addresses the inherent limitations of chemodynamic therapy and radiotherapy and underscores the feasibility and importance of using existing clinical weapons, such as radiotherapy, as auxiliary strategies to overcome certain flaws of emerging antitumor therapeutics like chemodynamic therapy.

Enzyme-responsive nanospheres target senescent cells for diabetic wound healing by employing chemodynamic therapy

Evidence indicates that prolonged low-level inflammation and elevated-glucose-induced oxidative stress in diabetic wounds can accelerate senescence. The accumulation of senescent cells, in turn, inhibits cellular proliferation and migration, aggravating the inflammatory response and oxidative stress, ultimately impeding wound healing. In this study, we exploited the heightened lysosomal β-galactosidase activity detected in senescent cells to develop an innovative drug delivery system by encapsulating Fe3O4 with galactose-modified poly (lactic-co-glycolic acid) (PLGA) (F@GP). We found that F@GP can selectively release Fe3O4 into senescent cells, inducing ferroptosis via the Fenton reaction in the presence of elevated intracellular H2O2 levels. This showed that F@GP administration can serve as a chemodynamic therapy to eliminate senescent cells and promote cell proliferation. Furthermore, the F@GP drug delivery system gradually released iron ions into the diabetic wound tissues, enhancing the attenuation of cellular senescence, stimulating cell proliferation, promoting re-epithelialization, and accelerating the healing of diabetic wounds in mice. Our groundbreaking approach unveiled the specific targeting of senescence by F@GP, demonstrating its profound effect on promoting the healing of diabetic wounds. This discovery underscores the therapeutic potential of F@GP in effectively addressing challenging cases of wound repair. STATEMENT OF SIGNIFICANCE: The development of galactose-modified PLGA nanoparticles loaded with Fe3O4 (F@GP) represents a significant therapeutic approach for the treatment of diabetic wounds. These nanoparticles exhibit remarkable potential in selectively targeting senescent cells, which accumulate in diabetic wound tissue, through an enzyme-responsive mechanism. By employing chemodynamic therapy, F@GP nanoparticles effectively eliminate senescent cells by releasing iron ions that mediate the Fenton reaction. This targeted approach holds great promise for promoting diabetic wound healing by selectively eliminating senescent cells, which play a crucial role in impairing the wound healing process. The innovative utilization of F@GP nanoparticles as a therapeutic intervention offers a novel and potentially transformative strategy for addressing the challenges associated with diabetic wound healing.

Glucose-responsive enzymatic biomimetic nanodots for H2O2 self-supplied catalytic photothermal/chemodynamic anticancer therapy

Photothermal therapy (PTT) combined with chemodynamic therapy (CDT) presents an appealing complementary anti-tumor strategy, wherein PTT accelerates the production of reactive oxygen species (ROS) in CDT and CDT eliminates residual tumor tissues that survive from PTT treatment. However, nanomaterials utilized in PTT/CDT are limited by non-specific damage to the entire organism. Herein, a glucose-responsive enzymatic Fe@HRP-ABTS/GOx nanodot is judiciously designed for tumor-specific PTT/CDT via a simple and clean protein-templated biomimetic mineralization synthesis. By oxidizing glucose in tumor cells, glucose oxidase (GOx) activates glucose-responsive tumor therapy and increases the concentration of H2O2 at the tumor site. More importantly, the self-supplied peroxide hydrogen (H2O2) can convert ABTS (2,2'-Hydrazine-bis(3-ethylbenzothiazoline-6-sulfonic acid) diamine salt) into oxidized ABTS (oxABTS) through horseradish peroxidase (HRP) catalysis for PTT and photoacoustic (PA) imaging. Furthermore, the Fe2+ arising from the reduction of Fe3+ by overexpressed GSH reacts with H2O2 to generate intensely reactive •OH through the Fenton reaction, concurrently depleting GSH and inducing efficient tumor CDT. The in vitro and in vivo experiments demonstrate superior cancer cell killing and tumor eradication effect of Fe@HRP-ABTS/GOx nanodot under near-infrared (NIR) laser irradiation. Collectively, the nanodots provide mutually reinforcing catalytic PTT/CDT anti-tumor strategies for treating liver cancer and potentially other malignancies. STATEMENT OF SIGNIFICANCE: Combinatorial antitumor therapy with nanomedicines presents great prospects for development. However, the limitation of non-specific damage to normal tissues hinders its further clinical application. In this work, we fabricated tumor-selective biomimetic Fe@HRP-ABTS/GOx nanodots for H2O2 self-supplied catalytic photothermal/chemodynamic therapy of tumors. The biomimetic synthesis strategy provides the nanodots with enzymatic activity in response to glucose to produce H2O2. The self-supplied H2O2 initiates photothermal therapy with oxidized ABTS and enhances chemodynamic therapy through simultaneous •OH generation and GSH depletion. Our work provides a new paradigm for developing tumor-selective catalytic nanomedicines and will guide further clinical translation of the enzymatic biomimetic synthesis strategy.

