Fragmented or otherwise miniaturized plastic materials in the form of micro- or nanoplastics have been of nagging environmental concern. Perturbation of organismal physiology and behavior by micro- and nanoplastics have been widely documented for marine invertebrates. Some of these effects are also manifested by larger marine vertebrates such as fishes. More recently, possible effects of micro- and nanoplastics on mammalian gut microbiota as well as host cellular and metabolic toxicity have been reported in mouse models. Human exposure to micro- and nanoplastics occurs largely through ingestion, as these are found in food or derived from food packaging, but also in a less well-defined manner though inhalation. The pathophysiological consequences of acute and chronic micro- and nanoplastics exposure in the mammalian system, particularly humans, are yet unclear. In this review, we focus on the recent findings related to the potential toxicity and detrimental effects of micro- and nanoplastics as demonstrated in mouse models as well as human cell lines. The prevailing data suggest that micro- and nanoplastics accumulation in mammalian and human tissues would likely have negative, yet unclear long-term consequences. There is a need for cellular and systemic toxicity due to micro- and nanoplastics to be better illuminated, and the underlying mechanisms defined by further work.

Toxicity of Microplastics and Nanoplastics in Mammalian Systems

Estimation of the mass of microplastics ingested - A pivotal first step towards human health risk assessment.

Microplastics and associated contaminants in the aquatic environment: A review on their ecotoxicological effects, trophic transfer, and potential impacts to human health.

Micro- and nanoplastic induced cellular toxicity in mammals: A review

In recent years, increasing global attention has focused on “microplastics” (MPs) and “nanoplastics” (NPs) resulting in many studies on the effects of these compounds on ecological and envi...

Potential adverse health effects of ingested micro- and nanoplastics on humans. Lessons learned from in vivo and in vitro mammalian models

Several studies have provided information on environmental nanoplastic particles/debris, but the in vitro cyto-genotoxicity is still insufficiently characterized. The aim of this study is to analyze the effects of polystyrene nanoparticles (PNPs) in the Hs27 cell line. The viability of Hs27 cells was determined following exposure at different time windows and PNP concentrations. The genotoxic effects of the PNPs were evaluated by the cytokinesis-block micronucleus (CBMN) assay after exposure to PNPs. We performed ROS analysis on HS27 cells to detect reactive oxygen species at different times and treatments in the presence of PNPs alone and PNPs added to the Crocus sativus L. extract. The different parameters of the CBMN test showed DNA damage, resulting in the increased formation of micronuclei and nuclear buds. We noted a greater increase in ROS production in the short treatment times, in contrast, PNPs added to Crocus sativus extract showed the ability to reduce ROS production. Finally, the SEM-EDX analysis showed a three-dimensional structure of the PNPs with an elemental composition given by C and O. This work defines PNP toxicity resulting in DNA damage and underlines the emerging problem of polystyrene nanoparticles, which extends transversely from the environment to humans; further studies are needed to clarify the internalization process.

In Vitro Genotoxicity of Polystyrene Nanoparticles on the Human Fibroblast Hs27 Cell Line.

The potential risks of environmental nanoparticles (NPs), in particular Polystyrene Nanoparticles (PNPs), is an emerging problem; specifically, the interaction of PNPs with intestinal cells has not been characterized so far. The mechanism by which polystyrene particles are transferred to humans has not yet been clarified, whether directly through ingestion from contaminated food. We evaluated the interaction between PNPs and colorectal adenocarcinoma cells (HCT116). Cells were exposed to different concentrations of PNPs, metabolic activity and the consequent cytotoxic potential were assessed through viability test; we evaluated the PNP genotoxic potential through the Cytokinesis-Block Micronucleus cytome (CBMN cyt) assay. Finally, we detected Reactive Oxygen Species (ROS) production after NPs exposure and performed Western Blot analysis to analyze the enzymes (SOD1, SOD2, Catalase, Glutathione Peroxidase) involved in the cell detoxification process that comes into play during the cell-PNPs interaction. This work analyzes the cyto and genotoxicity of PNPs in the colorectal HCT116 cell line, in particular the potential damage from oxidative stress produced by PNPs inside the cells related to the consequent nuclear damage. Our results show moderate toxicity of PNPs both in terms of ROS production and DNA damage. Further studies will be needed on different cell lines to have a more complete picture of the impact of environmental pollution on human health in terms of PNPs cytotoxicity and genotoxicity.

/pdf/genotoxicity-and-oxidative-stress-induction-by-polystyrene-3vbzzqiewq.pdf

Genotoxicity and oxidative stress induction by polystyrene nanoparticles in the colorectal cancer cell line HCT116.

