Manganese nanodepot augments host immune response against coronavirus

Impact of inorganic/organic nanomaterials on the immune system for disease treatment

The study of nanomaterials' nature, function, and biocompatibility highlights their potential in drug delivery, imaging, diagnostics, and therapeutics. Advancements in nanotechnology have fostered the development and application of diverse nanomaterials. These materials facilitate drug delivery and influence the immune system directly. Yet, understanding of their impact on the immune system is incomplete, underscoring the need to select materials to achieve desired outcomes carefully. In this review, we outline and summarize the distinctive characteristics and effector functions of inorganic nanomaterials and organic materials in inducing immune responses. We highlight the role and advantages of nanomaterial-induced immune responses in the treatment of immune-related diseases. Finally, we briefly discuss the current challenges and future opportunities for disease treatment and clinical translation of these nanomaterials.

An Overview of Nanoparticle-Based Delivery Platforms for mRNA Vaccines for Treating Cancer

With its unique properties and potential applications, nanoparticle-based delivery platforms for messenger RNA (mRNA) vaccines have gained significant attention in recent years. Nanoparticles have the advantages of enhancing immunogenicity, targeting delivery, and improving stability, providing a new solution for drug and vaccine delivery. In some clinical studies, a variety of nanoparticle delivery platforms have been gradually applied to a wide range of vaccine applications. Current research priorities are exploring various types of nanoparticles as vaccine delivery systems to enhance vaccine stability and immunogenicity. Lipid nanoparticles (LNPs) have shown promising potential in preclinical and clinical studies on the efficient delivery of antigens to immune cells. Moreover, lipid nanoparticles and other nanoparticles for nucleic acids, especially for mRNA delivery systems, have shown vast potential for vaccine development. In this review, we present various vaccine platforms with an emphasis on nanoparticles as mRNA vaccine delivery vehicles. We describe several novel nanoparticle delivery platforms for mRNA vaccines, such as lipid-, polymer-, and protein-based nanoparticles. In addition, we provide an overview of the anti-tumor immunity of nanovaccines against different tumors in cancer immunotherapy. Finally, we outline future perspectives and remaining challenges for this promising technology of nanoparticle-based delivery platforms for vaccines.

Spontaneous Fusion of Core-Shell Nanocapsules with Oil Cores and Oppositely Charged Polysaccharide Shells

Polymer nanocapsules with hydrophobic cores are promising candidates for nanoreactors to carry out (bio)chemical reactions mimicking the performance of natural cellular systems. Their architecture allows reagents to be encapsulated in the cores enabling reactions to proceed in confined environments in a controlled, and efficient manner. Polysaccharide-shell oil-core nanocapsules are proposed here as facile mergeable nanoreactors. Spontaneous fusion of oppositely charged polysaccharide capsules is demonstrated for the first time. Such capsules are formed and easily loaded with reagents by nanoemulsification of an aqueous solution of hydrophobically modified polysaccharides (chitosan, hyaluronate) and oleic acid with dissolved desired hydrophobic compounds. Efficient fusion of the formed nanocapsules dispersed in an aqueous medium at optimized conditions (pH, ionic strength) is followed using fluorescence microscopy by labeling both their cores and shells with fluorescent dyes. As a proof of concept, a model fluorogenic synthesis is also realized by fusing the capsules containing separated reagents and the catalyst. The nanocapsules and fusion process developed here establish a platform for realization of versatile reactions in a confined environment including model studies on biologically relevant processes taking place in natural systems.

A xanthan gum and carbomer-codispersed divalent manganese ion-loaded tannic acid nanoparticle adjuvanted inactivated pseudorabies virus vaccine induces balanced humoral and cellular immune responses

Adjuvants including aluminum adjuvant (Alum) and oil-water emulsion have been widely used in inactivated pseudorabies virus (PRV) vaccines to improve their performance, however, they are not sufficient to protect from PRV infection because of the weak immune response and poor Th1-type immune response. Divalent manganese ion (Mn2+) has been reported to increase the cellular immune response significantly. In this work, a xanthan gum and carbomer-dispersed Mn2+-loaded tannic acid-polyethylene glycol (TPMnXC) nanoparticle colloid is developed and used as an adjuvant to improve the performance of the inactivated PRV vaccine. The good in vitro and in vivo biocompatibility of the developed TPMnXC colloid has been confirmed by the cell viability assay, erythrocyte hemolysis, blood routine analysis, and histological analysis of mouse organs and injection site. The TPMnXC-adjuvanted inactivated PRV vaccine (TPMnXC@PRV) significantly promotes higher and more balanced immune responses indicating with an increased specific total IgG antibody and IgG2a/IgG1 ratio, efficient splenocytes proliferation, and elevated Th1- and Th2-type cytokine secretion than those of control groups. Wild PRV challenge experiment is performed using mice as a model animal, achieving a protection rate of up to 86.67 %, which is much higher than those observed from the commercial Alum. This work not only demonstrates the high potentiality of TPMnXC in practical applications but also provides a new way to develop the Mn2+-loaded nanoadjuvant for veterinary vaccines.

