Although the adsorption of pharmaceuticals by microplastics (MPLs) may reduce environmental contaminant concentrations, their effects on bioavailability and biological toxicity following ingestion remain poorly studied. To mimic environmentally relevant exposure, environmentally relevant polypropylene microplastics (PP-MPLs) derived from post-consumer plastic products (real-life) were used as carriers for the pharmaceuticals paracetamol (PCM) and ciprofloxacin (CFX), using Drosophila larvae in vivo model. Free PCM and CFX were tested at concentrations equivalent to their respective adsorption loadings on PP-MPLs (0.03% and 0.02% w/w, respectively), enabling direct comparison under environmentally realistic conditions. PP-MPLs, with or without adsorbed pharmaceuticals, retained their irregular morphology and heterogeneous size distribution, representing an environmentally relevant mixture of micro- and nanoscale particles. Following oral exposure, PP-MPLs, either alone or carrying adsorbed pharmaceuticals, sequentially traversed the intestinal barrier penetrating the peritrophic membrane, accumulating within enterocytes, and ultimately reaching hemolymph. Particle exposure induced extensive enterocyte vacuolation, significantly increased intracellular reactive oxygen species (ROS), and triggered targeted gene-expression changes involving antioxidant, immune, detoxification, and stress-response pathways, while genes associated with digestive function were consistently deregulated. Despite elevated oxidative stress, PP-MPLs did not alter mitochondrial membrane potential. In contrast, free PCM induced significant mitochondrial depolarization without increasing ROS, whereas this effect was abolished following adsorption onto PP-MPLs, potentially due to reduced bioavailability. Moreover, pharmaceutical-loaded PP-MPLs did not elicit additive molecular toxicity compared with PP–MPLs alone.
Nanoplastic (NPl) particles are increasingly found in aquatic environments due to the long-term degradation of mismanaged plastic waste, and their uptake and accumulation in aquatic organisms are progressively reported. However, their biodistribution and spatial association with biologically relevant elements after ingestion remain poorly understood. In this study, europium-doped polystyrene NPls (Eu-doped NPls) were used as model particles to investigate their spatial distribution in Daphnia magna, a representative freshwater organism, using synchrotron-based nanoprobe X-ray fluorescence (nano-XRF). Daphnia magna neonates (<24 h old) were exposed to 5-20 mg L-1 Eu-doped NPls for 48 h and by using Eu as the tracer, their biodistribution was mapped using nano-XRF at multiple resolutions. No mortality was observed during exposure, although body length was significantly reduced relative to the control under all tested conditions (p < 0.05). Reactive oxygen species (ROS)-associated fluorescence also increased significantly at 10 and 20 mg L-1, indicating an organism-level oxidative-stress response at higher exposure concentrations. Toxicokinetic analysis revealed rapid uptake and efficient depuration, yielding a low bioconcentration factor (BCF = 0.982 L g-1). Two-dimensional nano-XRF maps showed that most Eu-associated signals were localised within gut-associated regions and spatially co-occurred with endogenous elements including Fe, Ca and K. Eu-derived signal metrics increased with external exposure concentration, with broader distribution at lower concentration and more pronounced hotspot formation at higher concentrations. ROI-based co-localisation analysis showed increasing spatial association between Eu and endogenous elements, particularly Fe, suggesting that Eu-associated signals were spatially structured within gut-associated elemental microenvironments rather than uniformly distributed. This study demonstrates that Eu-doped NPls combined with ICP-MS and synchrotron nano-XRF provide a complementary element-specific framework for linking quantitative body-burden analysis with spatially resolved biodistribution in aquatic organisms.
