Hazard profiling of a combinatorial library of zinc oxide nanoparticles: Ameliorating light and dark toxicity through surface passivation

Zebrafish Insights into Nanomaterial Toxicity: A Focused Exploration on Metallic, Metal Oxide, Semiconductor, and Mixed-Metal Nanoparticles

Nanomaterials are widely used in various fields, and ongoing research is focused on developing safe and sustainable nanomaterials. Using zebrafish as a model organism for studying the potentially toxic effects of nanomaterials highlights the importance of developing safe and sustainable nanomaterials. Studies conducted on nanomaterials and their toxicity and potential risks to human and environmental health are vital in biomedical sciences. In the present review, we discuss the potential toxicity of nanomaterials (inorganic and organic) and exposure risks based on size, shape, and concentration. The review further explores various types of nanomaterials and their impacts on zebrafish at different levels, indicating that exposure to nanomaterials can lead to developmental defects, changes in gene expressions, and various toxicities. The review also covers the importance of considering natural organic matter and chorion membranes in standardized nanotoxicity testing. While some nanomaterials are biologically compatible, metal and semiconductor nanomaterials that enter the water environment can increase toxicity to aquatic creatures and can potentially accumulate in the human body. Further investigations are necessary to assess the safety of nanomaterials and their impacts on the environment and human health.

Toxicological assessment of divalent ion-modified ZnO nanomaterials through artificial intelligence and in vivo study

The nanotechnology-driven industrial revolution widely relies on metal oxide-based nanomaterial (NM). Zinc oxide (ZnO) production has rapidly increased globally due to its outstanding physical and chemical properties and versatile applications in industries including cement, rubber, paints, cosmetics, and more. Nevertheless, releasing Zn2+ ions into the environment can profoundly impact living systems and affect water-based ecosystems, including biological ones. In aquatic environments, Zn2+ ions can change water properties, directly influencing underwater ecosystems, especially fish populations. These ions can accumulate in fish tissues when fish are exposed to contaminated water and pose health risks to humans who consume them, leading to symptoms such as nausea, vomiting, and even organ damage. To address this issue, safety of ZnO NMs should be enhanced without altering their nanoscale properties, thus preventing toxic-related problems. In this study, an eco-friendly precipitation method was employed to prepare ZnO NMs. These NMs were found to reduce ZnO toxicity levels by incorporating elements such as Mg, Ca, Sr, and Ba. Structural, morphological, and optical properties of synthesized NMs were thoroughly investigated. In vitro tests demonstrated potential antioxidative properties of NMs with significant effects on free radical scavenging activities. In vivo, toxicity tests were conducted using Oreochromis mossambicus fish and male Swiss Albino mice to compare toxicities of different ZnO NMs. Fish and mice exposed to these NMs exhibited biochemical changes and histological abnormalities. Notably, ZnCaO NMs demonstrated lower toxicity to fish and mice than other ZnO NMs. This was attributed to its Ca2+ ions, which could enhance body growth metabolism compared to other metals, thus improving material safety. Furthermore, whether nanomaterials' surface roughness might contribute to their increased toxicity in biological systems was investigated utilizing computer vision (CV)-based AI tools to obtain SEM images of NMs, providing valuable image-based surface morphology data that could be correlated with relevant toxicology studies.

Zn2SnO4 ternary metal oxide for ultraviolet radiation filter application: a comparative study with TiO2 and ZnO

