Iron Oxide Nanoparticles-Based Vaccine Delivery for Cancer Treatment

A meta-analysis of the efficiency of metal nanoparticles in vaccine delivery against infectious disease

Background: Exploration of the efficiency of metal nanoparticles as adjuvants have reported varying results. Objective: The efficacy of metal nanoparticles as adjuvants was investigated Data sources: Database were searched using the terms 'metal nanoparticles' and 'vaccines'. Study eligibility criteria: Studies in animal models utilizing any metal-based vaccines, where the survival rate was described. Study appraisal: The quality of the studies was examined using aspects of the ARRIVE guidelines and assessment of the risk of bias of included studies. Results: Metal nanoparticle-based adjuvants were more effective compared with control (unvaccinated groups) but have not been more successful in competing with common adjuvants or even antigens alone. Limitation: More than 75% of articles have used only gold nanoparticles. Conclusion: Nano-adjuvants do not have a significant effect on reducing mortality.

Engineering Nanoparticles toward the Modulation of Emerging Cancer Immunotherapy

Cancer immunotherapy is a new therapeutic strategy to fight cancer by activating the patients' own immune system. At present, immunotherapy approaches such as cancer vaccines, immune checkpoint blockade (ICB), adoptive cell transfer (ACT), monoclonal antibodies (mAbs) therapy, and cytokines therapy have therapeutic potential in preclinical and clinical applications. However, the intrinsic limitations of conventional immunotherapy are difficulty of precise dosage control, insufficient enrichment in tumor tissues, partial immune response silencing or hyperactivity, and high cost. Engineering nanoparticles (NPs) have been emerging as a promising multifunctional platform to enhance conventional immunotherapy due to their intrinsic immunogenicity, convenient delivery function, controlled surface chemistry activity, multifunctional modifying potential, and intelligent targeting. This review presents the recent progress reflected by engineering NPs, including the diversified selection of functionalized NPs, the superiority of engineering NPs for enhancing conventional immunotherapy, and NP-mediated multiscale strategies for synergistic therapy consisting of compositions and their mechanism. Finally, the perspective on multifunctional NP-based cancer immunotherapy for boosting immunomodulation is discussed, which reveals the expanding landscape of engineering NPs in clinical translation.

Preparation of pH-sensitive chitosan/polyvinylpyrrolidone/α-Fe2O3 nanocomposite for drug delivery application: Emphasis on ameliorating restrictions

Chitosan (CS)/polyvinylpyrrolidone (PVP)/hematite (α-Fe₂O₃) nanocomposites loaded with Doxorubicin (drug model) were synthesized via an oil-in-water emulsification method to develop a biocompatible and pH-sensitive drug nanocarrier for the first time. A hydrogel, including CS, PVP, and α-Fe₂O₃, was fabricated successfully with glutaraldehyde (GA) as the cross-linker. Incorporating α-Fe₂O₃ into CS/PVP hydrogel improved the pH-sensitivity and developed beneficial hydrogel. FTIR and XRD analysis illustrated physical interactions between polymer-polymer, polymer-drug, and crystalline behavior of prepared nanocomposite. These analyses also confirmed chemical bonding in nanocomposite's structure. The FE-SEM analysis showed successful impregnation of α-Fe₂O₃ into CS/PVP matrix and spherical structure. To clarify the size distribution and surface charge of the drug-loaded nanocomposite (CS/PVP/α-Fe₂O₃/Dox), DLS and zeta analyses were conducted. They showed the mean size of nanocomposites at about 247 nm. Drug-loaded CS/PVP/α-Fe₂O₃ nanocomposite and CS/PVP/Dox were studied for their release behavior and kinetics. Furthermore, the effect of α-Fe₂O₃ on release from CS/PVP/α-Fe₂O₃/Dox nanocomposite was investigated. That showed an increase in encapsulation of Doxorubicin and beneficial release behavior such as slow-release and retention effect. The release from this drug-loaded nanocomposite revealed excellent pH-sensitive and controlled release of the drug. Besides, the in vitro cytotoxicity and cell apoptosis were studied to recognize biological properties. These analyses revealed that drug-loaded nanocomposite caused high inhibition to MCF-7 cells in presence of α-Fe₂O₃ and proved the hematite's anti-cancer effect. By and large, this study confirmed CS/PVP/α-Fe₂O₃ nanocomposites as a potential candidate for the controlled pH-sensitive release of the drug.

