Pulmonary and hepatic effects after low dose exposure to nanosilver: Early and long-lasting histological and ultrastructural alterations in rat

Plant-based synthesis, characterization approaches, applications and toxicity of silver nanoparticles: A comprehensive review

The development of an environmentally benign method for the synthesis of nanoparticles has been facilitated by green chemistry. "Green synthesis" uses a range of biological elements like microbes, plants, and other biodegradable materials to produce NPs. Active biomolecules that are secreted by natural strains and present in the plant extracts serve as both reducing and capping/stabilizing agents. Microorganisms' intracellular enzymes can reduce metal ions, which explains how NPs might potentially nucleate. Plant-based synthesis of nanomaterials is particularly promising owing to abundant resources, simplicity of synthesis, and low cost. Silver nanoparticles (AgNPs) are attracting great attention in the research community due to their wide variety of applications in chemistry, food technology, microbiology, and biomedicine. Recent years have seen a large amount of research on the bio-genic synthesis of AgNPs employing biomaterials like plant extract and bacteria as reducing agents. Herein we discuss a thorough overview of the plant-based synthesis of silver nanoparticles (AgNPs), characterization approaches, applications, and toxicity. The review covers the green chemistry and nanotechnology elements of producing AgNPs, including a thorough discussion of the plant extract mediated synthesis, detailed formation mechanism, and a well-balanced emphasis on hazards and advantages. Based on current developments, the optimisation strategies, applications, and interdisciplinary characteristics are also covered in detail.

Sex-specific behavioural, metabolic, and immunohistochemical changes after repeated administration of the synthetic cannabinoid AKB48 in mice

BACKGROUND AND PURPOSE

AKB48 is a synthetic cannabinoid illegally sold for its psychoactive cannabis-like effects that have been associated with acute intoxication and whose effects are poorly known.

EXPERIMENTAL APPROACH

Using a behavioural, neurochemical, and immunohistochemical approach, we investigated the pharmaco-toxicological effects, pharmacokinetics, and neuroplasticity at cannabinoid CB1 receptors in the cerebellum and cortex induced by repeated AKB48 administration in male and female mice.

KEY RESULTS

The effects of AKB48 varied significantly depending on sex and treatment duration. The first injection impaired sensorimotor responses and reduced body temperature, analgesia, and breath rate to a greater extent in females than in males; the second injection induced stronger effects in males while the third injection of AKB48 induced weaker responses in both sexes, suggesting emergence of tolerance. The CB1 receptor antagonist NESS-0327 prevented the effects induced by repeated AKB48, confirming a CB1 receptor-mediated action. Blood AKB48 levels were higher in females than in males and repeated administration caused a progressive rise of AKB48 levels in both sexes, suggesting an inhibitory effect on cytochrome activity. Finally, immunohistochemical analysis revealed higher expression of CB1 receptors in the cerebellum and cortex of females, and a rapid CB1 receptor down-regulation in cerebellar and cortical areas following repeated AKB48 injections, with neuroadaptation occurring generally more rapidly in females than in males.

CONCLUSION AND IMPLICATIONS

We have shown for the first time that AKB48 effects significantly vary with prolonged use and that sex affects the pharmacodynamic/pharmacokinetic responses to repeated administration, suggesting a sex-tailored approach in managing AKB48-induced intoxication.

NADPH Oxidase 3: Beyond the Inner Ear

Reactive oxygen species (ROS) were formerly known as mere byproducts of metabolism with damaging effects on cellular structures. The discovery and description of NADPH oxidases (Nox) as a whole enzyme family that only produce this harmful group of molecules was surprising. After intensive research, seven Nox isoforms were discovered, described and extensively studied. Among them, the NADPH oxidase 3 is the perhaps most underrated Nox isoform, since it was firstly discovered in the inner ear. This stigma of Nox3 as "being only expressed in the inner ear" was also used by me several times. Therefore, the question arose whether this sentence is still valid or even usable. To this end, this review solely focuses on Nox3 and summarizes its discovery, the structural components, the activating and regulating factors, the expression in cells, tissues and organs, as well as the beneficial and detrimental effects of Nox3-mediated ROS production on body functions. Furthermore, the involvement of Nox3-derived ROS in diseases progression and, accordingly, as a potential target for disease treatment, will be discussed.

