Submit to Toxics Review for Toxics Propose a Special Issue

Journal Menu

Journal Browser

Assessment of the (Eco)Toxicity of Nanomaterials

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Toxics (ISSN 2305-6304). This special issue belongs to the section "Exposome Analysis and Risk Assessment".

Deadline for manuscript submissions: closed (20 April 2022) | Viewed by 26797

Share This Special Issue

Special Issue Editor

Dr. Susana I. L. Gomes

E-Mail Website
Guest Editor

Department of Biology & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
Interests: nanotoxicology; soil ecotoxicology; toxicogenomics; biomarkers; mechanisms of response

Special Issue Information

Dear Colleagues

Nanomaterials (NMs) are present in our every day life, and the risks associated to their release into the environment, with the concomitant consequences to human and environmental health, are a real concern.

The common approach to assess NMs toxicity has been based on the standard guidelines, which do not necessarily cover nano-specific issues. The need for the adaptation of the current guidelines to deal with nano specificities or even the development of new ones becomes evident, and is ongoing (MALTA initiative). Further, the discussion of the application of New Approach Methodologies (NAMs) in regulatory science is currently in progress (by ECHA) due to NAMs recognized potential, e.g., to inform on the mechanisms of toxicity, which will contribute, among others, to support read-across as well as provide useful and usable information for screening and prioritisation.

This Special Issue aims to contribute to improving and supporting the current efforts on recognizing the best practices/test procedures for NMs risk assessment. Papers may include but are not limited to toxicokinetic and toxicodynamic studies; assessment of molecular or epigenetic mechanisms of toxicity; in vitro studies; phenotypic or behavioral outcomes; and/or predictive or computational toxicology approaches, supported by proper materials characterization.

Authors are invited and welcome to submit original research papers, reviews, and short communications.

Dr. Susana Gomes
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Toxics is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Nanomaterials/Nanoparticles/Nanoplastics
Risk assessment
Nanotoxicology
New Approach Methodologies
Systems Biology
Environment
Hazard and exposure assessment

Published Papers (11 papers)

Download All Papers

Research

Jump to: Review, Other

10 pages, 981 KiB

Open AccessArticle

Environmental Hazards of Nanobiomaterials (Hydroxyapatite-Based NMs)—A Case Study with Folsomia candida—Effects from Long Term Exposure

by Bruno Guimarães, Susana I. L. Gomes, Elisabetta Campodoni, Monica Sandri, Simone Sprio, Magda Blosi, Anna L. Costa, Mónica J. B. Amorim and Janeck J. Scott-Fordsmand

Toxics 2022, 10(11), 704; https://0-doi-org.brum.beds.ac.uk/10.3390/toxics10110704 - 18 Nov 2022

Cited by 2 | Viewed by 1235

Abstract

Hydroxyapatite (HA) is a calcium phosphate used in many fields, including biomedical applications. In particular, ion-doped HA nanomaterials (nHA) are developed for their increased bioactivity, particularly in the fields of regenerative medicine and nanomedicine. In this study, we assessed the ecotoxicological impact of five nHA materials: a synthesized calcium hydroxyapatite (CaP-HA), superparamagnetic iron-doped hydroxyapatite (Fe-HA), titanium-doped hydroxyapatite (Ti-HA), alginate/titanium-doped hydroxyapatite hybrid composite (Ti-HA-Alg), and a commercial HA. The soil ecotoxicology model species Folsomia candida (Collembola) was used, and besides the standard reproduction test (28 days), an extension to the standard for one more generation was performed (56 days). Assessed endpoints included the standard survival and reproduction, and additionally, growth. Exposure via the standard (28 days) did not cause toxicity, but reproduction increased in commercial HA (significantly at 320 mg HA/kg) whereas via the extension (56 days) it decreased in all tested concentrations. Juveniles’ size (56 days) was reduced in all tested nHA materials, except commercial HA. nHA materials seem to trigger a compromise between reproduction and growth. Long-term effects could not be predicted based on the standard shorter exposure; hence, the testing of at least two generations (56 days) is recommended to assess the toxicity of nanomaterials, particularly in F. candida. Further, we found that the inclusion of size as additional endpoint is highly relevant. Full article