The sixth revolution in pediatric vaccinology: immunoengineering and delivery systems

Infection is the predominant cause of mortality in early life, and immunization is the most promising biomedical intervention to reduce this burden. However, very young infants fail to respond optimally to most vaccines currently in use, especially neonates. In 2005, Stanley Plotkin proposed that new delivery systems would spur a new revolution in pediatric vaccinology, just as attenuation, inactivation, cell culture of viruses, genetic engineering, and adjuvantation had done in preceding decades. Recent advances in the field of immunoengineering, which is evolving alongside vaccinology, have begun to increasingly influence vaccine formulation design. Historically, the particulate nature of materials used in many vaccine formulations was empiric, often because of the need to stabilize antigens or reduce endotoxin levels. However, present vaccine delivery systems are rationally engineered to mimic the size, shape, and surface chemistry of pathogens, and are therefore often referred to as "pathogen-like particles". More than a decade from his original assessment, we re-assess Plotkin's prediction. In addition, we highlight how immunoengineering and advanced delivery systems may be uniquely capable of enhancing vaccine responses in vulnerable populations, such as infants. IMPACT: Immunoengineering and advanced delivery systems are leading to new developments in pediatric vaccinology. Summarizes delivery systems currently in use and development, and prospects for the future. Broad overview of immunoengineering's impact on vaccinology, catering to Pediatric Clinicians and Immunologists.

Advances in inorganic-based colloidal nanovehicles functionalized for nitric oxide delivery

Nitric oxide (NO) is an important pharmaceutical agent of considerable therapeutic interest ascribed to its vasodilative, tumoricidal and antibacterial effects. Rapid development of functional nanomaterials has provided opportunities for us to achieve controllable exogenous delivery of NO. In the current review, a variety of functionalized colloidal nanovehicles that have been developed to date for nitric oxide delivery are reported. Specifically, we focus on inorganic nanomaterials such as semiconductor quantum dots, silica nanoparticles, upconversion nanomaterials, carbon/graphene nanodots, gold nanoparticles, iron oxide nanoparticles as the functional or/and supporting materials to carry NO donors. N-diazeniumdiolates, S-nitrosothiols, nitrosyl metal complexes and organic nitrates as main types of NO donors have their own unique properties and molecular structures. Conjugating the NO donors of different forms with appropriate nanomaterials results in NO delivery nanovehicles capable of releasing NO in a dose-controllable or/and on-demand manner. We also consider the therapeutic applications of those NO delivery nanovehicles, especially their applications for cancer therapy. In the end, we discuss possible future directions for developing exogenous NO delivery systems with more desired structure and improved performance. This review aims to offer the readers an overall view of the advances in functionalized colloidal nanovehicles for NO delivery. It will be attractive to scientists and researchers in the areas of material science, nanotechnology, biomedical engineering, chemical biology, etc.

Understanding the influence of experimental factors on bio-interactions of nanoparticles: Towards improving correlation between in vitro and in vivo studies

Bionanotechnology has developed rapidly over the past two decades, owing to the extensive and versatile, functionalities and applicability of nanoparticles (NPs). Fifty-one nanomedicines have been approved by FDA since 1995, out of the many NPs based formulations developed to date. The general conformation of NPs consists of a core with ligands coating their surface, that stabilizes them and provides them with added functionalities. The physicochemical properties, especially the surface composition of NPs influence their bio-interactions to a large extent. This review discusses recent studies that help understand the nano-bio interactions of iron oxide and gold NPs with different surface compositions. We discuss the influence of the experimental factors on the outcome of the studies and, thus, the importance of standardization in the field of nanotechnology. Recent studies suggest that with careful selection of experimental parameters, it is possible to improve the positive correlation between in vitro and in vivo studies. This provides a fundamental understanding of the NPs which helps in assessing their potential toxic side effects and may aid in manipulating them further to improve their biocompatibility and biosafety.

Nanoparticles in cancer immunotherapies: An innovative strategy

Cancer has been one of the most significant causes of mortality, worldwide. Cancer immunotherapy has recently emerged as a competent, cancer-fighting clinical strategy. Nevertheless, due to the difficulty of such treatments, costs, and off-target adverse effects, the implementation of cancer immunotherapy described by the antigen-presenting cell (APC) vaccine and chimeric antigen receptor T cell therapy ex vivo in large clinical trials have been limited. Nowadays, the nanoparticles theranostic system as a promising target-based modality provides new opportunities to improve cancer immunotherapy difficulties and reduce their adverse effects. Meanwhile, the appropriate engineering of nanoparticles taking into consideration nanoparticle characteristics, such as, size, shape, and surface features, as well as the use of these physicochemical properties for suitable biological interactions, provides new possibilities for the application of nanoparticles in cancer immunotherapy. In this review article, we focus on the latest state-of-the-art nanoparticle-based antigen/adjuvant delivery vehicle strategies to professional APCs and engineering specific T lymphocyte required for improving the efficiency of tumor-specific immunotherapy.