Hericium erinaceus Extract Exerts Beneficial Effects on Gut-Neuroinflammaging-Cognitive Axis in Elderly Mice

Ageing is a biological phenomenon that determines the impairment of cognitive performances, in particular, affecting memory. Inflammation and cellular senescence are known to be involved in the pathogenesis of cognitive decline. The gut microbiota-brain axis could exert a critical role in influencing brain homeostasis during ageing, modulating neuroinflammation, and possibly leading to inflammaging. Due to their anti-ageing properties, medicinal mushrooms can be utilised as a resource for developing pharmaceuticals and functional foods. Specifically, Hericium erinaceus (He), thanks to its bioactive metabolites, exerts numerous healthy beneficial effects, such as reinforcing the immune system, counteracting ageing, and improving cognitive performance. Our previous works demonstrated the capabilities of two months of He1 standardised extract oral supplementation in preventing cognitive decline in elderly frail mice. Herein, we showed that this treatment did not change the overall gut microbiome composition but significantly modified the relative abundance of genera specifically involved in cognition and inflammation. Parallelly, a significant decrease in crucial markers of inflammation and cellular senescence, i.e., CD45, GFAP, IL6, p62, and γH2AX, was demonstrated in the dentate gyrus and Cornus Ammonis hippocampal areas through immunohistochemical experiments. In summary, we suggested beneficial and anti-inflammatory properties of He1 in mouse hippocampus through the gut microbiome-brain axis modulation.

Comparative toxicological evaluations of novel forms nano-pesticides in liver and lung of albino rats

Copper oxide Nanoparticles (CuONPs) are used in different agricultural applications. Large amounts of CuONPs cause organ dysfunction in animals. Our study aim to compare between the toxic effects of CuONanSphere (CuONSp) and CuONanoFlower (CuONF) as new nano-pesticides, determine a less toxic form when used in agricultural applications. To characterize CuONSp and CuONF, we used X-ray diffraction (XRD), Field emission scanning electron microscopy (SEM), and High resolution transmission electron microscopy (HRTEM) and Zeta-sizer device.18 adult male albino rats were divided into three groups (n = 6), (I) control group, (II) and (III) groups were given orally 50 mg/kg/day of CuONSp and CuONF 30 days respectively. CuONSp induced oxidant-antioxidant abnormalities, including an increase in malondialdhyde (MDA) and a decrease in glutathione (GSH) in comparison to CuONF-treated one. CuONSp induced an increase in liver enzymes activities compared to CuONF. Tumour necrosis factor-alfa (TNF-α) detected an increased in liver and lung compared to CuONF. However, histological examinations revealed changes in CuONSp group than CuONF group. Changes in immune-expressions of TNF-α, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kβ) and tumour suppressor gene (p53) were also more identified in CuONSp group than CuONF group. Ultrastructural studies of liver and lung tissues marked alternations were observed in CuONSp group than CuONF group. In conclusion, CuONSp induced biological alternation in liver and lung more than CuONF. So, CuONF is less toxic compared to CuONSp when used as nano-pesticide in agricultural applications.

Preliminary Toxicological Analysis in a Safe-by-Design and Adverse Outcome Pathway-Driven Approach on Different Silver Nanoparticles: Assessment of Acute Responses in A549 Cells

Silver nanoparticles (Ag NPs) are among the most widely used metal-based nanomaterials (NMs) and their applications in different products, also as antibacterial additives, are increasing. In the present manuscript, according to an adverse outcome pathway (AOP) approach, we tested two safe-by-design (SbD) newly developed Ag NPs coated with hydroxyethyl cellulose (HEC), namely AgHEC powder and AgHEC solution. These novel Ag NPs were compared to two reference Ag NPs (naked and coated with polyvinylpyrrolidone-PVP). Cell viability, inflammatory response, reactive oxygen species, oxidative DNA damage, cell cycle, and cell-particle interactions were analyzed in the alveolar in vitro model, A549 cells. The results show a different toxicity pattern of the novel Ag NPs compared to reference NPs and that between the two novel NPs, the AgHEC solution is the one with the lower toxicity and to be further developed within the SbD framework.

