Ru@CeO2 yolk shell nanozymes: Oxygen supply in situ enhanced dual chemotherapy combined with photothermal therapy for orthotopic/subcutaneous colorectal cancer

Cu,Zn,I-Doped Carbon Dots with Boosted Triple Antioxidant Nanozyme Activity for Treatment of DSS-Induced Colitis

Nanozyme-mediated antioxidative therapy is a promising star for treating a myriad of important diseases through eliminating excessive reactive oxygen species (ROS) such as O2·- and H2O2, a critical mechanism for inflammatory bowel disease (IBD). This work provides a high biocompatibility iodine-copper-zinc covalent doped carbon dots (Cu,Zn,I-CDs) with the catalase (CAT)-, superoxide dismutase (SOD)- and glutathione peroxidase (GPx)-like catalytic activities for treating ulcerative colitis (UC) by scavenging overproduced ROS. We found that I dopant aids in counteracting the positive charge at Cu,Zn dopants brought on by low pH, enabling Cu,Zn,I-CDs to process strong triple antioxidant nanozyme activities rather than Cu,Zn-CDs. Vitro experiments displayed that the Cu,Zn,I-CDs could scavenge the excessive ROS to protect cellular against oxidative stress and reduce the expression of proinflammatory cytokines, such as TNF-α, IL-1β, and IL-6. In sodium dextran sulfate (DSS)-induced colitis mice models, Cu,Zn,I-CDs with excellent biocompatibility could effectively relieve the inflammation of the colon, containing the reduction of the colon length, the damaged epithelium, the infiltration of inflammatory cells, and upregulation of antioxidant genes. Therefore, the therapy of Cu,Zn,I-CD antioxidant nanozymes is an effective approach and provides a novel strategy for UC treatment.

Crystal Facet Controlled Metal-Support Interaction in Uricase Mimics for Highly Efficient Hyperuricemia Treatment

The effect of strong metal-support interaction (SMSI) has never been systematically studied in the field of nanozyme-based catalysis before. Herein, by coupling two different Pd crystal facets with MnO2, i.e., (100) by Pd cube (Pdc) and (111) by Pd icosahedron (Pdi), we observed the reconstruction of Pd atomic structure within the Pd-MnO2 interface, with the reconstructed Pdc (100) facet more disordered than Pdi (111), verifying the existence of SMSI in such coupled system. The rearranged Pd atoms in the interface resulted in enhanced uricase-like catalytic activity, with Pdc@MnO2 demonstrating the best catalytic performance. Theoretical calculations suggested that a more disordered Pd interface led to stronger interactions with intermediates during the uricolytic process. In vitro cell experiments and in vivo therapy results demonstrated excellent biocompatibility, therapeutic effect, and biosafety for their potential hyperuricemia treatment. Our work provides a brand-new perspective for the design of highly efficient uricase-mimic catalysts.

In Vitro Synergistic Photodynamic, Photothermal, Chemodynamic, and Starvation Therapy Performance of Chlorin e6 Immobilized, Polydopamine-Coated Hollow, Porous Ceria-Based, Hypoxia-Tolerant Nanozymes Carrying a Cascade System

A synergistic therapy agent (STA) with photothermal, photodynamic, chemodynamic, and starvation therapy (PTT, PDT, CDT, and ST) functions was developed. Hollow, mesoporous, and nearly uniform CeO2 nanoparticles (H-CeO2 NPs) were synthesized using a staged shape templating sol-gel protocol. Chlorin e6 (Ce6) was adsorbed onto H-CeO2 NPs, and a thin polydopamine (PDA) layer was formed on Ce6-adsorbed H-CeO2 NPs. Glucose oxidase (GOx) was bound onto PDA-coated Ce6-adsorbed H-CeO2 NPs to obtain the targeted STA (H-CeO2@Ce6@PDA@GOx NPs). A reversible photothermal conversion behavior with the temperature elevations up to 34 °C was observed by NIR laser irradiation at 808 nm. A cascade enzyme system based on immobilized GOx and intrinsic catalase-like activity of H-CeO2 NPs was rendered on STA for enhancing the effectiveness of PDT by elevation of ROS generation and alleviation of hypoxia in a tumor microenvironment. Glucose-mediated generation of highly toxic hydroxyl radicals (·OH) was evaluated for CDT. The effectiveness of PDT on glioblastoma T98G cells was markedly enhanced by O2 generation started by the decomposition of glucose. A similar increase in cell death was also observed when ST and CDT functions were enhanced by photothermal action. The viability of T98G cells decreased to 10.6% by in vitro synergistic action including ST, CDT, PDT, and PTT without using any antitumor agent.

Nanozymes with biomimetically designed properties for cancer treatment

Nanozymes, as a type of nanomaterials with enzymatic catalytic activity, have demonstrated tremendous potential in cancer treatment owing to their unique biomedical properties. However, the heterogeneity of tumors and the complex tumor microenvironment pose significant challenges to the in vivo catalytic efficacy of traditional nanozymes. Drawing inspiration from natural enzymes, scientists are now using biomimetic design to build nanozymes from the ground up. This approach aims to replicate the key characteristics of natural enzymes, including active structures, catalytic processes, and the ability to adapt to the tumor environment. This achieves selective optimization of nanozyme catalytic performance and therapeutic effects. This review takes a deep dive into the use of these biomimetically designed nanozymes in cancer treatment. It explores a range of biomimetic design strategies, from structural and process mimicry to advanced functional biomimicry. A significant focus is on tweaking the nanozyme structures to boost their catalytic performance, integrating them into complex enzyme networks similar to those in biological systems, and adjusting functions like altering tumor metabolism, reshaping the tumor environment, and enhancing drug delivery. The review also covers the applications of specially designed nanozymes in pan-cancer treatment, from catalytic therapy to improved traditional methods like chemotherapy, radiotherapy, and sonodynamic therapy, specifically analyzing the anti-tumor mechanisms of different therapeutic combination systems. Through rational design, these biomimetically designed nanozymes not only deepen the understanding of the regulatory mechanisms of nanozyme structure and performance but also adapt profoundly to tumor physiology, optimizing therapeutic effects and paving new pathways for innovative cancer treatment.

Advances in Ferroptosis-Inducing Agents by Targeted Delivery System in Cancer Therapy

Currently, cancer remains one of the most significant threats to human health. Treatment of most cancers remains challenging, despite the implementation of diverse therapies in clinical practice. In recent years, research on the mechanism of ferroptosis has presented novel perspectives for cancer treatment. Ferroptosis is a regulated cell death process caused by lipid peroxidation of membrane unsaturated fatty acids catalyzed by iron ions. The rapid development of bio-nanotechnology has generated considerable interest in exploiting iron-induced cell death as a new therapeutic target against cancer. This article provides a comprehensive overview of recent advancements at the intersection of iron-induced cell death and bionanotechnology. In this respect, the mechanism of iron-induced cell death and its relation to cancer are summarized. Furthermore, the feasibility of a nano-drug delivery system based on iron-induced cell death for cancer treatment is introduced and analyzed. Secondly, strategies for inducing iron-induced cell death using nanodrug delivery technology are discussed, including promoting Fenton reactions, inhibiting glutathione peroxidase 4, reducing low glutathione levels, and inhibiting system Xc-. Additionally, the article explores the potential of combined treatment strategies involving iron-induced cell death and bionanotechnology. Finally, the application prospects and challenges of iron-induced nanoagents for cancer treatment are discussed.