Polydopamine-cloaked Fe-based metal organic frameworks enable synergistic multidimensional treatment of osteosarcoma

One of the major challenges in effective cancer therapy arises because of the hypoxic microenvironment in the tumor. This compromises the efficacy of both chemo- and radiotherapy, and thus hinders patient outcomes. To solve this problem, we constructed polydopamine (PDA)-cloaked Fe-based metal organic frameworks (MOFs) loaded with d-arginine (d-Arg), glucose oxidase (GOX), and the chemotherapeutic drug tirapazamine (TPZ). These offer simultaneous multifaceted therapy combining chemodynamic therapy (CDT)/radiotherapy (RT)/starvation therapy (ST)/gas therapy (GT) and chemotherapy. The particles further can act as contrast agents in magnetic resonance imaging. GOX catalyses the conversion of endogenous glucose and O2 to hydrogen peroxide and gluconic acid, blocking the cells' energy supply and providing ST. With the resultant acidification of the local environment, the breakdown of the MOF releases TPZ (for chemotherapy) and Fe3+, which reacts with H2O2 to produce reactive oxygen species and thus stimulates the conversion of d-Arg to NO for GT and RT sensitization. The PDA coating not only seals the pores and chelates Fe3+ to enhance the T1-weighted magnetic resonance imaging (MRI) properties, but also is used to graft folate bovine serum albumin (FA-BSA) and thereby target the tumor site. The combined administration of low doses of X-ray irradiation and nanoparticles reduces the side effects on healthy tissue and can prevent lung metastases in mice. This work highlights the synergistic treatment of osteosarcoma via ST/GT/CDT/RT/MRI/ chemotherapy using a PDA-cloaked MOF system.

Synergy effects of copper ion in doxorubicin-based chelate prodrug for cancer chemo-chemodynamic combination therapy

Doxorubicin (DOX) is a commonly studied chemotherapeutic agent for the treatment of solid tumors, but the severe side effects limit its clinical application. It is shown that DOX-metal chelate has lower in vitro cytotoxicity compared with DOX, as the anthracyclines of DOX can form coordinative interaction with transition metal ions. In addition, the transition metal ions could catalyze the production of hydroxyl radicals (·OH) via Fenton/Fenton-like reactions to achieve antitumor chemodynamic therapy (CDT). In this study, copper ions (Cu²⁺) were applied to obtain DOX/Cu(II) prodrug, and a liposomal formulation was used to avoid the rapid blood clearance and optimize the biodistribution of this prodrug. In vitro and in vivo antitumor results demonstrated that this pH sensitive Cu-chelating prodrug can reduce adverse effects of DOX but improve the antitumor efficiency due to the combination of chemotherapy and chemodynamic therapy. Our study provided a facile and effective approach of metal-chelating prodrug strategy for combination cancer therapy strategy.

Near infrared II excitation nanoplatform for photothermal/chemodynamic/antibiotic synergistic therapy combating bacterial biofilm infections