Ameliorative role of nanocurcumin against the toxicological effects of novel forms of Cuo as nanopesticides: a comparative study

Copper oxide nanoparticles (CuONPs) have a wide range of uses in agricultural applications. Nanocurcumin (NCur) acts as an antioxidant treatment. The goal of the study is to reduce the toxicity resulting from the use of CuONPs as nanopesticides on living organisms by inducing changes in the morphological shape of CuONPs or treating it with NCur. So, we induced a comparative study between three shapes of CuONPs: CuO nanosphere (CuONSp), CuO nanosheet (CuONS), and CuO nanoflower (CuONF). We characterize each nano-form by using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (HRTEM), and Zetasizer HT device; 36 rats were divided into six groups (n = 6): 1st group was the control group; 2nd group received 50 mg/kg/day of NCur orally for 30 days; 3rd, 4th, and 5th groups received orally 50 mg/kg/day of CuONSp, CuONS, and CuONF, respectively, for 30 days; 6th group received 50 mg/kg/day CuONSp plus 50 mg/kg/day of NCur orally for 30 days. An elevation occurred in malondialdehyde (MDA), liver and kidney functions, tumor necrosis factor-alpha (TNF-α), and B-cell lymphoma 2 (Bcl2) by CuONSp > CuONS > CuONF, respectively. An inhibition occurred in glutathione (GSH), superoxidase (SOD) catalase (CAT), apoptotic Bax gene (Bax), histopathological, and ultrastructural alterations by CuONSp < CuONS < CuONF, respectively. NCur ameliorated these alternations. In conclusion, CuONF is a better form compared to other forms of nanopesticide in agriculture due to its lower toxicity. NCur decreased the biological alternations which induced by CuONSp due to its antioxidant and anti-apoptotic properties.

Cognitive Healthy Aging in Mice: Boosting Memory by an Ergothioneine-Rich Hericium erinaceus Primordium Extract

Brain aging is a crucial risk factor for several neurodegenerative disorders and dementia. The most affected cognitive function is memory, worsening early during aging. Inflammation and oxidative stress are known to have a role in pathogenesis of cognitive impairments, and a link exists between aging/frailty and immunosenescence/inflammaging. Based on anti-aging properties, medicinal mushrooms represent a source to develop medicines and functional foods. In particular, Hericium erinaceus (He) displays several actions ranging from boosting the immune system to fighting senescence, due to its active ingredients/metabolites. Among these, Ergothioneine (ERGO) is known as the longevity vitamin. Currently, we demonstrated the efficacy of an ERGO-rich He primordium extract (He2) in preventing cognitive decline in a murine model of aging. We focused on recognition memory deterioration during aging, monitored through spontaneous behavioral tests assessing both memory components and frailty index. A parallel significant decrease in key markers of inflammation and oxidative stress, i.e., IL6, TGFβ1, GFAP, Nrf2, SOD1, COX2, NOS2, was revealed in the hippocampus by immunohistochemistry, accompanied by an enhancement of NMDAR1and mGluR2, crucially involved in glutamatergic neurotransmission. In summary, we disclosed a selective, preventive and neuroprotective effect of He2 on aged hippocampus, both on recognition memory as well on inflammation/oxidative stress/glutamate receptors expression.

Inflammatory and proapoptotic effects of inhaling gasoline fumes on the lung and ameliorative effects of fenugreek seeds

Impacts of inhaling gasoline fumes on the lungs of adult male rats and the alleviating role of fenugreek seeds were evaluated. Twenty-four rats were divided into four groups, unexposed control and fenugreek groups, gasoline exposed groups for 6 h/6 day/week for 10 weeks with and without supplementation of fenugreek seed powder in food (5% w/w). Rats exposed to gasoline fumes showed significant elevation in lung tumor necrosis factor-α, as an inflammatory marker, and the proapoptotic marker Bax with a reduction in the antiapoptotic marker Bcl2. Moreover, remarkable elevations in transforming growth factor-β1, collagen and hydroxyproline were observed as fibrotic markers. Lung oxidative stress markers (hydrogen peroxides, malondialdehyde, and protein carbonyl) increased significantly along with marked decrease in total antioxidant capacity, superoxide dismutase, and catalase levels. Additionally, marked decreases in white and red blood cell counts, hemoglobin content, platelet count, accompanied by elevated red cell distribution width percentage were observed, supporting the inflammatory status. Histopathological changes represented by hematoxylin&eosin, immunohistochemistry staining for Bax&Bcl2, and transmission electron microscopy supported the negative impacts of gasoline fumes compared to the control group. Fenugreek seeds supplementation with gasoline exposure showed pronounced alleviation of lung biochemical and histopathological changes compared to the gasoline-exposed group.