Revolutionizing Neurocare: Biomimetic Nanodelivery Via Cell Membranes

Brain disorders represent a significant challenge in medical science due to the formidable blood-brain barrier (BBB), which severely limits the penetration of conventional therapeutics, hindering effective treatment strategies. This review delves into the innovative realm of biomimetic nanodelivery systems, including stem cell-derived nanoghosts, tumor cell membrane-coated nanoparticles, and erythrocyte membrane-based carriers, highlighting their potential to circumvent the BBB's restrictions. By mimicking native cell properties, these nanocarriers emerge as a promising solution for enhancing drug delivery to the brain, offering a strategic advantage in overcoming the barrier's selective permeability. The unique benefits of leveraging cell membranes from various sources is evaluated and advanced technologies for fabricating cell membrane-encapsulated nanoparticles capable of masquerading as endogenous cells are examined. This enables the targeted delivery of a broad spectrum of therapeutic agents, ranging from small molecule drugs to proteins, thereby providing an innovative approach to neurocare. Further, the review contrasts the capabilities and limitations of these biomimetic nanocarriers with traditional delivery methods, underlining their potential to enable targeted, sustained, and minimally invasive treatment modalities. This review is concluded with a perspective on the clinical translation of these biomimetic systems, underscoring their transformative impact on the therapeutic landscape for intractable brain diseases.

A Unique Combination of Mn2+ and Aluminum Adjuvant Acted the Synergistic Effect

Introduction

The development of combinatorial adjuvants is a promising strategy to boost vaccination efficiency. Accumulating evidence indicates that manganese exerts strong immunocompetence and will become an enormous potential adjuvant. Here, we described a novel combination of Mn2+ plus aluminum hydroxide (AH) adjuvant that significantly exhibited the synergistic immune effect. Methodology. Initially, IsdB3 proteins as the immune-dominant fragment of IsdB proteins derived from Staphylococcus aureus (S. aureus) were prepared. IsdB3 proteins were identified by western blotting. Furthermore, we immunized C57/B6 mice with IsdB3 proteins plus Mn2+ and AH adjuvant. After the second immunization, the proliferation of lymphocytes was measured by the cell counting kit-8 (CCK-8) and the level of IFN-γ, IL-4, IL-10, and IL-17 cytokine from spleen lymphocytes in mice and generation of the antibodies against IsdB3 in serum was detected with ELISA, and the protective immune response was assessed through S. aureus challenge.

Results

IsdB3 proteins plus Mn2+ and AH obviously stimulated the proliferation of spleen lymphocytes and increased the secretion of IFN-γ, IL-4, IL-10, and IL-17 cytokine in mice, markedly enhanced the generation of the antibodies against IsdB3 in serum, observably decreased bacterial load in organs, and greatly improved the survival rate of mice.

Conclusion

These data showed that the combination of Mn2+ and AH significantly acted a synergistic effect, reinforced the immunogenicity of IsdB3, and offered a new strategy to increase vaccine efficiency.

In situ bio-mineralized Mn nanoadjuvant enhances anti-influenza immunity of recombinant virus-like particle vaccines