Modular design of Bi-specific nanoplatform engaged in malignant lymphoma immunotherapy

Nanocarrier systems play an important role in cancer immunotherapy. In this article, biotinylated CD20 and CD3 antibodies were conjugated onto the surface of streptavidin modified ultra-small Fe₃O₄ nanoparticles via specific binding between streptavidin and biotin to construct a bi-specific nanoplatform (BSNP). The synthesized BSNP with 30 nm hydrodynamic size provides a better magnetic resonance imaging ability than the clinical Gd-chelated contrast agents (r₁ value is 5.27 mM^-1 s^-1 and 4.52 mM^-1 s^-1 for BSNP and Magnevist, respectively). This nanoplatform can target CD20-positive Raji cells and enhance the T cell mediated cell killing effect in vitro. Further, it can also inhibit tumor growth and prolong the survival time of non-Hodgkin's lymphoma (NHL) xenograft model in vivo. The probable mechanism is that while BSNP can directly induce the apoptosis of Raji cell via aggregation of CD20, T cells are recruited around tumor cells by the BSNP leading to T cell-mediated tumor cell lysis. In addition, the enhanced dual-modal MRI-fluorescence images can be acquired. In summary, the modular designed BSNP provides an efficient immune-related cancer theranostic strategy, which is of great potential as a simple and universal nanoplatform by combining different antibodies to enhance the cancer theranostic efficacy.

Nanomedicine-based tumor photothermal therapy synergized immunotherapy

The emerging anti-tumor immunotherapy has made significant progress in clinical application. However, single immunotherapy is not effective for all anti-tumor treatments, owing to the low objective response rate and the risk of immune-related side effects. Meanwhile, photothermal therapy (PTT) has attracted significant attention because of its non-invasiveness, spatiotemporal controllability and small side effects. Combining PTT with immunotherapy overcomes the issue that single photothermal therapy cannot eradicate tumors with metastasis and recurrence. However, it improves the therapeutic effect of immunotherapy, as the photothermal therapy usually promotes release of tumor-related antigens, triggers immune response by the immunogenic cell death (ICD), thereby, endowing unique synergistic mechanisms for cancer therapy. This review summarizes recent research advances in utilizing nanomedicines for PTT in combination with immunotherapy to improve the outcome of cancer treatment. The strategies include immunogenic cell death, immune agonists and cancer vaccines, immune checkpoint blockades and tumor specific monoclonal antibodies, and small-molecule immune inhibitors. The combination of synergized PTT-immunotherapy with other therapeutic strategies is also discussed.

The design and synthesis of dextran-doxorubicin prodrug-based pH-sensitive drug delivery system for improving chemotherapy efficacy

Tumor cells show acidic conditions compared with normal cells, which further inspires scientist to build nanocarrier responsive to tumor microenvironment (TME) for enhancing tumor therapeutic efficacy. Here, we report a pH-sensitive and biocompatible polyprodrug based on dextran-doxorubicin (DOX) prodrug (DOXDT) for enhanced chemotherapy. High-density DOX component was covalently decorated on the nanocarrier and the drug molecules could be effectively released in the acidic tumor tissue/cells, improving chemotherapy efficacy. Specifically, a dextran-based copolymer was preliminarily prepared by one-step atom transfer radical polymerization (ATRP); then DOX was conjugated on the copolymer component via pH-responsive hydrazone bond. The structure of DOXDT can be well-controlled. The resulting DOXDT was able to further self-assemble into nanoscale micelles with a hydration diameter of about 32.4 nm, which presented excellent micellar stability. Compared to lipid-based drug delivery system, the DOXDT prodrug showed higher drug load capacity up to 23.6%. In addition, excellent stability and smaller size of the nanocarrier contributed to better tissue permeability and tumor suppressive effects in vivo. Hence, this amphipathic DOXDT prodrug is promising in the development of translational DOX formulations, which would be widely applied in cancer therapy.

An Alphavirus-derived replicon RNA vaccine induces SARS-CoV-2 neutralizing antibody and T cell responses in mice and nonhuman primates

The coronavirus disease 2019 (COVID-19) pandemic, caused by infection with the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is having a deleterious impact on health services and the global economy, highlighting the urgent need for an effective vaccine. Such a vaccine would need to rapidly confer protection after one or two doses and would need to be manufactured using components suitable for scale up. Here, we developed an Alphavirus-derived replicon RNA vaccine candidate, repRNA-CoV2S, encoding the SARS-CoV-2 spike (S) protein. The RNA replicons were formulated with lipid inorganic nanoparticles (LIONs) that were designed to enhance vaccine stability, delivery, and immunogenicity. We show that a single intramuscular injection of the LION/repRNA-CoV2S vaccine in mice elicited robust production of anti-SARS-CoV-2 S protein IgG antibody isotypes indicative of a type 1 T helper cell response. A prime/boost regimen induced potent T cell responses in mice including antigen-specific responses in the lung and spleen. Prime-only immunization of aged (17 months old) mice induced smaller immune responses compared to young mice, but this difference was abrogated by booster immunization. In nonhuman primates, prime-only immunization in one intramuscular injection site or prime/boost immunizations in five intramuscular injection sites elicited modest T cell responses and robust antibody responses. The antibody responses persisted for at least 70 days and neutralized SARS-CoV-2 at titers comparable to those in human serum samples collected from individuals convalescing from COVID-19. These data support further development of LION/repRNA-CoV2S as a vaccine candidate for prophylactic protection against SARS-CoV-2 infection.

