Intracellular signal modulation by nanomaterials

Insights into the mechanism of histamine synthesis and recycling disruption induced by exposure to CdO NPs in the fruit fly (Drosophila melanogaster)

Exposure to a sublethal concentration of CdO nanoparticles impairs the vision of the fruit fly (Drosophila melanogaster) by disrupting histamine (HA) synthesis and recycling mechanisms. To gain more insights, we measured HA titer using HPLC in CdO NP-treated vs. non-treated adults in the current study and found that CdO NPs caused an increase in the level of HA in the head and the decapitated body. We asked whether HA accumulation (increase) is a response of photoreceptors or CNS histaminergic neurons, and whether there is any difference in the expression levels of HA recycling and transport encoding genes (Lovit, CarT, Ebony, Tan, BalaT) between the adult fly head and decapitated body that could explain this HA accumulation. We used GAL4/UAS system tool with three GAL4 drivers: ubiquitous tubP-GAL4, nervous system driver (elav Gal4), and compound eye drivers (sev Gal4 and GMR Gal4) to silence HA synthesis in site specific manner followed by detecting the expression level of genes involved in HA recycling and transport in both the heads and the decapitated bodies of CdO treated and non-treated flies. We found an increase in Lovit expression in the heads of treated adults, which is responsible for HA loading into synaptic vesicles and release from photoreceptors, as well as a decrease in catalytic enzymes involved in HA recycling, which leads to HA accumulation without increasing the real signal. To conclude, both photoreceptors and CNS histaminergic neurons are responsible for the increase in HA in CdO NP-treated flies, but through different mechanisms. Our results provide more insights on the underlying molecular mechanism of vision impairment because of nano-sized cadmium particles exposure.

Characterization of microparticles derived from waste plastics and their bio-interaction with human lung A549 cells

Microplastics (MPs) represent a worldwide emerging relevant concern toward human and environmental health due to their intentional or unintentional release. Human exposure to MPs by inhalation is predicted to be among the most hazardous. MPs include both engineered, or primary MPs, and secondary MPs, materials obtained by fragmentation from any plastic good. The major part of the environmental MPs is constituted by the second ones that are irregular in size, shape and composition. These features make the study of the biological impact of heterogenous MPs of extremely high relevance to better estimate the real toxicological hazards of these materials on human and environmental organisms. The smallest fractions of plastic granules, relying on the micron-sized scale, can be considered as the most abundant component of the environmental MPs, and for this reason, they are typically used to perform toxicity tests using in vitro systems representative of an inhalation exposure scenario. In the present work, MPs obtained from industrial treatment of waste plastics (wMPs < 50 μm) were investigated, and after the physico-chemical characterization, the cytotoxic, inflammatory and genotoxic responses, as well as the modality of wMPs interactions with alveolar lung cells, were determined. Obtained results indicated that, at high concentrations (100 μg/ml) and prolonged exposure time (48 h), wMPs affect biological responses by inducing inflammation and genotoxicity, as a result of the cell-wMP interactions, also including the uptake of the smaller particles.

Nanomaterial Exposure, Extracellular Vesicle Biogenesis and Adverse Cellular Outcomes: A Scoping Review

