Engineering Multifunctional RNAi Nanomedicine To Concurrently Target Cancer Hallmarks for Combinatorial Therapy

Photothermally Reinforced Nanozyme Remodeling Tumor Microenvironment of Redox and Metabolic Homeostasis to Enhance Ferroptosis in Tumor Therapy

The acidity and high GSH level in the tumor microenvironment (TME) greatly limit the antitumor activity of nanozymes. Thus, enhancing nanozymes' activity is fundamentally challenging in tumor therapy. Although the combination of photothermal therapy (PTT) and nanozymes can enhance the catalytic activity, cancer cells will overexpress heat shock proteins (HSPs) at high temperature, aggravating the heat resistance of tumor cells, which in turn compromises the outcome of chemodynamic therapy. Herein, we propose an iron-doped metal-organic framework nanozyme (IB@Fe-ZIF8@PDFA) that can be activated under the weak acidity and high level of GSH, demonstrating the activities of GSH oxidation (GSH-OXD), peroxidase (POD), and NADH oxidase (NADH-OXD). Under laser irradiation, it displays photothermal-enhanced multienzyme activities to simultaneously eliminate tumors and inhibit tumor metastasis. While consuming endogenous GSH, IB@Fe-ZIF8@PDFA promotes the decomposition of H2O2 into ·OH, enhancing ferroptosis in tumor cells. Surprisingly, IB@Fe-ZIF8@PDFA nanozyme can oxide NADH and subsequently limit the ATP supply, reducing the expression of HSPs and significantly weakening the heat resistance of tumor cells during PTT. Meanwhile, H2O2 is generated during this procedure, which can endogenously replenish the consumed H2O2. Thus, this IB@Fe-ZIF8@PDFA nanozyme constitutes a self-cascading platform to consume GSH and NADH, endogenously replenish the H2O2 and continuously generate ·OH to facilitate ferroptosis by disrupting the redox and metabolic homeostasis in tumor cells, achieving tumor elimination and tumor metastasis inhibition.

The mRNA vaccine platform for veterinary species

Vaccination has proven to be an effective means of controlling pathogens in animals. Since the introduction of veterinary vaccines in the 19th century, several generations of vaccines have been introduced. These vaccines have had a positive impact on global animal health and production. Despite, the success of veterinary vaccines, there are still some pathogens for which there are no effective vaccines available, such as African swine fever. Further, animal health is under the constant threat of emerging and re-emerging pathogens, some of which are zoonotic and can pose a threat to human health. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has highlighted the need for new vaccine platforms that are safe and efficacious, but also importantly, are adaptable and can be modified rapidly to match the circulating pathogens. mRNA vaccines have been shown to be an effective vaccine platform against various viral and bacterial pathogens. This review will cover some of the recent advances in the field of mRNA vaccines for veterinary species. Moreover, various mRNA vaccines and their delivery methods, as well as their reported efficacy, will be discussed. Current limitations and future prospects of this vaccine platform in veterinary medicine will also be discussed.

Nanomaterials-Induced Redox Imbalance: Challenged and Opportunities for Nanomaterials in Cancer Therapy

Cancer cells typically display redox imbalance compared with normal cells due to increased metabolic rate, accumulated mitochondrial dysfunction, elevated cell signaling, and accelerated peroxisomal activities. This redox imbalance may regulate gene expression, alter protein stability, and modulate existing cellular programs, resulting in inefficient treatment modalities. Therapeutic strategies targeting intra- or extracellular redox states of cancer cells at varying state of progression may trigger programmed cell death if exceeded a certain threshold, enabling therapeutic selectivity and overcoming cancer resistance to radiotherapy and chemotherapy. Nanotechnology provides new opportunities for modulating redox state in cancer cells due to their excellent designability and high reactivity. Various nanomaterials are widely researched to enhance highly reactive substances (free radicals) production, disrupt the endogenous antioxidant defense systems, or both. Here, the physiological features of redox imbalance in cancer cells are described and the challenges in modulating redox state in cancer cells are illustrated. Then, nanomaterials that regulate redox imbalance are classified and elaborated upon based on their ability to target redox regulations. Finally, the future perspectives in this field are proposed. It is hoped this review provides guidance for the design of nanomaterials-based approaches involving modulating intra- or extracellular redox states for cancer therapy, especially for cancers resistant to radiotherapy or chemotherapy, etc.