Enhanced silver nanoparticle-induced pulmonary inflammation in a metabolic syndrome mouse model and resolvin D1 treatment

BACKGROUND

Metabolic syndrome (MetS) exacerbates susceptibility to inhalation exposures such as particulate air pollution, however, the mechanisms responsible remain unelucidated. Previously, we determined a MetS mouse model exhibited exacerbated pulmonary inflammation 24 h following AgNP exposure compared to a healthy mouse model. This enhanced response corresponded with reduction of distinct resolution mediators. We hypothesized silver nanoparticle (AgNP) exposure in MetS results in sustained pulmonary inflammation. Further, we hypothesized treatment with resolvin D1 (RvD1) will reduce exacerbations in AgNP-induced inflammation due to MetS.

RESULTS

To evaluate these hypotheses, healthy and MetS mouse models were exposed to vehicle (control) or AgNPs and a day later, treated with resolvin D1 (RvD1) or vehicle (control) via oropharyngeal aspiration. Pulmonary lung toxicity was evaluated at 3-, 7-, 14-, and 21-days following AgNP exposure. MetS mice exposed to AgNPs and receiving vehicle treatment, demonstrated exacerbated pulmonary inflammatory responses compared to healthy mice. In the AgNP exposed mice receiving RvD1, pulmonary inflammatory response in MetS was reduced to levels comparable to healthy mice exposed to AgNPs. This included decreases in neutrophil influx and inflammatory cytokines, as well as elevated anti-inflammatory cytokines.

CONCLUSIONS

Inefficient resolution may contribute to enhancements in MetS susceptibility to AgNP exposure causing an increased pulmonary inflammatory response. Treatments utilizing specific resolution mediators may be beneficial to individuals suffering MetS following inhalation exposures.

Hepatotoxic and Neurotoxic Potential of Iron Oxide Nanoparticles in Wistar Rats: a Biochemical and Ultrastructural Study

Iron oxide nanoparticles (IONPs) are increasingly being employed for in vivo biomedical nanotheranostic applications. The development of novel IONPs should be accompanied by careful scrutiny of their biocompatibility. Herein, we studied the effect of administration of three formulations of IONPs, based on their starting materials along with synthesizing methods, IONPs-chloride, IONPs-lactate, and IONPs-nitrate, on biochemical and ultrastructural aspects. Different techniques were utilized to assess the effect of different starting materials on the physical, morphological, chemical, surface area, magnetic, and particle size distribution accompanied with their surface charge properties. Their nanoscale sizes were below 40 nm and demonstrated surface up to 69m²/g, and increased magnetization of 71.273 emu/g. Moreover, we investigated the effects of an oral IONP administration (100 mg/kg/day) in rat for 14 days. The liver enzymatic functions were investigated. Liver and brain tissues were analyzed for oxidative stress. Finally, a transmission electron microscope (TEM) and inductively coupled plasma optical emission spectrometer (ICP-OES) were employed to investigate the ultrastructural alterations and to estimate content of iron in the selected tissues of IONP-exposed rats. This study showed that magnetite IONPs-chloride exhibited the safest toxicological profile and thus could be regarded as a promising nanotherapeutic candidate for brain or liver disorders.

Toxicologic Concerns with Current Medical Nanoparticles

Nanotechnology is one of the scientific advances in technology. Nanoparticles (NPs) are small materials ranging from 1 to 100 nm. When the shape of the supplied nanoparticles changes, the physiological response of the cells can be very different. Several characteristics of NPs such as the composition, surface chemistry, surface charge, and shape are also important parameters affecting the toxicity of nanomaterials. This review covered specific topics that address the effects of NPs on nanomedicine. Furthermore, mechanisms of different types of nanomaterial-induced cytotoxicities were described. The distributions of different NPs in organs and their adverse effects were also emphasized. This review provides insight into the scientific community interested in nano(bio)technology, nanomedicine, and nanotoxicology. The content may also be of interest to a broad range of scientists.

