Dysregulation of macrophage activation profiles by engineered nanoparticles

Understanding Macrophage Interaction with Antimony-Doped Tin Oxide Plasmonic Nanoparticles

Antimony-doped tin oxide nanoparticles (ATO NPs) have emerged as a promising tool in biomedical applications, namely robust photothermal effects upon near-infrared (NIR) light exposure, enabling controlled thermal dynamics to induce spatial cell death. This study investigated the interplay between ATO NPs and macrophages, understanding cellular uptake and cytokine release. ATO NPs demonstrated biocompatibility with no impact on macrophage viability and cytokine secretion. These findings highlight the potential of ATO NPs for inducing targeted cell death in cancer treatments, leveraging their feasibility, unique NIR properties, and safe interactions with immune cells. ATO NPs offer a transformative platform with significant potential for future biomedical applications by combining photothermal capabilities and biocompatibility.

Schizonepeta tenuifolia Briq-Saposhnikovia divaricata decoction alleviates atopic dermatitis via downregulating macrophage TRPV1

Objective

Schizonepeta tenuifolia -Saposhnikovia divaricata (Jingjie-Fangfeng, JF) has been used for years to treat allergic inflammatory skin diseases like atopic dermatitis, but the specific effects and mechanisms of JF are still unclear.

Purpose

We aim to investigate the therapeutic effect and mechanism of JF in MC903-induced atopic dermatitis-like model.

Methods

JF decoction was subjected to rigorous HPLC and GC analysis. The JF decoction was then freshly prepared and administered to MC903-induced atopic dermatitis -like mice models to investigate its therapeutic effects. Our evaluation focused on several markers of inflammation including the TEWL index, ear thickness, swelling, and specific inflammation indicators such as TSLP, IL33, IgE, and immune cell presence at the lesion sites. We measured Transient Receptor Potential Vanilloid 1 (TRPV1) expression levels through immunofluorescent staining in skin tissue from both atopic dermatitis patients and the MC903-treated mice. Furthermore, TRPV1 expression and macrophage activation markers were measured in LPS/IFN-γ-stimulated Raw264.7 and THP-1 cell models in vitro. Additionally, we developed cell lines that overexpress TRPV1 and investigated how JF treatment affects NF-κB p65 phosphorylation in these cells to understand better the role of TRPV1 in atopic dermatitis.

Results

The JF decoction met the standards outlined in the Chinese pharmacopeia. The JF decoction significantly alleviated inflammatory skin symptoms and helped restore skin barrier function. Additionally, it reduced the levels of IgE and pro-inflammatory cytokines TSLP, IL-33, and IL-4. There was also a noticeable decrease in mast cell infiltration and degranulation. Notably, JF decoction reduced infiltrated macrophages with limited affection on T cell infiltration. It also decreased F4/80+/TRPV1+ cells in atopic dermatitis mice and TRPV1 expression in LPS/IFNγ-stimulated microphages. Additionally, we observed that CD68+/TRPV1+ cells increased in human atopic dermatitis tissue. Further studies showed that JF water extract (JF-WE) suppressed TRPV1 expression in macrophages, potentially by affecting NF-κB p65 phosphorylation rather than the JAK-STAT6 pathway.

Conclusion

This study offers initial evidence of the effectiveness of JF-WE in suppressing inflammation in atopic dermatitis. The therapeutic effect might stems from its ability to downregulate TRPV1 expression and subsequent NF-κB p65 phosphorylation in macrophages.

Targeting and activation of macrophages in leishmaniasis. A focus on iron oxide nanoparticles

Macrophages play a pivotal role as host cells for Leishmania parasites, displaying a notable functional adaptability ranging from the proinflammatory, leishmanicidal M1 phenotype to the anti-inflammatory, parasite-permissive M2 phenotype. While macrophages can potentially eradicate amastigotes through appropriate activation, Leishmania employs diverse strategies to thwart this activation and redirect macrophages toward an M2 phenotype, facilitating its survival and replication. Additionally, a competition for iron between the two entities exits, as iron is vital for both and is also implicated in macrophage defensive oxidative mechanisms and modulation of their phenotype. This review explores the intricate interplay between macrophages, Leishmania, and iron. We focus the attention on the potential of iron oxide nanoparticles (IONPs) as a sort of immunotherapy to treat some leishmaniasis forms by reprogramming Leishmania-permissive M2 macrophages into antimicrobial M1 macrophages. Through the specific targeting of iron in macrophages, the use of IONPs emerges as a promising strategy to finely tune the parasite-host interaction, endowing macrophages with an augmented antimicrobial arsenal capable of efficiently eliminating these intrusive microbes.

Effects of superparamagnetic iron oxide nanoparticles (SPIONS) testicular injection on Leydig cell function and sperm production in a murine model

In the domain of medical advancement, nanotechnology plays a pivotal role, especially in the synthesis of biocompatible materials for therapeutic use. Superparamagnetic Iron Oxide Nanoparticles (SPIONs), known for their magnetic properties and low toxicity, stand at the forefront of this innovation. This study explored the reproductive toxicological effects of Sodium Citrate-functionalized SPIONs (Cit_SPIONs) in adult male mice, an area of research that holds significant potential yet remains largely unknown. Our findings reveal that Cit_SPIONs induce notable morphological changes in interstitial cells and the seminiferous epithelium when introduced via intratesticular injection. This observation is critical in understanding the interactions of nanomaterials within reproductive biological systems. A striking feature of this study is the rapid localization of Cit_SPIONs in Leydig cells post-injection, a factor that appears to be closely linked with the observed decrease in steroidogenic activity and testosterone levels. This data suggests a possible application in developing nanostructured therapies targeting androgen-related processes. Over 56 days, these nanoparticles exhibited remarkable biological distribution in testis parenchyma, infiltrating various cells within the tubular and intertubular compartments. While the duration of spermatogenesis remained unchanged, there were many Tunel-positive germ cells, a notable reduction in daily sperm production, and reduced progressive sperm motility in the treated group. These insights not only shed light on the intricate mechanisms of Cit_SPIONs interaction with the male reproductive system but also highlight the potential of nanotechnology in developing advanced biomedical applications.

Effects of iron oxide nanoparticles on the gene expression profiles of cerebral endotheliocytes and astrocytes

Iron oxide nanoparticles (IONPs) are considered as the most biocompatible magnetic materials suitable for biomedical applications. Nevertheless, there are many evidences of their toxicity for living organisms and partially neurotoxicity. The central nervous system is protected from undesirable substances circulating in the bloodstream by the blood-brain barrier (BBB). And even if being small enough, some nanoparticles could be able to penetrate cell membranes in other cells but will often be delayed by the BBB cells. However, the neurotoxicity of iron oxide is described even in the cases when IONPs should not uptake to the nervous system by experimental design. The aim of this study was to investigate what molecular changes in the cells-components of BBB - endotheliocytes and underlying astrocytes - may be caused by IONPs in the blood vessels of the brain. For this, a two-layer in vitro BBB model was created, consisting of rat cerebral endothelial cells and astrocytes. It was revealed that 100 and 200 mg/L of the nanoparticles induce metabolism alteration in the cells under study. Using RNA-sequencing, the up-regulation of pro-inflammatory chemokines encoding genes and changes in the expression of genes associated with detoxification in the endotheliocytes were demonstrated under the influence of 100 mg/L IONPs.

Boosting chemotherapy of bladder cancer cells by ferroptosis using intelligent magnetic targeting nanoparticles

A versatile nano-delivery platform was reported to enhance the tumor suppression effect of chemotherapy by augmenting tumor cells' ferroptosis. The platform consists of pomegranate-like magnetic nanoparticles (rPAE@SPIONs) fabricated by encapsulating superparamagnetic iron oxide nanoparticles (SPIONs) within a reduced poly(β-amino ester)s-PEG amphiphilic copolymer (rPAE). The resulting platform exhibits several functionalities. Firstly, it promotes the doxorubicin (DOX) release by leveraging the mild hyperthermia generated by NIR irradiation. Secondly, it triggers ferroptosis in tumor cells, inducing their demise. Thirdly, it induces polarization of macrophages towards an anti-tumor M1 phenotype, contributing to ferroptosis of tumor cells and enhanced tumor cell suppression. This study effectively capitalizes on the versatility of SPIONs and offers a simple yet powerful strategy for developing a new nanosized ferroptosis-inducing agent, ultimately improving the inhibition of bladder cancer cells.

