Thermodynamic Parameters at Bio-Nano Interface and Nanomaterial Toxicity: A Case Study on BSA Interaction with ZnO, SiO2, and TiO2

Re-evaluation of silicon dioxide (E 551) as a food additive in foods for infants below 16 weeks of age and follow-up of its re-evaluation as a food additive for uses in foods for all population groups

The present opinion is the follow-up of the conclusions and recommendations of the Scientific Opinion on the re-evaluation of silicon dioxide (E 551) as a food additive relevant to the safety assessment for all age groups. In addition, the risk assessment of silicon dioxide (E 551) for its use in food for infants below 16 weeks of age is performed. Based on the newly available information on the characterisation of the SAS used as E 551 and following the principles of the 2021 EFSA Guidance on Particle-TR, the conventional safety assessment has been complemented with nano-specific considerations. Given the uncertainties resulting from the limitations of the database and in the absence of genotoxicity concern, the Panel considered that it is not appropriate to derive an acceptable daily intake (ADI) but applied the margin of exposure (MOE) approach for the risk assessment. The Panel concluded that the MOE should be at least 36 for not raising a safety concern. The calculated MOEs considering the dietary exposure estimates for all population groups using the refined non-brand loyal scenario, estimated at the time of the 2018 re-evaluation, were all above 36. The Panel concluded that E 551 does not raise a safety concern in all population groups at the reported uses and use levels. The use of E 551 in food for infants below 16 weeks of age in FC 13.1.1 and FC 13.1.5.1 does not raise a safety concern at the current exposure levels. The Panel also concluded that the technical data provided support an amendment of the specifications for E 551 laid down in Commission Regulation (EU) No 231/2012. The paucity of toxicological studies with proper dispersion protocol (with the exception of the genotoxicity studies) creates uncertainty in the present assessment of the potential toxicological effects related to the exposure to E 551 nanosize aggregates.

Resveratrol Effect on α-Lactalbumin Thermal Stability

The effect of resveratrol (RESV) on α-lactalbumin (α-LA) thermal stability was evaluated using differential scanning calorimetry (DSC), circular dichroism (CD) and dynamic light scattering (DLS) measurements. Complementary information offered by molecular docking served to identify the binding site of the ligand on the native structure of protein and the type of interacting forces. DSC thermograms revealed a double-endotherm pattern with partial overlapping of the two components. The most relevant effect of RESV is manifested in the narrowing of the protein thermal fingerprint: the first process (peak temperature T1) is shifted to higher temperatures while the second one (peak temperature T2) to lower values. The CD data indicated partial conformational changes in the protein non-α-helix domain at T1, resulting in a β-sheet richer intermediate (BSRI) with an unaffected, native-like α-helix backbone. The RESV influence on this process may be defined as slightly demoting, at least within DSC conditions (linear heating rate of 1 K min-1). On further heating, unfolding of the α-helix domain takes place at T2, with RESV acting as a promoter of the process. Long time incubation at 333 K produced the same type of BSRI: no significant effect of RESV on the secondary structure content was detected by CD spectroscopy. Nevertheless, the size distribution of the protein population obtained from DLS measurements revealed the free (non-bound) RESV action manifested in the developing of larger size aggregates.

Differentially Induced Autophagy by Engineered Nanomaterial Treatment Has an Impact on Cellular Homeostasis and Cytotoxicity

Considering the increasing production of engineered nanomaterials (ENMs), new approach methodologies (NAMs) are essential for safe-by-design approaches and risk assessment. Our aim was to enhance screening strategies with a focus on reactivity-triggered toxicities. We applied in vitro tests to 10 selected benchmark ENMs in two cell models, lung epithelial A549 and differentiated THP-1 macrophage-like cells. Previously, we categorized ENMs based on surface reactivity. Here we elucidated their reactivity-triggered cytotoxicity and mode of action using the WST-1 assay (metabolic activity), LDH assay (cell membrane integrity), autophagosome detection, and proteomics. Nonreactive SiO2 NM-200 showed no significant impact on cell viability. Conversely, highly reactive CuO and ZnO (NM-110 and NM-111) disrupted cell homeostasis. Interestingly, moderately reactive TiO2 (NM-101 and NM-105) and CeO2 (NM-211 and NM-212), apparently without an adverse effect, induced autophagosome formation, evidencing autophagy as a defensive mechanism. Our improved in vitro testing strategy, combined with state-of-the-art reactivity information, screens ENMs for potential reactivity-triggered toxicity.