Development of Mannosylated Lipid Nanoparticles for mRNA Cancer Vaccine with High Antigen Presentation Efficiency and Immunomodulatory Capability

Insufficient accumulation of lipid nanoparticles (LNPs)-based mRNA vaccines in antigen presenting cells remains a key barrier to eliciting potent antitumor immune responses. Herein, we develop dendritic cells (DCs) targeting LNPs by taking advantage of mannose receptor-mediated endocytosis. Efficient delivery of mRNA to DCs is achieved in vitro and in vivo utilizing the sweet LNPs (STLNPs-Man). Intramuscular injection of mRNA vaccine (STLNPs-Man@mRNAOVA ) results in a four-fold higher uptake by DCs in comparison with commercially used LNPs. Benefiting from its DCs targeting ability, STLNPs-Man@mRNAOVA significantly promotes the antitumor performances, showing a comparable therapeutic efficacy by using one-fifth of the injection dosage as the vaccine prepared from normal LNPs, thus remarkably avoiding the side effects brought by conventional mRNA vaccines. More intriguingly, STLNPs-Man@mRNAOVA exhibits the ability to downregulate the expression of cytotoxic T-lymphocyte-associated protein 4 on T cells due to the blockade of CD206/CD45 axis, showing brilliant potentials in promoting antitumor efficacy combined with immune checkpoint blockade therapy.

Recent advances in nanomedicine for metabolism-targeted cancer therapy

Metabolism denotes the sum of biochemical reactions that maintain cellular function. Different from most normal differentiated cells, cancer cells adopt altered metabolic pathways to support malignant properties. Typically, almost all cancer cells need a large number of proteins, lipids, nucleotides, and energy in the form of ATP to support rapid division. Therefore, targeting tumour metabolism has been suggested as a generic and effective therapy strategy. With the rapid development of nanotechnology, nanomedicine promises to have a revolutionary impact on clinical cancer therapy due to many merits such as targeting, improved bioavailability, controllable drug release, and potentially personalized treatment compared to conventional drugs. This review comprehensively elucidates recent advances of nanomedicine in targeting important metabolites such as glucose, glutamine, lactate, cholesterol, and nucleotide for effective cancer therapy. Furthermore, the challenges and future development in this area are also discussed.

Copper nitroprusside: An innovative approach for targeted cancer therapy via ROS modulation

The clinical application of nanomaterials for chemodynamic therapy (CDT), which generate multiple reactive oxygen species (ROS), presents significant challenges. These challenges arise due to insufficient levels of endogenous hydrogen peroxide and catalytic ions necessary to initiate Fenton reactions. As a result, sophisticated additional delivery systems are required. In this study, a novel bimetallic copper (II) pentacyanonitrosylferrate (Cu(II)NP, Cu[Fe(CN) 5 NO]) material was developed to address these limitations. This material functions as a multiple ROS generator at tumoral sites by self-inducing hydrogen peroxide and producing peroxynitrite (ONOO-) species. The research findings demonstrate that this material exhibits low toxicity towards normal liver organoids, yet shows potent antitumoral effects on High Grade Serous Ovarian Cancer (HGSOC) organoid patients, regardless of platinum resistance. Significantly, this research introduces a promising therapeutic opportunity by proposing a single system capable of replacing the need for H2O2, additional catalysts, and NO-based delivery systems. This innovative system exhibits remarkable multiple therapeutic mechanisms, paving the way for potential advancements in clinical treatments.