Virus like particles (VLPs) have been well recognized as one of the most important vaccine platforms due to their structural similarity to natural viruses to induce effective humoral and cellular immune responses. Nevertheless, lack of viral nucleic acids in VLPs usually leads the vaccine candidates less efficient in provoking innate immune against viral infection. Here, we constructed a biomimetic dual antigen hybrid influenza nanovaccines THM-HA@Mn with robust immunogenicity via in situ synthesizing a stimulator of interferon genes (STING) agonist Mn3O4 inside the cavity of a recombinant Hepatitis B core antigen VLP (HBc VLP) having fused SpyTag and influenza M2e antigen peptides (Tag-HBc-M2e, THM for short), followed by conjugating a recombinant hemagglutinin (rHA) antigen on the surface of the nanoparticles through SpyTag/SpyCatcher ligating. Such inside Mn3O4 immunostimulator-outside rHA antigen design, together with the chimeric M2e antigen on the HBc skeleton, enabled the synthesized hybrid nanovaccines THM-HA@Mn to well imitate the spatial distribution of M2e/HA antigens and immunostimulant in natural influenza virus. In vitro cellular experiments indicated that compared with the THM-HA antigen without Mn3O4 and a mixture vaccine consisting of THM-HA + MnOx, the THM-HA@Mn hybrid nanovaccines showed the highest efficacies in dendritic cells uptake and in promoting BMDC maturation, as well as inducing expression of TNF-α and type I interferon IFN-β. The THM-HA@Mn also displayed the most sustained antigen release at the injection site, the highest efficacies in promoting the DC maturation in lymph nodes and germinal center B cells activation in the spleen of the immunized mice. The co-delivery of immunostimulant and antigens enabled the THM-HA@Mn nanovaccines to induce the highest systemic antigen-specific antibody responses and cellular immunogenicity in mice. Together with the excellent colloid dispersion stability, low cytotoxicity, as well as good biosafety, the synthetic hybrid nanovaccines presented in this study offers a promising strategy to design VLP-based vaccine with robust natural and adaptive immunogenicity against emerging viral pathogens.

Nanovaccines for Advancing Long-Lasting Immunity against Infectious Diseases

Infectious diseases, particularly life-threatening pathogens such as small pox and influenza, have substantial implications on public health and global economies. Vaccination is a key approach to combat existing and emerging pathogens. Immunological memory is an essential characteristic used to evaluate vaccine efficacy and durability and the basis for the long-term effects of vaccines in protecting against future infections; however, optimizing the potency, improving the quality, and enhancing the durability of immune responses remains challenging and a focus for research involving investigation of nanovaccine technologies. In this review, we describe how nanovaccines can address the challenges for conventional vaccines in stimulating adaptive immune memory responses to protect against reinfection. We discuss protein and nonprotein nanoparticles as useful antigen platforms, including those with highly ordered and repetitive antigen array presentation to enhance immunogenicity through cross-linking with multiple B cell receptors, and with a focus on antigen properties. In addition, we describe how nanoadjuvants can improve immune responses by providing enhanced access to lymph nodes, lymphnode targeting, germinal center retention, and long-lasting immune response generation. Nanotechnology has the advantage to facilitate vaccine induction of long-lasting immunity against infectious diseases, now and in the future.

Manganese-Based Nanoparticle Vaccine for Combating Fatal Bacterial Pneumonia

Bacterial pneumonia is the leading cause of death worldwide among all infectious diseases. However, currently available vaccines against fatal bacterial lung infections, e.g., pneumonic plague, are accompanied by limitations, including insufficient antigen-adjuvant co-delivery and inadequate immune stimulation. Therefore, there is an urgent requirement to develop next-generation vaccines to improve the interaction between antigen and adjuvant, as well as enhance the effects of immune stimulation. This study develops a novel amino-decorated mesoporous manganese silicate nanoparticle (AMMSN) loaded with rF1-V10 (rF1-V10@AMMSN) to prevent pneumonic plague. These results suggest that subcutaneous immunization with rF1-V10@AMMSN in a prime-boost strategy induces robust production of rF1-V10-specific IgG antibodies with a geometric mean titer of 315,844 at day 42 post-primary immunization, which confers complete protection to mice against 50 × LD50 of Yersinia pestis (Y. pestis) challenge via the aerosolized intratracheal route. Mechanistically, rF1-V10@AMMSN can be taken up by dendritic cells (DCs) and promote DCs maturation through activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway and production of type I interferon. This process results in enhanced antigen presentation and promotes rF1-V10-mediated protection against Y. pestis infection. This manganese-based nanoparticle vaccine represents a valuable strategy for combating fatal bacterial pneumonia.

Engineering core-shell chromium nanozymes with inflammation-suppressing, ROS-scavenging and antibacterial properties for pulpitis treatment

Oral diseases are usually caused by inflammation and bacterial infection. Reactive oxygen species (ROS), which come from both autologous inflammation tissue and bacterial infection, play an important role in this process. Thus, the elimination of excessive intracellular ROS can be a promising strategy for anti-inflammatory treatment. With the rapid development of nanomedicines, nanozymes, which can maintain the intracellular redox balance and protect cells against oxidative damage, have shown great application prospects in the treatment of inflammation-related diseases. However, their performance in pulpitis and their related mechanisms have yet to be explored. Herein, we prepared dozens of metallic nanoparticles with core-shell structures, and among them, chromium nanoparticles (NanoCr) were selected for their great therapeutic potential for pulpitis disease. NanoCr showed a broad antibacterial spectrum and strong anti-inflammatory function. Antibacterial assays showed that NanoCr could effectively inhibit a variety of common pathogens of oral infection. In vitro experiments offered evidence of the multienzyme activity of NanoCr and its function in suppressing ROS-induced inflammation reactions. The experimental results show that NanoCr has optimal antibacterial and anti-inflammatory properties in in vitro cell models, showing great potential for the treatment of pulpitis. Therefore, the use of NanoCr could become a new therapeutic strategy for clinical pulpitis.