A stable USPIO capable for MR lymphography with ultra-low effective dosage

Ultra-small superparamagnetic iron oxide (USPIO) nanoparticles appear to be promising tools for MR lymphography due to their unique magnetic properties. In clinical diagnosis, the effectiveness of USPIO will greatly affect the clinician's judgment to the enhanced MR images. In this study, we evaluated the effectiveness of CS015, a PAA-coated USPIO, with subcutaneous and intravenous administration. It appeared that subcutaneously injected particles had much higher efficiency to reach lymph nodes, and even worked at a very small dose 0.075 μmol/kg. Further, we compared CS015 with ferumoxytol and ferumoxtran-10 in MR lymphography and found that CS015 had the best performance. And the lymph node metastases in New Zealand rabbits were successfully detected using CS015 with one single dose. These merits of CS015 make it a promising MR lymphography contrast agent with potential applications in cancer therapy.

Single-dose replicating RNA vaccine induces neutralizing antibodies against SARS-CoV-2 in nonhuman primates

The ongoing COVID-19 pandemic, caused by infection with SARS-CoV-2, is having a dramatic and deleterious impact on health services and the global economy. Grim public health statistics highlight the need for vaccines that can rapidly confer protection after a single dose and be manufactured using components suitable for scale-up and efficient distribution. In response, we have rapidly developed repRNA-CoV2S, a stable and highly immunogenic vaccine candidate comprised of an RNA replicon formulated with a novel Lipid InOrganic Nanoparticle (LION) designed to enhance vaccine stability, delivery and immunogenicity. We show that intramuscular injection of LION/repRNA-CoV2S elicits robust anti-SARS-CoV-2 spike protein IgG antibody isotypes indicative of a Type 1 T helper response as well as potent T cell responses in mice. Importantly, a single-dose administration in nonhuman primates elicited antibody responses that potently neutralized SARS-CoV-2. These data support further development of LION/repRNA-CoV2S as a vaccine candidate for prophylactic protection from SARS-CoV-2 infection.

Nanotherapeutic systems for delivering cancer vaccines: recent advances

With an increase in the global burden of cancer-related deaths, the quest for developing new therapeutic solutions has taken momentum. In this regard, the idea of using cancer vaccines came to existence approximately 30 years ago, where gene therapy interventions have shown significant improvement in the therapeutic outcomes against several types of cancers. Cancer vaccines usually encounter a number of challenges with limited targeting ability to the tumors. Nanocarriers have been studied as a technological innovation for tumor targeting of gene therapeutics. This article provides a critical insight into the recent progress made in nanotherapeutic strategies for genetic vaccine delivery for treatment against various types of cancers. Moreover, the article intends to provide a summary of the research work being done on this topic.

The Intrinsic Biological Identities of Iron Oxide Nanoparticles and Their Coatings: Unexplored Territory for Combinatorial Therapies

Over the last 20 years, iron oxide nanoparticles (IONPs) have been the subject of increasing investigation due to their potential use as theranostic agents. Their unique physical properties (physical identity), ample possibilities for surface modifications (synthetic identity), and the complex dynamics of their interaction with biological systems (biological identity) make IONPs a unique and fruitful resource for developing magnetic field-based therapeutic and diagnostic approaches to the treatment of diseases such as cancer. Like all nanomaterials, IONPs also interact with different cell types in vivo, a characteristic that ultimately determines their activity over the short and long term. Cells of the mononuclear phagocytic system (macrophages), dendritic cells (DCs), and endothelial cells (ECs) are engaged in the bulk of IONP encounters in the organism, and also determine IONP biodistribution. Therefore, the biological effects that IONPs trigger in these cells (biological identity) are of utmost importance to better understand and refine the efficacy of IONP-based theranostics. In the present review, which is focused on anti-cancer therapy, we discuss recent findings on the biological identities of IONPs, particularly as concerns their interactions with myeloid, endothelial, and tumor cells. Furthermore, we thoroughly discuss current understandings of the basic molecular mechanisms and complex interactions that govern IONP biological identity, and how these traits could be used as a stepping stone for future research.

Nanoparticles to Improve the Efficacy of Peptide-Based Cancer Vaccines

Nanoparticles represent a potent antigen presentation and delivery system to elicit an optimal immune response by effector cells targeting tumor-associated antigens expressed by cancer cells. Many types of nanoparticles have been developed, such as polymeric complexes, liposomes, micelles and protein-based structures such as virus like particles. All of them show promising results for immunotherapy approaches. In particular, the immunogenicity of peptide-based cancer vaccines can be significantly potentiated by nanoparticles. Indeed, nanoparticles are able to enhance the targeting of antigen-presenting cells (APCs) and trigger cytokine production for optimal T cell response. The present review summarizes the categories of nanoparticles and peptide cancer vaccines which are currently under pre-clinical evaluation.

pH-Responsive Cascaded Nanocatalyst for Synergistic Like-Starvation and Chemodynamic therapy