Manipulating macrophage polarization with nanoparticles to control metastatic behavior in heterotypic breast cancer micro-tissues via exosome signaling

This study aimed to investigate the effects of nanoparticles on macrophage polarization and their subsequent influence on post-tumorigenic behavior. Initially, seven different nanoparticles were applied to macrophages, and Zn-Ni-FeO (100 nm) and palladium nanoparticles (PdNPs, ∼25 nm) were found to induce M1-polarization in macrophages. A co-culture experiment was then conducted to examine the effects of macrophages on MCF-7 breast cancer micro-tissues. The M2-macrophages promoted tumor proliferation, while M1- and PdNPs-induced macrophages showed anti-tumor effects by suppressing cell proliferation. To reveal the mechanisms of effect, exosomes isolated from M1 (M1-Exo), M0 (M0-Exo), M2 (M2-Exo), and PdNPs-induced (PdNPs-Exo) macrophages were applied to the heterotypic tumor micro-tissues including MCF-7, human umbilical vein endothelial cells (HUVECs), and primary human dermal fibroblasts (phDFs). M2-Exo was seen to promote the migration of cancer cells and induce epithelial-mesenchymal transition (EMT), while M1-Exo suppressed these behaviors. PdNPs-Exo was effective in suppressing the aggressive nature of breast cancer cells similar to M1-Exo, moreover, the efficacy of 5-fluorouracil (5-FU) was increased in combination with PdNPs-Exo in both MCF-7 and heterotypic micro-tissues. In conclusion, PdNPs-Exo has potential anti-tumor effects, can be used as a combination therapy to enhance the efficacy of anti-cancer drugs, as well as innovative implants for breast cancer treatment.

Cell and biomaterial delivery strategies to induce immune tolerance

The prevalence of immune-mediated disorders, including autoimmune conditions and allergies, is steadily increasing. However, current therapeutic approaches are often non-specific and do not address the underlying pathogenic condition, often resulting in impaired immunity and a state of generalized immunosuppression. The emergence of technologies capable of selectively inhibiting aberrant immune activation in a targeted, antigen (Ag)-specific manner by exploiting the body's intrinsic tolerance pathways, all without inducing adverse side effects, holds significant promise to enhance patient outcomes. In this review, we will describe the body's natural mechanisms of central and peripheral tolerance as well as innovative delivery strategies using cells and biomaterials targeting innate and adaptive immune cells to promote Ag-specific immune tolerance. Additionally, we will discuss the challenges and future opportunities that warrant consideration as we navigate the path toward clinical implementation of tolerogenic strategies to treat immune-mediated diseases.

Functional impact of oxygen-saturated zeolite nanoparticles on macrophages in the context of glioblastoma: an in vitro and in vivo study

In the context of glioblastoma (GBM), hypoxia and inflammation are two main players of the tumor microenvironment. Hypoxia stimulates various features involves in tumor growth and also maintains a specific environment that favors protumor macrophages. Therefore, targeting hypoxia could potentially restore an anti-tumor M1 phenotype in macrophages. Besides, iron demonstrated its capacity to stimulate the polarization of macrophages towards an M1-like phenotype. In this paper we took advantages of microporous nanoparticles to co-deliver both oxygen and iron to bone marrow derived macrophages (BMDM) enabling the investigation of changes in polarization status and proteomic profiles. The nanoparticles were used in two in vivo models of glioblastoma, specifically, in both immunodeficient and immunocompetent settings. Our in vitro findings revealed that iron doped nanoparticles, saturated with oxygen were deemed safe for macrophages but did not demonstrate the capacity to change the M1 or M2 phenotypes. However, these nanoparticles induced some changes in proteomics pathways. The present study reports on in vivo experimentation that revealed the effects of nanoparticles on the hypoxic fraction, tumor volume, and macrophage phenotype in a GBM model. The findings indicated that the presence of nanoparticles led to a reduction in the hypoxic fraction in one of the GBM models, while no significant changes were observed in the tumor volume or macrophage phenotype. The present data showed that nanoparticles possess the capability of delivering both oxygen and iron to macrophages; though, they do not possess the ability to effectively repolarize M2 macrophages. Such strategies could be used in conjunction with other potent molecules to avoid M1 macrophages to inevitably differentiate to M2 macrophages.

Adverse Responses following Exposure to Subtoxic Concentrations of Zinc Oxide and Nickle Oxide Nanoparticles in the Raw 264.7 Cells

The incorporation of engineered nanomaterials (ENMs) in biomedical and consumer products has been growing, leading to increased human exposure. Previous research was largely focused on studying direct ENM toxicity in unrealistic high-exposure settings. This could result in overlooking potential adverse responses at low and subtoxic exposure levels. This study investigated adverse cellular outcomes to subtoxic concentrations of zinc oxide (ZnONPs) or nickel oxide (NiONPs) nanoparticles in the Raw 264.7 cells, a macrophage-like cell model. Exposure to both nanoparticles resulted in a concentration-dependent reduction of cell viability. A subtoxic concentration of 6.25 µg/mL (i.e., no observed adverse effect level) was used in subsequent experiments. Exposure to both nanoparticles at subtoxic levels induced reactive oxygen species generation. Cellular internalization data demonstrated significant uptake of NiONPs, while there was minimal uptake of ZnONPs, suggesting a membrane-driven interaction. Although subtoxic exposure to both nanoparticles was not associated with cell activation (based on the expression of MHC-II and CD86 surface markers), it resulted in the modulation of the lipopolysaccharide-induced inflammatory response (TNFα and IL6), and cells exposed to ZnONPs had reduced cell phagocytic capacity. Furthermore, subtoxic exposure to the nanoparticles distinctly altered the levels of several cellular metabolites involved in cell bioenergetics. These findings suggest that exposure to ENMs at subtoxic levels may not be devoid of adverse health outcomes. This emphasizes the importance of establishing sensitive endpoints of exposure and toxicity beyond conventional toxicological testing.

Silica nanoparticles promoted pro-inflammatory macrophage and foam cell transformation via ROS/PPARγ/NF-κB signaling

Experimental evidence has pointed out silica nanoparticles (SiNPs) possessing a proatherogenic capability. However, the interplay between SiNPs and macrophages in the pathogenesis of atherosclerosis was poorly understood. Here, we demonstrated SiNPs could promote macrophage adhesion to endothelial cells, accompanied by elevated Vcam1 and Mcp1. Upon SiNPs stimuli, macrophages manifested enhanced phagocytic activity and a pro-inflammatory phenotype, as reflected by the transcriptional determination of M1/M2-related biomarkers. In particular, our data certified the increased macrophage M1 subset facilitated more lipid accumulation and resultant foam cell transformation in comparison to the M2 phenotype. More importantly, the mechanistic investigations revealed ROS-mediated PPARγ/NF-κB signaling was a key contributor to the above phenomena. That was, SiNPs caused ROS accumulation in macrophages, resulting in the deactivation of PPARγ, nuclear translocation of NF-κB, ultimately contributing to macrophage phenotype shift toward M1 and foam cell transformation. Collectively, we first revealed SiNPs facilitated pro-inflammatory macrophage and foam cell transformation via ROS/PPARγ/NF-κB signaling. These data would provide new insight into the atherogenic property of SiNPs in a macrophage model.

Modulation of macrophage polarization by iron-based nanoparticles

Macrophage polarization is an essential process involved in immune regulation. In response to different microenvironmental stimulation, macrophages polarize into cells with different phenotypes and functions, most typically M1 (pro-inflammatory) and M2 (anti-inflammatory) macrophages. Iron-based nanoparticles have been widely explored and reported to regulate macrophage polarization for various biomedical applications. However, the influence factors and modulation mechanisms behind are complicated and not clear. In this review, we systemically summarized different iron-based nanoparticles that regulate macrophage polarization and function and discussed the influence factors and mechanisms underlying the modulation process. This review aims to deepen the understanding of the modulation of macrophage polarization by iron-based nanoparticles and expects to provide evidence and guidance for subsequent design and application of iron-based nanoparticles with specific macrophage modulation functions.