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

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

Vaccine adjuvants: mechanisms and platforms

Adjuvants are indispensable components of vaccines. Despite being widely used in vaccines, their action mechanisms are not yet clear. With a greater understanding of the mechanisms by which the innate immune response controls the antigen-specific response, the adjuvants' action mechanisms are beginning to be elucidated. Adjuvants can be categorized as immunostimulants and delivery systems. Immunostimulants are danger signal molecules that lead to the maturation and activation of antigen-presenting cells (APCs) by targeting Toll-like receptors (TLRs) and other pattern recognition receptors (PRRs) to promote the production of antigen signals and co-stimulatory signals, which in turn enhance the adaptive immune responses. On the other hand, delivery systems are carrier materials that facilitate antigen presentation by prolonging the bioavailability of the loaded antigens, as well as targeting antigens to lymph nodes or APCs. The adjuvants' action mechanisms are systematically summarized at the beginning of this review. This is followed by an introduction of the mechanisms, properties, and progress of classical vaccine adjuvants. Furthermore, since some of the adjuvants under investigation exhibit greater immune activation potency than classical adjuvants, which could compensate for the deficiencies of classical adjuvants, a summary of the adjuvant platforms under investigation is subsequently presented. Notably, we highlight the different action mechanisms and immunological properties of these adjuvant platforms, which will provide a wide range of options for the rational design of different vaccines. On this basis, this review points out the development prospects of vaccine adjuvants and the problems that should be paid attention to in the future.

Antioxidant and Immune-Related Implications of Minerals in COVID-19: A Possibility for Disease Prevention and Management

Since the coronavirus disease 2019 (COVID-19) pandemic appeared, both governments and the scientific community have focused their efforts on the search for prophylactic and therapeutic alternatives in order to reduce its effects. Vaccines against SARS-CoV-2 have been approved and administered, playing a key role in the overcoming of this situation. However, they have not reached the whole world population, and several doses will be needed in the future in order to successfully protect individuals. The disease is still here, so other strategies should be explored with the aim of supporting the immune system before and during the infection. An adequate diet is certainly associated with an optimal inflammatory and oxidative stress status, as poor levels of different nutrients could be related to altered immune responses and, consequently, an augmented susceptibility to infections and severe outcomes derived from them. Minerals exert a wide range of immune-modulatory, anti-inflammatory, antimicrobial, and antioxidant activities, which may be useful for fighting this illness. Although they cannot be considered as a definitive therapeutic solution, the available evidence to date, obtained from studies on similar respiratory diseases, might reflect the rationality of deeper investigations of the use of minerals during this pandemic.

Nanovaccines Fostering Tertiary Lymphoid Structure to Attack Mimicry Nasopharyngeal Carcinoma

Tertiary lymphoid structures (TLSs) are formed in inflamed tissues, and recent studies demonstrated that the appearance of TLSs in tumor sites is associated with a good prognosis for tumor patients. However, the process of natural TLSs' formation was slow and uncontrollable. Herein, we developed a nanovaccine consisting of Epstein-Barr virus nuclear antigen 1 (EBNA1) and a bi-adjuvant of Mn²⁺ and cytosine-phosphate-guanine (CpG) formulated with tannic acid that significantly inhibited the development of mimicry nasopharyngeal carcinoma by fostering TLS formation. The nanovaccine activated LT-α and LT-β pathways, subsequently enhancing the expression of downstream chemokines, CCL19/CCL21, CXCL10 and CXCL13, in the tumor microenvironment. In turn, normalized blood and lymph vessels were detected in the tumor tissues of the nanovaccine group, correlated with increased infiltration of lymphocytes. Especially, the proportion of the B220⁺ CD8⁺ T, which was produced via trogocytosis between T and B cells during activation of T cells, was increased in tumors of the nanovaccine group. Furthermore, the intratumoral effector memory T cells (Tem), CD45⁺, CD3⁺, CD8⁺, CD44⁺, and CD62L^-, did not decrease after blocking the egress of T cells from tumor-draining lymph nodes by FTY-720. These results demonstrated that the nanovaccine can foster TLS formation, which thus enhances local immune responses significantly, delays tumor outgrowth, and prolongs the median survival time of murine models of mimicry nasopharyngeal carcinoma, demonstrating a promising strategy for nanovaccine development.

