The presence of plastic waste in our environment has continued growing and become an important environmental concern. Because of its degradation into micro- and nanoplastics (MNPLs), MNPLs are becoming environmental pollutants of special environmental/health concern. Since ingestion is one of the main exposure routes to MNPLs, the potential effects of digestion on the physicochemical/biological characteristics of polystyrene nanoplastics (PSNPLs) were determined. The results indicated a high tendency of digested PSNPLs to agglomerate and a differential presence of proteins on their surface. Interestingly, digested PSNPLs showed greater cell uptake than undigested PSNPLs in all three tested cell lines (TK6, Raji-B, and THP-1). Despite these differences in cell uptake, no differences in toxicity were observed except for high and assumed unrealistic exposures. When oxidative stress and genotoxicity induction were determined, the low effects observed after exposure to undigested PDNPLs were not observed in the digested ones. This indicated that the greater ability of digested PSNPLs to internalize was not accompanied by a greater hazard. This type of analysis should be performed with other MNPLs of varying sizes and chemical compositions.

In the environment, plastic waste degrades into small particles known as microplastics and nanoplastics (MNPLs), depending on their size. Given the potential harmful effects associated with MNPL exposure, it is crucial to develop environmentally representative particles for hazard assessment. These so-called true-to-life MNPLs are generated through in-house degradation of real-world plastic products. In this study, we produced titanium-doped nanoplastics (NPLs) from opaque polyethylene terephthalate (PET) milk bottles, which contain titanium dioxide as a filler. The resulting PET(Ti)-NPLs were thoroughly characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), mass spectrometry (MS), dynamic light scattering (DLS), ζ-potential measurements, transmission electron microscopy (TEM), and Fourier-transform infrared (FTIR) spectroscopy. Human-derived THP-1 monocytes were employed to investigate particle uptake kinetics, dosimetry, and genotoxicity. A combination of flow cytometry and inductively coupled plasma mass spectrometry (ICP-MS) enabled the quantification of internalized particles, while the comet assay assessed DNA damage. The results revealed dose- and time-dependent effects of PET(Ti)-NPLs on THP-1 cells, particularly in terms of internalization. Titanium doping facilitated detection and influenced genotoxic outcomes. This study demonstrates the relevance of using environmentally representative nanoplastic models for evaluating human health risks and underscores the importance of further mechanistic research.

Global plastic production and inadequate waste management have led to widespread environmental contamination with microplastics (MPs), now detected in food, water, and air. Their small size, diverse polymer composition, and capacity to carry chemical additives and co-pollutants facilitate intestinal uptake and raise concerns about their potential impact on gut microbiota. This review synthesizes current evidence on how MPs influence gut microbial composition and function, gut barrier integrity, and associated inflammatory and metabolic pathways. We conducted a narrative review of in vivo animal studies, in vitro simulated gut systems, and human observational studies that assessed MP exposure, gut microbiota profiles, and downstream toxicological outcomes. MPs originate from primary and secondary sources and can act as vectors for metals and organic pollutants. Following ingestion, they may cross the intestinal barrier via endocytic and persorption routes, acquire a protein corona, and be recognized by immune cells, activating TLR/NF-κB, and MAPK pathways alongside oxidative stress. In these models, MP exposure induces dysbiosis, characterized by loss of beneficial SCFA-producing bacteria (e.g., Bifidobacterium, Lactobacillus, Bacteroides) and expansion of pathobionts (e.g., Escherichia/Shigella, Staphylococcus, Enterobacteriaceae), accompanied by altered bile acid metabolism. These microbiota and metabolic alterations are linked to increased gut permeability, intestinal inflammation, metabolic dysfunction, and, in some studies, reproductive and neurobehavioral effects. Current evidence supports MPs as emerging modulators of gut microbial and intestinal homeostasis. However, heterogeneity across experimental models, reliance on high exposure doses, and lack of standardized MP characterization limit robust risk assessment. These limitations underscore the need for harmonized methodologies, longitudinal large-scale human studies, and the development of targeted mitigation strategies.

Bisphenol (BP) compounds are widely present in the environment, primarily due to their use as plastic additives. These substances involve health risks, particularly as endocrine disruptors. While the general population is chronically exposed, patients with end-stage chronic kidney disease undergoing hemodialysis (HD-CKD) represent a particularly vulnerable group. This is due to both impaired renal clearance of circulating BPs and potential contamination from plastic-containing dialyzers used in extracorporeal blood circulation. In this longitudinal study, from the 35 HD-CKD patients initially selected, 25 changed their conventional dialyzers to BPA-free dialyzers for 6 months. Blood serum samples were collected, at baseline and after the intervention, to quantify levels of five BP analogues: Bisphenol A (BPA), Bisphenol AF (BPAF), Bisphenol F (BPF), Bisphenol B (BPB), and Bisphenol S (BPS). Genotoxicity was assessed using the comet assay and the micronucleus test on peripheral white blood cells. Among the analyzed BPs, only BPAF showed a statistically significant reduction when using BPA-free dialyzers. In terms of genotoxicity, a significant decrease was observed only in primary DNA damage (mainly DNA strand breaks), with no notable changes in chromosomal damage. This is the first study to detect multiple BP analogues in HD-CKD patients, beyond BPA, and to associate human exposure to BPs with DNA damage biomarkers. The observed reduction in DNA damage in parallel with decreased BPAF levels highlights the importance of monitoring and minimizing BP exposure of this high-risk population.