Adverse effects and underlying mechanism of amorphous silica nanoparticles in liver

Amorphous silica nanoparticles (SiNPs) have been widely used and mass-producted due to its unique properties. With the life cycle of SiNPs-based products, SiNPs are further released into the air, soil, surface water and sediment, resulting in an increasing risk to humans. SiNPs could enter into the human body through vein, respiratory tract, digestive tract or skin. Moreover, recent evidences have showed that, regardless of exposure pathways, SiNPs could even be traced in liver, which is gradually considered as one of the main organs that SiNPs accumulate. Increasing evidences supported the link between SiNPs exposure and adverse liver effects. However, the research models are diverse and the molecular mechanisms have not been well integrated. In this review, the liver-related studies of SiNPs in vivo and in vitro were screened from the PubMed database by systematic retrieval method. We explored the interaction between SiNPs and the liver, and especially proposed a framework of SiNPs-caused liver toxicity, considering AOP Wiki and existing studies. We identified increased reactive oxygen species (ROS) as a molecular initiating event (MIE), oxidative stress, endoplasmic reticulum stress, lysosome disruption and mitochondrial dysfunction as subsequent key events (KEs), which gradually led to adverse outcomes (AOs) containing liver dysfunction and liver fibrosis through a series of key events about cell inflammation and death such as hepatocyte apoptosis/pyroptosis, hepatocyte autophagy dysfuncton and hepatic macrophages pyroptosis. To our best knowledge, this is the first AOP proposed on SiNPs-related liver toxicity. In the future, more epidemiological studies need to be performed and more biomarkers need to be explored to improve the AOP framework for SiNPs-associated liver toxicity.

Nanomaterials targeting macrophages in sepsis: A promising approach for sepsis management

Sepsis is a life-threatening organ dysfunction resulting from dysregulated host responses to infection. Macrophages play significant roles in host against pathogens and the immunopathogenesis of sepsis, such as phagocytosis of pathogens, secretion of cytokines, and phenotype reprogramming. However, the rapid progression of sepsis impairs macrophage function, and conventional antimicrobial and supportive treatment are not sufficient to restore dysregulated macrophages roles. Nanoparticles own unique physicochemical properties, surface functions, localized surface plasmon resonance phenomenon, passive targeting in vivo, good biocompatibility and biodegradability, are accessible for biomedical applications. Once into the body, NPs are recognized by host immune system. Macrophages are phagocytes in innate immunity dedicated to the recognition of foreign substances, including nanoparticles, with which an immune response subsequently occurs. Various design strategies, such as surface functionalization, have been implemented to manipulate the recognition of nanoparticles by monocytes/macrophages, and engulfed by them to regulate their function in sepsis, compensating for the shortcomings of sepsis traditional methods. The review summarizes the mechanism of nanomaterials targeting macrophages and recent advances in nanomedicine targeting macrophages in sepsis, which provides good insight for exploring macrophage-based nano-management in sepsis.

Influence of Impurities from Manufacturing Process on the Toxicity Profile of Boron Nitride Nanotubes

The toxicity of boron nitride nanotubes (BNNTs) has been the subject of conflicting reports, likely due to differences in the residuals and impurities that can make up to 30-60% of the material produced based on the manufacturing processes and purification employed. Four BNNTs manufactured by induction thermal plasma process with a gradient of BNNT purity levels achieved through sequential gas purification, water and solvent washing, allowed assessing the influence of these residuals/impurities on the toxicity profile of BNNTs. Extensive characterization including infrared and X-ray spectroscopy, thermogravimetric analysis, size, charge, surface area, and density captured the alteration in physicochemical properties as the material went through sequential purification. The material from each step is screened using acellular and in vitro assays for evaluating general toxicity, mechanisms of toxicity, and macrophage function. As the material increased in purity, there are more high-aspect-ratio particulates and a corresponding distinct increase in cytotoxicity, nuclear factor-κB transcription, and inflammasome activation. There is no alteration in macrophage function after BNNT exposure with all purity grades. The cytotoxicity and mechanism of screening clustered with the purity grade of BNNTs, illustrating that greater purity of BNNT corresponds to greater toxicity.

Superparamagnetic Iron Oxide Nanoparticles for Immunotherapy of Cancers through Macrophages and Magnetic Hyperthermia

Cancer immunotherapy has tremendous promise, but it has yet to be clinically applied in a wider variety of tumor situations. Many therapeutic combinations are envisaged to improve their effectiveness. In this way, strategies capable of inducing immunogenic cell death (e.g., doxorubicin, radiotherapy, hyperthermia) and the reprogramming of the immunosuppressive tumor microenvironment (TME) (e.g., M2-to-M1-like macrophages repolarization of tumor-associated macrophages (TAMs)) are particularly appealing to enhance the efficacy of approved immunotherapies (e.g., immune checkpoint inhibitors, ICIs). Due to their modular construction and versatility, iron oxide-based nanomedicines such as superparamagnetic iron oxide nanoparticles (SPIONs) can combine these different approaches in a single agent. SPIONs have already shown their safety and biocompatibility and possess both drug-delivery (e.g., chemotherapy, ICIs) and magnetic capabilities (e.g., magnetic hyperthermia (MHT), magnetic resonance imaging). In this review, we will discuss the multiple applications of SPIONs in cancer immunotherapy, focusing on their theranostic properties to target TAMs and to generate MHT. The first section of this review will briefly describe immune targets for NPs. The following sections will deal with the overall properties of SPIONs (including MHT). The last section is dedicated to the SPION-induced immune response through its effects on TAMs and MHT.

Smart and Multi-Functional Magnetic Nanoparticles for Cancer Treatment Applications: Clinical Challenges and Future Prospects

Iron oxide nanoparticle (IONPs) have become a subject of interest in various biomedical fields due to their magnetism and biocompatibility. They can be utilized as heat mediators in magnetic hyperthermia (MHT) or as contrast media in magnetic resonance imaging (MRI), and ultrasound (US). In addition, their high drug-loading capacity enabled them to be therapeutic agent transporters for malignancy treatment. Hence, smartening them allows for an intelligent controlled drug release (CDR) and targeted drug delivery (TDD). Smart magnetic nanoparticles (SMNPs) can overcome the impediments faced by classical chemo-treatment strategies, since they can be navigated and release drug via external or internal stimuli. Recently, they have been synchronized with other modalities, e.g., MRI, MHT, US, and for dual/multimodal theranostic applications in a single platform. Herein, we provide an overview of the attributes of MNPs for cancer theranostic application, fabrication procedures, surface coatings, targeting approaches, and recent advancement of SMNPs. Even though MNPs feature numerous privileges over chemotherapy agents, obstacles remain in clinical usage. This review in particular covers the clinical predicaments faced by SMNPs and future research scopes in the field of SMNPs for cancer theranostics.

Nano toolbox in immune modulation and nanovaccines

Despite the great success of vaccines over two centuries, the conventional strategy is based on attenuated/altered microorganisms. However, this is not effective for all microbes and often fails to elicit a protective immune response, and sometimes poses unexpected safety risks. The expanding nano toolbox may overcome some of the roadblocks in vaccine development given the plethora of unique nanoparticle (NP)-based platforms that can successfully induce specific immune responses leading to exciting and novel solutions. Nanovaccines necessitate a thorough understanding of the immunostimulatory effect of these nanotools. We present a comprehensive description of strategies in which nanotools have been used to elicit an immune response and provide a perspective on how nanotechnology can lead to future personalized nanovaccines.

In vivo and in vitro toxicity of a stainless-steel aerosol generated during thermal spray coating

Thermal spray coating is an industrial process in which molten metal is sprayed at high velocity onto a surface as a protective coating. An automated electric arc wire thermal spray coating aerosol generator and inhalation exposure system was developed to simulate an occupational exposure and, using this system, male Sprague-Dawley rats were exposed to stainless steel PMET720 aerosols at 25 mg/m³ × 4 h/day × 9 day. Lung injury, inflammation, and cytokine alteration were determined. Resolution was assessed by evaluating these parameters at 1, 7, 14 and 28 d after exposure. The aerosols generated were also collected and characterized. Macrophages were exposed in vitro over a wide dose range (0-200 µg/ml) to determine cytotoxicity and to screen for known mechanisms of toxicity. Welding fumes were used as comparative particulate controls. In vivo lung damage, inflammation and alteration in cytokines were observed 1 day post exposure and this response resolved by day 7. Alveolar macrophages retained the particulates even after 28 day post-exposure. In line with the pulmonary toxicity findings, in vitro cytotoxicity and membrane damage in macrophages were observed only at the higher doses. Electron paramagnetic resonance showed in an acellular environment the particulate generated free radicals and a dose-dependent increase in intracellular oxidative stress and NF-kB/AP-1 activity was observed. PMET720 particles were internalized via clathrin and caveolar mediated endocytosis as well as actin-dependent pinocytosis/phagocytosis. The results suggest that compared to stainless steel welding fumes, the PMET 720 aerosols were not as overtly toxic, and the animals recovered from the acute pulmonary injury by 7 days.