(This article belongs to the Special Issue Assessment of the (Eco)Toxicity of Nanomaterials)

► Show Figures

Figure 1

10 pages, 626 KiB

Open AccessArticle

Impacts of Longer-Term Exposure to AuNPs on Two Soil Ecotoxicological Model Species

by Bruno Guimarães, Susana I. L. Gomes, Janeck J. Scott-Fordsmand and Mónica J. B. Amorim

Toxics 2022, 10(4), 153; https://0-doi-org.brum.beds.ac.uk/10.3390/toxics10040153 - 22 Mar 2022

Cited by 5 | Viewed by 1634

Abstract

The production, use and disposal of nanoparticles (NPs) has been increasing continuously. Due to its unique properties, such as a high resistance to oxidation, gold NPs (AuNPs) are persistent in the environment, including the terrestrial, one of the major sinks of NPs. The present study aimed to assess the effects of AuNPs (from 10 to 1000 mg/kg) on two OECD standard ecotoxicological soil model species, Enchytraeus crypticus and Folsomia candida, based on the reproduction test (28 days) and on a longer-term exposure (56 days), and survival, reproduction, and size were assessed. AuNPs caused no significant hazard to F. candida, but for E. crypticus the lowest tested concentrations (10 and 100 mg AuNPs/kg) reduced reproduction. Further, AuNPs’ toxicity increased from the 28th to the 56th day mainly to F. candida, as observed in animals’ size reduction. Therefore, longer-term exposure tests are recommended as these often reveal increased hazards, not predicted when based on shorter exposures. Additionally, special attention should be given to the higher hazard of low concentrations of NPs, compared to higher concentrations. Full article

(This article belongs to the Special Issue Assessment of the (Eco)Toxicity of Nanomaterials)

► Show Figures

Figure 1

14 pages, 3617 KiB

Open AccessArticle

Double-Sided Nano-ZnO: Superior Antibacterial Properties and Induced Hepatotoxicity in Zebrafish Embryos

by Mingyue He, Xueting Li, Lidong Yu, Shuai Deng, Ning Gu, Li Li, Jianbo Jia and Bingsheng Li

Toxics 2022, 10(3), 144; https://0-doi-org.brum.beds.ac.uk/10.3390/toxics10030144 - 18 Mar 2022

Cited by 10 | Viewed by 2482

Abstract

Zinc oxide nanoparticles (Nano-ZnO) have been widely used in the food, cosmetics, and biomedical fields due to their excellent antibacterial and antioxidant properties. However, with the widespread application of Nano-ZnO, Nano-ZnO inevitably enters the environment and living organisms, causing harm to human health and ecosystem safety. Therefore, the biosafety and toxicological issues of Nano-ZnO are gradually being emphasized. Our study found that Nano-ZnO has superior antibacterial properties compared to ofloxacin in the fight against Staphylococcus aureus (S. aureus). Given that ofloxacin can inhibit bacterial-induced inflammation, we constructed a model of bacterial inflammation using S. aureus in zebrafish. We found that Nano-ZnO inhibited the NF-κB-mediated inflammatory signaling pathway. However, in the process, we found that Nano-ZnO caused hepatic steatosis in zebrafish. This suggested that Nano-ZnO had a certain hepatotoxicity, but did not affect liver development. Subsequently, we investigated the mechanism of hepatotoxicity produced by Nano-ZnO. Nano-ZnO triggered oxidative stress in the liver by generating ROS, which then induced endoplasmic reticulum stress to occur. It further activated srebp and its downstream genes fasn and acc1, which promoted the accumulation of fatty acid synthesis and the development of steatosis, leading to the development of nonalcoholic fatty liver disease (NAFLD). To address the hepatotoxicity of Nano-ZnO, we added carbon dots for the treatment of NAFLD. The carbon dots were found to normalize the steatotic liver. This provided a new strategy to address the hepatotoxicity caused by Nano-ZnO. In this work, we systematically analyzed the antibacterial advantages of Nano-ZnO in vivo and in vitro, explored the mechanism of Nano-ZnO hepatotoxicity, and proposed a new method to treat Nano-ZnO hepatotoxicity. Full article

(This article belongs to the Special Issue Assessment of the (Eco)Toxicity of Nanomaterials)