In chemico methodology for engineered nanomaterial categorization according to number, nature and oxidative potential of reactive surface sites

Methanol probe chemisorption quantifies the number of reactive sites at the surface of engineered nanomaterials, enabling normalization per reactive site in reactivity and toxicity tests, rather than per mass or physical surface area. Subsequent temperature-programmed surface reaction (TPSR) of chemisorbed methanol identifies the reactive nature of surface sites (acidic, basic, redox or combination thereof) and their reactivity. Complementary to the methanol assay, a dithiothreitol (DTT) probe oxidation reaction is used to evaluate the oxidation capacity. These acellular approaches to quantify the number, nature, and reactivity of surface sites constitute a new approach methodology (NAM) for site-specific classification of nanomaterials. As a proof of concept, CuO, CeO2, ZnO, Fe3O4, CuFe2O4, Co3O4 and two TiO2 nanomaterials were probed. A harmonized reactive descriptor for ENMs was obtained: the DTT oxidation rate per reactive surface site, or oxidative turnover frequency (OxTOF). CuO and CuFe2O4 ENMs exhibit the largest reactive site surface density and possess the highest oxidizing ability in the series, as estimated by the DTT probe reaction, followed by CeO2 NM-211 and then titania nanomaterials (DT-51 and NM-101) and Fe3O4. DTT depletion for ZnO NM-110 was associated with dissolved zinc ions rather than the ZnO particles; however, the basic characteristics of the ZnO NM-110 particles were evidenced by methanol TPSR. These acellular assays allow ranking the eight nanomaterials into three categories with statistically different oxidative potentials: CuO, CuFe2O4 and Co3O4 are the most reactive; ceria exhibits a moderate reactivity; and iron oxide and the titanias possess a low oxidative potential.

Herbal-Based Green Synthesis of TB-ZnO-TiO(II) Nanoparticles Composite From Terminalia bellirica: Characterization, Toxicity Assay, Antioxidant Assay, and Antimicrobial Activity

Background Terminalia bellirica leaf extract was used as an herbal to get an aqueous extract of Tb-ZnO-TiO2 (zinc and titanium dioxide) nanoparticles composite, and this was subsequently subjected to an analysis of its antioxidant properties and possible antimicrobial activity against gram-negative and gram-positive bacteria. Employing the 2,2-Diphenyl-1-picrylhydrazyl and hydrogen peroxide assay techniques for antioxidant properties. In addition to their biocompatibility, rapid biodegradability, and low toxicity, herbal-based nanoparticles (Tb-ZnO-TiO2 NPs composite) synthesized by T. bellirica have drawn a lot of interest as promising options for administering drugs and effective antimicrobial applications. Materials and methods The form and dimensions of the dispersion of the synthesized nanoparticles were investigated through scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy, and UV-visible for particle characterization. Nanoparticles were analyzed for antimicrobial activity using the well diffusion method. Ascorbic acid and vitamin E were used as two separate controls for antioxidant assay with different concentrations, and also toxicity assay was done by using zebrafish embryos. Results Tb-ZnO-TiO2 NPs composite were obtained as a powder, the X-beam diffraction (XRD) result revealed a small quantity of impurities and revealed that the structure was spherical in nature. A unique absorption peak for Tb-ZnO-TiO2 NPs composite may be seen in UV-Vis spectroscopy which is in the region of 260 to 320 nm. The Tb-ZnO-TiO2 NPs composite antibacterial efficacy was evaluated and showed noted antibacterial activity and free radical scavenging activity with less toxicity. Conclusion The results demonstrated the Tb-ZnO-TiO2 NPs composite has strong antioxidant qualities and enormous antibacterial activity obtained from T. bellirica extract. Therefore, the Tb-ZnO-TiO2 NPs composite synthesized nanoparticles can be used in biomedical applications as an effective antioxidant and antibacterial reagent.