Lung Models to Evaluate Silver Nanoparticles’ Toxicity and Their Impact on Human Health

Nanomaterials (NMs) solve specific problems with remarkable results in several industrial and scientific areas. Among NMs, silver nanoparticles (AgNPs) have been extensively employed as drug carriers, medical diagnostics, energy harvesting devices, sensors, lubricants, and bioremediation. Notably, they have shown excellent antimicrobial, anticancer, and antiviral properties in the biomedical field. The literature analysis shows a selective cytotoxic effect on cancer cells compared to healthy cells, making its potential application in cancer treatment evident, increasing the need to study the potential risk of their use to environmental and human health. A large battery of toxicity models, both in vitro and in vivo, have been established to predict the harmful effects of incorporating AgNPs in these numerous areas or those produced due to involuntary exposure. However, these models often report contradictory results due to their lack of standardization, generating controversy and slowing the advances in nanotoxicology research, fundamentally by generalizing the biological response produced by the AgNP formulations. This review summarizes the last ten years’ reports concerning AgNPs’ toxicity in cellular respiratory system models (e.g., mono-culture models, co-cultures, 3D cultures, ex vivo and in vivo). In turn, more complex cellular models represent in a better way the physical and chemical barriers of the body; however, results should be used carefully so as not to be misleading. The main objective of this work is to highlight current models with the highest physiological relevance, identifying the opportunity areas of lung nanotoxicology and contributing to the establishment and strengthening of specific regulations regarding health and the environment.

Combined effects of the exposure to silver nanoparticles and noise on hearing function and cochlea structure of the male rats

AIMS

This study intended to investigate whether exposure to the combination of noise and Ag-NPs in rats induces cochlear damage and hearing dysfunction.

MAIN METHODS

A total of 24Wistar rats were divided into four treatment groups and received/exposed to saline (IP), Ag-NPs (100 mg/kg, 5d/w for 4 weeks), 8 kHz narrowband noise (104 dB SPL, 6 h/day, 5d/w for 4 weeks) and Ag-NPs plus noise. The DPOAE, serum levels of MDA and SOD and changes in body weight were assessed. The rat cochlea was further stained for investigating the mRNA expression (TL-6, NOX3, and TNF-), IHC (TUJ-1 and MHC7), and histological alterations. The Ag-NPs characteristics were also analysed by SEM and XRD.

KEY FINDINGS

DPOAE values were remarkably reduced (p < 0.05) among the exposed groups. Furthermore, exposure to noise and Ag-NPs significantly increased MDA levels and decreased the SOD activity in the serum. In comparison to the control group, the expression of IL-6, TNF-, and NOX3 was shown to be elevated in the Ag-NPs plus noise group. The body weight also increased significantly in all groups with the exception of the Ag-NPs plus noise group. IHC tests showed remarkable down-regulation of TUJ1 and MYO7A. Morphological changes confirmed our findings as well. SEM and XRD data validated the production of Ag-NPs.

SIGNIFICANCE

According to the findings of this study, sub-acute exposure to noise and Ag-NPs causes permanent damage to the hair cells that are in charge of high-frequency perception.

Imperative role of electron microscopy in toxicity assessment: A review

Electron microscope (EM) was developed in 1931 and since then microscopical examination of both the biological and non-biological samples has been revolutionized. Modifications in electron microscopy techniques, such as scanning EM and transmission EM, have widened their applicability in the various sectors such as understanding of drug toxicity, development of mechanism, criminal site investigation, and characterization of the nano-molecule. The present review summarizes its role in important aspects such as toxicity assessment and disease diagnosis in special reference to SARS-COV2. In the biological system, EM studies have elucidated the impact of toxicants at the ultra-structural level in various tissue in conformity to physiological alterations. Thus, EM can be concluded as an important tool in toxicity assessment and disease prognosis.

Disruption of pulmonary resolution mediators contribute to exacerbated silver nanoparticle-induced acute inflammation in a metabolic syndrome mouse model