► Show Figures

Figure 1

15 pages, 5487 KiB

Open AccessArticle

Effects of Zinc Oxide Nanoparticles on Model Systems of the Intestinal Barrier

by Anna Mittag, Patricia Owesny, Christian Hoera, Alexander Kämpfe and Michael Glei

Toxics 2022, 10(2), 49; https://0-doi-org.brum.beds.ac.uk/10.3390/toxics10020049 - 21 Jan 2022

Cited by 3 | Viewed by 2533

Abstract

Zinc oxide nanoparticles (ZnO NP) are often used in the food sector, among others, because of their advantageous properties. As part of the human food chain, they are inevitably taken up orally. The debate on the toxicity of orally ingested ZnO NP continues due to incomplete data. Therefore, the aim of our study was to examine the effects of two differently sized ZnO NP (<50 nm and <100 nm primary particle size; 123–614 µmol/L) on two model systems of the intestinal barrier. Differentiated Caco-2 enterocytes were grown on Transwell inserts in monoculture and also in coculture with the mucus-producing goblet cell line HT29-MTX. Although no comprehensive mucus layer was detectable in the coculture, cellular zinc uptake was clearly lower after a 24-h treatment with ZnO NP than in monocultured cells. ZnO NP showed no influence on the permeability, metabolic activity, cytoskeleton and cell nuclei. The transepithelial electrical resistance was significantly increased in the coculture model after treatment with ≥307 µmol/L ZnO NP. Only small zinc amounts (0.07–0.65 µg/mL) reached the basolateral area. Our results reveal that the cells of an intact intestinal barrier interact with ZnO NP but do not suffer serious damage. Full article

(This article belongs to the Special Issue Assessment of the (Eco)Toxicity of Nanomaterials)

► Show Figures

Graphical abstract

11 pages, 3061 KiB

Open AccessArticle

Biokinetic Evaluation of Contrast Media Loaded Carbon Nanotubes Using a Radiographic Device

by Mieko Takasaka, Shinsuke Kobayashi, Yuki Usui, Hisao Haniu, Shuji Tsuruoka, Kaoru Aoki and Naoto Saito

Toxics 2021, 9(12), 331; https://0-doi-org.brum.beds.ac.uk/10.3390/toxics9120331 - 02 Dec 2021

Cited by 1 | Viewed by 2053

Abstract

Considerable progress has been made in various fields of applied research on the use of carbon nanotubes (CNTs). Because CNTs are fibrous nanomaterials, biosafety of CNTs has been discussed. The biokinetic data of CNTs, such as using the radioisotope of carbon and surface labeling of CNTs, have been reported. However, the use of radioisotopes requires a special facility. In addition, there are problems in the surface labeling of CNTs, including changes in surface properties and labels eliminating over time. In order to solve these problems and properly evaluate the biokinetics of CNTs, the authors synthesize peapods with platinum (Pt) encapsulated within the hollow region of Double-Walled CNTs (DWCNTs) and develop a new system to evaluate biokinetics using widely available imaging equipment. In the cell assay, no significant difference is observed with and without Pt in CNTs. In animal studies, radiography of the lungs of rats that inhaled Pt-peapods show the detectability of Pt inside the CNTs. This new method using Pt-peapods enables image evaluation with a standard radiographic imaging device without changing the surface property of the CNTs and is effective for biokinetics evaluation of CNTs. Full article

(This article belongs to the Special Issue Assessment of the (Eco)Toxicity of Nanomaterials)

► Show Figures

Figure 1

12 pages, 4122 KiB

Open AccessCommunication

Reactive Oxygen Species Detection Using Fluorescence in Enchytraeus crypticus—Method Implementation through Ag NM300K Case Study

by Susana I. L. Gomes, Ana B. Neves, Janeck J. Scott-Fordsmand and Mónica J. B. Amorim

Toxics 2021, 9(10), 232; https://0-doi-org.brum.beds.ac.uk/10.3390/toxics9100232 - 24 Sep 2021