Nanozymes and carbon-dots based nanoplatforms for cancer imaging, diagnosis and therapeutics: Current trends and challenges

Cancer patients face a significant clinical and socio-economic burden due to increased incidence, mortality, and poor survival. Factors like late diagnosis, recurrence, drug resistance, severe side effects, and poor bioavailability limit the scope of current therapies. There is a need for novel, cost-effective, and safe diagnostic methods, therapeutics to overcome recurrence and drug resistance, and drug delivery vehicles with enhanced bioavailability and less off-site toxicity. Advanced nanomaterial-based research is aiding cancer biologists by providing solutions for issues like hypoxia, tumor microenvironment, low stability, poor penetration, target non-specificity, and rapid drug clearance. Currently, nanozymes and carbon-dots are attractive due to their low cost, high catalytic activity, biocompatibility, and lower toxicity. Nanozymes and carbon-dots are increasingly used in imaging, biosensing, diagnosis, and targeted cancer therapy. Integrating these materials with advanced diagnostic tools like CT scans and MRIs can aid in clinical decision-making and enhance the effectiveness of chemotherapy, photothermal, photodynamic, and sonodynamic therapies, with minimal invasion and reduced collateral effects.

Application of Thermoresponsive Smart Polymers based in situ Gel as a Novel Carrier for Tumor Targeting

The temperature-triggered in situ gelling system has been revolutionized by introducing an intelligent polymeric system. Temperature-triggered polymer solutions are initially in a sol state and then undergo a phase transition to form a gel at body temperature due to various parameters like pH, temperature, and so on. These smart polymers offer a number of advantages, including ease of administration, long duration of release of the drug, low administration frequency with good patient compliance, and targeted drug delivery with fewer adverse effects. Polymers such as poly(N-isopropylacrylamide) (PNIPAAm), polyethylene glycol (PEG), poly (N, N'-diethyl acrylamide), and polyoxypropylene (PPO) have been briefly discussed. In addition to various novel Drug Delivery Systems (DDS), the smart temperature-triggered polymeric system has various applications in cancer therapy and many other disease conditions. This review focuses on the principals involved in situ gelling systems using various temperature-triggered polymers for chemotherapeutic purposes, using smart DDS, and their advanced application in cancer therapy, as well as available marketed formulations and recent advances in these thermoresponsive sol-gel transforming systems.

Nanozymes: A comprehensive review on emerging applications in cancer diagnosis and therapeutics

Nanozymes, a new class of nanomaterials-based artificial enzymes, have gained huge attraction due to their high operational stability, working efficiency in extreme conditions, and resistance towards protease digestion. Nowadays, they are effectively substituted for natural enzymes for catalysis by closely resembling the active sites found in natural enzymes. Nanozymes can compensate for natural enzymes' drawbacks, such as high cost, poor stability, low yield, and storage challenges. Due to their transforming nature, nanozymes are of utmost importance in the detection and treatment of cancer. They enable precise cancer detection, tailored drug delivery, and catalytic therapy. Through enhanced diagnosis, personalized therapies, and reduced side effects, their adaptability and biocompatibility can transform the management of cancer. The review focuses on metal and metal oxide-based nanozymes, highlighting their catalytic processes, and their applications in the prevention and treatment of cancer. It emphasizes their potential to alter diagnosis and therapy, particularly when it comes to controlling reactive oxygen species (ROS). The article reveals the game-changing importance of nanozymes in the future of cancer care and describes future research objectives, making it a useful resource for researchers, and scientists. Lastly, outlooks for future perspective areas in this rapidly emerging field have been provided in detail.

Leveraging Coupling Effect-Enhanced Surface Plasmon Resonance of Ruthenium Nanocrystal-Decorated Mesoporous Silica Nanoparticles for Boosted Photothermal Immunotherapy

Photothermal immunotherapy (PTI) has emerged as a promising approach for cancer treatment, while its efficacy is often hindered by the immunosuppressive tumor microenvironment (TME). Here, this work presents a multifunctional platform for tumor PTI based on ruthenium nanocrystal-decorated mesoporous silica nanoparticles (RuNC-MSN). By precisely regulating the distance between RuNC on MSN, this work achieves a remarkable enhancement in surface plasmon resonance of RuNC, leading to a significant improvement in the photothermal efficiency of RuNC-MSN. Furthermore, the inherent catalase-like activity of RuNC-MSN enables effective modulation of the immunosuppressive TME, thereby facilitating an enhanced immune response triggered by the photothermal effect-mediated immunogenic cell death (ICD). As a result, RuNC-MSN exhibits superior PTI performance, resulting in pronounced inhibition of primary tumor and metastasis. This study highlights the rational design of PTI agents with coupling effect-enhanced surface plasmon resonance, enabling simultaneous induction of ICD and regulation of the immunosuppressive TME, thereby significantly boosting PTI efficacy.

Deep Insight of Design, Mechanism, and Cancer Theranostic Strategy of Nanozymes

Since the discovery of enzyme-like activity of Fe3O4 nanoparticles in 2007, nanozymes are becoming the promising substitutes for natural enzymes due to their advantages of high catalytic activity, low cost, mild reaction conditions, good stability, and suitable for large-scale production. Recently, with the cross fusion of nanomedicine and nanocatalysis, nanozyme-based theranostic strategies attract great attention, since the enzymatic reactions can be triggered in the tumor microenvironment to achieve good curative effect with substrate specificity and low side effects. Thus, various nanozymes have been developed and used for tumor therapy. In this review, more than 270 research articles are discussed systematically to present progress in the past five years. First, the discovery and development of nanozymes are summarized. Second, classification and catalytic mechanism of nanozymes are discussed. Third, activity prediction and rational design of nanozymes are focused by highlighting the methods of density functional theory, machine learning, biomimetic and chemical design. Then, synergistic theranostic strategy of nanozymes are introduced. Finally, current challenges and future prospects of nanozymes used for tumor theranostic are outlined, including selectivity, biosafety, repeatability and stability, in-depth catalytic mechanism, predicting and evaluating activities.

Recent Advances on Cerium Oxide-Based Biomaterials: Toward the Next Generation of Intelligent Theranostics Platforms

Disease or organ damage due to unhealthy living habits, or accidents, is inevitable. Discovering an efficient strategy to address these problems is urgently needed in the clinic. In recent years, the biological applications of nanotechnology have received extensive attention. Among them, as a widely used rare earth oxide, cerium oxide (CeO2 ) has shown good application prospects in biomedical fields due to its attractive physical and chemical properties. Here, the enzyme-like mechanism of CeO2 is elucidated, and the latest research progress in the biomedical field is reviewed. At the nanoscale, Ce ions in CeO2 can be reversibly converted between +3 and +4. The conversion process is accompanied by the generation and elimination of oxygen vacancies, which give CeO2 the performance of dual redox properties. This property facilitates nano-CeO2 to catalyze the scavenging of excess free radicals in organisms, hence providing a possibility for the treatment of oxidative stress diseases such as diabetic foot, arthritis, degenerative neurological diseases, and cancer. In addition, relying on its excellent catalytic properties, customizable life-signaling factor detectors based on electrochemical techniques are developed. At the end of this review, an outlook on the opportunities and challenges of CeO2 in various fields is provided.