The progressively increasing use of nanomaterials (NMs) has awakened issues related to nanosafety and its potential toxic effects on human health. Emerging studies suggest that NMs alter cell communication by reshaping and altering the secretion of extracellular vesicles (EVs), leading to dysfunction in recipient cells. However, there is limited understanding of how the physicochemical characteristics of NMs alter the EV content and their consequent physiological functions. Therefore, this review explored the relevance of EVs in the nanotoxicology field. The current state of the art on how EVs are modulated by NM exposure and the possible regulation and modulation of signaling pathways and physiological responses were assessed in detail. This review followed the manual for reviewers produced by The Joanna Brigs Institute for Scoping Reviews and the PRISMA extension for Scoping Reviews (PRISMA-ScR): checklist and explanation. The research question, "Do NMs modulate cellular responses mediated by EVs?" was analyzed following the PECO model (P (Population) = EVs, E (Exposure) = NMs, C (Comparator) = EVs without exposure to NMs, O (Outcome) = Cellular responses/change in EVs) to help methodologically assess the association between exposure and outcome. For each theme in the PECO acronym, keywords were defined, organized, and researched in PubMed, Science Direct, Scopus, Web of Science, EMBASE, and Cochrane databases, up to 30 September 2021. In vitro, in vivo, ex vivo, and clinical studies that analyzed the effect of NMs on EV biogenesis, cargo, and cellular responses were included in the analysis. The methodological quality assessment was conducted using the ToxRTool, ARRIVE guideline, Newcastle Ottawa and the EV-TRACK platform. The search in the referred databases identified 2944 articles. After applying the eligibility criteria and two-step screening, 18 articles were included in the final review. We observed that depending on the concentration and physicochemical characteristics, specific NMs promote a significant increase in EV secretion as well as changes in their cargo, especially regarding the expression of proteins and miRNAs, which, in turn, were involved in biological processes that included cell communication, angiogenesis, and activation of the immune response, etc. Although further studies are necessary, this work suggests that molecular investigations on EVs induced by NM exposure may become a potential tool for toxicological studies since they are widely accessible biomarkers that may form a bridge between NM exposure and the cellular response and pathological outcome.

On Placental Toxicology Studies and Cerium Dioxide Nanoparticles

The human placenta is a transient organ essential for pregnancy maintenance, fetal development and growth. It has several functions, including that of a selective barrier against pathogens and xenobiotics from maternal blood. However, some pollutants can accumulate in the placenta or pass through with possible repercussions on pregnancy outcomes. Cerium dioxide nanoparticles (CeO₂ NPs), also termed nanoceria, are an emerging pollutant whose impact on pregnancy is starting to be defined. CeO₂ NPs are already used in different fields for industrial and commercial applications and have even been proposed for some biomedical applications. Since 2010, nanoceria have been subject to priority monitoring by the Organization for Economic Co-operation and Development in order to assess their toxicity. This review aims to summarize the current methods and models used for toxicology studies on the placental barrier, from the basic ones to the very latest, as well as to overview the most recent knowledge of the impact of CeO₂ NPs on human health, and more specifically during the sensitive window of pregnancy. Further research is needed to highlight the relationship between environmental exposure to CeO₂ and placental dysfunction with its implications for pregnancy outcome.

Enthralling the impact of engineered nanoparticles on soil microbiome: A concentric approach towards environmental risks and cogitation

Nanotechnology is an avant-garde field of scientific research that revolutionizes technological advancements in the present world. It is a cutting-edge scientific approach that has undoubtedly a plethora of functions in controlling environmental pollutants for the welfare of the ecosystem. However, their unprecedented utilization and hysterical release led to a huge threat to the soil microbiome. Nanoparticles(NPs) hamper physicochemical properties of soil along with microbial metabolic activities within rhizospheric soils.Here in this review shed light on concentric aspects of NP-biosynthesis, types, toxicity mechanisms, accumulation within the ecosystem. However, the accrual of tiny NPs into the soil system has dramatically influenced rhizospheric activities in terms of soil properties and biogeochemical cycles. We have focussed on mechanistic pathways engrossed by microbes to deal with NPs.Also, we have elaborated the fate and behavior of NPs within soils. Besides, a piece of very scarce information on NPs-toxicity towards environment and rhizosphere communities is available. Therefore, the present review highlights ecological perspectives of nanotechnology and solutions to such implications. We have comprehend certain strategies such as avant-garde engineering methods, sustainable procedures for NP synthesis along with vatious regulatory actions to manage NP within environment. Moreover, we have devised risk management sustainable and novel strategies to utilize it in a rationalized and integrated manner. With this background, we can develop a comprehensive plan about NPs with novel insights to understand the resistance and toxicity mechanisms of NPs towards microbes. Henceforth, the orientation towards these issues would enhance the understanding of researchers for proper recommendation and promotion of nanotechnology in an optimized and sustainable manner.