Efficacy and tolerability of an mRNA vaccine expressing gB and pp38 antigens of Marek's disease virus in chickens

Marek's disease is a contagious proliferative disease of chickens caused by an alphaherpesvirus called Marek's disease virus. A bivalent mRNA vaccine encoding MDV's glycoprotein-B and phosphoprotein-38 antigens was synthesized and encapsulated in lipid nanoparticles. Tumor incidence, lesion score, organ weight indices, MDV genome load and cytokine expression were used to evaluate protection and immunostimulatory effects of the tested mRNA vaccine after two challenge trials. Results from the first trial showed decreased tumor incidence and a reduction in average lesion scores in chickens that received the booster dose. The second trial demonstrated that vaccination with the higher dose of the vaccine (10 μg) significantly decreased tumor incidence, average lesion scores, bursal atrophy, and MDV load in feather tips when compared to the controls. Changes in expression of type I and II interferons suggested a possible role for these cytokines in initiation and maintenance of the vaccine-originated immune responses.

Self-assembled Cupric Oxide Nanoclusters for Highly efficient chemodynamic therapy

Chemodynamic therapy (CDT) based on Fenton and Fenton-like reactions induces cancer cell killing via in situ catalyzing H₂ O₂ and generating highly oxidative hydroxyl radicals (⋅OH) in tumor sites. Their application is not limited by tumor grown depth or hypoxic microenvironment. However, the reaction efficiency is still hampered due to the structure of catalytic agents and the requirement for low pH environment. Here, we design a porous CuO nanocluster (CuO NC) through self-assembly of oleylamine stabilized CuO NPs (OAm-CuO NPs), and functionalize it with folic acid (CuO NC-FA) for specific tumor cell targeting. It can catalyze H₂ O₂ with high efficiency in nearly neutral environment. Besides, the porous structure of CuO NC also helps the diffusion of H₂ O₂ to the interior of nanocluster to further improve Fenton-like reaction efficiency. The convenient synthesis of CuO NC-FA with good Fenton-like reaction efficiency at neutral environment demonstrates good chemodynamic therapy effect.

Self-Assembly of Copper-DNAzyme Nanohybrids for Dual-Catalytic Tumor Therapy

Despite the great efforts of using DNAzyme for gene therapy, its clinical success is limited by the lack of simple delivery systems and limited anticancer efficacy. Here, we develop a simple approach for the synthesis of hybrid nanostructures that exclusively consist of DNAzyme and Cu²⁺ with ultra-high loading capacity. The Cu-DNAzyme nanohybrids allow to effectively co-deliver DNAzyme and Cu²⁺ into cancer cells for combinational catalytic therapy. The released Cu²⁺ can be reduced to Cu⁺ by glutathione and then catalyze endogenous H₂ O₂ to form cytotoxic hydroxyl radicals for chemodynamic therapy (CDT), while the 10-23 DNAzyme enables the catalytic cleavage of VEGFR2 mRNA and activates gene silencing for gene therapy. We demonstrate that the system can efficiently accumulate in the tumor and exhibit amplified cascade antitumor effects with negligible systemic toxicity. Our work paves an extremely simple way to integrate DNAzyme with CDT for the dual-catalytic tumor treatment.

Core-shell FePt-cube@covalent organic polymer nanocomposites: a multifunctional nanocatalytic agent for primary and metastatic tumor treatment

Metastasis and spread are currently the main factors leading to high mortality of cancer, so developing a synergetic antitumor strategy with high specificity and hypotoxicity is in urgent demand. Based on the design concept of "nanocatalytic medicine", multifunctional nanotherapeutic agent FePt@COP-FA nanocomposites (FPCF NCs) are developed for cancer treatment. Specifically, in the tumor microenvironment (TME), FePt could catalyze intracellular over-expressed H2O2 to generate highly active hydroxyl radicals (˙OH), which could not only induce the apoptosis of tumor cells, but also activate the "ferroptosis" pathway resulting in the lipid peroxide accumulation and ferroptotic cell death. Moreover, owing to the excellent photothermal effect, the FPCF NCs could effectively ablate primary tumors under near-infrared (NIR) laser irradiation and produce numerous tumor-associated antigens in situ. With the assistance of a checkpoint blockade inhibitor, anti-CTLA4 antibody, the body's specific immune response would be initiated to inhibit the growth of metastatic tumors. In particular, such synergistic therapeutics could produce an effective immunological memory effect, which could prevent tumor metastasis and recurrence again. In summary, the FPCF NC is an effective multifunctional antitumor therapeutic agent for nanocatalytic/photothermal/checkpoint blockade combination therapy, which exhibits great potential in nanocatalytic anticancer therapeutic applications.

