The impact of species and cell type on the nanosafety profile of iron oxide nanoparticles in neural cells

Background: While nanotechnology is advancing rapidly, nanosafety tends to lag behind since general mechanistic insights into cell-nanoparticle (NP) interactions remain rare. To tackle this issue, standardization of nanosafety assessment is imperative. In this regard, we believe that the cell type selection should not be overlooked since the applicability of cell lines could be questioned given their altered phenotype. Hence, we evaluated the impact of the cell type on in vitro nanosafety evaluations in a human and murine neuroblastoma cell line, neural progenitor cell line and in neural stem cells. Acute toxicity was evaluated for gold, silver and iron oxide (IO) NPs, and the latter were additionally subjected to a multiparametric analysis to assess sublethal effects. Results: The stem cells and murine neuroblastoma cell line respectively showed most and least acute cytotoxicity. Using high content imaging, we observed cell type-and species-specific responses to the IONPs on the level of reactive oxygen species production, calcium homeostasis, mitochondrial integrity and cell morphology, indicating that cellular homeostasis is impaired in distinct ways. Conclusions: Our data reveal cell type-specific toxicity profiles and demonstrate that a single cell line or toxicity end point will not provide sufficient information on in vitro nanosafety. We propose to identify a set of standard cell lines for screening purposes and to select cell types for detailed nanosafety studies based on the intended application and/or expected exposure

The cellular interactions of PEGylated gold nanoparticles : effect of PEGylation on cellular uptake and cytotoxicity

Poly(ethylene glycol) (PEG) is frequently used to coat various medical nanoparticles (NPs). As PEG is known to minimize NP interactions with biological specimens, the question remains whether PEGylated NPs are intrinsically less toxic or whether this is caused by reduced NP uptake. In the present work, the effect of gold NP PEGylation on uptake by three cell types is compared and evaluated the effect on cell viability, oxidative stress, cell morphology, and functionality using a multiparametric methodology. The data reveal that PEGylation affects cellular NP uptake in a cell-type-dependent manner and influences toxicity by different mechanisms. At similar intracellular NP numbers, PEGylated NPs are found to yield higher levels of cell death, mostly by induction of oxidative stress. These findings reveal that PEGylation significantly reduces NP uptake, but that at similar functional (= cell-associated) NP levels, non-PEGylated NPs are better tolerated by the cells

Перспективы развития фундаментальных наук. Т. 2 : Химия

Сборник содержит труды участников XV Международной конференции студентов, аспирантов и молодых учёных «Перспективы развития фундаментальных наук», представленные на секции «Химия». Для студентов, аспирантов, молодых ученых и преподавателей, специализирующихся в области синтеза и изучения свойств функциональных материалов, физико-химических методов исследования материалов, наноматериалов, экологии, органического синтеза, а также катализа и нефтехимии

Intracellular Nanoparticle Coating Stability Determines Nanoparticle Diagnostics Efficacy and Cell Functionality

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Genotoxic capacity of Cd/Se semiconductor quantum dots with differing surface chemistries.

Quantum dots (QD) have unique electronic and optical properties promoting biotechnological advances. However, our understanding of the toxicological structure-activity relationships remains limited. This study aimed to determine the biological impact of varying nanomaterial surface chemistry by assessing the interaction of QD with either a negative (carboxyl), neutral (hexadecylamine; HDA) or positive (amine) polymer coating with human lymphoblastoid TK6 cells. Following QD physico-chemical characterisation, cellular uptake was quantified by optical and electron microscopy. Cytotoxicity was evaluated and genotoxicity was characterised using the micronucleus assay (gross chromosomal damage) and the HPRT forward mutation assay (point mutagenicity). Cellular damage mechanisms were also explored, focusing on oxidative stress and mitochondrial damage. Cell uptake, cytotoxicity and genotoxicity were found to be dependent on QD surface chemistry. Carboxyl-QD demonstrated the smallest agglomerate size and greatest cellular uptake, which correlated with a dose dependent increase in cytotoxicity and genotoxicity. Amine-QD induced minimal cellular damage, while HDA-QD promoted substantial induction of cell death and genotoxicity. However, HDA-QD were not internalised by the cells and the damage they caused was most likely due to free cadmium release caused by QD dissolution. Oxidative stress and induced mitochondrial reactive oxygen species were only partially associated with cytotoxicity and genotoxicity induced by the QD, hence were not the only mechanisms of importance. Colloidal stability, nanoparticle (NP) surface chemistry, cellular uptake levels and the intrinsic characteristics of the NPs are therefore critical parameters impacting genotoxicity induced by QD