Pre-existing conditions modulate sensitivity to numerous xenobiotic exposures such as air pollution. Specifically, individuals suffering from metabolic syndrome (MetS) demonstrate enhanced acute inflammatory responses following particulate matter inhalation. The mechanisms associated with these exacerbated inflammatory responses are unknown, impairing interventional strategies and our understanding of susceptible populations. We hypothesize MetS-associated lipid dysregulation influences mediators of inflammatory resolution signaling contributing to increased acute pulmonary toxicity. To evaluate this hypothesis, healthy and MetS mouse models were treated with either 18-hydroxy eicosapentaenoic acid (18-HEPE), 14-hydroxy docosahexaenoic acid (14-HDHA), 17-hydroxy docosahexaenoic acid (17-HDHA), or saline (control) via intraperitoneal injection prior to oropharyngeal aspiration of silver nanoparticles (AgNP). In mice receiving saline treatment, AgNP exposure resulted in an acute pulmonary inflammatory response that was exacerbated in MetS mice. A targeted lipid assessment demonstrated 18-HEPE, 14-HDHA, and 17-HDHA treatments altered lung levels of specialized pro-resolving lipid mediators (SPMs). 14-HDHA and 17-HDHA treatments more efficiently reduced the exacerbated acute inflammatory response in AgNP exposed MetS mice as compared to 18-HEPE. This included decreased neutrophilic influx, diminished induction of inflammatory cytokines/chemokines, and reduced alterations in SPMs. Examination of SPM receptors determined baseline reductions in MetS mice compared to healthy as well as decreases due to AgNP exposure. Overall, these results demonstrate AgNP exposure disrupts inflammatory resolution, specifically 14-HDHA and 17-HDHA derived SPMs, in MetS contributing to exacerbated acute inflammatory responses. Our findings identify a potential mechanism responsible for enhanced susceptibility in MetS that can be targeted for interventional therapeutic approaches.

Serum ceruloplasmin monitoring in a case of silver intoxication due to intravenous silver infusion

INTRODUCTION

Colloidal silver packaged as a dietary supplement is readily available online and is thought to be safe. Literature describing its toxicity in humans is scarce.

CASE REPORT

A 47-year-old man presented to us for sensory and gait problems. He had unremarkable past health except dystrophic nails. He further volunteered a history of receiving chronic oral and intravenous administration of colloidal silver. We confirmed his plasma silver was 1200-fold elevated, measuring 11990 nmol/L (normal < 10 nmol/L). He had deranged liver function tests, and liver biopsy showed distorted acinar architecture, bridging fibrosis and lymphocytic infiltrate with silver particles clustering along the vascular endothelium and portal venules. Brain magnetic resonance imagining showed features of mineralization over bilateral globus pallidi. There was biochemical evidence of central adrenal insufficiency, intracellular iron overload and hypoceruloplasminemia (<0.05 g/L). Gradual clinical and biochemical improvement was noted after silver cessation: his plasma silver dropped to 4800 nmol/L (3 months) and 1650 nmol/L (12 months), and serum ceruloplasmin reverted to 0.13 g/L (10 months) and 0.29 g/L (20 months).

CONCLUSIONS

The potential effects of silver to liver and copper metabolism were shown in this case. Serum ceruloplasmin also serves as a surrogate marker in monitoring silver intoxication.

Progress in the Application of Nano- and Micro-based Drug Delivery Systems in Pulmonary Drug Delivery

Nanotechnology is associated with the development of particles in the nano-size range that can be used in a wide range of applications in the medical field. It has gained more importance in the pharmaceutical research field particularly in drug delivery, as it results in enhanced therapeutic drug performance, improved drug solubility, targeted drug delivery to the specific sites, minimized side effects, and prolonged drug retention time in the targeted site. To date, the application of nanotechnology continues to offer several benefits in the treatment of various chronic diseases and results in remarkable improvements in treatment outcomes. The use of nano-based delivery systems such as liposomes, micelles, and nanoparticles in pulmonary drug delivery have shown to be a promising strategy in achieving drug deposition and maintained controlled drug release in the lungs. They have been widely used to minimize the risks of drug toxicity in vivo. In this review, recent advances in the application of nano- and micro-based delivery systems in pulmonary drug delivery for the treatment of various pulmonary diseases, such as lung cancer, asthma, and chronic obstructive pulmonary disease, are highlighted. Limitations in the application of these drug delivery systems and some key strategies in improving their formulation properties to overcome challenges encountered in drug delivery are also discussed.