Reactive Oxygen Species-Regulating Strategies Based on Nanomaterials for Disease Treatment

Reactive oxygen species (ROS) play an essential role in physiological and pathological processes. Studies on the regulation of ROS for disease treatments have caused wide concern, mainly involving the topics in ROS-regulating therapy such as antioxidant therapy triggered by ROS scavengers and ROS-induced toxic therapy mediated by ROS-elevation agents. Benefiting from the remarkable advances of nanotechnology, a large number of nanomaterials with the ROS-regulating ability are developed to seek new and effective ROS-related nanotherapeutic modalities or nanomedicines. Although considerable achievements have been made in ROS-based nanomedicines for disease treatments, some fundamental but key questions such as the rational design principle for ROS-related nanomaterials are held in low regard. Here, the design principle can serve as the initial framework for scientists and technicians to design and optimize the ROS-regulating nanomedicines, thereby minimizing the gap of nanomedicines for biomedical application during the design stage. Herein, an overview of the current progress of ROS-associated nanomedicines in disease treatments is summarized. And then, by particularly addressing these known strategies in ROS-associated therapy, several fundamental and key principles for the design of ROS-associated nanomedicines are presented. Finally, future perspectives are also discussed in depth for the development of ROS-associated nanomedicines.

Redox Dyshomeostasis Strategy for Hypoxic Tumor Therapy Based on DNAzyme-Loaded Electrophilic ZIFs

Redox homeostasis is one of the main reasons for reactive oxygen species (ROS) tolerance in hypoxic tumors, limiting ROS-mediated tumor therapy. Proposed herein is a redox dyshomeostasis (RDH) strategy based on a nanoplatform, FeCysPW@ZIF-82@CAT Dz, to disrupt redox homeostasis, and its application to improve ROS-mediated hypoxic tumor therapy. Once endocytosed by tumor cells, the catalase DNAzyme (CAT Dz) loaded zeolitic imidazole framework-82 (ZIF-82@CAT Dz) shell can be degraded into Zn²⁺ as cofactors for CAT Dz mediated CAT silencing and electrophilic ligands for glutathione (GSH) depletion under hypoxia, both of which lead to intracellular RDH and H₂ O₂ accumulation. These "disordered" cells show reduced resistance to ROS and are effectively killed by ferrous cysteine-phosphotungstate (FeCysPW) induced chemodynamic therapy (CDT). In vitro and in vivo data demonstrate that the pH/hypoxia/H₂ O₂ triple stimuli responsive nanocomposite can efficiently kill hypoxic tumors. Overall, the RDH strategy provides a new way of thinking about ROS-mediated treatment of hypoxic tumors.

MnOx Nanospikes as Nanoadjuvants and Immunogenic Cell Death Drugs with Enhanced Antitumor Immunity and Antimetastatic Effect

Despite the widespread applications of manganese oxide nanomaterials (MONs) in biomedicine, the intrinsic immunogenicity of MONs is still unclear. MnO_x nanospikes (NSs) as tumor microenvironment (TME)-responsive nanoadjuvants and immunogenic cell death (ICD) drugs are proposed for cancer nanovaccine-based immunotherapy. MnO_x NSs with large mesoporous structures show ultrahigh loading efficiencies for ovalbumin and tumor cell fragment. The combination of ICD via chemodynamic therapy and ferroptosis inductions, as well as antigen stimulations, presents a better synergistic immunopotentiation action. Furthermore, the obtained nanovaccines achieve TME-responsive magnetic resonance/photoacoustic dual-mode imaging contrasts, while effectively inhibiting primary/distal tumor growth and tumor metastasis.