A tumor microenvironment (TME) responsive cascade nanocatalyst was built based on copper-embedded hollow mesoporous silica (HMSN-Cu) decorated with glucose oxidase (GOD) on the surface, realizing tumor-selected cascade catalyst for elegant combination of starving therapy and chemodynamic therapy. Specifically, benefited from the strong demand for glucose metabolism in tumor cells, this HMSN-Cu-GOD could catalyze rich glucose into H2O2 in the presence of O2, along with localized declined pH in situ to in turn degrade HMSN-Cu and thus release Cu2+/Cu+. Importantly, abound hydroxyl radical (•OH) with high oxidative activity generated in the Fenton reaction between H2O2 and Cu2+/Cu+. Interesting, the high-expressed GSH and exacerbated hypoxia in tumor cells, will facilitate accumulation of Cu+ with much higher reaction efficiency, further enhanced Chemodynamic therapy (CDT) efficiency. Compared with monotherapy, in vitro and vivo tumor inhibition experiments demonstrated the superior synergistic effect of CDT and starving therapy based on a simple but effective biodegradable nanosystem.

Nanoparticle formulated vaccines: opportunities and challenges

Vaccines harness the inherent properties of the immune system to prevent diseases or treat existing ones. Continuous efforts have been devoted to both gaining a mechanistic understanding of how the immune system operates and designing vaccines with high efficacies and effectiveness. Advancements in nanotechnology in recent years have generated unique opportunities to meet the daunting challenges associated with immunology and vaccine development. Firstly, nanoparticle formulated systems provide ideal model systems for studying the operation of the immune system, making it possible to systematically identify key factors and understand their roles in specific immune responses. Also, the versatile compositions/architectures of nanoparticle systems enable new strategies/novel platforms for developing vaccines with high efficacies and effectiveness. In this review, we discuss the advantages of nanoparticles and the challenges faced during vaccine development, through the framework of the immunological mechanisms of vaccination, with the aim of bridging the gap between immunology and materials science, which are both involved in vaccine design. The knowledge obtained provides general guidelines for future vaccine development.

Induction of apoptosis and ferroptosis by a tumor suppressing magnetic field through ROS-mediated DNA damage

Magnetic field (MF) is being used in antitumor treatment; however, the underlying biological mechanisms remain unclear. In this study, the potency and mechanism of a previously published tumor suppressing MF exposure protocol were further investigated. This protocol, characterized as a 50 Hz electromagnetic field modulated by static MF with time-average intensity of 5.1 mT, when applied for 2 h daily for over 3 consecutive days, selectively inhibited the growth of a broad spectrum of tumor cell lines including lung cancer, gastric cancer, pancreatic cancer and nephroblastoma. The level of intracellular reactive oxygen species (ROS) increased shortly after field exposure and persisted. Subsequently, pronounced DNA damage and activation of DNA repair pathways were identified both in vitro and in vivo. Furthermore, use of free radical scavenger alleviated DNA damage and partially reduced cell death. Finally, this field was found to inhibit cell proliferation, and simultaneously induced two types of programmed cell death, apoptosis and ferroptosis. In conclusion, this tumor suppressing MF could determine cell fate through ROS-induced DNA damage, inducing oxidative stress and activation of the DNA damage repair pathways, eventually lead to apoptosis and ferroptosis, as well as inhibition of tumor growth.

Metal nanomaterials: Immune effects and implications of physicochemical properties on sensitization, elicitation, and exacerbation of allergic disease

The recent surge in incorporation of metallic and metal oxide nanomaterials into consumer products and their corresponding use in occupational settings have raised concerns over the potential for metals to induce size-specific adverse toxicological effects. Although nano-metals have been shown to induce greater lung injury and inflammation than their larger metal counterparts, their size-related effects on the immune system and allergic disease remain largely unknown. This knowledge gap is particularly concerning since metals are historically recognized as common inducers of allergic contact dermatitis, occupational asthma, and allergic adjuvancy. The investigation into the potential for adverse immune effects following exposure to metal nanomaterials is becoming an area of scientific interest since these characteristically lightweight materials are easily aerosolized and inhaled, and their small size may allow for penetration of the skin, which may promote unique size-specific immune effects with implications for allergic disease. Additionally, alterations in physicochemical properties of metals in the nano-scale greatly influence their interactions with components of biological systems, potentially leading to implications for inducing or exacerbating allergic disease. Although some research has been directed toward addressing these concerns, many aspects of metal nanomaterial-induced immune effects remain unclear. Overall, more scientific knowledge exists in regards to the potential for metal nanomaterials to exacerbate allergic disease than to their potential to induce allergic disease. Furthermore, effects of metal nanomaterial exposure on respiratory allergy have been more thoroughly-characterized than their potential influence on dermal allergy. Current knowledge regarding metal nanomaterials and their potential to induce/exacerbate dermal and respiratory allergy are summarized in this review. In addition, an examination of several remaining knowledge gaps and considerations for future studies is provided.