Biodistribution and pulmonary metabolic effects of silver nanoparticles in mice following acute intratracheal instillations

The respiratory tract is the route of entry for accidentally inhaled AgNPs, which can reach the lungs and redistribute to other main organs through systemic circulation. In the present work, we aimed to evaluate silver biodistribution and biological effects after 1 or 2 intratracheal instillations (IT) of two differently sized PVP-coated AgNPs (5 and 50 nm-3 mg/kg) and ionic silver (AgNO₃-1 mg/kg bw) in mice. Furthermore, nuclear magnetic resonance (NMR) metabolomics was applied to unveil pulmonary metabolic variations. Animals exposed to 5 nm AgNP (AgNP5) showed higher levels of ionic silver in organs, especially in the lung, spleen, kidney and liver, while animals exposed to 50 nm AgNP (AgNP50) showed higher levels of silver in the blood. Animals exposed to AgNP50 excreted higher amounts of silver than those exposed to AgNP5, which is consistent with higher tissue accumulation of silver in animals exposed to the latter. Lung metabolic profiling revealed several Ag-induced alterations in metabolites involved in different pathways, such as glycolysis and tricarboxylic acid (TCA) cycle, amino acid and phospholipid metabolism, and antioxidant defense. Notably, most of the metabolic changes observed after 1 IT were absent in animals subjected to 2 IT of AgNO₃, or reversed for AgNPs, suggesting adaptation mechanisms to cope with the initial insult and recover homeostasis. Graphical abstract.

Neutrophil activation by nanomaterials in vitro: comparing strengths and limitations of primary human cells with those of an immortalized (HL-60) cell line

Assessment of nanomaterial (NM) induced inflammatory responses has largely relied on rodent testing via measurement of leukocyte accumulation in target organs. Despite observations that NMs activate neutrophil driven inflammatory responses in vivo, a limited number of studies have investigated neutrophil responses to NMs in vitro. We compared responses between the human neutrophil-like HL-60 cell line and human primary neutrophils following exposure to silver (Ag), zinc oxide (ZnO), copper oxide (CuO) and titanium dioxide (TiO₂) NMs. NM cytotoxicity and neutrophil activation were assessed by measuring cellular metabolic activity, cytokine production, respiratory burst, and release of neutrophil extracellular traps. We observed a similar pattern of response between HL-60 cells and primary neutrophils, however we report that some neutrophil functions are compromised in the cell line. Ag NMs were consistently observed to stimulate neutrophil activation, with CuO NMs inducing similar though weaker responses. TiO₂ NMs did not induce a neutrophil response in either cell type. Interestingly, ZnO NMs readily induced activation of HL-60 cells but did not appear to activate primary cells. Our findings are relevant to the development of a tiered testing strategy for NM hazard assessment which promotes the use of non-rodent models. Whilst we acknowledge that HL-60 cells may not be a perfect substitute for primary cells and require further investigation regarding their ability to predict neutrophil activation, we recommend their use for initial screening of NM-induced inflammation. Primary human neutrophils can then be used for more focused assessments of neutrophil activation before progressing to in vivo models where necessary.

From a Medicinal Mushroom Blend a Direct Anticancer Effect on Triple-Negative Breast Cancer: A Preclinical Study on Lung Metastases

Bioactive metabolites isolated from medicinal mushrooms (MM) used as supportive treatment in conventional oncology have recently gained interest. Acting as anticancer agents, they interfere with tumor cells and microenvironment (TME), disturbing cancer development/progression. Nonetheless, their action mechanisms still need to be elucidated. Recently, using a 4T1 triple-negative mouse BC model, we demonstrated that supplementation with Micotherapy U-Care, a MM blend, produced a striking reduction of lung metastases density/number, paralleled by decreased inflammation and oxidative stress both in TME and metastases, together with QoL amelioration. We hypothesized that these effects could be due to either a direct anticancer effect and/or to a secondary/indirect impact of Micotherapy U-Care on systemic inflammation/immunomodulation. To address this question, we presently focused on apoptosis/proliferation, investigating specific molecules, i.e., PARP1, p53, BAX, Bcl2, and PCNA, whose critical role in BC is well recognized. We revealed that Micotherapy U-Care is effective to influence balance between cell death and proliferation, which appeared strictly interconnected and inversely related (p53/Bax vs. Bcl2/PARP1/PCNA expression trends). MM blend displayed a direct effect, with different efficacy extent on cancer cells and TME, forcing tumor cells to apoptosis. Yet again, this study supports the potential of MM extracts, as adjuvant supplement in the TNBC management.

The contribution of animal models to understanding the role of the immune system in human idiopathic pulmonary fibrosis

Pulmonary fibrosis occurs in a heterogeneous group of lung disorders and is characterised by an excessive deposition of extracellular matrix proteins within the pulmonary interstitium, leading to impaired gas transfer and a loss of lung function. In the past 10 years, there has been a dramatic increase in our understanding of the immune system and how it contributes to fibrogenic processes within the lung. This review will compare some of the models used to investigate the pathogenesis and treatment of pulmonary fibrosis, in particular those used to study immune cell pathogenicity in idiopathic pulmonary fibrosis, highlighting their advantages and disadvantages in dissecting human disease.