The Relevance of Physico-Chemical Properties and Protein Corona for Evaluation of Nanoparticles Immunotoxicity-In Vitro Correlation Analysis on THP-1 Macrophages

Alongside physiochemical properties (PCP), it has been suggested that the protein corona of nanoparticles (NPs) plays a crucial role in the response of immune cells to NPs. However, due to the great variety of NPs, target cells, and exposure protocols, there is still no clear relationship between PCP, protein corona composition, and the immunotoxicity of NPs. In this study, we correlated PCP and the protein corona composition of NPs to the THP-1 macrophage response, focusing on selected toxicological endpoints: cell viability, reactive oxygen species (ROS), and cytokine secretion. We analyzed seven commonly used engineered NPs (SiO2, silver, and TiO2) and magnetic NPs. We show that with the exception of silver NPs, all of the tested TiO2 types and SiO2 exhibited moderate toxicities and a transient inflammatory response that was observed as an increase in ROS, IL-8, and/or IL-1β cytokine secretion. We observed a strong correlation between the size of the NPs in media and IL-1β secretion. The induction of IL-1β secretion was completely blunted in NLR family pyrin domain containing 3 (NLRP3) knockout THP-1 cells, indicating activation of the inflammasome. The correlations analysis also implicated the association of specific NP corona proteins with the induction of cytokine secretion. This study provides new insights toward a better understanding of the relationships between PCP, protein corona, and the inflammatory response of macrophages for different engineered NPs, to which we are exposed on a daily basis.

Copper oxide nanoparticles trigger macrophage cell death with misfolding of Cu/Zn superoxide dismutase 1 (SOD1)

Background

Copper oxide (CuO) nanoparticles (NPs) are known to trigger cytotoxicity in a variety of cell models, but the mechanism of cell death remains unknown. Here we addressed the mechanism of cytotoxicity in macrophages exposed to CuO NPs versus copper chloride (CuCl₂).

Methods

The mouse macrophage cell line RAW264.7 was used as an in vitro model. Particle uptake and the cellular dose of Cu were investigated by transmission electron microscopy (TEM) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. The deposition of Cu in lysosomes isolated from macrophages was also determined by ICP-MS. Cell viability (metabolic activity) was assessed using the Alamar Blue assay, and oxidative stress was monitored by a variety of methods including a luminescence-based assay for cellular glutathione (GSH), and flow cytometry-based detection of mitochondrial superoxide and mitochondrial membrane potential. Protein aggregation was determined by confocal microscopy using an aggresome-specific dye and protein misfolding was determined by circular dichroism (CD) spectroscopy. Lastly, proteasome activity was investigated using a fluorometric assay.

Results

We observed rapid cellular uptake of CuO NPs in macrophages with deposition in lysosomes. CuO NP-elicited cell death was characterized by mitochondrial swelling with signs of oxidative stress including the production of mitochondrial superoxide and cellular depletion of GSH. We also observed a dose-dependent accumulation of polyubiquitinated proteins and loss of proteasomal function in CuO NP-exposed cells, and we could demonstrate misfolding and mitochondrial translocation of superoxide dismutase 1 (SOD1), a Cu/Zn-dependent enzyme that plays a pivotal role in the defense against oxidative stress. The chelation of copper ions using tetrathiomolybdate (TTM) prevented cell death whereas inhibition of the cellular SOD1 chaperone aggravated toxicity. Moreover, CuO NP-triggered cell death was insensitive to the pan-caspase inhibitor, zVAD-fmk, and to wortmannin, an inhibitor of autophagy, implying that this was a non-apoptotic cell death. ZnO NPs, on the other hand, triggered autophagic cell death.

Conclusions

CuO NPs undergo dissolution in lysosomes leading to copper-dependent macrophage cell death characterized by protein misfolding and proteasomal insufficiency. Specifically, we present novel evidence for Cu-induced SOD1 misfolding which accords with the pronounced oxidative stress observed in CuO NP-exposed macrophages. These results are relevant for our understanding of the consequences of inadvertent human exposure to CuO NPs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-022-00467-w.

Overcoming Multidrug Resistance of Antibiotics via Nanodelivery Systems

Antibiotic resistance has become a threat to microbial therapies nowadays. The conventional approaches possess several limitations to combat microbial infections. Therefore, to overcome such complications, novel drug delivery systems have gained pharmaceutical scientists’ interest. Significant findings have validated the effectiveness of novel drug delivery systems such as polymeric nanoparticles, liposomes, metallic nanoparticles, dendrimers, and lipid-based nanoparticles against severe microbial infections and combating antimicrobial resistance. This review article comprises the specific mechanism of antibiotic resistance development in bacteria. In addition, the manuscript incorporated the advanced nanotechnological approaches with their mechanisms, including interaction with the bacterial cell wall, inhibition of biofilm formations, activation of innate and adaptive host immune response, generation of reactive oxygen species, and induction of intracellular effect to fight against antibiotic resistance. A section of this article demonstrated the findings related to the development of delivery systems. Lastly, the role of microfluidics in fighting antimicrobial resistance has been discussed. Overall, this review article is an amalgamation of various strategies to study the role of novel approaches and their mechanism to fight against the resistance developed to the antimicrobial therapies.

Immunotoxicity of nanomaterials in health and disease: Current challenges and emerging approaches for identifying immune modifiers in susceptible populations

Nanosafety assessment has experienced an intense era of research during the past decades driven by a vivid interest of regulators, industry, and society. Toxicological assays based on in vitro cellular models have undergone an evolution from experimentation using nanoparticulate systems on singular epithelial cell models to employing advanced complex models more realistically mimicking the respective body barriers for analyzing their capacity to alter the immune state of exposed individuals. During this phase, a number of lessons were learned. We have thus arrived at a state where the next chapters have to be opened, pursuing the following objectives: (1) to elucidate underlying mechanisms, (2) to address effects on vulnerable groups, (3) to test material mixtures, and (4) to use realistic doses on (5) sophisticated models. Moreover, data reproducibility has become a significant demand. In this context, we studied the emerging concept of adverse outcome pathways (AOPs) from the perspective of immune activation and modulation resulting in pro-inflammatory versus tolerogenic responses. When considering the interaction of nanomaterials with biological systems, protein corona formation represents the relevant molecular initiating event (e.g., by potential alterations of nanomaterial-adsorbed proteins). Using this as an example, we illustrate how integrated experimental-computational workflows combining in vitro assays with in silico models aid in data enrichment and upon comprehensive ontology-annotated (meta)data upload to online repositories assure FAIRness (Findability, Accessibility, Interoperability, Reusability). Such digital twinning may, in future, assist in early-stage decision-making during therapeutic development, and hence, promote safe-by-design innovation in nanomedicine. Moreover, it may, in combination with in silico-based exposure-relevant dose-finding, serve for risk monitoring in particularly loaded areas, for example, workplaces, taking into account pre-existing health conditions. This article is categorized under: Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials.