The yin and yang of imaging tumor associated macrophages with PET and MRI

Tumor associated macrophages (TAM) are key players in the cancer microenvironment. Molecular imaging modalities such as MRI and PET can be used to track and monitor TAM dynamics in tumors non-invasively, based on specific uptake and quantification of MRI-detectable nanoparticles or PET-detectable radiotracers. Particular molecular signatures can be leveraged to target anti-inflammatory TAM, which support tumor growth, and pro-inflammatory TAM, which suppress tumor growth. In addition, TAM-directed imaging probes can be designed to include immune modulating properties, thereby leading to combined diagnostic and therapeutic (theranostic) effects. In this review, we will discuss the complementary role of TAM-directed radiotracers and iron oxide nanoparticles for monitoring cancer immunotherapies with PET and MRI technologies. In addition, we will outline how TAM-directed imaging and therapy is interdependent and can be connected towards improved clinical outcomes

Engineered nano-immunopotentiators efficiently promote cancer immunotherapy for inhibiting and preventing lung metastasis of melanoma

Malignant melanoma, one of the most aggressive types of cancer easily metastasizes, making it extremely difficult to treat and unresponsive to current therapies. Recent breakthroughs in nanomaterials-based cancer immunotherapy have provided potential specific strategy for tumor and metastasis inhibition. With the development of nanotechnology, inorganic nanomaterials have been increasingly studied for their potential cancer therapeutic and molecular imaging functions. However, only iron-based nanomaterials have been approved by the Food and Drug Administration (FDA) in inorganic nanomedicines. For promising clinical application, a new type of nanocomposite is engineered by combining ultra-small iron oxide nanoparticles (Fe₃O₄ NPs) and ovalbumin (OVA), denoted as Fe₃O₄-OVA nanocomposites in this study. Interestingly, this is the first time that Fe₃O₄ NPs are found as nano-immunopotentiators helping nanocomposites efficiently stimulate dendritic cell-based immunotherapy and potentially-activate macrophages. These nanocomposites efficiently stimulate the maturation level of bone marrow derived dendritic cell (BMDCs) and corresponding activation of T cells and also potentially-activate macrophages. With the help of the Fe₃O₄ nano-immunopotentiators (Fe₃O₄ NPs), this therapeutic and prophylactic Fe₃O₄-OVA vaccine can not only efficiently inhibit the subcutaneous and metastatic B16-OVA tumor growth but also successfully prevent the formation of subcutaneous and metastatic tumor, providing a promising strategy for expanding the clinical use of Fe-based nanomaterials.

Vaccines against anthrax based on recombinant protective antigen: problems and solutions

Introduction: Anthrax is a dangerous bio-terror agent because Bacillus anthracis spores are highly resilient and can be easily aerosolized and disseminated. There is a threat of deliberate use of anthrax spores aerosol that could lead to serious fatal diseases outbreaks. Existing control measures against inhalation form of the disease are limited. All of this has provided an impetus to the development of new generation vaccines. Areas сovered: This review is devoted to challenges and achievements in the design of vaccines based on the anthrax recombinant protective antigen (rPA). Scientific databases have been searched, focusing on causes of PA instability and solutions to this problem, including new approaches of rPA expression, novel rPA-based vaccines formulations as well as the simultaneous usage of PA with other anthrax antigens. Expert opinion: PA is a central anthrax toxin component, playing a key role in the defense against encapsulated and unencapsulated strains. Subunit rPA-based vaccines have a good safety and protective profile. However, there are problems of PA instability that are greatly enhanced when using aluminum adjuvants. New adjuvant compositions, dry formulations and resistant to proteolysis and deamidation mutant PA forms can help to handle this issue. Devising a modern anthrax vaccine requires huge efforts.

HBs antigen and mannose loading on the surface of iron oxide nanoparticles in order to immuno-targeting: fabrication, characterization, cellular and humoral immunoassay

Mannosylation of nanovaccine is an appropriate strategy for targeting the mannose receptors on DCs. Here, HBsAg and mannose loaded on the surface of iron oxide nanoparticles to increases HBsAg vaccine potency. Nanoparticles are made by co-precipitation method and bonded to the HBsAg and mannose by chemical bonding. The physicochemical properties of nano-vaccines, their toxicity and antigenicity were determined. The synthesized nano-vaccine showed spherical shape with a mean particle size of 60 nm, a zeta potential of -44 mV, an antigen-binding efficiency of around 100% and for mannose 78%. In vitro release of nanoparticles exhibited about 30% at the first day and about 60% until the third day. SDSPAGE analysis confirmed structural integrity of HBsAg loaded on nanoparticles. The HBsAg-loaded LCMNP and MLCMNP nanoparticles had no toxic effects on HEK293 cell line. The quantification of the intracellular Fe by ICP-OES as a criterion of nano-vaccine uptake revealed mannose intensify uptake of MLCMNP. In addition, mannose in the structure of MLCMNP improved IL-6, TNF-α and IFN-γ (>16 fold) cytokines genes expression by macrophage/dendritic cells after exposure in 12 h. Immunization of experimental mice (subcutaneously, two times with 2-week intervals) with 5 µg of HBsAg loaded on MLCMNP nanoparticles increased specific total IgG and IgG2a/IgG1 ratio. In addition, TNF-α, IL-12, IL-2 and IL-4 cytokines in mannosylated nano-vaccine increased versus nano-vaccine group while lymphocyte proliferation and IFN-γ responses in the targeted nano-vaccine group show a tiny increase versus the nano-vaccine group. The results show that mannosylated nano-vaccine promotes higher level of cellular and humoural immune responses against HBsAg nano-vaccine.