Nano-enabled colorectal cancer therapy

Colorectal cancer (CRC), one of the most common and deadliest diseases worldwide, poses a great health threat and social burden. The clinical treatments of CRC encompassing surgery, chemotherapy, and radiotherapy are challenged with toxicity, therapy resistance, and recurrence. In the past two decades, targeted therapy and immunotherapy have greatly improved the therapeutic benefits of CRC patients but they still suffer from drug resistance and low response rates. Very recently, gut microbiota regulation has exhibited a great potential in preventing and treating CRC, as well as in modulating the efficacy and toxicity of chemotherapy and immunotherapy. In this review, we provide a cutting-edge summary of nanomedicine-based treatment in colorectal cancer, highlighting the recent progress of oral and systemic tumor-targeting and/or tumor-activatable drug delivery systems as well as novel therapeutic strategies against CRC, including nano-sensitizing immunotherapy, anti-inflammation, gut microbiota modulation therapy, etc. Finally, the recent endeavors to address therapy resistance, metastasis, and recurrence in CRC were discussed. We hope this review could offer insight into the design and development of nanomedicines for CRC and beyond.

Antioxidant and Prooxidant Nanozymes: From Cellular Redox Regulation to Next-Generation Therapeutics

Nanozymes, nanomaterials with enzyme-mimicking activity, have attracted tremendous interest in recent years owing to their ability to replace natural enzymes in various biomedical applications, such as biosensing, therapeutics, drug delivery, and bioimaging. In particular, the nanozymes capable of regulating the cellular redox status by mimicking the antioxidant enzymes in mammalian cells are of great therapeutic significance in oxidative-stress-mediated disorders. As the distinction of physiological oxidative stress (oxidative eustress) and pathological oxidative stress (oxidative distress) occurs at a fine borderline, it is a great challenge to design nanozymes that can differentially sense the two extremes in cells, tissues and organs and mediate appropriate redox chemical reactions. In this Review, we summarize the advances in the development of redox-active nanozymes and their biomedical applications. We primarily highlight the therapeutic significance of the antioxidant and prooxidant nanozymes in various disease model systems, such as cancer, neurodegeneration, and cardiovascular diseases. The future perspectives of this emerging area of research and the challenges associated with the biomedical applications of nanozymes are described.

Efficient Nanozyme-Triggered Pressure Sensor for Point-of-Care Immunoassay: Visual Sensing and Time Readout Device

Point-of-care testing (POCT), with its portability and high sensitivity, is an analytical device for rapid on-site sensing and detection. In this study, a POCT device was designed for the portable detection of illegal additives by integrating a coil device that can visually sense color distance and a two-electrode electrochemical system. Real-time monitoring of pressure changes was achieved by driving CeO₂@Pt/Au nanoparticle (NP)-labeled antibodies into a competitive immunoreaction, in which CeO₂ and Pt/Au synergistically catalyzed the production of large amounts of O₂ from H₂O₂, leading to a significant increase in gas within the closed chamber. Attractively, the coil device converted the pressure stimulus into visually readable change in distance for semi-quantitative detection of the target substance, while the electrical signal output caused by the changes of the solution around the electrodes achieved accurate and reliable quantification of the target. In addition, the proposed dual-mode pressure immunoassay device has acceptable selectivity, stability, and reproducibility. Herein, this portable device, which enables target concentration readings by converting pressure into multiple signals, provides an effective way to visualize POCT assays in resource-limited areas.

Chiral Ruthenium Nanozymes with Self-Cascade Reaction Driven the NO Generation Induced Macrophage M1 Polarization Realizing the Lung Cancer "Cocktail Therapy"

Macrophages as the main cause of cancer immunosuppression, how to effectively induce macrophage M1 polarization remain the major challenge in lung cancer therapy. Herein, inspired by endogenous reactions, a strategy is proposed to coactivate macrophage M1 polarization by reactive oxygen species (ROS) and nitric oxide (NO) with self-autocatalytic cascade reaction. To enhance the generation of NO and ROS, NO Precursor-Arginine as capping agents for inducing synthesis two kinds of chiral ruthenium nanozyme (D/L-Arginine@Ru). Under the properties of Ru nanozymes through synchronously mimicking the activity of oxidase and nitric oxide synthase (NOS), chiral Ru nanozyme can rapidly generate ¹ O₂ and O₂ at first stage, and then catalyze Arginine to produce sufficient NO, thus enhance macrophage M1 polarization to reverse tumor immunosuppression. Moreover, combination the antitumor activity of ¹ O₂ , NO, the chiral Ru nanozymes realize the "cocktail therapy" by inducing tumor cell apoptosis as well as ferroptosis. In addition, the chirality influences the bioactivity of Ru nanozymes that L-Arginine@Ru shows the better therapeutic effect with stronger catalytic activity and natural homology. It is hoped the high performance of chiral Ru nanozyme with "cocktail therapy" is an effective therapeutic reagent and can provide a feasible treatment strategy for tumor catalytic therapy.

Effect of size and morphology of functionalized upconversion nanoparticle labeled probe on stem cell absorption

In order to improve the application of stem cell therapy, it is important to monitor the proliferation and differentiation of transplanted stem cells in real time, high sensitivity and high precision. Upconversion nanoparticles (UCNPs) have been employed as bioimaging agents and delivery vehicles for gene therapeutics in several types of cells. Herein, we fabricated multiple functional upconversion nanoparticles (FUC-NPs) as exogenous contrast agents to investigate the effect of FUC-NPs size on the efficiency of tracking human umbilical cord mesenchymal stem cells (HUCMSCs). We used TEM, DLS, MTT, etc. systematically detected the effects of nanoparticle dose and exposure time on HUCMSCs cytotoxicity. Our data showed that incubation of FUC-NPs, HUCMSCs are able to maintain their viability and differentiation ability. Interestingly, the small size FUC-NPs examined, S-FUCs, had a much higher uptake capability than the other FUC-NPs (B-FUCs, H-FUCs and R-FUCs).The study will aid in UCNPs for the engineering of stem cell application in the future.