Cited by 2 | Viewed by 2138

Abstract

An imbalance between reactive oxygen species (ROS) and antioxidants in a living organism results in oxidative stress. Measures of such imbalance can be used as a biomarker of stress in ecotoxicology. In this study, we implemented the ROS detection method based on the oxidant-sensing probe dichloro-dihydro-fluorescein diacetate (DCFH-DA), detected by fluorescence microscopy, in Enchytraeus crypticus adults and cocoons, i.e., also covering the embryo stage. Hydrogen peroxide (H₂O₂), a well-known ROS inducer, was used both to optimize the method and as positive control. Implementation was successful, and the method was used to assess ROS formation in E. crypticus cocoons and adults when exposed to the reference silver nanomaterial Ag NM300K, at two effect concentrations (EC20 and EC50) for both hatching and reproduction over 3 and 7 days. The measured ROS levels varied with time, concentration, and developmental stage, with higher levels detected in adults compared with cocoons. In cocoons, ROS levels were higher at the EC20 than the EC50, which could be explained by non-monotonic concentration-response curve for hatching and reproduction, as previously observed. The increase in ROS levels at day 3 preceded the oxidative damage, as reported to occur later (day 7) in adults. The DCFH-DA method was successfully implemented here and can be further used as a new tool to detect ROS formation in E. crypticus, especially after short-term exposure to chemicals, including nanomaterials. We recommend the use of 3 and 7 days in the exposure design for this assessment. Full article

(This article belongs to the Special Issue Assessment of the (Eco)Toxicity of Nanomaterials)

► Show Figures

Graphical abstract

20 pages, 15781 KiB

Open AccessArticle

A Co-Culture Model of the Human Respiratory Tract to Discriminate the Toxicological Profile of Cationic Nanoparticles According to Their Surface Charge Density

by Yasmin Arezki, Juliette Cornacchia, Mickaël Rapp, Luc Lebeau, Françoise Pons and Carole Ronzani

Toxics 2021, 9(9), 210; https://0-doi-org.brum.beds.ac.uk/10.3390/toxics9090210 - 31 Aug 2021

Cited by 2 | Viewed by 2724

Abstract

This study aimed at discriminating with sensitivity the toxicological effects of carbon dots (CDs) with various zeta potential (ζ) and charge density (Q_ek) in different cellular models of the human respiratory tract. One anionic and three cationic CDs were synthetized as follows: CD-COOH (ζ = −43.3 mV); CD-PEI600 (Q_ek = 4.70 µmol/mg; ζ = +31.8 mV); CD-PEHA (Q_ek = 3.30 µmol/mg; ζ = +29.2 mV) and CD-DMEDA (Q_ek = 0.01 µmol/mg; ζ = +11.1 mV). Epithelial cells (A549) and macrophages (THP-1) were seeded alone or as co-cultures with different A549:THP-1 ratios. The obtained models were characterized, and multiple biological responses evoked by CDs were assessed in the mono-cultures and the best co-culture model. With 14% macrophages, the 2:1 ratio co-culture best mimicked the in vivo conditions and responded to lipopolysaccharides. The anionic CD did not induce any effect in the mono-cultures nor in the co-culture. Among the cationic CDs, the one with the highest charge density (CD-PEI600) induced the most pronounced responses whatever the culture model. The cationic CDs of low charge density (CD-PEHA and CD-DMEDA) evoked similar responses in the mono-cultures, whereas in the co-culture, the three cationic CDs ranked according to their charge density (CD-PEI600 > CD-PEHA > CD-DMEDA), when taking into account their inflammatory effect. Thus, the co-culture system developed in this study appears to be a sensitive model for finely discriminating the toxicological profile of cationic nanoparticles differing by the density of their surface charges. Full article

(This article belongs to the Special Issue Assessment of the (Eco)Toxicity of Nanomaterials)

► Show Figures

Figure 1

24 pages, 7785 KiB

Open AccessEditor’s ChoiceArticle

Cellular Uptake and Toxicological Effects of Differently Sized Zinc Oxide Nanoparticles in Intestinal Cells

by Anna Mittag, Christian Hoera, Alexander Kämpfe, Martin Westermann, Jochen Kuckelkorn, Thomas Schneider and Michael Glei

Toxics 2021, 9(5), 96; https://0-doi-org.brum.beds.ac.uk/10.3390/toxics9050096 - 27 Apr 2021