Organ-on-a-chip technology for nanoparticle research

The last two decades have witnessed explosive growth in the field of nanoengineering and nanomedicine. In particular, engineered nanoparticles have garnered great attention due to their potential to enable new capabilities such as controlled and targeted drug delivery for treatment of various diseases. With rapid progress in nanoparticle research, increasing efforts are being made to develop new technologies for in vitro modeling and analysis of the efficacy and safety of nanotherapeutics in human physiological systems. Organ-on-a-chip technology represents the most recent advance in this effort that provides a promising approach to address the limitations of conventional preclinical models. In this paper, we present a concise review of recent studies demonstrating how this emerging technology can be applied to in vitro studies of nanoparticles. The specific focus of this review is to examine the use of organ-on-a-chip models for toxicity and efficacy assessment of nanoparticles used in therapeutic applications. We also discuss challenges and future opportunities for implementing organ-on-a-chip technology for nanoparticle research.

Nanoparticles as Novel Emerging Therapeutic Antibacterial Agents in the Antibiotics Resistant Era

Microorganisms are highly resistant to the antibiotics that are commonly used and thus are becoming serious public health problem. There is an urgent need for new approaches to monitor microbial behavior, and hence, nanomaterial can be a very promising solution. Nanotechnology has led to generation of novel antimicrobial agents such as gold, silver, zinc, copper, poly-£-lysine, iron, and chitosan which have shown remarkable potential, demonstrating their applicability as proficient antibiotic agents against various pathogenic bacterial species. The antimicrobial nanoproduct physically kills the organism's cell membranes that prevent the production of drug-resistant microorganisms. These nanosized particles can also be used as diagnostic agents, targeted drug delivery vehicle, noninvasive imaging technologies, and in vivo visual monitoring of tumors angiogenesis. These nanomaterials provide a promising platform for diagnostics, prognostic, drug delivery, and treatment of diseases by means of nanoengineered products/devices. This owes to their small size, prolonged antimicrobial efficacy with insignificant toxicity creating less environmental hazard or toxicity. Scientists address several problems such as health, bioethical problems, toxicity risks, physiological, and pharmaceutical concerns related with the usage of NPs as antimicrobial agents as current research lack adequate data and information on the safe use of certain tools and materials.

Anionic nanoparticle-induced perturbation to phospholipid membranes affects ion channel function

Understanding the mechanisms of nanoparticle interaction with cell membranes is essential for designing materials for applications such as bioimaging and drug delivery, as well as for assessing engineered nanomaterial safety. Much attention has focused on nanoparticles that bind strongly to biological membranes or induce membrane damage, leading to adverse impacts on cells. More subtle effects on membrane function mediated via changes in biophysical properties of the phospholipid bilayer have received little study. Here, we combine electrophysiology measurements, infrared spectroscopy, and molecular dynamics simulations to obtain insight into a mode of nanoparticle-mediated modulation of membrane protein function that was previously only hinted at in prior work. Electrophysiology measurements on gramicidin A (gA) ion channels embedded in planar suspended lipid bilayers demonstrate that anionic gold nanoparticles (AuNPs) reduce channel activity and extend channel lifetimes without disrupting membrane integrity, in a manner consistent with changes in membrane mechanical properties. Vibrational spectroscopy indicates that AuNP interaction with the bilayer does not perturb the conformation of membrane-embedded gA. Molecular dynamics simulations reinforce the experimental findings, showing that anionic AuNPs do not directly interact with embedded gA channels but perturb the local properties of lipid bilayers. Our results are most consistent with a mechanism in which anionic AuNPs disrupt ion channel function in an indirect manner by altering the mechanical properties of the surrounding bilayer. Alteration of membrane mechanical properties represents a potentially important mechanism by which nanoparticles induce biological effects, as the function of many embedded membrane proteins depends on phospholipid bilayer biophysical properties.