Trametes versicolor laccase activity modulated by the interaction with gold nanoparticles

In this study, the impact of gold nanoparticles (AuNPs) on the structure and activity of laccase from Trametes versicolor (Lc) was described. Fluorescence experiments revealed that AuNPs efficiently quench Lc's tryptophan fluorescence by a static and dynamic process. By using differential scanning microcalorimetry and circular dichroism spectroscopy, it was determined how the concentration of nanoparticles and the composition of the medium affected the secondary structure of Lc. The data revealed that upon binding with AuNPs, conformational changes take place mainly in presence of high amounts of nanoparticles. The complex kinetic analysis unveiled the Lc activity enhancement at low concentrations of AuNPs as opposed to the concentrated regime, where it can be reduced by up to 55%. The Michaelis-Menten tests highlighted that the activity of the biocatalyst is closely related to the concentration of AuNPs, while the Selwyn analysis demonstrated that even in a concentrated regime of Lc it is not deactivated regardless of the amount of AuNPs added. The thermal parameters improved by twofold in the presence of low AuNPs concentration, whereas the activation energy increased with AuNPs content, implying that not all collisions are beneficial to the enzyme structure. The effect of AuNPs on the decomposition of a recalcitrant dye (naphthol green B, NG) by Lc was also evaluated, and the Michaelis-Menten model revealed that only the high AuNPs content influenced negatively the Lc activity. The isothermal titration calorimetry revealed that hydrogen bonds are the main intermolecular forces between Lc and AuNPs, while electrostatic interactions are responsible for NG adsorption to AuNPs. The results of the docking analysis show the binding of NG near the copper T1 site of Lc with hydrogen bonds, electrostatic and hydrophobic interactions. The findings of this work provide important knowledge for laccase-based bio-nanoconjugates and their use in the field of environmental remediation.

pH-Dependent Changes in Structural Stabilities of Bt Cry1Ac Toxin and Contrasting Model Proteins following Adsorption on Montmorillonite

The environmental fate of insecticidal Cry proteins, including time-dependent conservation of biological properties, results from their structural stability in soils. The complex cascade of reactions involved in biological action requires Cry proteins to be in solution. However, the pH-dependent changes in conformational stability and the adsorption-desorption mechanisms of Cry protein on soil minerals remain unclear. We used Derjaguin-Landau-Verwey-Overbeek (DLVO) calculation and differential scanning calorimetry to interpret the driving forces and structural stabilities of Cry1Ac and two contrasting model proteins adsorbed by montmorillonite. The structural stability of Cry1Ac is closer to that of the "hard" protein, α-chymotrypsin, than that of the "soft" bovine serum albumin (BSA). The pH-dependent adsorption of Cry1Ac and α-chymotrypsin could be explained by DLVO theory, whereas the BSA adsorption deviated from it. Patch-controlled electrostatic attraction, hydrophobic effects, and entropy changes following protein unfolding on a mineral surface could contribute to Cry1Ac adsorption. Cry1Ac, like chymotrypsin, was partly denatured on montmorillonite, and its structural stability decreased with an increase in pH. Moreover, small changes in the conformational heterogeneity of both Cry1Ac and chymotrypsin were observed following adsorption. Conversely, adsorbed BSA was completely denatured regardless of the solution pH. The moderate conformational rearrangement of adsorbed Cry1Ac may partially explain why the insecticidal activity of Bt toxin appears to be conserved in soils, albeit for a relatively short time period.

Influences of protein-corona on stability and aggregation kinetics of Ti3C2Tx nanosheets in aquatic environment

Proteins existed in aquatic environments strongly influence the transport, fate of nanomaterials due to the formation of protein-corona surrounding nanomaterials. To date, how do proteins affect the aggregation behaviors of MXene, a new family of two-dimensional materials, in aquatic environment remains unknown. Here the aggregation kinetics of MXene Ti₃C₂T_x nanosheets in various electrolytes (NaCl, CaCl₂ and Na₂SO₄) was investigated by time-resolved dynamic light scattering in absence or presence of bovine serum albumin (BSA). Results showed that BSA affected the aggregation of Ti₃C₂T_x in a concentration-dependent manner. Addition of 3 mg/L BSA decreased the critical coagulation concentrations (CCCs) of Ti₃C₂T_x about 1.6-2.1 times, showing obvious destabilization effect; while BSA greater than 30 mg/L created a high-protein environment covering Ti₃C₂T_x, producing high spatial repulsion and enhancing the dispersibility of Ti₃C₂T_x. Ca²⁺ ions have greater effect on the aggregation of Ti₃C₂T_x due to the larger surface charge and bridging effect. The interaction between Ti₃C₂T_x and BSA followed Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, and mainly attributed to hydrogen bonding and van der Waals forces, while positively charged lysine and arginine in BSA might attract onto Ti₃C₂T_x through electrostatic attraction. The interaction decreased the content of α-helix structure in BSA from 74.7% to 53.1%. Ti₃C₂T_x easily suffered from aggregation and their long-distance transport seemed impossible in synthetic or natural waters. The present findings provided new insights for understanding the transfer and fate of this nanomaterial in aquatic environments.