Ultraviolet (UV) radiation causes serious health risks. Inorganic metal oxides, such as titanium dioxide (TiO2) and zinc oxide (ZnO), have long been recognized for their effectiveness as UV radiation filters/blockers in sunscreen formulations. TiO2 and ZnO as UV-blocking materials have some limitations and issues such as producing harmful radicals and toxicity, respectively. As a result, there is a growing need to develop efficient and safe UV-blocking materials to overcome these limitations associated with the conventional TiO2 and ZnO materials. Zinc stannate (Zn2SnO4), as a ternary metal oxide, is expected to be a promising candidate due to its optical properties and potential for UV-blocking capability. This study presents a comprehensive investigation into the development and characterization of Zn2SnO4 as a potential alternative UV filter to TiO2 and ZnO. The fundamental characteristics, including structural, optical, and photocatalytic characteristics, as well as cell viability, were investigated for two Zn2SnO4 morphologies: cubic aggregate Zn2SnO4 nanoparticles (ZTO CANP) and Zn2SnO4 nanoparticles (ZTO NP), which were compared with the performance of TiO2 nanoparticles (TiO2 NP) and ZnO nanoparticles (ZnO NP). Interestingly, in addition to their promising UVB and partial UVA blocking properties, ZTO CANP and ZTO NP were found to be relativity photocatalytically inactive materials, which means they produce less free radical species as in the case of TiO2 NP, and they cannot be considered as toxic materials as in the case of ZnO NP. To the best of our knowledge, this is the first direct comparison study examining the performance of Zn2SnO4 ternary metal oxide for its potential use as a UV filter. Further research and optimization need to be conducted on these materials, particularly on ZTO CANP as a promising alternative UV filter.

The potential of dietary nanoparticles to enhance allergenicity of milk proteins: an in vitro investigation

In recent years, the popularity of dietary nanoparticles (NPs) in the food industry as additives has raised concerns because of the lack of knowledge about potential adverse health outcomes ensuing from the interactions of NPs with components of the food matrix and gastrointestinal system. In this study, we used a transwell culture system that consisted of human colorectal adenocarcinoma (Caco-2) cells in the apical insert and Laboratory of Allergic Diseases 2 mast cells in the basal compartment to study the effect of NPs on milk allergen delivery across the epithelial layer, mast cell responses and signaling between epithelial and mast cells in allergenic inflammation. A library of dietary particles (silicon dioxide NPs, titanium dioxide NPs and silver NPs) that varied in particle size, surface chemistry and crystal structures with or without pre-exposure to milk was used in this investigation. Milk-interacted particles were found to acquire surface corona and increased the bioavailability of milk allergens (casein and β-lactoglobulin) across the intestinal epithelial layer. The signaling between epithelial cells and mast cells resulted in significant changes in the early phase and late-phase activation of the mast cells. This study suggested that antigen challenge in mast cells with the presence of dietary NPs may cause the transition of allergic responses from an immunoglobulin E (IgE)-dependent mechanism to a mixed mechanism (both IgE-dependent and IgE-independent mechanisms).

Zinc oxide nanoparticles trigger dysfunction of mitochondrial respiratory complexes and repair dynamics in human alveolar cells

Zinc oxide nanoparticles (ZnO NP) are commonly used engineered NPs with extensive usage in consumer products, thus leading to direct exposure to humans. The direct route of exposure is through inhalation. Once inhaled, these particles accumulate in the lungs, increasing the chances of respiratory tract illness through cellular organelle damage. Zinc oxide nanoparticle-treated lung cells are reported to display cytotoxicity, increase DNA damage, and induce oxidative stress. The current study focused on the effects of ZnO NPs on mitochondrial dynamics (fission and fusion) in human lung epithelial cells (A549). The lung cells were exposed to ZnO NPs at 50 and 100 μg/ml concentrations, and their mitochondrial dynamics were assessed to understand the effects of the NPs. Treatment with ZnO NPs reduced the activity of mitochondrial complex I and complex III and altered mitochondrial structural and functional characteristics in a concentration-dependent manner. Zinc oxide nanoparticles exposure showed an increase in small and round-shaped mitochondria. The expression of various fission proteins (Drp1 and Fis1) and fusion proteins (Mfn1, Mfn2, and OPA1) was altered upon exposure to ZnO NPs. Our studies showed dysfunction of the mitochondria induced by ZnO NPs. In fibroblast mitochondrial dynamics, fission symbolizes threshold damage. In this paper, we have shown that the mitochondrial fission phenotype increased upon exposure to ZnO NPs. The paper emphasizes that these particles enter mitochondria, triggering a stress response that results in the removal of mitochondria via fission. It provides relevant data for safety guidelines to ensure the safer use of these particles.