Analysis of the Direct and Indirect Effects of Nanoparticle Exposure on Microglial and Neuronal Cells In Vitro

Environmental or biomedical exposure to nanoparticles (NPs) can results in translocation and accumulation of NPs in the brain, which can lead to health-related problems. NPs have been shown to induce toxicity to neuronal cells through several direct mechanisms, but only a few studies have also explored the indirect effects of NPs, through consequences due to the exposure of neighboring cells to NPs. In this study, we analysed possible direct and indirect effects of NPs (polyacrylic acid (PAA) coated cobalt ferrite NP, TiO2 P25 and maghemite NPs) on immortalized mouse microglial cells and differentiated CAD mouse neuronal cells in monoculture (direct toxicity) or in transwell co-culture system (indirect toxicity). We showed that although the low NP concentrations (2-25 µg/mL) did not induce changes in cell viability, cytokine secretion or NF-κB activation of microglial cells, even low NP concentrations of 10 µg/mL can affect the cells and change their secretion of protein stress mediators. These can in turn influence neuronal cells in indirect exposure model. Indirect toxicity of NPs is an important and not adequately assessed mechanism of NP toxicity, since it not only affects cells on the exposure sites, but through secretion of signaling mediators, can also affect cells that do not come in direct contact with NPs.

Understanding Nanoparticle Toxicity Mechanisms To Inform Redesign Strategies To Reduce Environmental Impact

There has been a surge of consumer products that incorporate nanoparticles, which are used to improve or impart new functionalities to the products based on their unique physicochemical properties. With such an increase in products containing nanomaterials, there is a need to understand their potential impacts on the environment. This is often done using various biological models that are abundant in the different environmental compartments where the nanomaterials may end up after use. Beyond studying whether nanomaterials simply kill an organism, the molecular mechanisms by which nanoparticles exhibit toxicity have been extensively studied. Some of the main mechanisms include (1) direct nanoparticle association with an organism's cell surface, where the membrane can be damaged or initiate internal signaling pathways that damage the cell, (2) dissolution of the material, releasing toxic ions that impact the organism, generally through impairing important enzyme functions or through direct interaction with a cell's DNA, and (3) the generation of reactive oxygen species and subsequent oxidative stress on an organism, which can also damage important enzymes or an organism's genetic material. This Account reviews these toxicity mechanisms, presenting examples for each with different types of nanomaterials. Understanding the mechanism of nanoparticle toxicity will inform efforts to redesign nanoparticles with reduced environmental impact. The redesign strategies will need to be chosen based on the major mode of toxicity, but also considering what changes can be made to the nanomaterial without impacting its ability to perform in its intended application. To reduce interactions with the cell surface, nanomaterials can be designed to have a negative surface charge, use ligands such as polyethylene glycol that reduce protein binding, or have a morphology that discourages binding with a cell surface. To reduce the nanoparticle dissolution to toxic ions, the toxic species can be replaced with less toxic elements that have similar properties, the nanoparticle can be capped with a shell material, the morphology of the nanoparticle can be chosen to minimize surface area and thus minimize dissolution, or a chelating agent can be co-introduced or functionalized onto the nanomaterial's surface. To reduce the production of reactive oxygen species, the band gap of the material can be tuned either by using different elements or by doping, a shell layer can be added to inhibit direct contact with the core, or antioxidant molecules can be tethered to the nanoparticle surface. When redesigning nanoparticles, it will be important to test that the redesign strategy actually reduces toxicity to organisms from relevant environmental compartments. It is also necessary to confirm that the nanomaterial still demonstrates the critical physicochemical properties that inspired its inclusion in a product or device.