Fate of engineered nanomaterials at the human epithelial lung tissue barrier in vitro after single and repeated exposures

The understanding of the engineered nanomaterials (NMs) potential interaction with tissue barriers is important to predict their accumulation in cells. Herein, the fate, e.g., cellular uptake/adsorption at the cell membrane and translocation, of NMs with different physico-chemical properties across an A549 lung epithelial tissue barrier, cultured on permeable transwell inserts, were evaluated. We assessed the fate of five different NMs, known to be partially soluble, bio-persistent passive and bio-persistent active. Single exposure measurements using 100 µg/ml were performed for barium sulfate (BaSO4), cerium dioxide (CeO2), titanium dioxide (TiO2), and zinc oxide (ZnO) NMs and non-nanosized crystalline silica (DQ12). Elemental distribution of the materials in different compartments was measured after 24 and 80 h, e.g., apical, apical wash, intracellular and basal, using inductively coupled plasma optical emission spectrometry. BaSO4, CeO2, and TiO2 were mainly detected in the apical and apical wash fraction, whereas for ZnO a significant fraction was detected in the basal compartment. For DQ12 the major fraction was found intracellularly. The content in the cellular fraction decreased from 24 to 80 h incubation for all materials. Repeated exposure measurements were performed exposing the cells on four subsequent days to 25 µg/ml. After 80 h BaSO4, CeO2, and TiO2 NMs were again mainly detected in the apical fraction, ZnO NMs in the apical and basal fraction, while for DQ12 a significant concentration was measured in the cell fraction. Interestingly the cellular fraction was in a similar range for both exposure scenarios with one exception, i.e., ZnO NMs, suggesting a potential different behavior for this material under single exposure and repeated exposure conditions. However, we observed for all the NMs, a decrease of the amount detected in the cellular fraction within time, indicating NMs loss by cell division, exocytosis and/or possible dissolution in lysosomes. Overall, the distribution of NMs in the compartments investigated depends on their composition, as for inert and stable NMs the major fraction was detected in the apical and apical wash fraction, whereas for partially soluble NMs apical and basal fractions were almost similar and DQ12 could mainly be found in the cellular fraction.

Advanced Respiratory Models for Hazard Assessment of Nanomaterials—Performance of Mono-, Co- and Tricultures

Advanced in vitro models are needed to support next-generation risk assessment (NGRA), moving from hazard assessment based mainly on animal studies to the application of new alternative methods (NAMs). Advanced models must be tested for hazard assessment of nanomaterials (NMs). The aim of this study was to perform an interlaboratory trial across two laboratories to test the robustness of and optimize a 3D lung model of human epithelial A549 cells cultivated at the air–liquid interface (ALI). Potential change in sensitivity in hazard identification when adding complexity, going from monocultures to co- and tricultures, was tested by including human endothelial cells EA.hy926 and differentiated monocytes dTHP-1. All models were exposed to NM-300K in an aerosol exposure system (VITROCELL^® cloud-chamber). Cyto- and genotoxicity were measured by AlamarBlue and comet assay. Cellular uptake was investigated with transmission electron microscopy. The models were characterized by confocal microscopy and barrier function tested. We demonstrated that this advanced lung model is applicable for hazard assessment of NMs. The results point to a change in sensitivity of the model by adding complexity and to the importance of detailed protocols for robustness and reproducibility of advanced in vitro models.

Impact of in vitro digested zinc oxide nanoparticles on intestinal model systems

Background

Zinc oxide nanoparticles (ZnO NP) offer beneficial properties for many applications, especially in the food sector. Consequently, as part of the human food chain, they are taken up orally. The toxicological evaluation of orally ingested ZnO NP is still controversial. In addition, their physicochemical properties can change during digestion, which leads to an altered biological behaviour. Therefore, the aim of our study was to investigate the fate of two different sized ZnO NP (< 50 nm and < 100 nm) during in vitro digestion and their effects on model systems of the intestinal barrier. Differentiated Caco-2 cells were used in mono- and coculture with mucus-producing HT29-MTX cells. The cellular uptake, the impact on the monolayer barrier integrity and cytotoxic effects were investigated after 24 h exposure to 123–614 µM ZnO NP.