Drug-resistant bacterial biofilm infections (BBIs) are refractory to elimination. Near-infrared-II photothermal therapy (NIR-II PTT) and chemodynamic therapy (CDT) are emerging antibiofilm approaches because of the heavy damage they inflict upon bacterial membrane structures and minimal drug-resistance. Hence, synergistic NIR-II PTT and CDT hold great promise for enhancing the therapeutic efficacy of BBIs. Herein, we propose a biofilm microenvironment (BME)-responsive nanoplatform, BTFB@Fe@Van, for use in the synergistic NIR-II PTT/CDT/antibiotic treatment of BBIs. BTFB@Fe@Van was prepared through the self-assembly of phenylboronic acid (PBA)-modified small-molecule BTFB, vancomycin, and the CDT catalyst Fe2+ ions in DSPE-PEG2000. Vancomycin was conjugated with BTFB through a pH-sensitive PBA-diol interaction, while the Fe2+ ions were bonded to the sulfur and nitrogen atoms of BTFB. The PBA-diol bonds decomposed in the acidic BME, simultaneously freeing the vancomycin and Fe2+ irons. Subsequently, the catalytic product hydroxyl radical was generated by the Fe2+ ions in the oxidative BME overexpressed with H2O2. Moreover, under 1064 nm laser, BTFB@Fe@Van exhibited outstanding hyperthermia and accelerated the release rate of vancomycin and the efficacy of CDT. Furthermore, the BTFB@Fe@Van nanoplatform enabled the precise NIR-II imaging of the infected sites. Both in-vitro and in-vivo experiments demonstrated that BTFB@Fe@Van possesses a synergistic NIR-II PTT/CDT/antibiotic mechanism against BBIs.

Chemodynamic therapy agent optimized mesoporous TiO2 nanoparticles for Glutathione-Enhanced and Hypoxia-Tolerant synergistic Chemo-Sonodynamic therapy

Sonodynamic therapy (SDT) can generate reactive oxygen species to kill cancer cells by activating sonosensitizers under ultrasound (US) irradiation. Nevertheless, its application is greatly limited by low quantum yield of sonosensitizers, high levels of endogenous glutathione (GSH) and tumor hypoxia. Herein, a GSH-activated sonosensitizers with synergistic therapy effect (chemodynamic therapy (CDT) and SDT) are developed by depositing Fe(III)-artemisinin infinite coordination polymers (Fe(III)-ART CPs) in pores of mesoporous TiO2 nanoparticles (NPs). The formed Fe(III)-ART-TiO2 NPs have high sono-induced electron-hole separation efficiency because the deposited Fe(III)-ART CPs can provide isolated intermediate bands to capture sono-induced electrons in TiO2 NPs. Meanwhile, Fe3+ in Fe(III)-ART-TiO2 NPs are reduced to Fe2+ by GSH with oxygen-deficient sites generated to further capture sono-induced electrons in TiO2 NPs. Based on this, the reaction efficiency between water molecules and sono-induced holes is high enough to generate numerous hydroxyl radicals (•OH) without oxygen participated for overcoming tumor hypoxia. Additionally, through consuming GSH, the generated Fe2+ can catalyze ART to produce C-centered free radicals for CDT. Owing to these characteristics, Fe(III)-ART-TiO2 NPs show significant tumor suppression ability and good biocompatibility in vivo. The strategy of using CDT agent to modify sonosensitizers offers new options to improve SDT effect without introducing harmful substances.

Surface curvature-induced oriented assembly of sushi-like Janus therapeutic nanoplatform for combined chemodynamic therapy

BACKGROUND

Chemodynamic therapy (CDT) based on Fenton/Fenton-like reaction has emerged as a promising cancer treatment strategy. Yet, the strong anti-oxidation property of tumor microenvironment (TME) caused by endogenous glutathione (GSH) still severely impedes the effectiveness of CDT. Traditional CDT nanoplatforms based on core@shell structure possess inherent interference of different subunits, thus hindering the overall therapeutic efficiency. Consequently, it is urgent to construct a novel structure with isolated functional units and GSH depletion capability to achieve desirable combined CDT therapeutic efficiency.