Application of Bayesian networks in determining nanoparticle-induced cellular outcomes using transcriptomics

Inroads have been made in our understanding of the risks posed to human health and the environment by nanoparticles (NPs) but this area requires continuous research and monitoring. Machine learning techniques have been applied to nanotoxicology with very encouraging results. This study deals with bridging physicochemical properties of NPs, experimental exposure conditions and in vitro characteristics with biological effects of NPs on a molecular cellular level from transcriptomics studies. The bridging is done by developing and implementing Bayesian Networks (BNs) with or without data preprocessing. The BN structures are derived either automatically or methodologically and compared. Early stage nanotoxicity measurements represent a challenge, not least when attempting to predict adverse outcomes and modeling is critical to understanding the biological effects of exposure to NPs. The preprocessed data-driven BN showed improved performance over automatically structured BN and the BN with unprocessed datasets. The prestructured BN captures inter relationships between NP properties, exposure condition and in vitro characteristics and links those with cellular effects based on statistic correlation findings. Information gain analysis showed that exposure dose, NP and cell line variables were the most influential attributes in predicting the biological effects. The BN methodology proposed in this study successfully predicts a number of toxicologically relevant cellular disrupted biological processes such as cell cycle and proliferation pathways, cell adhesion and extracellular matrix responses, DNA damage and repair mechanisms etc., with a success rate >80%. The model validation from independent data shows a robust and promising methodology for incorporating transcriptomics outcomes in a hazard and, by extension, risk assessment modeling framework by predicting affected cellular functions from experimental conditions.

Nanoparticles induce apoptosis via mediating diverse cellular pathways

With a special size and structure, nanoparticles (NPs) have excellent application prospects in various fields and are widely used in the biomedicine, cosmetics and chemical industries nowadays. However, there have been some reports on the biosafety of this new type of material, pointing out its cytotoxicity in inducing apoptosis. With different physicochemical properties in size, shape, surface charge, and ligand, NPs exhibit different biocompatibilities when interacting with different cells. Therefore, a comprehensive and deep study into the proapoptotic mechanism of NPs is necessary. In the present review, we summarize the NP-triggered apoptotic signal pathways in detail and highlight some important functional molecules involved. We hope our findings and perspectives provide a new direction for the sound development of nanotechnology in the future.

Probing Cellular Processes Using Engineered Nanoparticles

Nanoparticles, the building blocks of nanotechnology, have been widely utilized in various biomedical applications, such as detection, diagnosis, imaging, and therapy. However, another emerging, albeit under-represented, area is the employment of nanoparticles as tools to understand cellular processes (e.g., oxidative stress-induced signaling cascades). Such investigations have enormous potential to characterize a disease from a different perspective and unravel some new features that otherwise would have remained a mystery. In this review, we summarize the intrinsic biological properties of unmodified as well surface modified nanoparticles and discuss how such properties could be utilized to interrogate biological processes and provide a perspective for future evolution of this field.

Unintended effects of drug carriers: Big issues of small particles

Humoral and cellular host defense mechanisms including diverse phagocytes, leukocytes, and immune cells have evolved over millions of years to protect the body from microbes and other external and internal threats. These policing forces recognize engineered sub-micron drug delivery systems (DDS) as such a threat, and react accordingly. This leads to impediment of the therapeutic action, extensively studied and discussed in the literature. Here, we focus on side effects of DDS interactions with host defenses. We argue that for nanomedicine to reach its clinical potential, the field must redouble its efforts in understanding the interaction between drug delivery systems and the host defenses, so that we can engineer safer interventions with the greatest potential for clinical success.