"Electron Transport Chain Interference" Strategy of Amplified Mild-Photothermal Therapy and Defect-Engineered Multi-Enzymatic Activities for Synergistic Tumor-Personalized Suppression

Arming activatable mild-photothermal therapy (PTT) with the property of relieving tumor thermotolerance holds great promise for overcoming traditional mild PTT limitations such as thermoresistance, insufficient therapeutic effect, and off-target heating. Herein, a mitochondria-targeting, defect-engineered AFCT nanozyme with enhanced multi-enzymatic activity was elaborately designed as a tumor microenvironment (TME)-activatable phototheranostic agent to achieve remarkable anti-tumor therapy via "electron transport chain (ETC) interference and synergistic adjuvant therapy". Density functional theory calculations revealed that the synergistic effect among multi-enzyme active centers endows the AFCT nanozymes with excellent catalytic activity. In TME, open sources of H₂O₂ can be achieved by superoxide dismutase-mimicking AFCT nanozymes. In response to the dual stimuli of H₂O₂ and mild acidity, the peroxidase-mimicking activity of AFCT nanozymes not only catalyzes the accumulation of H₂O₂ to generate ·OH but also converts the loaded 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) into its oxidized form with strong near-infrared absorption, specifically unlocking its photothermal and photoacoustic imaging properties. Intriguingly, the undesired thermoresistance of tumor cells can be greatly alleviated owing to the reduced expression of heat shock proteins enabled by NADH POD-mimicking AFCT-mediated NADH depletion and consequent restriction of ATP supply. Meanwhile, the accumulated ·OH can facilitate both apoptosis and ferroptosis in tumor cells, resulting in synergistic therapeutic outcomes in combination with TME-activated mild PTT.

Enzymatic bionanocatalysts for combating peri-implant biofilm infections by specific heat-amplified chemodynamic therapy and innate immunomodulation

Bacterial biofilm-associated infection is a life-threatening emergency contributing from drug resistance and immune escape. Herein, a novel non-antibiotic strategy based on the synergy of bionanocatalysts-driven heat-amplified chemodynamic therapy (CDT) and innate immunomodulation is proposed for specific biofilm elimination by the smart design of a biofilm microenvironment (BME)-responsive double-layered metal-organic framework (MOF) bionanocatalysts (MACG) composed of MIL-100 and CuBTC. Once reaching the acidic BME, the acidity-triggered degradation of CuBTC allows the sequential release of glucose oxidase (GOx) and an activable photothermal agent, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). GOx converts glucose into H₂O₂ and gluconic acid, which can further acidify the BME to accelerate the CuBTC degradation and GOx/ABTS release. The in vitro and in vivo results show that horseradish peroxidase (HRP)-mimicking MIL-100 in the presence of self-supplied H₂O₂ can catalyze the oxidation of ABTS into oxABTS to yield a photothermal effect that breaks the biofilm structure via eDNA damage. Simultaneously, the Cu ion released from the degraded CuBTC can deplete glutathione and catalyze the splitting of H₂O₂ into •OH, which can effectively penetrate the heat-induced loose biofilms and kill sessile bacteria (up to 98.64%), such as E. coli and MRSA. Particularly, MACG-stimulated M1-macrophage polarization suppresses the biofilm regeneration by secreting pro-inflammatory cytokines (e.g., IL-6, TNF-α, etc.) and forming a continuous pro-inflammatory microenvironment in peri-implant biofilm infection animals for at least 14 days. Such BME-responsive strategy has the promise to precisely eliminate refractory peri-implant biofilm infections with extremely few adverse effects.

Macrophage Polarization Induced by Bacteria-Responsive Antibiotic-Loaded Nanozymes for Multidrug Resistance-Bacterial Infections Management

Inherited bacterial resistance and biofilm-induced local immune inactivation are important factors in the failure of antibiotics to fight against bacterial infections. Herein, antibiotic-loaded mesoporous nanozymes (HA@MRuO₂ -Cip/GOx) are fabricated for overcoming bacterial resistance, and activating the local immunosuppression in biofilm microenvironment (BME). HA@MRuO₂ -Cip/GOx are prepared by physical adsorption between ciprofloxacin (Cip) or glucose oxidase (GOx) and MRuO₂ NPs, and modified with hyaluronic acid (HA). In vitro, HA@MRuO₂ -Cip/GOx cleaves extracellular DNA (eDNA) to disrupt biofilm, thereby enhancing Cip kill planktonic bacteria. Furthermore, HA@MRuO₂ -Cip/GOx can induce polarization and enhance phagocytosis of a macrophage-derived cell line. More importantly, in vivo therapeutic performance confirms that HA@MRuO₂ -Cip/GOx can trigger macrophage-related immunity, and effectively alleviate MRSA-bacterial lung infections. Accordingly, nanocatalytic therapy combined with targeted delivery of antibiotics could enhance the treatment of bacterial infections.

2D-CuPd nanozyme overcome tamoxifen resistance in breast cancer by regulating the PI3K/AKT/mTOR pathway

Tamoxifen is the most commonly used treatment for estrogen-receptor (ER) positive breast cancer patients, but its efficacy is severely hampered by resistance. PI3K/AKT/mTOR pathway inhibition was proven to augment the benefit of endocrine therapy and exhibited potential for reversing tamoxifen-induced resistance. However, the vast majority of PI3K inhibitors currently approved for clinical use are unsatisfactory in terms of safety and efficacy. We developed two-dimensional CuPd (2D-CuPd) nanosheets with oxidase and peroxidase nanozyme activities to offer a novel solution to inhibit the activity of the PI3K/AKT/mTOR pathway. 2D-CuPd exhibit superior dual nanozyme activities converting hydrogen peroxide accumulated in drug-resistant cells into more lethal hydroxyl radicals while compensating for the insufficient superoxide anion produced by tamoxifen. The potential clinical utility was further demonstrated in an orthotopically implanted tamoxifen-resistant PDX breast cancer model. Our results reveal a novel nanozyme ROS-mediated protein mechanism for the regulation of the PI3K subunit, illustrate the cellular pathways through which increased p85β protein expression contributes to tamoxifen resistance, and reveal p85β protein as a potential therapeutic target for overcoming tamoxifen resistance. 2D-CuPd is the first reported nanomaterial capable of degrading PI3K subunits, and its high performance combined with further materials engineering may lead to the development of nanozyme-based tumor catalytic therapy.

Deciphering the catalytic mechanism of superoxide dismutase activity of carbon dot nanozyme

Nanozymes with superoxide dismutase (SOD)-like activity have attracted increasing interest due to their ability to scavenge superoxide anion, the origin of most reactive oxygen species in vivo. However, SOD nanozymes reported thus far have yet to approach the activity of natural enzymes. Here, we report a carbon dot (C-dot) SOD nanozyme with a catalytic activity of over 10,000 U/mg, comparable to that of natural enzymes. Through selected chemical modifications and theoretical calculations, we show that the SOD-like activity of C-dots relies on the hydroxyl and carboxyl groups for binding superoxide anions and the carbonyl groups conjugated with the π-system for electron transfer. Moreover, C-dot SOD nanozymes exhibit intrinsic targeting ability to oxidation-damaged cells and effectively protect neuron cells in the ischemic stroke male mice model. Together, our study sheds light on the structure-activity relationship of C-dot SOD nanozymes, and demonstrates their potential for treating of oxidation stress related diseases.