Results

In vitro digested ZnO NP went through a morphological and chemical transformation with about 70% free zinc ions after the intestinal phase. The cellular zinc content increased dose-dependently up to threefold in the monoculture and fourfold in the coculture after treatment with digested ZnO NP. This led to reactive oxygen species but showed no impact on cellular organelles, the metabolic activity, and the mitochondrial membrane potential. Only very small amounts of zinc (< 0.7%) reached the basolateral area, which is due to the unmodified transepithelial electrical resistance, permeability, and cytoskeletal morphology.

Conclusions

Our results reveal that digested and, therefore, modified ZnO NP interact with cells of an intact intestinal barrier. But this is not associated with serious cell damage.

Food Additive Zinc Oxide Nanoparticles: Dissolution, Interaction, Fate, Cytotoxicity, and Oral Toxicity

Food additive zinc oxide (ZnO) nanoparticles (NPs) are widely used as a Zn supplement in the food and agriculture industries. However, ZnO NPs are directly added to complex food-matrices and orally taken through the gastrointestinal (GI) tract where diverse matrices are present. Hence, the dissolution properties, interactions with bio- or food-matrices, and the ionic/particle fates of ZnO NPs in foods and under physiological conditions can be critical factors to understand and predict the biological responses and oral toxicity of ZnO NPs. In this review, the solubility of ZnO NPs associated with their fate in foods and the GI fluids, the qualitative and quantitative determination on the interactions between ZnO NPs and bio- or food-matrices, the approaches for the fate determination of ZnO NPs, and the interaction effects on the cytotoxicity and oral toxicity of ZnO NPs are discussed. This information will be useful for a wide range of ZnO applications in the food industry at safe levels.

Engineered Nanoparticle-Protein Interactions Influence Protein Structural Integrity and Biological Significance

Engineered nanoparticles (ENPs) are artificially synthesized particles with unique physicochemical properties. ENPs are being extensively used in several consumer items, elevating the probability of ENP exposure to biological systems. ENPs interact with various biomolecules like lipids, proteins, nucleic acids, where proteins are most susceptible. The ENP-protein interactions are mostly studied for corona formation and its effect on the bio-reactivity of ENPs, however, an in-depth understanding of subsequent interactive effects on proteins, such as alterations in their structure, conformation, free energy, and folding is still required. The present review focuses on ENP-protein interactions and the subsequent effects on protein structure and function followed by the therapeutic potential of ENPs for protein misfolding diseases.

TiO2@BSA nano-composites investigated through orthogonal multi-techniques characterization platform

Biocompatible coating based on bovine serum albumin (BSA) was applied on two different TiO₂ nanoparticles (aeroxide P25 and food grade E171) to investigate properties and stability of resulting TiO₂@BSA composites, under the final perspective to create a "Safe-by-Design" coating, able to uniform, level off and mitigate surface chemistry related phenomena, as naturally occurring when nano-phases come in touch with proteins enriched biological fluids. The first step towards validating the proposed approach is a detailed characterization of surface chemistry with the quantification of amount and stability of BSA coating deposited on nanoparticles' surfaces. At this purpose, we implemented an orthogonal multi-techniques characterization platform, providing important information on colloidal behavior, particle size distribution and BSA-coating structure of investigated TiO₂ systems. Specifically, the proposed orthogonal approach enabled the quantitative determination of bound and free (not adsorbed) BSA, a key aspect for the design of intentionally BSA coated nano-structures, in nanomedicine and, overall, for the control of nano-surface reactivity. In fact, the BSA-coating strategy developed and the orthogonal characterisation performed can be extended to different designed nanomaterials in order to further investigate the protein-corona formation and promote the implementation of BSA engineered coating as a strategy to harmonize the surface reactivity and minimize the biological impact.

Hydration of a small protein under carbon nanotube confinement: Adsorbed substates induce selective separation of the dynamical response

The co-involvement of biological molecules and nanomaterials has increasingly come to the fore in modern-day applications. While the "bio-nano" (BN) interface presents physico-chemical characteristics that are manifestly different from those observed in isotropic bulk conditions, the underlying molecular reasons remain little understood; this is especially true of anomalies in interfacial hydration. In this paper, we leverage atomistic simulations to study differential adsorption characteristics of a small protein on the inner (concave) surface of a single-walled carbon nanotube whose diameter exceeds dimensions conducive to single-file water movement. Our findings indicate that the extent of adsorption is decided by the degree of foldedness of the protein conformational substate. Importantly, we find that partially folded substates, but not the natively folded one, induce reorganization of the protein hydration layer into an inner layer water closer to the nanotube axis and an outer layer water in the interstitial space near the nanotube walls. Further analyses reveal sharp dynamical differences between water molecules in the two layers as observed in the onset of increased heterogeneity in rotational relaxation and the enhanced deviation from Fickian behavior. The vibrational density of states reveals that the dynamical distinctions are correlated with differences in crucial bands in the power spectra. The current results set the stage for further systematic studies of various BN interfaces vis-à-vis control of hydration properties.