Biosynthesized colloidal silver and gold nanoparticles as emerging leishmanicidal agents: an insight

Many recent key innovations in nanotechnology have greatly fascinated scientists to explore new avenues in treatment and diagnosis of emerging diseases. Due to extensive utilization of metallic nanoparticles (NPs) in diverse biomedical applications, scientists are looking forward to green synthesis of NPs as safer, simple, fast, and low-cost method over chemical and physical methods. Due to enriched phytochemistry, no need for maintenance and ready availability, plants are preferred for green synthesis of silver (AgNPs) and gold NPs (AuNPs). Recently, several researchers have exploited these biogenic NPs as potential antileishmanial agents. The current article is focused to mechanistically explain the antileishmanial activity of biogenic AuNPs and AgNPs with a futuristic discussion on the faith of these particles as emerging antileishmanial agents.

Crosstalk of Nanosystems Induced Extracellular Vesicles as Promising Tools in Biomedical Applications

Hybrid vesicles are considered as a bridge between natural nanosystems (NNSs) and artificial nanosystems (ANSs). NNSs are extracellular vesicles (EVs), membranous, bio-formed endogenously, which act as endogenous cargoes, and reflecting cellular dynamics. EVs have cellular tropism, permeate tight junctions, and are non-immunogenic. EVs are used as tools in the development of diagnostic and therapeutic agents. ANSs can induce biogenesis of hybrid vesicles as promising smart diagnostic agents, and innovative drug cargoes. EVs can encapsulate small molecules, macromolecules, and ANSs. The manipulation of EVs during biogenesis was suggested for engineering hybrid EVs. This review article highlights the role of ANSs in the biogenesis of NNSs, and introduces hybrid nanosystems research.

Nanoparticles Associate with Intrinsically Disordered RNA-Binding Proteins

Nanoparticles are capable of penetrating cells, but little is known about the way they interact with intracellular proteome. Here we show that inorganic nanoparticles associate with low-complexity, intrinsically disordered proteins from HeLa cytosolic protein extracts in nondenaturing in vitro nanoparticle pull-down assays. Intrinsic protein disorder associates with structural mobility, suggesting that side-chain flexibility plays an important role in the driving of a protein to nanoparticle absorption. Disordered protein domains are often found in a diverse group of RNA-binding proteins. Consequently, the nanoparticle-associated proteomes were enriched in subunits of RNA-processing protein complexes. In turn, this indicates that within a cell, nanoparticles might interfere with protein synthesis triggering a range of cellular responses.

Current Challenges toward In Vitro Cellular Validation of Inorganic Nanoparticles

An impressive development has been achieved toward the production of well-defined "smart" inorganic nanoparticles, in which the physicochemical properties can be controlled and predicted to a high degree of accuracy. Nanoparticle design is indeed highly advanced, multimodal and multitargeting being the norm, yet we do not fully understand the obstacles that nanoparticles face when used in vivo. Increased cooperation between chemists and biochemists, immunologists and physicists, has allowed us to think outside the box, and we are slowly starting to understand the interactions that nanoparticles undergo under more realistic situations. Importantly, such an understanding involves awareness about the limitations when assessing the influence of such inorganic nanoparticles on biological entities and vice versa, as well as the development of new validation strategies.

Photodynamic N-TiO2 Nanoparticle Treatment Induces Controlled ROS-mediated Autophagy and Terminal Differentiation of Leukemia Cells

In this study, we used nitrogen-doped titanium dioxide (N-TiO₂) NPs in conjugation with visible light, and show that both reactive oxygen species (ROS) and autophagy are induced by this novel NP-based photodynamic therapy (PDT) system. While well-dispersed N-TiO₂ NPs (≤100 μg/ml) were inert, their photo-activation with visible light led to ROS-mediated autophagy in leukemia K562 cells and normal peripheral lymphocytes, and this increased in parallel with increasing NP concentrations and light doses. At a constant light energy (12 J/cm²), increasing N-TiO₂ NP concentrations increased ROS levels to trigger autophagy-dependent megakaryocytic terminal differentiation in K562 cells. By contrast, an ROS challenge induced by high N-TiO₂ NP concentrations led to autophagy-associated apoptotic cell death. Using chemical autophagy inhibitors (3-methyladenine and Bafilomycin A1), we confirmed that autophagy is required for both terminal differentiation and apoptosis induced by photo-activated N-TiO₂. Pre-incubation of leukemic cells with ROS scavengers muted the effect of N-TiO₂ NP-based PDT on cell fate, highlighting the upstream role of ROS in our system. In summary, PDT using N-TiO₂ NPs provides an effective method of priming autophagy by ROS induction. The capability of photo-activated N-TiO₂ NPs in obtaining desirable cellular outcomes represents a novel therapeutic strategy of cancer cells.