The siRNAsome: A Cation-Free and Versatile Nanostructure for siRNA and Drug Co-delivery

Nanoparticles show great potential for drug delivery. However, suitable nanostructures capable of loading a range of drugs together with the co-delivery of siRNAs, which avoid the problem of cation-associated cytotoxicity, are lacking. Herein, we report an small interfering RNA (siRNA)-based vesicle (siRNAsome), which consists of a hydrophilic siRNA shell, a thermal- and intracellular-reduction-sensitive hydrophobic median layer, and an empty aqueous interior that meets this need. The siRNAsome can serve as a versatile nanostructure to load drug agents with divergent chemical properties, therapeutic proteins as well as co-delivering immobilized siRNAs without transfection agents. Importantly, the inherent thermal/reduction-responsiveness enables controlled drug loading and release. When siRNAsomes are loaded with the hydrophilic drug doxorubicin hydrochloride and anti-P-glycoprotein siRNA, synergistic therapeutic activity is achieved in multidrug resistant cancer cells and a tumor model.

From one to all: self-assembled theranostic nanoparticles for tumor-targeted imaging and programmed photoactive therapy

Background

In recent years, multifunctional theranostic nanoparticles have been fabricated by integrating imaging and therapeutic moieties into one single nano-formulations. However, Complexity of production and safety issues limits their further application.

Results

Herein, we demonstrated self-assembled nanoparticles with single structure as a “from one to all” theranostic platform for tumor-targeted dual-modal imaging and programmed photoactive therapy (PPAT). The nanoparticles were successfully developed through self-assembling of hyaluronic acid (HA)-cystamine-cholesterol (HSC) conjugate, in which IR780 was simultaneously incorporated (HSCI NPs). Due to the proper hydrodynamic size and intrinsic targeting ability of HA, the HSCI NPs could accumulate at the tumor site effectively after systemic administration. In the presence of incorporated IR780, in vivo biodistribution and accumulation behaviors of HSCI NPs could be monitored by photoacoustic imaging. After cellular uptake, the HSCI NPs would disintegrate resulting from cystamine reacting with over-expressed GSH. The released IR780 would induce fluorescence “turn-on” conversion, which could be used to image tumor sites effectively. Upon treatment with 808 nm laser irradiation, PPAT could be achieved in which generated reactive oxygen species (ROS) would produce photodynamic therapy (PDT), and subsequently the raised temperature would be beneficial to tumor photothermal therapy (PTT).

Conclusion

The self-assembled HSCI NPs could act as “from one to all” theranostic platform for high treatment efficiency via PPAT pattern, which could also real-time monitor NPs accumulation by targeted and dual-modal imaging in a non-invasive way.

Electronic supplementary material

The online version of this article (10.1186/s12951-019-0450-x) contains supplementary material, which is available to authorized users.

Cancer Treatment through Nanoparticle-Facilitated Fenton Reaction

Currently, cancer is the second largest cause of death worldwide and has reached critical levels. In spite of all the efforts, common treatments including chemotherapy, photodynamic therapy, and photothermal therapy suffer from various problems which limit their efficiency and performance. For this reason, different strategies are being explored which improve the efficiency of these traditional therapeutic methods or treat the tumor cells directly. One such strategy utilizing the Fenton reaction has been investigated by many groups for the possible treatment of cancer cells. This approach is based on the knowledge that high levels of hydrogen peroxide exist within cancer cells and can be used to catalyze the Fenton reaction, leading to cancer-killing reactive oxygen species. Analysis of the current literature has shown that, due to the diverse morphologies, different sizes, various chemical properties, and the tunable structure of nanoparticles, nanotechnology offers the most promising method to facilitate the Fenton reaction with cancer therapy. This review aims to highlight the use of the Fenton reaction using different nanoparticles to improve traditional cancer therapies and the emerging Fenton-based therapy, highlighting the obstacles, challenges, and promising developments in each of these areas.