Nanoceria: an innovative strategy for cancer treatment

Nanoceria or cerium oxide nanoparticles characterised by the co-existing of Ce³⁺ and Ce⁴⁺ that allows self-regenerative, redox-responsive dual-catalytic activities, have attracted interest as an innovative approach to treating cancer. Depending on surface characteristics and immediate environment, nanoceria exerts either anti- or pro-oxidative effects which regulate reactive oxygen species (ROS) levels in biological systems. Nanoceria mimics ROS-related enzymes that protect normal cells at physiological pH from oxidative stress and induce ROS production in the slightly acidic tumour microenvironment to trigger cancer cell death. Nanoceria as nanozymes also generates molecular oxygen that relieves tumour hypoxia, leading to tumour cell sensitisation to improve therapeutic outcomes of photodynamic (PDT), photothermal (PTT) and radiation (RT), targeted and chemotherapies. Nanoceria has been engineered as a nanocarrier to improve drug delivery or in combination with other drugs to produce synergistic anti-cancer effects. Despite reported preclinical successes, there are still knowledge gaps arising from the inadequate number of studies reporting findings based on physiologically relevant disease models that accurately represent the complexities of cancer. This review discusses the dual-catalytic activities of nanoceria responding to pH and oxygen tension gradient in tumour microenvironment, highlights the recent nanoceria-based platforms reported to be feasible direct and indirect anti-cancer agents with protective effects on healthy tissues, and finally addresses the challenges in clinical translation of nanoceria based therapeutics.

A platinum-ruthenium hybrid prodrug with multi-enzymatic activities for chemo-catalytic therapy of hypoxic tumors

Regulation of tumor hypoxia and redox homeostasis is a promising strategy for cancer therapy. Nanocatalytic medicine has played more and more important roles in this field because it can cleverly convert the efficiency and selectivity of catalysis into high therapeutic efficiency. Herein, we developed a platinum(iv)-ruthenium hybrid prodrug, named as Pt-Ru, for efficient chemo-catalytic synergistic therapy of hypoxic tumors. The ruthenium hybridization endowed the Pt(iv) prodrug with multi-enzyme catalytic activity, that is, mimicking catalase (CAT) to generate O2 in situ, mimicking peroxidase (POD) to produce reactive oxygen species, and mimicking glutathione peroxidase (GPx) to deplete GSH, thus effectively overcoming tumor hypoxia and cisplatin resistance. As a result, Pt-Ru treatment led to a superior anticancer efficacy to cisplatin both in vitro and in vivo. This work suggested redox homeostasis regulation as a tantalizing angle for developing the next generation of platinum drugs.

Biomimetic nanomaterial-facilitated oxygen generation strategies for enhancing tumour treatment outcomes

Hypoxia, as a typical hallmark of the tumour microenvironment (TME), has been verified to exist in most malignancies and greatly hinders the outcome of tumour treatments, including chemotherapy, photodynamic therapy, radiotherapy, and immunotherapy. Various approaches to alleviate tumour hypoxia have been reported. Among them, biomimetic nanomaterial-facilitated tumour oxygenation strategies, based on the engagement of human endogenous proteins, red blood cells, the cell membrane, and catalase, are the most impressive due to their excellent tumour active-targeting ability and superior tumour-selective capability, which, however, have not yet been systematically reviewed. Herein, we are ready to describe the current progress in biomimetic nanomaterial-facilitated tumour oxygenation strategies and corresponding improvements in tumour treatment outputs. In this review, the underlying mechanism behind the superior effect of these biomimetic nanomaterials, compared with other materials, on alleviating the hypoxic TME is highlighted. Additionally, the ongoing problems and potential solutions are also discussed.

In situ-transition nanozyme triggered by tumor microenvironment boosts synergistic cancer radio-/chemotherapy through disrupting redox homeostasis

Disrupting redox homeostasis in the tumor microenvironment (TME), like excessive H2O2, glutathione (GSH) and weak acidity, has been proved as an effective tumor therapeutic strategy. Herein, we constructed a TME-responsive nanozyme, DOX@HMSN/Mn3O4(R), with reversible Mn3+/Mn2+ transition in situ triggered by TME to perturb the intrinsic redox homeostasis and catalyze reactive oxygen species (ROS) overproduction. In addition, this nanozyme could react with excess GSH in TME to produce GSSG, resulting in the consumption of reducing agents to suppress ROS clearance. Density functional theory calculations further confirmed that the nanozyme mainly exhibited the oxidase-like activity to catalyze the formation of hydroxyl radicals from O2, thus strengthening the oxidation environment in the TME. Combined with radiotherapy, the high-energy X-ray could excite the outer-layer electrons in the nanozyme, forming photoelectrons that participate in the oxidase-like enzymatic reaction, thus intensifying ROS accumulation and amplifying the radio-/chemotherapeutic efficacy.

Fabrication of novel ruthenium loaded silk fibroin nanomaterials for fingolimod release improved antitumor efficacy in hepatocellular carcinoma

Cancer targeted nanomaterials-based drug delivery systems have been described as promising. In this work, we employed silk fibroin (SF), ruthenium nanomaterials (RuNMs), heptapeptide (T7), and fingolimod (FTY720) to construct a pH-responsive smart nanomaterials drug delivery system. They were spherical with a mean size of around 120 nm, which may have contributed to the improved penetration and retention of the NMs in tumour areas. T7-FTY720@SF-RuNMs had an encapsulation efficiency (EE) of 72.51 ± 4.02%. When the pH of an environment is acidic, the release of FTY720 from nanocarriers is enhanced. T7-FTY720@SF-RuNMs demonstrated increased cellular uptake selective and anticancer efficacy for hepatocellular cancer in both in vitro and in vivo experiments. Additionally, the in vivo biodistribution investigation showed that T7-FTY720@SF-RuNMs could efficiently aggregate in the tumour location, improving their in vivo potential to kill cancer cells. T7-FTY720@SF-RuNMs demonstrated little toxicity to tumour-bearing animals in investigations of histology and immunohistochemistry, showing that the fabricated NMs are biocompatible in vivo. For the treatment of hepatocellular cancer, the T7-FTY720@SF-RuNMs delivery method offers significant promise.

Applications of resveratrol in the treatment of gastrointestinal cancer

Natural product compounds have lately attracted interest in the scientific community as a possible treatment for gastrointestinal (GI) cancer, due to their anti-inflammatory and anticancer properties. There are many preclinical, clinical, and epidemiological studies, suggesting that the consumption of polyphenol compounds, which are abundant in vegetables, grains, fruits, and pulses, may help to prevent various illnesses and disorders from developing, including several GI cancers. The development of GI malignancies follows a well-known path, in which normal gastrointestinal cells acquire abnormalities in their genetic composition, causing the cells to continuously proliferate, and metastasize to other sites, especially the brain and liver. Natural compounds with the ability to affect oncogenic pathways might be possible treatments for GI malignancies, and could easily be tested in clinical trials. Resveratrol is a non-flavonoid polyphenol and a natural stilbene, acting as a phytoestrogen with anti-cancer, cardioprotective, anti-oxidant, and anti-inflammatory properties. Resveratrol has been shown to overcome resistance mechanisms in cancer cells, and when combined with conventional anticancer drugs, could sensitize cancer cells to chemotherapy. Several new resveratrol analogs and nanostructured delivery vehicles with improved anti-GI cancer efficacy, absorption, and pharmacokinetic profiles have already been developed. This present review focuses on the in vitro and in vivo effects of resveratrol on GI cancers, as well as the underlying molecular mechanisms of action.