pH-Sensitive and Biodegradable Mn3(PO4)2·3H2O Nanoparticles as an Adjuvant of Protein-Based Bivalent COVID-19 Vaccine to Induce Potent and Broad-Spectrum Immunity

Developing a novel and potent adjuvant with great biocompatibility for immune response augmentation is of great significance to enhance vaccine efficacy. In this work, we prepared a long-term stable, pH-sensitive, and biodegradable Mn3(PO4)2·3H2O nanoparticle (nano-MnP) by simply mixing MnCl2/NaH2PO4/Na2HPO4 solution for the first time and employed it as an immune stimulant in the bivalent COVID-19 protein vaccine comprised of wild-type S1 (S1-WT) and Omicron S1 (S1-Omicron) proteins as antigens to elicit a broad-spectrum immunity. The biological experiments indicated that the nano-MnP could effectively activate antigen-presenting cells through the cGAS-STING pathway. Compared with the conventional Alum-adjuvanted group, the nano-MnP-adjuvanted bivalent vaccine elicited approximately 7- and 8-fold increases in IgG antibody titers and antigen-specific IFN-γ secreting T cells, respectively. Importantly, antisera of the nano-MnP-adjuvanted group could effectively cross-neutralize the SARS-CoV-2 and its five variants of concern (VOCs) including Alpha, Beta, Gamma, Delta, and Omicron, demonstrating that this bivalent vaccine based on S1-WT and S1-Omicron proteins is an effective vaccine design strategy to induce broad-spectrum immune responses. Collectively, this nano-MnP material may provide a novel and efficient adjuvant platform for various prophylactic and therapeutic vaccines and provide insights for the development of the next-generation manganese adjuvant.

Immunomodulatory activity of manganese dioxide nanoparticles: Promising for novel vaccines and immunotherapeutics

Manganese (Mn), a nutrient inorganic trace element, is necessary for a variety of physiological processes of animal body due to their important roles in oxidative regulation effects and other aspects of activities. Moreover, manganese ion (Mn²⁺) has widely reported to be crucial for the regulations of different immunological responses, thus showing promising application as potential adjuvants and immunotherapeutics. Taking the advantages of Mn-based biological and immunological activities, Manganese dioxide nanoparticles (MnO₂ NPs) are a new type of inorganic nanomaterials with numerous advantages, including simple preparation, low cost, environmental friendliness, low toxicity, biodegradable metabolism and high bioavailability. MnO₂ NPs, as a kind of drug carrier, have also shown the ability to catalyze hydrogen peroxide (H₂O₂) to produce oxygen (O₂) under acidic conditions, which can enhance the efficacy of radiotherapy, chemotherapy and other therapeutics for tumor treatment by remodeling the tumor microenvironment. More importantly, MnO₂ NPs also play important roles in immune regulations both in innate and adaptive immunity. In this review, we summarize the biological activities of Manganese, followed by the introduction for the biological and medical functions and mechanisms of MnO₂ NPs. What's more, we emphatically discussed the immunological regulation effects and mechanisms of MnO₂ NPs, as well as their potentials to serve as adjuvants and immunomodulators, which might benefit the development of novel vaccines and immunotherapies for more effective disease control.

Progress of cGAS-STING signaling in response to SARS-CoV-2 infection

Coronavirus disease 2019 (COVID-19) is an epidemic respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that can cause infections in millions of individuals, who can develop lung injury, organ failure, and subsequent death. As the first line of host defense, the innate immune system is involved in initiating the immune response to SARS-CoV-2 infection and the hyperinflammatory phenotype of COVID-19. However, the interplay between SARS-CoV-2 and host innate immunity is not yet well understood. It had become known that the cGAS-STING pathway is involved in the detection of cytosolic DNA, which elicits an innate immune response involving a robust type I interferon response against viral and bacterial infections. Nevertheless, several lines of evidence indicate that SARS-CoV-2, a single-stranded positive-sense RNA virus, triggered the cGAS-STING signaling pathway. Therefore, understanding the molecular and cellular details of cGAS-STING signaling upon SARS-CoV-2 infection is of considerable biomedical importance. In this review, we discuss the role of cGAS-STING signaling in SARS-CoV-2 infection and summarize the potential therapeutics of STING agonists as virus vaccine adjuvants.