Cited by 21 | Viewed by 2788

Abstract

Due to their beneficial properties, the use of zinc oxide nanoparticles (ZnO NP) is constantly increasing, especially in consumer-related areas, such as food packaging and food additives, which is leading to an increased oral uptake of ZnO NP. Consequently, the aim of our study was to investigate the cellular uptake of two differently sized ZnO NP (<50 nm and <100 nm; 12–1229 µmol/L) using two human intestinal cell lines (Caco-2 and LT97) and to examine the possible resulting toxic effects. ZnO NP (<50 nm and <100 nm) were internalized by both cell lines and led to intracellular changes. Both ZnO NP caused time- and dose-dependent cytotoxic effects, especially at concentrations of 614 µmol/L and 1229 µmol/L, which was associated with an increased rate of apoptotic and dead cells. ZnO NP < 100 nm altered the cell cycle of LT97 cells but not that of Caco-2 cells. ZnO NP < 50 nm led to the formation of micronuclei in LT97 cells. The Ames test revealed no mutagenicity for both ZnO NP. Our results indicate the potential toxicity of ZnO NP after oral exposure, which should be considered before application. Full article

(This article belongs to the Special Issue Assessment of the (Eco)Toxicity of Nanomaterials)

► Show Figures

Graphical abstract

Review

Jump to: Research, Other

30 pages, 9333 KiB

Open AccessEditor’s ChoiceReview

Use of Nanotechnology to Mitigate Biofouling in Stainless Steel Devices Used in Food Processing, Healthcare, and Marine Environments

by Hugo Pérez, Gregorio Vargas and Rodolfo Silva

Toxics 2022, 10(1), 35; https://0-doi-org.brum.beds.ac.uk/10.3390/toxics10010035 - 12 Jan 2022

Cited by 10 | Viewed by 3482 | Correction

Abstract

In humid environments, the formation of biofilms and microfouling are known to be the detrimental processes that first occur on stainless steel surfaces. This is known as biofouling. Subsequently, the conditions created by metabolites and the activity of organisms trigger corrosion of the metal and accelerate corrosion locally, causing a deterioration in, and alterations to, the performance of devices made of stainless steel. The microorganisms which thus affect stainless steel are mainly algae and bacteria. Within the macroorganisms that then damage the steel, mollusks and crustaceans are the most commonly observed. The aim of this review was to identify the mechanisms involved in biofouling on stainless steel and to evaluate the research done on preventing or mitigating this problem using nanotechnology in humid environments in three areas of human activity: food manufacturing, the implantation of medical devices, and infrastructure in marine settings. Of these protective processes that modify the steel surfaces, three approaches were examined: the use of inorganic nanoparticles; the use of polymeric coatings; and, finally, the generation of nanotextures. Full article

(This article belongs to the Special Issue Assessment of the (Eco)Toxicity of Nanomaterials)

► Show Figures

Figure 1

20 pages, 1273 KiB

Open AccessReview

State of the Art on Toxicological Mechanisms of Metal and Metal Oxide Nanoparticles and Strategies to Reduce Toxicological Risks

by Victor García-Torra, Amanda Cano, Marta Espina, Miren Ettcheto, Antoni Camins, Emma Barroso, Manel Vazquez-Carrera, Maria Luisa García, Elena Sánchez-López and Eliana B. Souto

Toxics 2021, 9(8), 195; https://0-doi-org.brum.beds.ac.uk/10.3390/toxics9080195 - 23 Aug 2021

Cited by 15 | Viewed by 3279

Abstract

Metal nanoparticles have been extensively investigated for different types of pharmaceutical applications. However, their use has raised some concerns about their toxicity involving the increase of reactive oxygen species causing cellular apoptosis. Therefore, in this review we summarize the most relevant toxicity mechanisms of gold, silver, copper and copper oxide nanoparticles as well as production methods of metal nanoparticles. Parameters involved in their toxicity such as size, surface charge and concentration are also highlighted. Moreover, a critical revision of the literature about the strategies used to reduce the toxicity of this type of nanoparticles is carried out throughout the review. Additionally, surface modifications using different coating strategies, nanoparticles targeting and morphology modifications are deeply explained. Full article

(This article belongs to the Special Issue Assessment of the (Eco)Toxicity of Nanomaterials)

► Show Figures