Assessing the Impact of Polyethylene Nano/Microplastic Exposure on Human Vaginal Keratinocytes

Beyond microbeads: Examining the role of cosmetics in microplastic pollution and spotlighting unanswered questions

The presence of microplastics in cosmetics and personal care products (C&PCPs) has been increasingly in the public eye since the early 2010s. Despite increasing research into the potential environmental and health effects of microplastics, most research to date on microplastics in C&PCPs has investigated "rinse-off" products, while the potential impacts of "leave-on" C&PCPs have been largely neglected, despite these products being purchased in greater volumes and often having two or more microplastic ingredients in their formulations(CosmeticsEurope, 2018b). This review aims to synthesize the current knowledge of microplastic in C&PCPs, assessing the potential environmental and human health impacts of C&PCPs and discussing the regulatory implications. The lack of studies on leave-on C&PCPs is significant, suggesting a severe knowledge gap regarding microplastic presence in, and emissions from, C&PCPs. There is a noticeable lack of studies on the (eco)toxicological consequences of microplastic exposure from C&PCPs. As a result, significant aspects of microplastic contamination may be overlooked in the microplastic legislations emerging globally (including from the European Commission), which intend to restrict microplastic use in C&PCPs but focus on rinse-off C&PCPs only. This review highlights the potential consequences of microplastics in leave-on C&PCPs for regulatory decision-making, particularly as alternatives to microplastics are considered during the phase-out periods and spotlights the need for sufficient monitoring and research on these alternatives, to avoid unforeseen consequences.

Nano/micro-plastic, an invisible threat getting into the brain

Due to weather and working/operational conditions, plastic degradation produces toxic and non-biodegradable nano and microplastics (N/M-Ps, ranging from 10 nm to 5 mm), and over time these N/M-Ps have integrated with the human cycle through ingestion and inhalation. These N/M-Ps, as serious emerging pollutants, are causing considerable adverse health issues due to up-taken by the cells, tissue, and organs, including the brain. It has been proven that N/M-Ps can cross the blood-brain barrier (via olfactory and blood vessels) and affect the secretion of neuroinflammatory (cytokine and chemokine), transporters, and receptor markers. Neurotoxicity, neuroinflammation, and brain injury, which may result in such scenarios are a serious concern and may cause brain disorders. However, the related pathways and pathogenesis are not well-explored but are the focus of upcoming emerging research. Therefore, as a focus of this editorial, well-organized multidisciplinary research is required to explore associated pathways and pathogenesis, leading to brain mapping and nano-enabled therapeutics in acute and chronic N/M - Ps exposure.

Antitumour effects of SFX-01 molecule in combination with ionizing radiation in preclinical and in vivo models of rhabdomyosarcoma

BACKGROUND

Despite a multimodal approach including surgery, chemo- and radiotherapy, the 5-year event-free survival rate for rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in childhood, remains very poor for metastatic patients, mainly due to the selection and proliferation of tumour cells driving resistance mechanisms. Personalised medicine-based protocols using new drugs or targeted therapies in combination with conventional treatments have the potential to enhance the therapeutic effects, while minimizing damage to healthy tissues in a wide range of human malignancies, with several clinical trials being started. In this study, we analysed, for the first time, the antitumour activity of SFX-01, a complex of synthetic d, l-sulforaphane stabilised in alpha-cyclodextrin (Evgen Pharma plc, UK), used as single agent and in combination with irradiation, in four preclinical models of alveolar and embryonal RMS. Indeed, SFX-01 has shown promise in preclinical studies for its ability to modulate cellular pathways involved in inflammation and oxidative stress that are essential to be controlled in cancer treatment.

METHODS

RH30, RH4 (alveolar RMS), RD and JR1 (embryonal RMS) cell lines as well as mouse xenograft models of RMS were used to evaluate the biological and molecular effects induced by SFX-01 treatment. Flow cytometry and the modulation of key markers analysed by q-PCR and Western blot were used to assess cell proliferation, apoptosis, autophagy and production of intracellular reactive oxygen species (ROS) in RMS cells exposed to SFX-01. The ability to migrate and invade was also investigated with specific assays. The possible synergistic effects between SFX-01 and ionising radiation (IR) was studied in both the in vitro and in vivo studies. Student's t-test or two-way ANOVA were used to test the statistical significance of two or more comparisons, respectively.

RESULTS

SFX-01 treatment exhibited cytostatic and cytotoxic effects, mediated by G2 cell cycle arrest, apoptosis induction and suppression of autophagy. Moreover, SFX-01 was able to inhibit the formation and the proliferation of 3D tumorspheres as monotherapy and in combination with IR. Finally, SFX-01, when orally administered as single agent, displayed a pattern of efficacy at reducing the growth of tumour masses in RMS xenograft mouse models; when combined with a radiotherapy regime, it was observed to act synergistically, resulting in a more positive outcome than would be expected by adding each exposure alone.

CONCLUSIONS

In summary, our results provide evidence for the antitumour properties of SFX-01 in preclinical models of RMS tumours, both as a standalone treatment and in combination with irradiation. These forthcoming findings are crucial for deeper investigations of SFX-01 molecular mechanisms against RMS and for setting up clinical trials in RMS patients in order to use the SFX-01/IR co-treatment as a promising therapeutic approach, particularly in the clinical management of aggressive RMS disease.