Cyto- and genotoxic effects of metallic nanoparticles in untransformed human fibroblast

AbstractMetallic nanoparticles such as silver (Ag), cerium dioxide (CeO2) and titanium dioxide (TiO2) are produced at a large scale and included in many consumer products. It is well known that most metallic NPs are toxic to humans which raise concerns about these engineered particles. Various studies have already been published on the subject, however, almost all of these studies have been conducted in cancer or transformed cell lines. In this work we performed a comparative evaluation of these metallic NPs on normal untransformed human fibroblasts (GM07492) detecting cyto- and geno-toxic responses after exposure to these NPs. Our results showed that all three metallic NPs were able to cross the plasma membrane and were mainly found in endocytic vesicles. The Ag and TiO2 NPs affected mitochondrial enzymatic activity (XTT), increased DNA fragmentation, oxidative damage (Comet assay) and induced cell death mainly by the apoptotic pathway. Ag NPs increased GADD45α transcript levels and the phosphorylation of proteins γH2AX. Transient genotoxicity was also observed from exposure to CeO2 NPs while TiO2 NPs showed no increase in DNA damage at sub-cytotoxic concentrations. In comparison, Ag NPs were found to be the most cyto-genotoxic NPs to fibroblasts. Thus, these results support the use of normal fibroblast as a more informative tool to detect the mechanisms of action induced by metallic NPs

Cell type-dependent changes in CdSe/ZnS quantum dot uptake and toxic endpoints.

Toxicity of nanoparticles (NPs) is often correlated with the physicochemical characteristics of the materials. However, some discrepancies are noted in in-vitro studies on quantum dots (QDs) with similar physicochemical properties. This is partly related to variations in cell type. In this study, we show that epithelial (BEAS-2B), fibroblast (HFF-1), and lymphoblastoid (TK6) cells show different biological responses following exposure to QDs. These cells represented the 3 main portals of NP exposure: bronchial, skin, and circulatory. The uptake and toxicity of negatively and positively charged CdSe:ZnS QDs of the same core size but with different surface chemistries (carboxyl or amine polymer coatings) were investigated in full and reduced serum containing media following 1 and 3 cell cycles. Following thorough physicochemical characterization, cellular uptake, cytotoxicity, and gross chromosomal damage were measured. Cellular damage mechanisms in the form of reactive oxygen species and the expression of inflammatory cytokines IL-8 and TNF-α were assessed. QDs uptake and toxicity significantly varied in the different cell lines. BEAS-2B cells demonstrated the highest level of QDs uptake yet displayed a strong resilience with minimal genotoxicity following exposure to these NPs. In contrast, HFF-1 and TK6 cells were more susceptible to toxicity and genotoxicity, respectively, as a result of exposure to QDs. Thus, this study demonstrates that in addition to nanomaterial physicochemical characterization, a clear understanding of cell type-dependent variation in uptake coupled to the inherently different capacities of the cell types to cope with exposure to these exogenous materials are all required to predict genotoxicity

Longitudinal in vivo assessment of host-microbe interactions in a murine model of pulmonary aspergillosis

The fungus Aspergillus fumigatus is ubiquitous in nature and the most common cause of invasive pulmonary aspergillosis (IPA) in patients with a compromised immune system. The development of IPA in patients under immunosuppressive treatment or in patients with primary immunodeficiency demonstrates the importance of the host immune response in controlling aspergillosis. However, study of the host-microbe interaction has been hampered by the lack of tools for their non-invasive assessment. We developed a methodology to study the response of the host's immune system against IPA longitudinally in vivo by using fluorine-19 magnetic resonance imaging (F-19 MRI). We showed the advantage of a perfluorocarbon-based contrast agent for the in vivo labeling of macrophages and dendritic cells, permitting quantification of pulmonary inflammation in different murine IPA models. Our findings reveal the potential of F-19 MRI for the assessment of rapid kinetics of innate immune response against IPA and the permissive niche generated through immunosuppression