Mangasese doped polypyrole nanoparticels for photothermal/chemodynamic therapy and immune activation

Photothermal therapy (PTT) is a promising treatment that efficiently suppresses local cancer, but fails to induce a robust antitumor immune response against tumor metastasis and recurrence. In this study, a NIR responsive nano-immunostimulant (Mn/A-HP NI) is fabricated by entrapping manganese and azo-initiator (AIPH) into hyaluronic acid-based polypyrrole nanoparticle. The as-prepared Mn/A-HP NIs with a high photothermal conversion efficiencey of 20.17% dramatically induced the imunogenic cell death of tumor cells and triggered the release ATP and HMGB1. Meanwhile, the hyperthermia induced AIPH decomposition to produce alkyl radicals which further destroyed cancer cells. Furthermore, the Mn/A-HP NIs were capable of promoting the maturation and antigen cross-presentation ability of dendritic cells. Consequently, the multifunctional Mn/A-HP NIs provided a combined treatment via integrating PTT/chemo-dynamic therapy and immune activation for tumor therapy.

Manganese-based nanoadjuvants for enhancement of immune effect of DNA vaccines

As a highly pathogenic avian influenza virus, influenza A (H5N1) has been reported to infect humans, posing a major threat to both poultry industry and public health. It is an urgent need to develop a kind of effective vaccine to prevent death and reduce the incidence rate of H5N1 avian influenza. Compared with traditional inactivated or attenuated vaccines, deoxyribonucleic (DNA) vaccines have the advantages of continuously expressing plasmid-encoded antigens and inducing humoral and cellular immunity. However, the immune effect of DNA vaccines is limited to its poor immunogenicity. Using of nanoadjuvants with DNA vaccines holds a great promise to increase the transfection efficiency and immunogenicity of DNA vaccines. In this study, we developed a nano co-delivery system with a manganese-based liposome as adjuvant for delivery of a DNA vaccine. This system has been found to protect DNA vaccine, enhance phagocytosis as well as promote activation of antigen-presenting cells (APCs) and immune cells in draining lymph nodes. In addition, the effect of this nanovaccine has been evaluated in mouse models, where it induces highly potent hemagglutination inhibitory antibody (HI) and IgG antibodies, while activating both humoral and cellular immunity in the host. Overall, this strategy opens up a new prospect for manganese nanoadjuvants in increasing the immunogenicity of DNA vaccines.

Tumor microenvironment regulation - enhanced radio - immunotherapy

Radiotherapy (RT) is frequently utilized for cancer treatment in clinical practice and has been proved to have immune stimulation potency in recent years. However, its inhibitory effect on tumor growth, especially on tumor metastasis, is still limited by many factors, including the complex tumor microenvironment (TME). Therefore, the TME - regulating SiO₂@MnO₂ nanoparticles (SM NPs) were prepared and applied to the combination of RT and immunotherapy. In a bilateral animal model, SM NPs not only enhanced the inhibitory effect of RT on primary tumor growth, but also strengthened the abscopal effect to inhibit the growth of distant untreated tumors. As for the distant untreated tumor, 40% of mice showed complete inhibition of tumor growth and 40% showed a suppressed tumor growth. Moreover, SM NPs showed modulation functions for TME through inducing the increase in intracellular levels of oxygen and reactive oxygen species after their reaction with hydrogen peroxide and the main antioxidative agent glutathione in TME. Lastly, SM NPs also effectively induced the increase in the amounts of cytokines secreted by macrophage - like cells, indicating modulation functions for immune responses. This work highlighted a potential strategy of simultaneously inhibiting tumor growth and metastasis through the regulation of TME and immune responses by SM NPs - enhanced radio - immunotherapy.