Environmental Aspects of Oxide Nanoparticles: Probing Oxide Nanoparticle Surface Processes Under Different Environmental Conditions

Surface chemistry affects the physiochemical properties of nanoparticles in a variety of ways. Therefore, there is great interest in understanding how nanoparticle surfaces evolve under different environmental conditions of pH and temperature. Here, we discuss the use of vibrational spectroscopy as a tool that allows for in situ observations of oxide nanoparticle surfaces and their evolution due to different surface processes. We highlight oxide nanoparticle surface chemistry, either engineered anthropogenic or naturally occurring geochemical nanoparticles, in complex media, with a focus on the impact of (a) pH on adsorption, intermolecular interactions, and conformational changes; (b) surface coatings and coadsorbates on protein adsorption kinetics and protein conformation; (c) surface adsorption on the temperature dependence of protein structure phase changes; and (d) the use of two-dimensional correlation spectroscopy to analyze spectroscopic results for complex systems. An outlook of the field and remaining challenges is also presented.

Testing Strategies of the In Vitro Micronucleus Assay for the Genotoxicity Assessment of Nanomaterials in BEAS-2B Cells

The evaluation of the frequency of micronuclei (MN) is a broadly utilised approach in in vitro toxicity testing. Nevertheless, the specific properties of nanomaterials (NMs) give rise to concerns regarding the optimal methodological variants of the MN assay. In bronchial epithelial cells (BEAS-2B), we tested the genotoxicity of five types of NMs (TiO₂: NM101, NM103; SiO₂: NM200; Ag: NM300K, NM302) using four variants of MN protocols, differing in the time of exposure and the application of cytochalasin-B combined with the simultaneous and delayed co-treatment with NMs. Using transmission electron microscopy, we evaluated the impact of cytochalasin-B on the transport of NMs into the cells. To assess the behaviour of NMs in a culture media for individual testing conditions, we used dynamic light scattering measurement. The presence of NMs in the cells, their intracellular aggregation and dispersion properties were comparable when tests with or without cytochalasin-B were performed. The genotoxic potential of various TiO₂ and Ag particles differed (NM101 < NM103 and NM302 < NM300K, respectively). The application of cytochalasin-B tended to increase the percentage of aberrant cells. In conclusion, the comparison of the testing strategies revealed that the level of DNA damage induced by NMs is affected by the selected methodological approach. This fact should be considered in the interpretation of the results of genotoxicity tests.

Towards FAIR nanosafety data

Nanotechnology is a key enabling technology with billions of euros in global investment from public funding, which include large collaborative projects that have investigated environmental and health safety aspects of nanomaterials, but the reuse of accumulated data is clearly lagging behind. Here we summarize challenges and provide recommendations for the efficient reuse of nanosafety data, in line with the recently established FAIR (findable, accessible, interoperable and reusable) guiding principles. We describe the FAIR-aligned Nanosafety Data Interface, with an aggregated findability, accessibility and interoperability across physicochemical, bio-nano interaction, human toxicity, omics, ecotoxicological and exposure data. Overall, we illustrate a much-needed path towards standards for the optimized use of existing data, which avoids duplication of efforts, and provides a multitude of options to promote safe and sustainable nanotechnology.

Genotoxicity of Nanomaterials: Advanced In Vitro Models and High Throughput Methods for Human Hazard Assessment-A Review

Changes in the genetic material can lead to serious human health defects, as mutations in somatic cells may cause cancer and can contribute to other chronic diseases. Genotoxic events can appear at both the DNA, chromosomal or (during mitosis) whole genome level. The study of mechanisms leading to genotoxicity is crucially important, as well as the detection of potentially genotoxic compounds. We consider the current state of the art and describe here the main endpoints applied in standard human in vitro models as well as new advanced 3D models that are closer to the in vivo situation. We performed a literature review of in vitro studies published from 2000-2020 (August) dedicated to the genotoxicity of nanomaterials (NMs) in new models. Methods suitable for detection of genotoxicity of NMs will be presented with a focus on advances in miniaturization, organ-on-a-chip and high throughput methods.