The strategy of precise targeting and in situ oxygenating for enhanced triple-negative breast cancer chemophototherapy

The absence of effective therapeutic targets and tumor hypoxia are the main causes of failure in the treatment of triple-negative breast cancer (TNBC). Biomimetic nanotechnology and tumor microenvironment (TME) responsiveness bring hope and opportunity to address this problem. Here, we develop a core membrane nanoplatform (HM/D-I-BL) using hollow mesoporous manganese dioxide (HM) coated with a biomimetic cancer cell membrane for enhanced chemotherapy/phototherapy via the strategy of precise drug delivery and hypoxia amelioration. Cancer cell membrane modification endows HM/D-I-BL with excellent homologous targeting and immune escape performance. Cellular uptake and fluorescence imaging studies confirmed that HM/D-I-BL can be accurately delivered to tumor sites. HM/D-I-BL also features efficient in situ O₂ generation in tumors upon laser irradiation, and subsequently enhanced chemotherapy/phototherapy, pointing to its usefulness as a TME-responsive nanozyme to alleviate tumor hypoxia in the presence of H₂O₂. In addition, HM/D-I-BL showed good fluorescence and magnetic resonance imaging performances, which offers a reliable multimodal image-guided combination tumor therapy for precision theranostics in the future. In general, this intelligent biomimetic nanoplatform with its homotypic tumor targeting, in situ alleviation of tumor hypoxia and synergetic chemophototherapy would open up a new dimension for the precision treatment of TNBC.

Smart PdH@MnO2 Yolk-Shell Nanostructures for Spatiotemporally Synchronous Targeted Hydrogen Delivery and Oxygen-Elevated Phototherapy of Melanoma

Hydrogen therapy, an emerging therapeutic strategy, has recently attracted much attention in anticancer medicine. Evidence suggests that hydrogen (H₂) can selectively reduce intratumoral overexpressed hydroxyl radicals (•OH) to break the redox homeostasis and thereby lead to redox stress and cell damage. However, the inability to achieve stable hydrogen storage and efficient hydrogen delivery hinders the development of hydrogen therapy. Furthermore, oxygen (O₂) deficiency in the tumor microenvironment (TME) and the electron-hole separation inefficiency in photosensitizers have severely limited the efficacy of photodynamic therapy (PDT). Herein, a smart PdH@MnO₂/Ce6@HA (PHMCH) yolk-shell nanoplatform is designed to surmount these challenges. PdH tetrahedrons combine stable hydrogen storage and high photothermal conversion efficiency of palladium (Pd) nanomaterials with near-infrared-controlled hydrogen release. Subsequently, the narrow bandgap semiconductor manganese dioxide (MnO₂) and the photosensitizer chlorin e6 (Ce6) are introduced into the PHMCH nanoplatform. Upon irradiation, the staggered energy band edges in heterogeneous materials composed of MnO₂ and Ce6 can efficiently facilitate electron-hole separation for increasing singlet oxygen (¹O₂). Moreover, MnO₂ nanoshells generate O₂ in TME for ameliorating hypoxia and further improving O₂-dependent PDT. Finally, the hyaluronic acid-modified PHMCH nanoplatform shows negligible cytotoxicity and selectively targets CD44-overexpressing melanoma cells. The synergistic antitumor performance of the H₂-mediated gas therapy combined with photothermal and enhanced PDT can explore more possibilities for the design of gas-mediated cancer therapy.

Constructing virus-like SiOx/CeO2/VOx nanozymes for 1064 nm light-triggered mild-temperature photothermal therapy and nanozyme catalytic therapy

The construction of nanoplatforms with combined photothermal properties and cascading enzymatic activities has become an active area of anticancer research. However, the overheating of photothermal therapy (PTT) and the specific properties of tumor microenvironment (TME) greatly impaired the therapeutic efficiency. Herein, we rationally fabricated a virus-like SiO_x/CeO₂/VO_x (SCV) nanoplatform for 1064 nm near-infrared (NIR) triggered mild-temperature PTT and nanozyme catalytic therapy. Firstly, the virus-like shape of SiO_x/CeO₂/VO_x made it favorable for cell adhesion and improved its phagocytosis in cells, and the SCV generated an effective PTT effect upon 1064 nm laser irradiation. Particularly, the produced VO²⁺ in TME could be used as a heat shock protein inhibitor to inhibit the expression of heat shock protein 60 (HSP60) to enhance the PTT efficiency. Moreover, the SCV nanozyme exhibited obvious peroxidase-mimic (POD) catalytic activity, which could generate highly toxic free radical ions (˙OH) under acidic conditions. The mild-temperature heat and ˙OH produced by enzymatic catalysis effectively blocked the tumor growth, as verified firmly by in vitro and in vivo tests. Our designed virus-like SCV nanozyme with POD mimic enzyme activity and a mild photothermal effect may provide a new way of thinking about the combination therapy model.

Rare-Earth Doping in Nanostructured Inorganic Materials

Impurity doping is a promising method to impart new properties to various materials. Due to their unique optical, magnetic, and electrical properties, rare-earth ions have been extensively explored as active dopants in inorganic crystal lattices since the 18th century. Rare-earth doping can alter the crystallographic phase, morphology, and size, leading to tunable optical responses of doped nanomaterials. Moreover, rare-earth doping can control the ultimate electronic and catalytic performance of doped nanomaterials in a tunable and scalable manner, enabling significant improvements in energy harvesting and conversion. A better understanding of the critical role of rare-earth doping is a prerequisite for the development of an extensive repertoire of functional nanomaterials for practical applications. In this review, we highlight recent advances in rare-earth doping in inorganic nanomaterials and the associated applications in many fields. This review covers the key criteria for rare-earth doping, including basic electronic structures, lattice environments, and doping strategies, as well as fundamental design principles that enhance the electrical, optical, catalytic, and magnetic properties of the material. We also discuss future research directions and challenges in controlling rare-earth doping for new applications.

Advanced applications of cerium oxide based nanozymes in cancer

Cerium oxide nanozymes have emerged as a new type of bio-antioxidants in recent years. CeO2 nanozymes possess enzyme mimetic activities with outstanding free radical scavenging activity, facile synthesis conditions, and excellent biocompatibility. Based on these extraordinary properties, use of CeO2 nanozymes has been demonstrated to be a highly versatile therapeutic method for many diseases, such as for inflammation, rheumatoid arthritis, hepatic ischemia-reperfusion injury and Alzheimer's disease. In addition to that, CeO2 nanozymes have been widely used in the diagnosis and treatment of cancer. Many examples can be found in the literature, such as magnetic resonance detection, tumour marker detection, chemotherapy, radiotherapy, photodynamic therapy (PDT), and photothermal therapy (PTT). This review systematically summarises the latest applications of CeO2-based nanozymes in cancer research and treatment. We believe that this paper will help develop value-added CeO2 nanozymes, offering great potential in the biotechnology industry and with great significance for the diagnosis and treatment of a wide range of malignancies.