Metallic Implants Used in Lumbar Interbody Fusion

Over the last decade, pedicle fixation systems have evolved and modifications in spinal fusion techniques have been developed to increase fusion rates and improve clinical outcomes after lumbar interbody fusion (LIF). Regarding materials used for screw and rod manufacturing, metals, especially titanium alloys, are the most popular resources. In the case of pedicle screws, that biomaterial can be also doped with hydroxyapatite, CaP, ECM, or tantalum. Other materials used for rod fabrication include cobalt-chromium alloys and nitinol (nickel-titanium alloy). In terms of mechanical properties, the ideal implant used in LIF should have high tensile and fatigue strength, Young's modulus similar to that of the bone, and should be 100% resistant to corrosion to avoid mechanical failures. On the other hand, a comprehensive understanding of cellular and molecular pathways is essential to identify preferable characteristics of implanted biomaterial to obtain fusion and avoid implant loosening. Implanted material elicits a biological response driven by immune cells at the site of insertion. These reactions are subdivided into innate (primary cellular response with no previous exposure) and adaptive (a specific type of reaction induced after earlier exposure to the antigen) and are responsible for wound healing, fusion, and also adverse reactions, i.e., hypersensitivity. The main purposes of this literature review are to summarize the physical and mechanical properties of metal alloys used for spinal instrumentation in LIF which include fatigue strength, Young's modulus, and corrosion resistance. Moreover, we also focused on describing biological response after their implantation into the human body. Our review paper is mainly focused on titanium, cobalt-chromium, nickel-titanium (nitinol), and stainless steel alloys.

Effect of Different Adjuvants on Immune Responses Elicited by Protein-Based Subunit Vaccines against SARS-CoV-2 and Its Delta Variant

The global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become more serious because of the continuous emergence of variants of concern (VOC), thus calling for the development of broad-spectrum vaccines with greater efficacy. Adjuvants play important roles in enhancing the immunogenicity of protein-based subunit vaccines. In this study, we compared the effect of three adjuvants, including aluminum, nanoparticle manganese and MF59, on the immunogenicity of three protein-based COVID-19 vaccine candidates, including RBD-Fc, RBD and S-trimer. We found that the nanoparticle manganese adjuvant elicited the highest titers of SARS-CoV-2 RBD-specific IgG, IgG1 and IgG2a, as well as neutralizing antibodies against infection by pseudotyped SARS-CoV-2 and its Delta variant. What is more, the nanoparticle manganese adjuvant effectively reduced the viral load of the authentic SARS-CoV-2 and Delta variant in the cell culture supernatants. These results suggest that nanoparticle manganese, known to facilitate cGAS-STING activation, is an optimal adjuvant for protein-based COVID-19 subunit vaccines.

A Perspective on the Roles of Adjuvants in Developing Highly Potent COVID-19 Vaccines

Several countries have made unremitting efforts to develop an optimal vaccine in the fight against coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the increasing occurrence of SARS-CoV-2 variants, current vaccines show decreased neutralizing activities, especially towards the Omicron variant. In this context, adding appropriate adjuvants to COVID-19 vaccines can substantially reduce the number of required doses and improve efficacy or cross-neutralizing protection. We mainly focus on research progress and achievements associated with adjuvanted COVID-19 subunit and inactivated vaccines. We further compare the advantages and disadvantages of different adjuvant formulations in order to provide a scientific reference for designing an effective strategy for future vaccine development.

Nanoagent-based theranostic strategies against human coronaviruses

The emergence of human coronaviruses (HCoVs), especially the current pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), engender severe threats to public health globally. Despite the outstanding breakthrough of new vaccines and therapeutic medicines in the past years, HCoVs still undergo unpredictable mutations, thus demanding more effective diagnostic and therapeutic strategies. Benefitting from the unique physicochemical properties and multiple nano-bio interactions, nanomaterials hold promising potential to fight against various HCoVs, either by providing sensitive and economic nanosensors for rapid viral detection, or by developing translatable nanovaccines and broad-spectrum nanomedicines for HCoV treatment. Herein, we systemically summarized the recent applications of nanoagents in diagnostics and therapeutics for HCoV-induced diseases, as well as their limitations and perspectives against HCoV variants. We believe this review will promote the design of innovative theranostic nanoagents for the current and future HCoV-caused pandemics.

SARS-CoV-2 subunit vaccine adjuvants and their signaling pathways

INTRODUCTION

Vaccines are the agreed upon weapon against the COVID-19 pandemic. This review discusses about COVID-19 subunit vaccines adjuvants and their signaling pathways, which could provide a glimpse into the selection of appropriate adjuvants for prospective vaccine development studies.

AREAS COVERED

In the introduction, a brief background about the SARS-CoV-2 pandemic, the vaccine development race and classes of vaccine adjuvants were provided. . The antigen, trial stage, and types of adjuvants were extracted from the included articles and thun assimilated. Finally, the pattern recognition receptors (PRRs), their classes, cognate adjuvants, and potential signaling pathways were comprehended.