RESULTS

Herein, a surface curvature-induced oriented assembly strategy is proposed to synthesize a sushi-like novel Janus therapeutic nanoplatform which is composed of two functional units, a FeOOH nanospindle serving as CDT subunit and a mSiO2 nanorod serving as drug-loading subunit. The FeOOH CDT subunit is half covered by mSiO2 nanorod along its long axis, forming sushi-like structure. The FeOOH nanospindle is about 400 nm in length and 50 nm in diameter, and the mSiO2 nanorod is about 550 nm in length and 100 nm in diameter. The length and diameter of mSiO2 subunit can be tuned in a wide range while maintaining the sushi-like Janus structure, which is attributed to a Gibbs-free-energy-dominating surface curvature-induced oriented assembly process. In this Janus therapeutic nanoplatform, Fe3+ of FeOOH is firstly reduced to Fe2+ by endogenous GSH, the as-generated Fe2+ then effectively catalyzes overexpressed H2O2 in TME into highly lethal ·OH to achieve efficient CDT. The doxorubicin (DOX) loaded in the mSiO2 subunit can be released to achieve combined chemotherapy. Taking advantage of Fe3+-related GSH depletion, Fe2+-related enhanced ·OH generation, and DOX-induced chemotherapy, the as-synthesized nanoplatform possesses excellent therapeutic efficiency, in vitro eliminating efficiency of tumor cells is as high as ~ 87%. In vivo experiments also show the efficient inhibition of tumor, verifying the synthesized sushi-like Janus nanoparticles as a promising therapeutic nanoplatform.

CONCLUSIONS

In general, our work provides a successful paradigm of constructing novel therapeutic nanoplatform to achieve efficient tumor inhibition.

Mixed-valence gold-porphyrin two-dimensional coordination networks for repurposing of chrysotherapy

Catalytic gold nanomaterials typically exhibit antibacterial properties, albeit significantly weaker than ionic gold in chrysotherapy. The inherent stability of gold nanoparticles prevents the release of gold ions, limiting their ability to achieve efficient antibacterial therapy. To address this limitation, we propose a novel sustained ionic gold release strategy through the construction of a mixed-valence gold-porphyrin coordination network (Au-Por). By adjusting the ratio of Au to porphyrin molecule, an ultrathin two-dimensional Au-Por nanosheet was successfully synthesized, which contains 85.9 % of Au (III). In addition, the remaining gold existed in the form of uniformly distributed ultrasmall nanoclusters on the Au-Por nanosheet. Notably, the Au-Por nanosheet exhibited a sustained release of gold ions. Thus, a multimodal antibacterial therapy was achieved by integrating the direct bactericidal action of ionic gold and lethal reactive oxygen species (ROS) generated through the peroxidase (POD)-like activity of gold nanoclusters and photodynamic therapy (PDT) using porphyrins. The innovative Au-Por exerted broad-spectrum bactericidal activity against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria mediated by bacterial membrane disruption and DNA damage. Moreover, in vivo studies demonstrated the synergistic effect of Au-Por on combating skin wound infections and facilitating wound healing. Comprehensive safety evaluations proved that Au-Por exhibited no hematotoxicity or hepatorenal toxicity, and it also displayed rapid renal clearance after treatment, indicating favorable biocompatibility. The repurposing of chrysotherapy has revolutionized the antibacterial strategy of nanoscale gold, resulting in a dramatic boost in antibacterial activity and valuable insights for designing highly efficient nanoscale antibacterial agents.

ROS-producing nanomaterial engineered from Cu(I) complexes with P2N2-ligands for cancer cells treating

The work presents core-shell nanoparticles (NPs) built from the novel Cu(I) complexes with cyclic P2N2-ligands (1,5-diaza-3,7-diphosphacyclooctanes) that can visualize their entry into cancer and normal cells using a luminescent signal and treat cells by self-enhancing generation of reactive oxygen species (ROS). Variation of P- and N-substituents in the series of P2N2-ligands allows structure optimization of the Cu(I) complexes for the formation of the luminescent NPs with high chemical stability. The non-covalent modification of the NPs with triblock copolymer F-127 provides their high colloidal stability, followed by efficient cell internalization of the NPs visualized by their blue (⁓450 nm) luminescence. The cytotoxic effects of the NPs toward the normal and some of cancer cells are significantly lower than those of the corresponding molecular complexes, which correlates with the chemical stability of the NPs in the solutions. The ability of the NPs to self-enhanced and H2O2-induced ROS generation is demonstrated in solutions and intracellular space by means of the standard electron spin resonance (ESR) and fluorescence techniques correspondingly. The anticancer specificity of the NPs toward HuTu 80 cancer cells and the apoptotic cell death pathway correlate with the intracellular level of ROS, which agrees well with the self-enhancing ROS generation of the NPs. The enhanced level of ROS revealed in HuTu 80 cells incubated with the NPs can be associated with the significant level of their mitochondrial localization.