Disposition of intravenously or orally administered silver nanoparticles in pregnant rats and the effect on the biochemical profile in urine

Few investigations have been conducted on the disposition and fate of silver nanoparticles (AgNP) in pregnancy. The distribution of a single dose of polyvinylpyrrolidone (PVP)-stabilized AgNP was investigated in pregnant rats. Two sizes of AgNP, 20 and 110 nm, and silver acetate (AgAc) were used to investigate the role of AgNP diameter and particle dissolution in tissue distribution, internal dose and persistence. Dams were administered AgNP or AgAc intravenously (i.v.) (1 mg kg^-1 ) or by gavage (p.o.) (10 mg kg^-1 ), or vehicle alone, on gestation day 18 and euthanized at 24 or 48 h post-exposure. The silver concentration in tissues was measured using inductively-coupled plasma mass spectrometry. The distribution of silver in dams was influenced by route of administration and AgNP size. The highest concentration of silver (μg Ag g^-1 tissue) at 48 h was found in the spleen for i.v. administered AgNP, and in the lungs for AgAc. At 48 h after p.o. administration of AgNP, the highest concentration was measured in the cecum and large intestine, and for AgAc in the placenta. Silver was detected in placenta and fetuses for all groups. Markers of cardiovascular injury, oxidative stress marker, cytokines and chemokines were not significantly elevated in exposed dams compared to vehicle-dosed control. NMR metabolomics analysis of urine indicated that AgNP and AgAc exposure impact the carbohydrate, and amino acid metabolism. This study demonstrates that silver crosses the placenta and is transferred to the fetus regardless of the form of silver. Copyright © 2016 John Wiley & Sons, Ltd.

Neuroprotective effects of three different sizes nanochelating based nano complexes in MPP(+) induced neurotoxicity

Parkinson's disease (PD) is the world's second most common dementia, which the drugs available for its treatment have not had effects beyond slowing the disease process. Recently nanotechnology has induced the chance for designing and manufacturing new medicines for neurodegenerative disease. It is demonstrated that by tuning the size of a nanoparticle, the physiological effect of the nanoparticle can be controlled. Using novel nanochelating technology, three nano complexes: Pas (150 nm), Paf (100 nm) and Pac (40 nm) were designed and in the present study their neuroprotective effects were evaluated in PC12 cells treated with 1-methyl-4-phenyl-pyridine ion (MPP (+)). PC12 cells were pre-treated with the Pas, Paf or Pac nano complexes, then they were subjected to 10 μM MPP (+). Subsequently, cell viability, intracellular free Calcium and reactive oxygen species (ROS) levels, mitochondrial membrane potential, catalase (CAT) and superoxide dismutase (SOD) activity, Glutathione (GSH) and malondialdehyde (MDA) levels and Caspase 3 expression were evaluated. All three nano complexes, especially Pac, were able to increase cell viability, SOD and CAT activity, decreased Caspase 3 expression and prevented the generation of ROS and the loss of mitochondrial membrane potential caused by MPP(+). Pre-treatment with Pac and Paf nano complexes lead to a decrease of intracellular free Calcium, but Pas nano complex could not decrease it. Only Pac nano complex decreased MDA levels and other nano complexes could not change this parameter compared to MPP(+) treated cells. Hence according to the results, all nanochelating based nano complexes induced neuroprotective effects in an experimental model of PD, but the smallest nano complex, Pac, showed the best results.