Titanium dioxide nanoparticles (TiO₂ NPs) are among the most widely produced engineered nanomaterials, yet a mechanistic understanding of how their physicochemical properties govern biological interactions remains incomplete. Here we present an integrated, multi-scale computational workflow for the mechanistic in silico characterization of TiO₂ NPs spanning two crystallographic polymorphs (anatase and rutile) and four morphology classes (bipyramidal, cuboctahedral, spherical and amorphous), across a systematic size series of approximately 1-3 nm. At the quantum-mechanical level, density functional theory (DFT) calculations characterize the electronic structure, surface energetics and reactive-site distribution of each nanoparticle. These intrinsic descriptors are linked to mechanistic bio-interaction endpoints through three complementary approaches: (i) molecular docking followed by molecular dynamics (MD) simulations against a curated panel of 98 proteins (97 of them human), mapping the NP-protein binding landscape for individual proteins in isolation, which informs but does not by itself determine protein-corona composition; (ii) COSMO-RS-based thermodynamic modelling of nanoparticle-lipid bilayer interactions to estimate passive membrane permeability; and (iii) explicit all-atom MD simulations of NP interactions with two model cell-membrane systems, representing human keratinocytes and the rainbow-trout gill cell line RTgill-W1. Quantitative cross-tier analysis shows that these endpoints are not redundant: docking affinity and predicted membrane permeability are statistically independent across the nanoparticles common to both tiers (Spearman ρ = +0.03, n = 6), whereas particle size correlates strongly with both docking affinity (ρ = -0.77, n = 10, p = 0.009) and permeability (ρ = -0.83, n = 6, p = 0.042). The most robust structure-activity signal is morphological: faceted particles (bipyramidal, cuboctahedral, rutile) and rounded particles (spherical, amorphous) are completely separated in predicted permeability (mean log P - 5.8 versus +1.3; Mann-Whitney U = 0, p = 0.036). A complementary nano-SAR classification model built on 61 curated literature cytotoxicity records retains predictive performance under publication- and material-grouped cross-validation (AUC-ROC 0.83 versus 0.87 for random splits) and passes y-randomization, but its applicability domain is narrow and is defined explicitly here. We present this workflow as a tool for mechanistic interpretation and early-stage hazard prioritization rather than as a validated, regulatory-grade hazard-assessment platform: protein adsorption, membrane association and changes in membrane properties are mechanistic descriptors and are not equivalent to toxicity, and the framework has not yet been externally validated against experimental data. Used with these limitations in mind, it can support the hazard-screening component of Safe-and-Sustainable-by-Design workflows, which additionally require exposure, functional performance, environmental and life-cycle assessment that are outside the scope of this study.
V2C is a type of two-dimensional transition metal carbide (MXene) with rapidly expanding applications in energy, sensor, electronic information, and biomedicine. However, compared with Ti3C2, its health risk assessment remains inconclusive, posing a potential constraint on its further application. In this study, we examined immune and hematopoietic alterations in adult mice following pulmonary exposure to V2C nanosheets (NSs) on days 1 and 7, using Ti3C2 NSs as a reference. Exposure to V2C NSs induced a sustained elevation of neutrophils in the blood, lung, and bone marrow. This response differed markedly from the transient neutrophil increase followed by monocyte-mediated resolution observed with Ti3C2 NSs. Both MXenes upregulated G-csf in lung to activate emergency granulopoiesis, associated with reduced lung granulocyte-monocyte progenitors (GMPs) but expanded bone-marrow GMPs on day 1. By day 7, this effect persisted in V2C NSs, whereas Ti3C2 NSs increased lung GMPs as G-csf returned to baseline and selectively induced Mcp-1 and modulated Il-1β, thereby promoting monocyte recruitment and regulating myelopoiesis. Compared with the in vitro high biocompatibility of Ti3C2 NSs, V2C NSs exhibited pronounced cytotoxicity and elevated reactive oxygen species. Our study implied that V2C NSs demonstrated higher pulmonary immunotoxicity via persistent, neutrophil-driven inflammation due to the different chemical composition and biological activity from Ti3C2 NSs. This emphasized the need for tailored safety evaluations in the development and application of emerging nanomaterials.
Graphene is increasingly produced and utilized in industrial applications, raising concerns regarding occupational exposure and associated health risks. While numerous toxicological studies have investigated the hazard potential of laboratory-produced graphene, relatively little is known about exposure to airborne graphene particles in actual workplace environments or the toxicity of samples collected in the workplace. In the present study, we combined occupational exposure assessment in a graphene production facility with in vitro toxicological evaluation of graphene samples produced by liquid-phase exfoliation of graphite versus particulate matter collected in the same production facility. Workplace air sampling was performed using stationary and personal samplers and particulate matter was collected for elemental carbon (EC) analysis, Raman microscopy-spectroscopy, and toxicological testing using human lung cell lines (A549 and BEAS-2B). Personal EC concentrations ranged from 3 to 484 μg/m3, with the highest exposure levels observed during graphite powder handling. Raman analysis confirmed the presence of graphene in the collected samples. Toxicological assessments showed that samples collected in the workplace did not elicit cytotoxic effects at the tested concentrations while dispersions of as-produced graphene evoked a dose-dependent loss of cell viability. Overall, this pilot study demonstrates the feasibility of combining occupational exposure measurements with toxicological testing of real-world samples and suggests that airborne materials collected during graphene production exhibit low hazard potential in human lung cells.