In Vivo Distribution of Poly(ethylene glycol) Functionalized Iron Oxide Nanoclusters: An Ultrastructural Study

The in vivo distribution of 50 nm clusters of polyethylene glycol-conjugated superparamagnetic iron oxide nanoparticles (SPIONs-PEG) was conducted in this study. SPIONs-PEG were synthesized de novo, and their structure and paramagnetic behaviors were analyzed by specific methods (TEM, DLS, XRD, VSM). Wistar rats were treated with 10 mg Fe/kg body weight SPIONs-PEG and their organs and blood were examined at two intervals for short-term (15, 30, 60, 180 min) and long-term (6, 12, 24 h) exposure evaluation. Most exposed organs were investigated through light and transmission electron microscopy, and blood and urine samples were examined through fluorescence spectrophotometry. SPIONs-PEG clusters entered the bloodstream after intraperitoneal and intravenous administrations and ended up in the urine, with the highest clearance at 12 h. The skin and spleen were within normal histological parameters, while the liver, kidney, brain, and lungs showed signs of transient local anoxia or other transient pathological affections. This study shows that once internalized, the synthesized SPIONs-PEG disperse well through the bloodstream with minor to nil induced tissue damage, are biocompatible, have good clearance, and are suited for biomedical applications.

Biodegradation of graphdiyne oxide in classically activated (M1) macrophages modulates cytokine production

Graphdiyne oxide (GDYO) is a carbon-based nanomaterial possessing sp² and sp-hybridized carbon atoms with many promising applications. However, its biocompatibility and potential biodegradability remain poorly understood. Using human primary monocyte-derived macrophages as a model we show here that GDYO elicited little or no cytotoxicity toward classically activated (M1) and alternatively activated (M2) macrophages. Moreover, GDYO reprogrammed M2 macrophages towards M1 macrophages, as evidenced by the elevation of specific cell surface markers and cytokines and the induction of NOS2 expression. We could also show inducible nitric oxide synthase (iNOS)-dependent biodegradation of GDYO in M1 macrophages, and this was corroborated in an acellular system using the peroxynitrite donor, SIN-1. Furthermore, GDYO elicited the production of pro-inflammatory cytokines in a biodegradation-dependent manner. Our findings shed new light on the reciprocal interactions between GDYO and human macrophages. This is relevant for biomedical applications of GDYO such as the re-education of tumor-associated macrophages or TAMs.

Less is more: biological effects of NiSe2/rGO nanocomposites with low dose provide new insight for risk assessment

Nickel selenide nanomaterials (NiSe₂ NMs) with different vacancies demonstrated high catalytic activity as electrocatalyst in oxygen evolution reaction. As the growing needs of the industrial applications in electrocatalyst, the increased occupational exposure and environmental releasing of NMs would be unavoidable. While, much efforts have been made to evaluate the ecological safety of such engineered NMs at unrealistically high concentrations, failed to provide the comprehensively guideline for exposure thresholds. To supplement the current knowledge gap, we testified the cytotoxicity of NiSe₂/rGO nanocomposites with different surface defects under more realistic exposure mode. Compared with the short-term exposure and repetitive exposure, rat lung macrophages exhibited the augmented oxidative stress, dysfunction of mitochondria, damage of DNA and disorder of calcium homeostasis under the long-term NiSe₂/rGO exposure. Noteworthily, no significant differences could be found between the NiSe₂/rGO with different surface defects, indicated that the defect type of NMs were not the accurate predictor for real risk assessment. Collectively, the study provided the real potential toxic effects and exposure thresholds of NMs that might be highly possible industrial produced, and appealed the new insight for risk assessments of engineered NMs under the long-term exposure, which exhibited difference from the traditional evaluation of short-term and repetitive exposure.

Ozone-dependent increases in lung glucocorticoids and macrophage response: Effect modification by innate stress axis function

Although considerable inter-individual variability exists in health effects associated with air pollutant exposure, underlying reasons remain unclear. We examined whether innate differences in stress axis function modify lung glucocorticoid and macrophage responses to ozone (O3). Highly-stress responsive Fischer (F344) and less responsive Lewis (LEW) rats were exposed for 4 h by nose-only inhalation to air or O3 (0.8 ppm). Ozone increased corticosterone recovered by bronchoalveolar lavage in both strains (F344 > LEW). Higher corticosterone in F344 was associated with a blunted response to O3 of macrophage pro-inflammatory genes compared to LEW. Pharmacological inhibition of O3-dependent corticosterone production in F344 enhanced the inflammatory gene response to O3, mimicking the LEW phenotype. Examination of potential impacts of glucocorticoids on macrophage function using a human monocyte-derived macrophage cell line (THP-1) showed that cortisol modified phagocytosis in a macrophage phenotype-dependent manner. Overall, our data implicate endogenous glucocorticoids in the regulation of pulmonary macrophage responses to O3.

Inorganic material based macrophage regulation for cancer therapy: basic concepts and recent advances

Macrophages with the M1 phenotype are a type of immune cell with exciting prospects for cancer therapy; however, when these macrophages infiltrate into tumours, many of them are induced by the tumour microenvironment to transform into the M2 type, which can enable tumour defence against external therapeutic strategies, assisting in tumour development. Macrophages have strong plasticity and functional heterogeneity, and their phenotypic transformation is complex and still poorly understood in relation to cancer therapy. Recent material advances in inorganic nanomaterials, especially inorganic elements in vivo, have accelerated the development of macrophage regulation-based cancer treatments. This review summarizes the basics of recent research on macrophage phenotype transformation and discusses the current challenges in macrophage type regulation. Then, the current achievements involving inorganic material-based macrophage regulation and the related anticancer effects of induced macrophages and their extracellular secretions are reviewed systematically. Importantly, inorganic nanomaterial-based macrophage phenotype regulation is flexible and can be adapted for different types of cancer therapies, presenting a possible novel approach for the generation of immune materials for cancer therapy.

Pulmonary toxicity and gene expression changes after short-term inhalation exposure to surface-modified copper oxide nanoparticles

Copper oxide nanoparticles (CuO NPs) have previously been shown to cause dose-dependent pulmonary toxicity following inhalation. Here, CuO NPs (10 nm), coated with polyethylenimine (PEI) or ascorbate (ASC) resulting in positively or negatively charged NPs, respectively, were evaluated. Rats were exposed nose-only to similar exposure dose levels of ASC or PEI coated CuO NPs for 5 consecutive days. On day 6 and day 27 post-exposure, pulmonary toxicity markers in bronchoalveolar lavage fluid (BALF), lung histopathology and genome-wide transcriptomic changes in lungs, were assessed. BALF analyses showed a dose-dependent pulmonary inflammation and cell damage, which was supported by the lung histopathological findings of hypertrophy/hyperplasia of bronchiolar and alveolar epithelium, interstitial and alveolar inflammation, and paracortical histiocytosis in mediastinal lymph nodes for both types of CuO NPs. Transcriptomics analysis showed that pathways related to inflammation and cell proliferation were significantly activated. Additionally, we found evidence for the dysregulation of drug metabolism-related genes, especially in rats exposed to ASC-coated CuO NPs. Overall, no differences in the type of toxic effects and potency between the two surface coatings could be established, except with respect to the (regional) dose that initiates bronchiolar and alveolar hypertrophy. This disproves our hypothesis that differences in surface coatings affect the pulmonary toxicity of CuO NPs.

Blue light-triggered Fe2+-release from monodispersed ferrihydrite nanoparticles for cancer iron therapy

Site-specific Fe²⁺ generation is promising for tumor therapy. Up to now, reported materials or systems for Fe²⁺ delivery do not naturally exist in the body, and their biological safety and toxicity are concerned. Herein, inspired by the natural biomineral ferrihydrite in ferritin, we synthesized monodispersed ferrihydrite nanoparticles and demonstrated a light triggered Fe²⁺ generation on tumor sites. Ferrihydrite nanoparticles of 20-30 nm in diameter possessed high cellular uptake efficiency and good biocompatibility. Under common blue light illumination, a large amount of Fe²⁺ could be released from ferrihydrite and promote the iron/reactive oxygen species (ROS)-related irreversible DNA fragmentation and glutathione peroxidase 4 (GPX4) inhibition, which led to the apoptosis- and ferroptosis-depended cancer cell proliferation inhibition. On mice, this method induced tumor associated macrophage (TAM) polarization from the tumor-promoting M2 type to the tumor-killing M1 type. With the intravenous pre-injection of ferrihydrite, the combinational effects of the light/Fe²⁺-approach attenuated pulmonary metastasis on mice. These results demonstrated a novel external light controlled Fe²⁺-generation approach based on biomineral, which will fully tap the anti-cancer potential of Fe²⁺ in chemo-dynamic, photo-dynamic and immune-activating therapies.