Novel Medicinal Mushroom Blend as a Promising Supplement in Integrative Oncology: A Multi-Tiered Study using 4T1 Triple-Negative Mouse Breast Cancer Model

Although medicinal mushroom extracts have been proposed as promising anti-cancer agents, their precise impacts on metastatic breast cancer are still to be clarified. For this purpose, the present study exploited the effect of a novel medicinal mushroom blend, namely Micotherapy U-care, in a 4T1 triple-negative mouse breast cancer model. Mice were orally administered with Micotherapy U-care, consisting of a mixture of Agaricus blazei, Ophiocordyceps sinensis, Ganoderma lucidum, Grifola frondosa, and Lentinula edodes. The syngeneic tumor-bearing mice were generated by injecting 4T1 cells in both supplemented and non-supplemented mice. After sacrifice 35 days later, specific endpoints and pathological outcomes of the murine pulmonary tissue were evaluated. (i) Histopathological and ultrastructural analysis and (ii) immunohistochemical assessment of TGF-ß1, IL-6 and NOS2, COX2, SOD1 as markers of inflammation and oxidative stress were performed. The QoL was comparatively evaluated. Micotherapy U-care supplementation, starting before 4T1 injection and lasting until the end of the experiment, dramatically reduced the pulmonary metastases density, also triggering a decrease of fibrotic response, and reducing IL-6, NOS, and COX2 expression. SOD1 and TGF-ß1 results were also discussed. These findings support the valuable potential of Micotherapy U-care as adjuvant therapy in the critical management of triple-negative breast cancer.

Exacerbation of Nanoparticle-Induced Acute Pulmonary Inflammation in a Mouse Model of Metabolic Syndrome

Nanotechnology has the capacity to revolutionize numerous fields and processes, however, exposure-induced health effects are of concern. The majority of nanoparticle (NP) safety evaluations have been performed utilizing healthy models and have demonstrated the potential for pulmonary toxicity. A growing proportion of individuals suffer diseases that may enhance their susceptibility to exposures. Specifically, metabolic syndrome (MetS) is increasingly prevalent and is a risk factor for the development of chronic diseases including type-2 diabetes, cardiovascular disease, and cancer. MetS is a combination of conditions which includes dyslipidemia, obesity, hypertension, and insulin resistance. Due to the role of lipids in inflammatory signaling, we hypothesize that MetS-associated dyslipidemia may modulate NP-induced immune responses. To examine this hypothesis, mice were fed either a control diet or a high-fat western diet (HFWD) for 14-weeks. A subset of mice were treated with atorvastatin for the final 7-weeks to modulate lipids. Mice were exposed to silver NPs (AgNPs) via oropharyngeal aspiration and acute toxicity endpoints were evaluated 24-h post-exposure. Mice on the HFWD demonstrated MetS-associated alterations such as increased body weight and cholesterol compared to control-diet mice. Cytometry analysis of bronchoalveolar lavage fluid (BALF) demonstrated exacerbation of AgNP-induced neutrophilic influx in MetS mice compared to healthy. Additionally, enhanced proinflammatory mRNA expression and protein levels of monocyte chemoattractant protein-1, macrophage inflammatory protein-2, and interleukin-6 were observed in MetS mice compared to healthy following exposure. AgNP exposure reduced mRNA expression of enzymes involved in lipid metabolism, such as arachidonate 5-lipoxygenase and arachidonate 15-lipoxygenase in both mouse models. Exposure to AgNPs decreased inducible nitric oxide synthase gene expression in MetS mice. An exploratory lipidomic profiling approach was utilized to screen lipid mediators involved in pulmonary inflammation. This assessment indicates the potential for reduced levels of lipids mediators of inflammatory resolution (LMIR) in the MetS model compared to healthy mice following AgNP exposure. Statin treatment inhibited enhanced inflammatory responses as well as alterations in LMIR observed in the MetS model due to AgNP exposure. Taken together our data suggests that MetS exacerbates the acute toxicity induced by AgNPs exposure possibly via a disruption of LMIR leading to enhanced pulmonary inflammation.