Liver Toxicity of Cadmium Telluride Quantum Dots (CdTe QDs) Due to Oxidative Stress in Vitro and in Vivo

With the applications of quantum dots (QDs) expanding, many studies have described the potential adverse effects of QDs, yet little attention has been paid to potential toxicity of QDs in the liver. The aim of this study was to investigate the effects of cadmium telluride (CdTe) QDs in mice and murine hepatoma cells alpha mouse liver 12 (AML 12). CdTe QDs administration significantly increased the level of lipid peroxides marker malondialdehyde (MDA) in the livers of treated mice. Furthermore, CdTe QDs caused cytotoxicity in AML 12 cells in a dose- and time-dependent manner, which was likely mediated through the generation of reactive oxygen species (ROS) and the induction of apoptosis. An increase in ROS generation with a concomitant increase in the gene expression of the tumor suppressor gene p53, the pro-apoptotic gene Bcl-2 and a decrease in the anti-apoptosis gene Bax, suggested that a mitochondria mediated pathway was involved in CdTe QDs' induced apoptosis. Finally, we showed that NF-E2-related factor 2 (Nrf2) deficiency blocked induced oxidative stress to protect cells from injury induced by CdTe QDs. These findings provide insights into the regulatory mechanisms involved in the activation of Nrf2 signaling that confers protection against CdTe QDs-induced apoptosis in hepatocytes.

Partial protection of N-acetylcysteine against MPA-capped CdTe quantum dot-induced neurotoxicity in rat primary cultured hippocampal neurons

CdTe QD exposure caused death and apoptosis of rat primary cultured hippocampal neurons via generating reactive oxygen species and increasing intracellular calcium levels, which could be reversed by a common antioxidant NAC.

In vitro biocompatibility of mesoporous metal (III; Fe, Al, Cr) trimesate MOF nanocarriers

The high porosity and versatile composition of the benchmarked mesoporous metal (Fe, Al, Cr) trimesate metal–organic frameworks (MIL-100(Fe, Al, Cr)) make them very promising solids in different strategic industrial and societal domains (separation, catalysis, biomedicine, etc.).

[Physio-pathological impacts of inhaled nanoparticles]

Nanomaterials are defined as materials with any external dimension in the nanoscale or having an internal structure or surface structure in the nanoscale, approximately 1 nm to 100 nm. They exhibit new or reinforced properties as compared to the same material at the micrometric scale, providing a benefit in numerous technological applications. However, their specific surface properties in addition to their shape, composition, size are suspected to elicit adverse responses from biological systems, underlining the need for a thorough hazard assessment. Increasing use of nanomaterials in industrial as well as consumer products extends the possibilities of environmental and occupational human exposures. During all their life cycle, from their production to their destruction through their use, engineered nanoparticles can be released and the respiratory route is one of the main unintentional routes of exposure. Although the respiratory tract is equipped with efficient clearance mechanisms, there is increasing evidence that nanoparticles exhibit an ability to cross biological barriers, getting access to the bloodstream and secondary target organs. Different features of nanomaterials (size, form, surface reactivity...) contribute to their internalization and translocation through the respiratory barrier. Short term inhalation exposure to nanoparticles induces pulmonary inflammation the extent of which is dependent on the type of nanoparticles according to shape, size, solubility...Oxidative stress is considered as a major toxicity pathway triggered by nanomaterials as they can intrinsically produce reactive oxygen species or induced the intracellular production of reactive oxygen species or anti-oxidant depletion upon interaction with cells. Alternative mechanisms are suspected, related to the ability of nanoparticles to interact with proteins. As they get in contact with biological fluids, nanoparticles are covered by a protein corona that modifies their interactions with cells, their fate and their effects. There is still a need to increase our mechanistic understanding of the toxicological events triggered by nanomaterials in order to provide relevant data for risk assessment as well as in helping to develop nanomaterials with a safer design.