Manually curated transcriptomics data collection for toxicogenomic assessment of engineered nanomaterials

Toxicogenomics (TGx) approaches are increasingly applied to gain insight into the possible toxicity mechanisms of engineered nanomaterials (ENMs). Omics data can be valuable to elucidate the mechanism of action of chemicals and to develop predictive models in toxicology. While vast amounts of transcriptomics data from ENM exposures have already been accumulated, a unified, easily accessible and reusable collection of transcriptomics data for ENMs is currently lacking. In an attempt to improve the FAIRness of already existing transcriptomics data for ENMs, we curated a collection of homogenized transcriptomics data from human, mouse and rat ENM exposures in vitro and in vivo including the physicochemical characteristics of the ENMs used in each study.

Can the biomolecular corona induce an allergic reaction?-A proof-of-concept study

Ferumoxytol nanoparticles are being used clinically for the treatment of anemia and molecular imaging in patients. It is well documented that while most patients tolerate ferumoxytol well, a small percentage of patients (i.e., 0.01%) develop severe allergic reactions. The purpose of our proof-of-concept study was to determine whether patients with or without hypersensitivity reactions have specific protein corona profiles around ferumoxytol nanoparticles. In a retrospective, institutional review board approved pilot study, we enrolled 13 pediatric patients (5 girls, 8 boys, mean age 16.9 ± 8.2 years) who received a ferumoxytol-enhanced magnetic resonance imaging and who did (group 1, n = 5) or did not (group 2, n = 8) develop an allergic reaction. Blood samples of these patients were incubated with ferumoxytol, and the formation of a hard protein corona around ferumoxytol nanoparticles was measured by dynamic light scattering, zeta potential, and liquid chromatography-mass spectrometry. We also performed in vitro immune response analyses to randomly selected coronas from each group. Our results provide preliminary evidence that ex vivo analysis of the biomolecular corona may provide useful and predictive information on the possibility of severe allergic reactions to ferumoxytol nanoparticles. In the future, patients with predisposition of an allergic reaction to ferumoxytol may be diagnosed based on the proteomic patterns of the corona around ferumoxytol in their blood sample.

Designing and Immunomodulating Multiresponsive Nanomaterial for Cancer Theranostics

Cancer has been widely investigated yet limited in its manifestation. Cancer treatment holds innovative and futuristic strategies considering high disease heterogeneity. Chemotherapy, radiotherapy and surgery are the most explored pillars; however optimal therapeutic window and patient compliance recruit constraints. Recently evolved immunotherapy demonstrates a vital role of the host immune system to prevent metastasis recurrence, still undesirable clinical response and autoimmune adverse effects remain unresolved. Overcoming these challenges, tunable biomaterials could effectively control the co-delivery of anticancer drugs and immunomodulators. Current status demands a potentially new approach for minimally invasive, synergistic, and combinatorial nano-biomaterial assisted targeted immune-based treatment including therapeutics, diagnosis and imaging. This review discusses the latest findings of engineering biomaterial with immunomodulating properties and implementing novel developments in designing versatile nanosystems for cancer theranostics. We explore the functionalization of nanoparticle for delivering antitumor therapeutic and diagnostic agents promoting immune response. Through understanding the efficacy of delivery system, we have enlightened the applicability of nanomaterials as immunomodulatory nanomedicine further advancing to preclinical and clinical trials. Future and present ongoing improvements in engineering biomaterial could result in generating better insight to deal with cancer through easily accessible immunological interventions.

Brake dust exposure exacerbates inflammation and transiently compromises phagocytosis in macrophages

Studies have emphasised the importance of combustion-derived particles in eliciting adverse health effects, especially those produced by diesel vehicles. In contrast, few investigations have explored the potential toxicity of particles derived from tyre and brake wear, despite their significant contributions to total roadside particulate mass. The objective of this study was to compare the relative toxicity of compositionally distinct brake abrasion dust (BAD) and diesel exhaust particles (DEP) in a cellular model that is relevant to human airways. Although BAD contained considerably more metals/metalloids than DEP (as determined by inductively coupled plasma mass spectrometry) similar toxicological profiles were observed in U937 monocyte-derived macrophages following 24 h exposures to 4-25 μg ml-1 doses of either particle type. Responses to the particles were characterised by dose-dependent decreases in mitochondrial depolarisation (p ≤ 0.001), increased secretion of IL-8, IL-10 and TNF-α (p ≤ 0.05 to p ≤ 0.001) and decreased phagocytosis of S. aureus (p ≤ 0.001). This phagocytic deficit recovered, and the inflammatory response resolved when challenged cells were incubated for a further 24 h in particle-free media. These responses were abrogated by metal chelation using desferroxamine. At minimally cytotoxic doses both DEP and BAD perturbed bacterial clearance and promoted inflammatory responses in U937 cells with similar potency. These data emphasise the requirement to consider contributions of abrasion particles to traffic-related clinical health effects.

The Impact of Nanoparticles on Innate Immune Activation by Live Bacteria

The innate immune system evolved to detect and react against potential dangers such as bacteria, viruses, and environmental particles. The advent of modern technology has exposed innate immune cells, such as monocytes, macrophages, and dendritic cells, to a relatively novel type of particulate matter, i.e., engineered nanoparticles. Nanoparticles are not inherently pathogenic, and yet cases have been described in which specific nanoparticle types can either induce innate/inflammatory responses or modulate the activity of activated innate cells. Many of these studies rely upon activation by agonists of toll-like receptors, such as lipopolysaccharide or peptidoglycan, instead of the more realistic stimulation by whole live organisms. In this review we examine and discuss the effects of nanoparticles on innate immune cells activated by live bacteria. We focus in particular on how nanoparticles may interfere with bacterial processes in the context of innate activation, and confine our scope to the effects due to particles themselves, rather than to molecules adsorbed on the particle surface. Finally, we examine the long-lasting consequences of coexposure to nanoparticles and bacteria, in terms of potential microbiome alterations and innate immune memory, and address nanoparticle-based vaccine strategies against bacterial infection.

Use of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) via Multiple Imaging Modalities and Modifications to Reduce Cytotoxicity: An Educational Review

The aim of the present educational review on superparamagnetic iron oxide nanoparticles (SPIONs) is to inform and guide young scientists and students about the potential use and challenges associated with SPIONs. The present review discusses the basic concepts of magnetic resonance imaging (MRI), basic construct of SPIONs, cytotoxic challenges associated with SPIONs, shape and sizes of SPIONs, site-specific accumulation of SPIONs, various methodologies applied to reduce cytotoxicity including coatings with various materials, and application of SPIONs in targeted delivery of chemotherapeutics (Doxorubicin), biotherapeutics (DNA, siRNA), and positron emission tomography (PET) imaging applications.

Organ-specific toxicity of magnetic iron oxide-based nanoparticles

The unique properties of magnetic iron oxide nanoparticles determined their widespread use in medical applications, the food industry, textile industry, which in turn led to environmental pollution. These factors determine the long-term nature of the effect of iron oxide nanoparticles on the body. However, studies in the field of chronic nanotoxicology of magnetic iron particles are insufficient and scattered. Studies show that toxicity may be increased depending on oral and inhalation routes of administration rather than injection. The sensory nerve pathway can produce a number of specific effects not seen with other routes of administration. Organ systems showing potential toxic effects when injected with iron oxide nanoparticles include the nervous system, heart and lungs, the thyroid gland, and organs of the mononuclear phagocytic system (MPS). A special place is occupied by the reproductive system and the effect of nanoparticles on the health of the first and second generations of individuals exposed to the toxic effects of iron oxide nanoparticles. This knowledge should be taken into account for subsequent studies of the toxicity of iron oxide nanoparticles. Particular attention should be paid to tests conducted on animals with pathologies representing human chronic socially significant diseases. This part of preclinical studies is almost in its infancy but of great importance for further medical translation on nanomaterials to practice.