An oral hydrogel carrier for delivering resveratrol into intestine-specific target released with high encapsulation efficiency and loading capacity based on structure-selected alginate and pectin

Resveratrol (RES) has many beneficial effects on the human body, but it is always unstable, resulting in low oral bioavailability, especially in the gastrointestinal tract.

Enzyme-responsive strategy as a prospective cue to construct intelligent biomaterials for disease diagnosis and therapy

Stimuli-responsive materials have been widely studied and applied in biomedical field. Under the stimulation of enzymes, the enzyme-responsive materials (ERMs) can be triggered to change their structures, properties and functions....

Oxygenic Enrichment in Hybrid Ruthenium Sulfide Nanoclusters for an Optimized Photothermal Effect

Transition-metal dichalcogenide (TMD)-based nanomaterials have been extensively explored for the photonic therapy. To the best of our knowledge, near-infrared (NIR) light is a requirement for the photothermal therapy (PTT) to achieve the feature of deep-tissue penetration, whereas no obvious absorption peaks existing in the NIR region for existing TMD nanomaterials limit their therapeutic efficacy. As one category of TMD nanomaterials, ruthenium sulfide-based nanomaterials have been less exploited in biomedical applications including tumor therapy so far. Here, we develop a facile biomineralization-assisted bottom-up strategy to synthesize oxygenic hybrid ruthenium sulfide nanoclusters (RuS_x NCs) by regulating the oxygen amounts and sulfur defects for the optimized PTT. By regulating the increasing initial molar ratios of Ru to S, RuS_x NCs with small sizes were endowed with increasing oxygen contents and sulfur defects, leading to the photothermal conversion efficiency (PCE) increasing from 32.8 to 41.9%, which were higher than that of most small-sized inorganic photothermal nanoagents. In contrast to commercial indocyanine green, these RuS_x NCs exhibited higher photostability under NIR laser irradiation. The high PCE and superior photostability allowed RuS_x NCs to effectively and completely ablate cancer cells. Thus, the proposed defect engineering strategy endows RuS_x NCs with an excellent photothermal effect for the PTT of tumors of living mice, which also proves the potential of further exploring the properties of RuS_x NCs for future biomedical applications.

A Functionalized Octahedral Palladium Nanozyme as a Radical Scavenger for Ameliorating Alzheimer's Disease

Oxidative stress is always mentioned as a pathologic appearance of Alzheimer's disease (AD). It is attributed to mitochondrial dysfunction closely linked to Aβ deposition and neurofibrillary tangles (NFTs). Octahedral palladium nanoparticles (Pd NPs) exhibited excellent antioxidant enzyme-like activity and outstanding biocompatibility, but the poor blood-brain barrier (BBB) permeability limits their application in the treatment of Alzheimer's disease. Herein, we constructed a borneol (Bor)-modified octahedral palladium (Pd@PEG@Bor) nanozyme platform to eliminate intracellular reactive oxygen species (ROS) and elevate epithelial cell penetrability. Based on in vitro and in vivo studies, we demonstrate that the Pd@PEG@Bor could efficiently reduce ROS and Ca²⁺ contents, maintain the mitochondrial membrane potential, and further protect the mitochondria in SH-SY5Y cells. Furthermore, the nanozymes could quickly accumulate in the brain of AD mice and alleviate pathological characteristics such as Aβ plaque deposition, neuron loss, and neuroinflammation. The learning ability and memory function of AD mice are also significantly improved. Overall, this work indicates that the Pd@PEG@Bor nanozymes could delay the progression of AD by regulating ROS levels and also provides a new strategy for the treatment of AD.

Nanozymes in Tumor Theranostics

Nanozymes, a new generation of enzyme mimics, have recently attracted great attention. Nanozymes could catalyze chemical reactions as biological enzymes under physiologically mild conditions with higher-efficiency catalytic activities. Moreover, nanozymes could overcome the shortcomings of natural enzymes, such as easy inactivation, high cost, and low yield. With the development of more and more smart and multi-functional nanosystems, nanozymes display great achievement in tumor biology. In this review, we outline the recent advances of nanozymes in tumor and tumor microenvironment diagnosis, therapy, and theranostics.

A diselenide bond-containing ROS-responsive ruthenium nanoplatform delivers nerve growth factor for Alzheimer's disease management by repairing and promoting neuron regeneration

Alzheimer's disease (AD) is an incurable neurodegenerative disease. Repairing damaged nerves and promoting nerve regeneration are key ways to relieve AD symptoms. However, due to the lack of effective strategies to deliver nerve growth factor (NGF) to the brain, achieving neuron regeneration is a major challenge for curing AD. Herein, a ROS-responsive ruthenium nanoplatform (R@NGF-Se-Se-Ru) drug delivery system for AD management by promoting neuron regeneration and Aβ clearance was investigated. Under near-infrared (NIR) irradiation, nanoclusters have good photothermal properties, which can effectively inhibit the aggregation of Aβ and disaggregate Aβ fibrils. Interestingly, the diselenide bond in the nanoclusters is broken, and the nanoclusters are degraded into small ruthenium nanoparticles in the high reactive oxygen species (ROS) environment of the diseased area. Besides, NGF can promote neuronal regeneration and repair damaged nerves. Furthermore, R@NGF-Se-Se-Ru efficiently crosses the blood-brain barrier (BBB) owing to the covalently grafted target peptides of RVG (R). In vivo studies demonstrate that R@NGF-Se-Se-Ru nanoclusters decrease Aβ deposits, inhibit Aβ-induced cytotoxicity, and promote neurite outgrowth. The study confirms that promoting both Aβ clearance and neuron regeneration is an important therapeutic target for anti-AD drugs and provides a novel insight for AD therapy.

A ruthenium nanoframe/enzyme composite system as a self-activating cascade agent for the treatment of bacterial infections

The cascade catalytic strategy could effectively enhance the antibacterial activity by regulating the production of hydroxyl radicals (˙OH) in the sites of bacterial infection. In this work, a ruthenium metal nanoframe (Ru NF) was successfully synthesized via the palladium template method. The cascade catalysis in the bacterial infection microenvironment was achieved by physically adsorbed natural glucose oxidase (GOx), and hyaluronic acid (HA) was coated on the outer layer of the system for locating the infection sites accurately. Eventually, a composite nano-catalyst (HA-Ru NFs/GOx) based on the ruthenium nanoframe was constructed, which exhibited excellent cascade catalytic activity and good biocompatibility. The prepared HA-Ru NFs/GOx enhances the antibacterial activity and inhibits bacterial regeneration through the outbreak of reactive oxygen species (ROS) caused by self-activating cascade reactions. In addition, in vivo experiments indicate that HA-Ru NFs/GOx could efficiently cause bacterial death and significantly promote wound healing/skin regeneration. Accordingly, ruthenium metal framework nanozymes could be used as an effective cascade catalytic platform to inhibit bacterial regeneration and promote wound healing, and have great potential as new antibacterial agents against antibiotic-resistant bacteria.