Current trends and challenges in cancer management and therapy using designer nanomaterials

Nanotechnology has the potential to circumvent several drawbacks of conventional therapeutic formulations. In fact, significant strides have been made towards the application of engineered nanomaterials for the treatment of cancer with high specificity, sensitivity and efficacy. Tailor-made nanomaterials functionalized with specific ligands can target cancer cells in a predictable manner and deliver encapsulated payloads effectively. Moreover, nanomaterials can also be designed for increased drug loading, improved half-life in the body, controlled release, and selective distribution by modifying their composition, size, morphology, and surface chemistry. To date, polymeric nanomaterials, metallic nanoparticles, carbon-based materials, liposomes, and dendrimers have been developed as smart drug delivery systems for cancer treatment, demonstrating enhanced pharmacokinetic and pharmacodynamic profiles over conventional formulations due to their nanoscale size and unique physicochemical characteristics. The data present in the literature suggest that nanotechnology will provide next-generation platforms for cancer management and anticancer therapy. Therefore, in this critical review, we summarize a range of nanomaterials which are currently being employed for anticancer therapies and discuss the fundamental role of their physicochemical properties in cancer management. We further elaborate on the topical progress made to date toward nanomaterial engineering for cancer therapy, including current strategies for drug targeting and release for efficient cancer administration. We also discuss issues of nanotoxicity, which is an often-neglected feature of nanotechnology. Finally, we attempt to summarize the current challenges in nanotherapeutics and provide an outlook on the future of this important field.

Up-to-date vaccine delivery systems: robust immunity elicited by multifarious nanomaterials upon administration through diverse routes

In this review, we summarize the recent design strategies (2015-present) of nanomaterial-based vaccine delivery systems via multiple routes to induce robust protective immunity. The selected topics are focused on the novel design strategies of nanomaterial carriers for vaccine delivery. Inspired by recent advances, we also briefly introduce the emerging administration routes that may give rise to synergistic immune effects with advanced delivery systems. Ultimately, we present the existing challenges and survey the prospective development of various nanoparticle vaccine delivery systems.

Fabrication of Hybrid Nanostructures Based on Fe3O4 Nanoclusters as Theranostic Agents for Magnetic Resonance Imaging and Drug Delivery

Combining anticancer drugs with inorganic nanocrystals to construct multifunctional hybrid nanostructures has become a powerful tool for cancer treatment and tumor suppression. However, it remains a critical challenge to synthesize compact, multifunctional nanostructures with improved functionality and reproducibility. In this study, we report the fabrication of magnetite hybrid nanostructures employing Fe3O4 nanoparticles (NPs) to form multifunctional magnetite nanoclusters (NCs) by combining an oil-in-water microemulsion assembly and a layer-by-layer (LBL) method. The Fe3O4 NCs were firstly prepared via a microemulsion self-assembly technique. Then, polyelectrolyte layers composed of poly(allylamine hydrochloride) (PAH) and poly(sodium 4-styrenesulfonate) (PSS) and doxorubicin hydrochloride (DOX) were capped on Fe3O4 NCs to construct the Fe3O4 NC/PAH/PSS/DOX hybrid nanostructures via LBL method. The as-prepared hybrid nanostructures loaded with DOX demonstrated the pH-responsive drug release and higher cytotoxicity towards human lung cancer (A549) cells in vitro and can serve as T2-weighted magnetic resonance imaging (MRI) contrast agents, which can significantly improve T2 relaxivity and lead to a better cellular MRI contrast effect. The loaded DOX emitting red signals under excitation with 490 nm are suitable for bioimaging applications. This work provides a novel strategy to build a Fe3O4-based multifunctional theranostic nanoplatform with T2-weighted MRI, fluorescence imaging, and drug delivery.

Magnetic multiwalled carbon nanotubes with controlled release of epirubicin: an intravesical instillation system for bladder cancer

Background

Traditional intravesical instillation treatment in bladder cancer has limited efficacy, which results in a high frequency of recurrence.

Purpose

The aim of this study was to report on an epirubicin (EPI)-loaded magnetic multi-walled carbon nanotube (mMWCNTs-EPI) system for intravesical instillation in place of the current formulation.

Methods

The mMWCNTs-EPI system was formulated with carboxylated MWCNTs, Fe₃O₄ magnetic nanoparticles, and EPI. Features and antitumor activity of the system were investigated.