Air pollution in the urban environment is a topical subject. Aero-suspended particles can cause respiratory diseases in humans, ranging from inflammation to asthma and cancer. One of the components that is most prevalent in particulate matter (PM) in urban areas is the set of tire microparticles (1–20 μm) and nanoparticles (<1 μm) that are formed due to the friction of wheels with asphalt and are increased in slow-moving areas that involve a lot of braking actions. In this work, we studied the effect that microparticles generated from passenger tires (PTWP, passenger tire wear particles) have in vitro on murine macrophages cells RAW 264.7 at two concentrations of 25 and 100 μg/mL, for 24 and 48 h. In addition to the chemical characterization of the material and morphological characterization of the treated cells by transmission electron microscopy, gene expression analysis with RT-PCR and active protein analysis with Western blotting were performed. Growth curves were obtained, and the genotoxic effect was evaluated with a comet assay. The results indicate that initially, an induction of the apoptotic process is observable, but this is subsequently reversed by Bcl2. No genotoxic damage is present, but mild cellular abnormalities were observed in the treated cells.

/pdf/particle-debris-generated-from-passenger-tires-induces-3dy2f3qf.pdf

Particle Debris Generated from Passenger Tires Induces Morphological and Gene Expression Alterations in the Macrophages Cell Line RAW 264.7

Humans have always been exposed to tiny particles via dust storms, volcanic ash, and other natural processes, and our bodily systems are well adapted to protect us from these potentially harmful external agents. However, technological advancement has dramatically increased the production of nanometer-sized particles or nanoparticles (NPs), and many epidemiological studies have confirmed a correlation between NP exposure and the onset of cardiovascular diseases and various cancers. Among the adverse effects on human health, in recent years, potential hazards of nanomaterials on female reproductive organs have received increasing concern. Several animal and human studies have shown that NPs can translocate to the ovary, uterus, and placenta, thus negatively impacting female reproductive potential and fetal health. However, NPs are increasingly being used for therapeutic purposes as tools capable of modifying the natural history of degenerative diseases. Here we briefly summarize the toxic effects of few but widely diffused NPs on female fertility and also the use of nanotechnologies as a new molecular approach for either specific pathological conditions, such as ovarian cancer and infertility, or the cryopreservation of gametes and embryos.

/pdf/the-impact-of-metal-nanoparticles-on-female-reproductive-1k1kpxf4.pdf

The Impact of Metal Nanoparticles on Female Reproductive System: Risks and Opportunities

Indoor air pollutants (IAP), which can pose a serious risk to human health, include biological pollutants, nitric oxide (NO), nitrogen dioxide (NO2), volatile organic compounds (VOC), sulfur dioxide (SO2), carbon monoxide (CO), carbon dioxide (CO2), silica, metals, radon, and particulate matter (PM). The aim of our work is to conduct a multidisciplinary study of fine silica particles (<2.5 μm) in the presence or absence of ozone (O3), and evaluate their potential cytotoxicity using MTS, micronucleus, and the comet test in two cell lines. We analyzed A549 (human basal alveolar epithelial cell adenocarcinoma) and Hs27 (human normal fibroblasts) exposed to dynamic conditions by an IRC simulator under ozone flow (120 ppb) and in the presence of silica particles (40 μg/h). The viability of A549 and Hs27 cells at 48 and 72 h of exposure to silica or silica/ozone decreases, except at 72 h in Hs27 treated with silica/ozone. The micronucleus and comet tests showed a significant increase in the number of micronuclei and the % of DNA in the queue, compared to the control, in both lines in all treatments, even if in different cell times/types. We found that silica alone or with more O3 causes more pronounced genotoxic effects in A549 tumor cells than in normal Hs27 fibroblasts.

/pdf/genotoxicity-response-of-fibroblast-cells-and-human-1lw5xu04.pdf

Massimo Aloisi

Papers

In Vitro Genotoxicity of Polystyrene Nanoparticles on the Human Fibroblast Hs27 Cell Line.

Genotoxicity and oxidative stress induction by polystyrene nanoparticles in the colorectal cancer cell line HCT116.

Particle Debris Generated from Passenger Tires Induces Morphological and Gene Expression Alterations in the Macrophages Cell Line RAW 264.7

The Impact of Metal Nanoparticles on Female Reproductive System: Risks and Opportunities

Genotoxicity Response of Fibroblast Cells and Human Epithelial Adenocarcinoma In Vitro Model Exposed to Bare and Ozone-Treated Silica Microparticles