Ruthenium Complexes: An Alternative to Platinum Drugs in Colorectal Cancer Treatment

Colorectal cancer (CRC) is one of the intimidating causes of death around the world. CRC originated from mutations of tumor suppressor genes, proto-oncogenes and DNA repair genes. Though platinum (Pt)-based anticancer drugs have been widely used in the treatment of cancer, their toxicity and CRC cells' resistance to Pt drugs has piqued interest in the search for alternative metal-based drugs. Ruthenium (Ru)-based compounds displayed promising anticancer activity due to their unique chemical properties. Ru-complexes are reported to exert their anticancer activities in CRC cells by regulating different cell signaling pathways that are either directly or indirectly associated with cell growth, division, proliferation, and migration. Additionally, some Ru-based drug candidates showed higher potency compared to commercially available Pt-based anticancer drugs in CRC cell line models. Meanwhile Ru nanoparticles coupled with photosensitizers or anticancer agents have also shown theranostic potential towards CRC. Ru-nanoformulations improve drug efficacy, targeted drug delivery, immune activation, and biocompatibility, and therefore may be capable of overcoming some of the existing chemotherapeutic limitations. Among the potential Ru-based compounds, only Ru (III)-based drug NKP-1339 has undergone phase-Ib clinical trials in CRC treatment.

Nanoscale metal-organic frameworks for tumor phototherapy

Metal-Organic Frameworks (MOFs) are constructed from metal ions/cluster nodes and functional organic ligands through coordination bonds. Owing to the advantages of diverse synthetic methods, easy modification after synthesis, large adsorption capacity for heavy metals, and short equilibrium time, considerable attention has recently been paid to MOFs for tumor phototherapy. Through rational tuning of metal ions and ligands, MOFs present abundant properties for various applications. Light-triggered phototherapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), is an emerging cancer treatment approach. Nanosized MOFs can be applied as phototherapeutic agents to accomplish phototherapy with excellent phototherapeutic efficacy. This review outlines the latest advances in the field of phototherapy with various metal ion-based MOFs.

Iridium oxide nanoparticles mediated enhanced photodynamic therapy combined with photothermal therapy in the treatment of breast cancer

Photodynamic therapy (PDT) of tumor has achieved good results, but the treatment efficiency is not high due to the lack of effective photosensitizers and tumor hypoxia. In this study, iridium dioxide nanoparticles (IrO₂ NPs) with excellent photothermal/photodynamic effects and catalase like activity were synthesized by a simple method. The combination of glucose oxidase (GOx) and IrO₂ NPs is formed by hyaluronic acid (HA), which have the activities of glucose oxidase and catalase, can target tumor sites and form in situ amplifiers in tumor microenvironment (IrO₂-GOx@HA NPs). Firstly, GOx convert the high levels of glucose in the tumor to hydrogen peroxide (H₂O₂), and then IrO₂ NPs convert H₂O₂ to oxygen (O₂), which can enhance the type II of PDT. IrO₂ NPs also can be used as a thermosensitive agent for photothermal therapy (PTT). In cancer cells, IrO₂-GOx@HA NPs-mediated amplifier enhances the effect of type II of PDT, aggravating the apoptosis of breast cancer (4T1) cells and cooperating with its own PTT to further improve the overall treatment effect. Under simulated hypoxic conditions of tumor tissue, it was found that IrO₂-GOx@HA NPs treatment can effectively relieve hypoxia inside tumor tissue. In addition, the results in vivo further proved that, IrO₂-GOx@HA NPs can enhance the role of II PDT and cooperate with PTT to treat breast cancer effectively. The results highlight the prospect of IrO₂-GOx@HA NPs in controlling and regulating tumor hypoxia to overcome the limitations of current cancer therapy.

A hybrid nanozymes in situ oxygen supply synergistic photothermal/chemotherapy of cancer management

Hypoxia in the solid tumor microenvironment (TME) can easily induce tumor recurrence, metastasis, and drug resistance. The use of man-made nanozymes is considered to be an effective strategy for regulating hypoxia in the TME. Herein, Ru@MnO2 nanozymes were constructed via an in situ reduction method, and they showed excellent photothermal conversion efficiency and catalytic activity. The anti-tumor drug DOX with fluorescence was loaded on the Ru@MnO2 nanozymes, and an erythrocyte membrane was further coated on the surface of the Ru@MnO2 nanozymes to construct nanozymes with on-demand release abilities. The erythrocyte membrane (RBCm) enhances the biocompatibility of the Ru@MnO2 nanozymes and prolongs their circulation time in the blood. Ru@MnO2 nanozymes can catalyze endogenous H2O2 to produce O2 to relieve hypoxia in the TME to enhance the efficacy of the photothermal therapy/chemotherapy of cancer. In vitro studies confirmed that the Ru@MnO2 nanozymes showed good tumor penetration abilities and a synergistic anti-tumor effect. Importantly, both in vivo and in vitro studies have confirmed that the oxygen supply in situ enhanced the efficacy of the PTT/chemotherapy of cancer. Accordingly, this study demonstrated that Ru@MnO2 nanozymes can be used as an effective integrated system allowing catalysis, photothermal therapy, and chemotherapy for cancer management.

Cationic chitosan@Ruthenium dioxide hybrid nanozymes for photothermal therapy enhancing ROS-mediated eradicating multidrug resistant bacterial infection

Antibiotic resistanceand biofilm formation are the main challenges of bacterial infectious diseases, and enhancing the permeability of drugs to biofilms may be a promising strategy. Herein, we constructed a cationic chitosan coated ruthenium dioxide nanozyme (QCS-RuO₂@RBT, SRT NSs)。RuO₂ nanosheets (RuO₂ NSs) are modified with positively charged Quaternary ammonium-chitosan (QCS) to improve biocompatibility, and enhance the interaction between RuO₂ nanozymes and bacterial membranes. An antibacterial drug, [Ru(bpy)₂(tip)]²⁺ (RBT) can be loaded onto QCS-RuO₂ by π-π stacking and hydrophobic interaction. SRT NSs exhibit NIR light enhanced peroxidase-like catalytic activity, thereby effectively fighting against planktonic bacteria and damaging biofilms. In the biofilm, extracellular DNA (eDNA) was cleaved by high levels of hydroxyl radicals (•OH) catalyzed by SRT NSs, thereby disrupting the rigid biofilm. In addition, in vivo studies demonstrate that SRT NSs can significantly rescue skin wound infections and the chronic lung infection in mice caused by P. aeruginosa, and hold the same therapeutic efficacy as first-line clinically anchored anti P. aeruginosa drug ciprofloxacin. Accordingly, the research work has realized the efficient production of ·OH, and the permeability of drugs to biofilms.it provides a promising response strategy for the management of biofilm-associated infections, including chronic lung infection.