Results

Under the effect of external magnets, the mMWCNTs-EPI system showed sustained release and prolonged retention behavior and better antitumor activity than free EPI. The mMWCNTs-EPI system had higher efficiency in enhancing cytotoxicity and inhibiting proliferation in vitro and in vivo than free EPI. Our studies also revealed the atoxic nature of mMWCNTs.

Conclusion

These findings suggested that mMWCNTs are effective intravesical instillation agents with great potential for clinical application.

Iron Metabolism in Cancer

Demanded as an essential trace element that supports cell growth and basic functions, iron can be harmful and cancerogenic though. By exchanging between its different oxidized forms, iron overload induces free radical formation, lipid peroxidation, DNA, and protein damages, leading to carcinogenesis or ferroptosis. Iron also plays profound roles in modulating tumor microenvironment and metastasis, maintaining genomic stability and controlling epigenetics. in order to meet the high requirement of iron, neoplastic cells have remodeled iron metabolism pathways, including acquisition, storage, and efflux, which makes manipulating iron homeostasis a considerable approach for cancer therapy. Several iron chelators and iron oxide nanoparticles (IONPs) has recently been developed for cancer intervention and presented considerable effects. This review summarizes some latest findings about iron metabolism function and regulation mechanism in cancer and the application of iron chelators and IONPs in cancer diagnosis and therapy.

Bioactive Nanoparticles for Cancer Immunotherapy

Currently, immunotherapy is considered to be one of the effective treatment modalities for cancer. All the developments and discoveries in this field up to the recent Nobel Prize add to the interest for research into this vast area of study. Targeting tumor environment as well as the immune system is a suitable strategy to be applied for cancer treatment. Usage of nanoparticle systems for delivery of immunotherapeutic agents to the body being widely studied and found to be a promising area of research to be considered and investigated further. Nanoparticles for immunotherapy would be one of the effective treatment options for cancer therapy in the future due to their high specificity, efficacy, ability to diagnose, imaging, and therapeutic effect. Among the many nanoparticle systems, polylactic-co-glycolic acid (PLGA) nanoparticles, liposomes, micelles, gold nanoparticles, iron oxide, dendrimers, and artificial exosomes are widely used for immunotherapy of cancer. Moreover, the combination therapy found to be the more effective way of treating the tumor. Here, we review the current trends in nanoparticle therapy and efficiency of these nanosystems in delivering antigens, adjuvants, therapeutic drugs, and other immunotherapeutic agents. This review summarizes the currently available bioactive nanoparticle systems for cancer immunotherapy.

Anti-tumor macrophages activated by ferumoxytol combined or surface-functionalized with the TLR3 agonist poly (I : C) promote melanoma regression

Macrophages orchestrate inflammation and control the promotion or inhibition of tumors and metastasis. Ferumoxytol (FMT), a clinically approved iron oxide nanoparticle, possesses anti-tumor therapeutic potential by inducing pro-inflammatory macrophage polarization. Toll-like receptor 3 (TLR3) activation also potently enhances the anti-tumor response of immune cells. Herein, the anti-tumor potential of macrophages harnessed by FMT combined with the TLR3 agonist, poly (I:C) (PIC), and FP-NPs (nanoparticles composed of amino-modified FMT (FMT-NH2) surface functionalized with PIC) was explored. Methods: Proliferation of B16F10 cells co-cultured with macrophages was measured using immunofluorescence or flow cytometry (FCM). Phagocytosis was analyzed using FCM and fluorescence imaging. FP-NPs were prepared through electrostatic interactions and their properties were characterized using dynamic light scattering, transmission electron microscopy, and gel retardation assay. Anti-tumor and anti-metastasis effects were evaluated in B16F10 tumor-bearing mice, and tumor-infiltrating immunocytes were detected by immunofluorescence staining and FCM. Results: FMT, PIC, or the combination of both hardly impaired B16F10 cell viability. However, FMT combined with PIC synergistically inhibited their proliferation by shifting macrophages to a tumoricidal phenotype with upregulated TNF-α and iNOS, increased NO secretion and augmented phagocytosis induced by NOX2-derived ROS in vitro. Combined treatment with FMT/PIC and FMT-NH2/PIC respectively resulted in primary melanoma regression and alleviated pulmonary metastasis with elevated pro-inflammatory macrophage infiltration and upregulation of pro-inflammatory genes in vivo. In comparison, FP-NPs with properties of internalization by macrophages and accumulation in the lung produced a more pronounced anti-metastatic effect accompanied with decreased myeloid-derived suppressor cells, and tumor-associated macrophages shifted to M1 phenotype. In vitro mechanistic studies revealed that FP-NPs nanoparticles barely affected B16F10 cell viability, but specifically retarded their growth by steering macrophages to M1 phenotype through NF-κB signaling. Conclusion: FMT synergized with the TLR3 agonist PIC either in combination or as a nano-composition to induce macrophage activation for primary and metastatic melanoma regression, and the nano-composition of FP-NPs exhibited a more superior anti-metastatic efficacy.