EXPERT OPINION

Adjuvants are unsung heroes of subunit vaccines. The in silico studies are very vital in avoiding several costly trial errors and save much work times. The majority of the (pre)clinical studies are promising. It is encouraging that most of the selected adjuvants are novel. Much emphasis must be paid to the optimal paring of antigen-adjuvant-PRRs for obtaining the desired vaccine effect. A good subunit vaccine/adjuvant is one that has high efficacy, safety, dose sparing, and rapid seroconversion rate and broad spectrum of immune response. In the years to come, COVID-19 adjuvanted subunit vaccines are expected to have superior utility than any other vaccines for various reasons.

A polymeric co-assembly of subunit vaccine with polyoxometalates induces enhanced immune responses

Long-lasting protective immune responses are expected following vaccination. However, most vaccines alone are inability to evoke an efficient protection. The combinatory administration of adjuvants with vaccines is critical for generating the enhanced immune responses. Herein, with biocompatible poly(4-vinylpyridine) (P4VP) as template, 2.5 nm iron/molybdenum oxide cluster, {Mo72Fe30}, is applied as an adjuvant to co-assemble with antigens of Mycobacterium bovis via hydrogen bonding at molecular scale. Molecular scale integration of the antigens and {Mo72Fe30} and their full exposure to body fluid media contribute to the augmentation of both humoral and cellular immune responses of the vaccines after inoculation in mice. Anti-inflammatory factor IL-10 gradually increases after 2 weeks followed by a final back to normal level by the 5th week. The balance between proinflammatory cytokines and anti-inflammatory factors suggests that immune system can be activated in the early stage of infection by the antigens carried by the supra-particles and secrete acute inflammatory factors for host defense and antiinflammatory factors for immune protection.

Electronic Supplementary Material

Supplementary material (further structural analysis and biological analsyis) is available in the online version of this article at 10.1007/s12274-021-4004-9.

A magnetic resonance nanoprobe with STING activation character collaborates with platinum-based drug for enhanced tumor immunochemotherapy

BACKGROUND

Immunochemotherapy is a potent anti-tumor strategy, however, how to select therapeutic drugs to enhance the combined therapeutic effect still needs to be explored. METHODS AND RESULTS: Herein, a magnetic resonance nanoprobe (MnP@Lip) with STING (Stimulator of INterferon Genes) activation character was synthesized and co-administered with platinum-based chemotherapeutics for enhanced immunochemotherapy. MnP@Lip nanoparticles was prepared by simple fabrication process with good reproducibility, pH-sensitive drug release behavior and biocompatibility. In vitro experiments elucidated that Mn²⁺ can promote the polarization of M0 and/or M2 macrophages to M1 phenotype, and promote the maturation of BMDC cells. Upon Mn²⁺ treatment, the STING pathway was activated in tumor cells, mouse lung epithelial cells, and immune cells. More importantly, anti-tumor experiments in vivo proved that MnP@Lip combined with platinum-based chemotherapeutics increased T cells infiltration in the tumor microenvironment, and inhibited tumor growth in the orthotopic therapeutic and postoperative tumor models.

CONCLUSIONS

This kind of therapeutic strategy that combined MnP@Lip nanoparticles with platinum-based chemotherapeutics may provide a novel insight for immunochemotherapy.

Recent Advances on Nanomaterials to COVID-19 Management: A Systematic Review on Antiviral/Virucidal Agents and Mechanisms of SARS-CoV-2 Inhibition/Inactivation

The current pandemic of coronavirus disease 2019 (COVID-19) is recognized as a public health emergency of worldwide concern. Nanomaterials can be effectively used to detect, capture/inactivate or inhibit coronavirus cell entry/replication in the human host cell, preventing infection. Their potential for nanovaccines, immunoengineering, diagnosis, repurposing medication, and disinfectant surfaces targeting the novel coronavirus (SARS-CoV-2) is highlighted. In this systematic review the aim is to present an unbiased view of which and how nanomaterials can reduce the spread of COVID-19. Herein, the focus is on SARS-CoV-2, analyzing 46 articles retrieved before December 31, 2020. The interface between nanomaterials is described, and the main mechanisms to inhibit SARS-CoV-2 pathogenesis and viral inactivation are also discussed. Nanocarbons, biopolymeric, copper, and silver nanoparticles are potential antiviral and virucidal agents toward self-cleaning and reusable filter media and surfaces (e.g., facial masks), drug administration, vaccines, and immunodiagnostic assays. Trends in toxicology research and safety tests can help fill the main gaps in the literature and overcome health surveillance's challenges. Phytochemicals delivery by nanocarriers also stand out as candidates to target and bio-friendly therapy. Nanocellulose might fill in the gaps. Future research using nanomaterials targeting novel therapies/prophylaxis measures to COVID-19 and future outbreaks is discussed.