The triple exposure nexus of microplastic particles, plastic-associated chemicals, and environmental pollutants from a human health perspective

The presence of microplastics (MPs) is increasing at a dramatic rate globally, posing risks for exposure and subsequent potential adverse effects on human health. Apart from being physical objects, MP particles contain thousands of plastic-associated chemicals (i.e., monomers, chemical additives, and non-intentionally added substances) captured within the polymer matrix. These chemicals are often migrating from MPs and can be found in various environmental matrices and human food chains; increasing the risks for exposure and health effects. In addition to the physical and chemical attributes of MPs, plastic surfaces effectively bind exogenous chemicals, including environmental pollutants (e.g., heavy metals, persistent organic pollutants). Therefore, MPs can act as vectors of environmental pollution across air, drinking water, and food, further amplifying health risks posed by MP exposure. Critically, fragmentation of plastics in the environment increases the risk for interactions with cells, increases the presence of available surfaces to leach plastic-associated chemicals, and adsorb and transfer environmental pollutants. Hence, this review proposes the so-called triple exposure nexus approach to comprehensively map existing knowledge on interconnected health effects of MP particles, plastic-associated chemicals, and environmental pollutants. Based on the available data, there is a large knowledge gap in regard to the interactions and cumulative health effects of the triple exposure nexus. Each component of the triple nexus is known to induce genotoxicity, inflammation, and endocrine disruption, but knowledge about long-term and inter-individual health effects is lacking. Furthermore, MPs are not readily excreted from organisms after ingestion and they have been found accumulated in human blood, cardiac tissue, placenta, etc. Even though the number of studies on MPs-associated health impacts is increasing rapidly, this review underscores that there is a pressing necessity to achieve an integrated assessment of MPs' effects on human health in order to address existing and future knowledge gaps.

Connecting the Dots: Livestock Animals as Missing Links in the Chain of Microplastic Contamination and Human Health

Plastic pollution is a global diffuse threat, especially considering its fragmentation into microplastics (MPs) and nanoplastics (NPs). Since the contamination of the aquatic environment is already well studied, most studies have now focused on the soil. Moreover, the number of studies on the exposure routes and toxic effects of MNPs in humans is continuously increasing. Although MNPs can cause inflammation, cytotoxicity, genotoxicity and immune toxicity in livestock animals, which can accumulate ingested/inhaled plastic particles and transfer them to humans through the food chain, research on this topic is still lacking. In considering farm animals as the missing link between soil/plant contamination and human health effects, this paper aims to describe their importance as carriers and vectors of MNP contamination. As research on this topic is in its early stages, there is no standard method to quantify the amount and the characteristics of MNPs in different matrices. Therefore, the creation of a common database where researchers can report data on MNP characteristics and quantification methods could be helpful for both method standardization and the future training of an AI tool for predicting the most abundant/dangerous polymer(s), thus supporting policy decisions to reduce plastic pollution and perfectly fitting with One Health principles.

Polyethylene nanoplastics cause reproductive toxicity associated with activation of both estrogenic hormone receptor NHR-14 and DNA damage checkpoints in C. elegans

As the most commercial polymer, the polyethylene nanoparticle (PE-NP) has been discharged into the environment and poses potential risks to organisms. However, the possible reproductive toxicity of PE-NP and underlying mechanisms remain largely unknown. In this study, Caenorhabditis elegans was employed as the animal model to effects of PE-NP (100 nm) and their leachates on reproduction and underlying mechanisms. Nematodes were exposed to PE-NP at 0.1-100 μg/L from L1-larvae to adult day 1 (approximately 4.5 days). Both brood size and number of fertilized eggs in uterus were decreased by 10 and 100 μg/L PE-NP, but could not be affected by their leachates. In addition, number of mitotic cells, length, and area of gonad were reduced by 10 and 100 μg/L PE-NP, but were not altered by their leachates. Accompanied with alteration in expressions of genes (egl-1, ced-9, ced-4, and ced-3) governing cell apoptosis, germline apoptosis was enhanced by PE-NP. Meanwhile, DNA damage was involved in the enhancement germline apoptosis after PE-NP exposure. PE-NP further increased expression of nhr-14 encoding estrogenic hormone receptor, and RNAi of nhr-14 suppressed PE-NP reproductive toxicity. Moreover, RNAi of nhr-14 decreased expression of egl-1, ced-4, ced-3, and mrt-2 in PE-NP exposed nematodes. Therefore, exposure to PE-NPs rather than in their leachates potentially caused reproductive toxicity by activating both estrogenic hormone receptor NHR-14 and DNA damage checkpoints (CLK-2, HUS-1, and MRT-2) in nematodes. These findings provide important insights into the exposure risk of PE-NPs on reproduction of environmental organisms.

Adverse Effects of Micro- and Nanoplastics on Humans and the Environment

The pervasive pollution caused by nano- and microplastics (N/MPLs) is a pressing concern, and was exacerbated during the COVID-19 pandemic due to the substantial release of disposable Personal Protective Equipment (PPE) into the environment [...].