Multiparametric Profiling of Engineered Nanomaterials: Unmasking the Surface Coating Effect

Despite considerable efforts, the properties that drive the cytotoxicity of engineered nanomaterials (ENMs) remain poorly understood. Here, the authors inverstigate a panel of 31 ENMs with different core chemistries and a variety of surface modifications using conventional in vitro assays coupled with omics-based approaches. Cytotoxicity screening and multiplex-based cytokine profiling reveals a good concordance between primary human monocyte-derived macrophages and the human monocyte-like cell line THP-1. Proteomics analysis following a low-dose exposure of cells suggests a nonspecific stress response to ENMs, while microarray-based profiling reveals significant changes in gene expression as a function of both surface modification and core chemistry. Pathway analysis highlights that the ENMs with cationic surfaces that are shown to elicit cytotoxicity downregulated DNA replication and cell cycle responses, while inflammatory responses are upregulated. These findings are validated using cell-based assays. Notably, certain small, PEGylated ENMs are found to be noncytotoxic yet they induce transcriptional responses reminiscent of viruses. In sum, using a multiparametric approach, it is shown that surface chemistry is a key determinant of cellular responses to ENMs. The data also reveal that cytotoxicity, determined by conventional in vitro assays, does not necessarily correlate with transcriptional effects of ENMs.

Metadata Stewardship in Nanosafety Research: Community-Driven Organisation of Metadata Schemas to Support FAIR Nanoscience Data

The emergence of nanoinformatics as a key component of nanotechnology and nanosafety assessment for the prediction of engineered nanomaterials (NMs) properties, interactions, and hazards, and for grouping and read-across to reduce reliance on animal testing, has put the spotlight firmly on the need for access to high-quality, curated datasets. To date, the focus has been around what constitutes data quality and completeness, on the development of minimum reporting standards, and on the FAIR (findable, accessible, interoperable, and reusable) data principles. However, moving from the theoretical realm to practical implementation requires human intervention, which will be facilitated by the definition of clear roles and responsibilities across the complete data lifecycle and a deeper appreciation of what metadata is, and how to capture and index it. Here, we demonstrate, using specific worked case studies, how to organise the nano-community efforts to define metadata schemas, by organising the data management cycle as a joint effort of all players (data creators, analysts, curators, managers, and customers) supervised by the newly defined role of data shepherd. We propose that once researchers understand their tasks and responsibilities, they will naturally apply the available tools. Two case studies are presented (modelling of particle agglomeration for dose metrics, and consensus for NM dissolution), along with a survey of the currently implemented metadata schema in existing nanosafety databases. We conclude by offering recommendations on the steps forward and the needed workflows for metadata capture to ensure FAIR nanosafety data.

Susceptibility Factors in Chronic Lung Inflammatory Responses to Engineered Nanomaterials

Engineered nanomaterials (ENMs) are products of the emerging nanotechnology industry and many different types of ENMs have been shown to cause chronic inflammation in the lungs of rodents after inhalation exposure, suggesting a risk to human health. Due to the increasing demand and use of ENMs in a variety of products, a careful evaluation of the risks to human health is urgently needed. An assessment of the immunotoxicity of ENMs should consider susceptibility factors including sex, pre-existing diseases, deficiency of specific genes encoding proteins involved in the innate or adaptive immune response, and co-exposures to other chemicals. This review will address evidence from experimental animal models that highlights some important issues of susceptibility to chronic lung inflammation and systemic immune dysfunction after pulmonary exposure to ENMs.

How Reversible Are the Effects of Fumed Silica on Macrophages? A Proteomics-Informed View

Synthetic amorphous silica is one of the most used nanomaterials, and numerous toxicological studies have studied its effects. Most of these studies have used an acute exposure mode to investigate the effects immediately after exposure. However, this exposure modality does not allow the investigation of the persistence of the effects, which is a crucial aspect of silica toxicology, as exemplified by crystalline silica. In this paper, we extended the investigations by studying not only the responses immediately after exposure but also after a 72 h post-exposure recovery phase. We used a pyrolytic silica as the test nanomaterial, as this variant of synthetic amorphous silica has been shown to induce a more persistent inflammation in vivo than precipitated silica. To investigate macrophage responses to pyrolytic silica, we used a combination of proteomics and targeted experiments, which allowed us to show that most of the cellular functions that were altered immediately after exposure to pyrolytic silica at a subtoxic dose, such as energy metabolism and cell morphology, returned to normal at the end of the recovery period. However, some alterations, such as the inflammatory responses and some aldehyde detoxification proteins, were persistent. At the proteomic level, other alterations, such as proteins implicated in the endosomal/lysosomal pathway, were also persistent but resulted in normal function, thus suggesting cellular adaptation.

Nanoparticles retard immune cells recruitment in vivo by inhibiting chemokine expression

The large-scale utilization of nanotechnology depends on public and consumer confidence in the safety of this new technology. Studying the interaction of nanoparticles with immune cells plays a vital role in the safety assessment of nanomedicine. Although some researches have indicated that the immune cells undergo severe interfere after phagocytosis of nanoparticles, the impact on immune system of the whole body are still unclear. Here, we use immune cells labeled transgenic zebrafish to study the mechanisms of nanoparticles on zebrafish immune cells. We demonstrate that gold nanoparticles (Au NPs) phagocytized by immune cells can reduce and retard the sensitivity of immune response, resulting nanoparticle-induced bluntness in immune cell (NIBIC). RNA-seq and functional analysis reveal that NIBIC is mainly induced by the inhibiting expression of chemokine receptor 5 (CCR5). Furthermore, PVP-modified Au NPs can eliminate NIBIC by inhibiting the cell phagocytosis. Our results highlight the potential risk for Au NPs in vivo and further the understanding of the mechanism of the interaction between Au NPs and the immune response. We should consider this factor in future material design and pay more attention to the process of using nanomedicines on immune diseases.

The nanomaterial-induced bystander effects reprogrammed macrophage immune function and metabolic profile

Bystander effects in biological systems are the responses shown by nontargeted neighboring cells, and critical to the bio-nano interface interactions. In addition to direct effects, bystander effects also determine the design, applications and safety of nanomaterials, although the related information of nanomaterial-induced bystander effects remain largely unknown. A coculture system of A549 and THP-1 was established to mimic the lung microenvironment to study the bystander effects of WS₂ nanosheets (representative transition-metal dichalcogenide nanosheets) on microenvironment macrophages during the inhalation exposure or the nanomaterial biomedical application in the lung. Lung cells exposed to WS₂ nanosheet resulted in an increase in reactive oxygen species and the depolarization of mitochondrial membrane potential in neighboring macrophages. Bystander exposure also induced macrophage polarization toward the anti-inflammatory M2 phenotype, which is adverse to disease therapy. Metabolomics showed that WS₂ nanosheets disturbed the energy metabolism and amino acid metabolism of macrophages, consistent with the metabolic characteristics of M2 macrophages. Nitric oxide-transforming growth factor-β1 played an important mediator in the bystander effects. Importantly, WS₂ nanosheet bystander exposure affected macrophage phagocytosis and migration and altered the macrophage immune response to endotoxin. This study improves the current understanding of bio-nano interactions and highlights the importance of neighboring cell responses, allowing us to use the maximum benefits of nanomaterials while limiting their adverse bystander effects.

Surface functionalization of exosomes for target-specific delivery and in vivo imaging & tracking: Strategies and significance

Exosomes are natural nanovesicles excreted by many cells for intercellular communication and for transfer of materials including proteins, nucleic acids and even synthetic therapeutic agents. Surface modification of exosomes imparts additional functionality to the exosomes to enable site specific drug delivery and in vivo imaging and tracking and is an emerging area in drug delivery research. The present review focuses upon these modifications on the exosomal surface, the chemistry involved and their impact on targeted drug delivery for the treatment of brain, breast, lung, liver, colon tumors and, heart diseases and for understanding their in vivo fate including their uptake mechanisms, pharmacokinetics and biodistribution. The specific exosomal membrane proteins such as tetraspanins (CD63, CD81, CD9), lactadherin (LA), lysosome associated membrane protein-2b (Lamp-2b) and, glycosyl-phosphatidyl-inositol (GPI) involved in functionalization of exosome surface have also been discussed along with different strategies of surface modification like genetic engineering, covalent modification (click chemistry and metabolic engineering of parent cells of exosomes) and non-covalent modification (multivalent electrostatic interactions, ligand-receptor interaction, hydrophobic interaction, aptamer based modification and modification by anchoring CP05 peptide) along with optical (fluorescent and bioluminescent) and radioactive isotope labelling techniques of exosomes for imaging purpose.

When Would Immunologists Consider a Nanomaterial to be Safe? Recommendations for Planning Studies on Nanosafety

The immune system is professional in recognizing and responding to non-self, including nanomaterials. Immune responses by professional and nonprofessional immune cells are thus nearly inevitable upon exposure of cells and organisms to such materials. The state of research into taking the immune system into account in nanosafety studies is reviewed and three aspects in which further improvements are desirable are identified: 1) Due to technical limitations, more stringent testing for endotoxin contamination should be made. 2) Since under overdose conditions immunity shows unphysiological responses, all doses used should be justified by being equivalent to tissue-delivered doses. 3) When markers of acute inflammation or cell stress are observed, functional assays are necessary to distinguish between homeostatic fluctuation and genuine defensive or tolerogenic responses. Since immune activation can also indicate that the immune system considers a stimulus to be harmless and induces tolerance, activation markers by themselves do not necessarily imply a danger to the body. Guidelines such as these are necessary to approach the point where specific nanomaterials are classified as safe based on reliable testing strategies.

Mechanistic Differences in Cell Death Responses to Metal-Based Engineered Nanomaterials in Kupffer Cells and Hepatocytes

The mononuclear phagocyte system in the liver is a frequent target for nanoparticles (NPs). A toxicological profiling of metal-based NPs is performed in Kupffer cell (KC) and hepatocyte cell lines. Sixteen NPs are provided by the Nanomaterial Health Implications Research Consortium of the National Institute of Environmental Health Sciences to study the toxicological effects in KUP5 (KC) and Hepa 1-6 cells. Five NPs (Ag, CuO, ZnO, SiO2 , and V2 O5 ) exhibit cytotoxicity in both cell types, while SiO2 and V2 O5 induce IL-1β production in KC. Ag, CuO, and ZnO induced caspase 3 generated apoptosis in both cell types is accompanied by ion shedding and generation of mitochondrial reactive oxygen species (ROS) in both cell types. However, the cell death response to SiO2 in KC differs by inducing pyroptosis as a result of potassium efflux, caspase 1 activation, NLRP3 inflammasome assembly, IL-1β release, and cleavage of gasdermin-D. This releases pore-performing peptide fragments responsible for pyroptotic cell swelling. Interestingly, although V2 O5 induces IL-1β release and delays caspase 1 activation by vanadium ion interference in membrane Na+ /K+ adenosine triphosphate (ATP)ase activity, the major cell death mechanism in KC (and Hepa 1-6) is caspase 3 mediated apoptosis. These findings improve the understanding of the mechanisms of metal-based engineered nanomaterial (ENM) toxicity in liver cells toward comprehensive safety evaluation.

Silver nanoparticle immunomodulatory potential in absence of direct cytotoxicity in RAW 264.7 macrophages and MPRO 2.1 neutrophils

Engineered nanomaterials (ENM) are being used in a wide range of consumer products and pharmaceuticals; hence, there is an increasing risk for human exposure and potential adverse outcomes. The immune system, vital in host defense and protection against environmental agents, is typically initiated and executed by innate effector immune cells including macrophages and neutrophils. Previous literature has reported the immune system as a major target of ENM toxicity; however, there is inconsistency regarding the immunotoxicity of ENM. This could be attributed to differences in ENM physicochemical properties, cellular models examined, biocorona formation, etc. Thus, the current study examined the toxicity and immunomodulatory effects of silver nanoparticles (AgNP), one of the most utilized ENM in consumer and medical products, in two key innate immune cell models, e.g. RAW 264.7 cells (macrophages) and differentiated MPRO 2.1 cells (promyelocytes/neutrophils). The results showed that despite a generation of reactive oxygen species, exposure to 20 nm citrate-coated AgNP was not associated with major oxidative damage, inflammatory responses, nor cytotoxicity. Nevertheless, and most importantly, pre-exposure to the AgNP for 24 h enhanced RAW 264.7 cell phagocytic ability as well as the release of inflammatory cytokine interleukin-6 in response to lipopolysaccharide (LPS). In MPRO 2.1 cells, AgNP pre-exposure also resulted in enhanced phagocytic ability; however, these cells manifest reduced cell degranulation (elastase release) and oxidative burst in response to phorbol myristate acetate (PMA). Taken together, these findings indicated to us that exposure to AgNP, despite not being directly (cyto)toxic to these cells, had the potential to alter immune cell responses. The findings underscore the import of assessing immune cell function post-exposure to ENM beyond the standard endpoints such as oxidative stress and cytotoxicity. In addition, these findings further illustrate the importance of understanding the underlying molecular mechanisms of ENM-cellular interactions, particularly in the immune system.

Targeting of Hepatic Macrophages by Therapeutic Nanoparticles

Hepatic macrophage populations include different types of cells with plastic properties that can differentiate into diverse phenotypes to modulate their properties in response to different stimuli. They often regulate the activity of other cells and play an important role in many hepatic diseases. In response to those pathological situations, they are activated, releasing cytokines and chemokines; they may attract circulating monocytes and exert functions that can aggravate the symptoms or drive reparation processes. As a result, liver macrophages are potential therapeutic targets that can be oriented toward a variety of aims, with emergent nanotechnology platforms potentially offering new perspectives for macrophage vectorization. Macrophages play an essential role in the final destination of nanoparticles (NPs) in the organism, as they are involved in their uptake and trafficking in vivo. Different types of delivery nanosystems for macrophage recognition and targeting, such as liposomes, solid-lipid, polymeric, or metallic nanoparticles, have been developed. Passive targeting promotes the accumulation of the NPs in the liver due to their anatomical and physiological features. This process is modulated by NP characteristics such as size, charge, and surface modifications. Active targeting approaches with specific ligands may also be used to reach liver macrophages. In order to design new systems, the NP recognition mechanism of macrophages must be understood, taking into account that variations in local microenvironment may change the phenotype of macrophages in a way that will affect the uptake and toxicity of NPs. This kind of information may be applied to diseases where macrophages play a pathogenic role, such as metabolic disorders, infections, or cancer. The kinetics of nanoparticles strongly affects their therapeutic efficacy when administered in vivo. Release kinetics could predict the behavior of nanosystems targeting macrophages and be applied to improve their characteristics. PBPK models have been developed to characterize nanoparticle biodistribution in organs of the reticuloendothelial system (RES) such as liver or spleen. Another controversial issue is the possible toxicity of non-degradable nanoparticles, which in many cases accumulate in high percentages in macrophage clearance organs such as the liver, spleen, and kidney.

A proteome-wide assessment of the oxidative stress paradigm for metal and metal-oxide nanomaterials in human macrophages

Responsible implementation of engineered nanomaterials (ENMs) into commercial applications is an important societal issue, driving demand for new approaches for rapid and comprehensive evaluation of their bioactivity and safety. An essential part of any research focused on identifying potential hazards of ENMs is the appropriate selection of biological endpoints to evaluate. Herein, we use a tiered strategy employing both targeted biological assays and untargeted quantitative proteomics to elucidate the biological responses of human THP-1 derived macrophages across a library of metal/metal oxide ENMs, raised as priority ENMs for investigation by NIEHS's Nanomaterial Health Implications Research (NHIR) program. Our results show that quantitative cellular proteome profiles readily distinguish ENM types based on their cytotoxic potential according to induction of biological processes and pathways involved in the cellular antioxidant response, TCA cycle, oxidative stress, endoplasmic reticulum stress, and immune responses as major processes impacted. Interestingly, bioinformatics analysis of differentially expressed proteins also revealed new biological processes that were influenced by all ENMs independent of their cytotoxic potential. These included biological processes that were previously implicated as mechanisms cells employ as adaptive responses to low levels of oxidative stress, including cell adhesion, protein translation and protein targeting. Unsupervised clustering revealed the most striking proteome changes that differentiated ENM classes highlight a small subset of proteins involved in the oxidative stress response (HMOX1), protein chaperone functions (HS71B, DNJB1), and autophagy (SQSTM), providing a potential new panel of markers of ENM-induced cellular stress. To our knowledge, the results represent the most comprehensive profiling of the biological responses to a library of ENMs conducted using quantitative mass spectrometry-based proteomics. The results provide a basis to identify the patterns of a diverse set of cellular pathways and biological processes impacted by ENM exposure in an important immune cell type, laying the foundation for multivariate, pathway-level structure activity assessments of ENMs in the future.