Nanoparticle-induced inflammation and fibrosis in ex vivo murine precision-cut liver slices and effects of nanoparticle exposure conditions

Abstract

Chronic exposure and accumulation of persistent nanomaterials by cells have led to safety concerns on potential long-term effects induced by nanoparticles, including chronic inflammation and fibrosis. With this in mind, we used murine precision-cut liver tissue slices to test potential induction of inflammation and onset of fibrosis upon 72 h exposure to different nanomaterials (0–200 µg/ml). Tissue slices were chosen as an advanced ex vivo 3D model to better resemble the complexity of the in vivo tissue environment, with a focus on the liver where most nanomaterials accumulate. Effects on the onset of fibrosis and inflammation were investigated, with particular care in optimizing nanoparticle exposure conditions to tissue. Thus, we compared the effects induced on slices exposed to nanoparticles in the presence of excess free proteins (in situ), or after corona isolation. Slices exposed to daily-refreshed nanoparticle dispersions were used to test additional effects due to ageing of the dispersions. Exposure to amino-modified polystyrene nanoparticles in serum-free conditions led to strong inflammation, with stronger effects with daily-refreshed dispersions. Instead, no inflammation was observed when slices were exposed to the same nanoparticles in medium supplemented with serum to allow corona formation. Similarly, no clear signs of inflammation nor of onset of fibrosis were detected after exposure to silica, titania or carboxylated polystyrene in all conditions tested. Overall, these results show that liver slices can be used to test nanoparticle-induced inflammation in real tissue, and that the exposure conditions and ageing of the dispersions can strongly affect tissue responses to nanoparticles.

Best Practices and Progress in Precision-Cut Liver Slice Cultures

“…Dragoni et al confirmed the internalization and active uptake of gold particles in all three cell types [64]. Bartucci et al, on the other hand, demonstrated the nanosafety after long-term (72 h) exposure to nanoparticles [56]. These experimental set-ups demonstrate the applicability of PCLS cultures not only for disease modelling but clinical applications as well.…”

“…Next to H&E stainings, mostly a Picrosirius Red (PiSR) staining or to a lesser extent, a DAB (3,3 -Diaminobenzidine) staining are performed. A few papers also make use of cryosections for immunofluorescence (IF) [56,57] or Oil Red O (ORO, lipid accumulation) stainings [22,58] and some studies do not even section the slices for the ORO staining [59,60]. Overall, only a few PCLS research papers (<10% of investigated papers) show immunostainings, with HSC markers (e.g., αSMA, Collagen) and Ki67 being the mostly used antigens.…”

“…Bartucci et al published the only paper where dissociation of cultured PCLS is described. They performed enzymatic digestion of 12 pooled (5 mm) slices to obtain a single cell suspension, after which flow cytometry was used to analyze the uptake of nanoparticles of individual cells [56]. We are also not aware of reports that have carried out single cell RNA sequencing on slices cultures.…”

Multiscale Synchrotron-Based Imaging Analysis for the Transfer of PEGylated Gold Nanoparticles In Vivo

“…In the study, hepatocyte uptake of PEG-GNPs provoked intracellular multivesicular endosome (MVE) formation and exosome secretion both of which have been reported as natural Trojan horses to trigger induction, amplification, and/or modulation of immune responses in immune signaling. , We have shown that PEG-GNP treatment induced significant upregulation of stress response-related and proinflammation-associated gene expressions; , thus, the elevation of related proteins could occur. In addition, the elevation of proinflammatory cytokines would recruit blood inflammatory cells (leukocytes, neutrophils, and lymphocytes) to the hepatic inflammatory sites, thereafter elevating the contents of a protein, lipid, and nucleic acid. Further, the significant upregulation of lipogenesis-related gene expression in the liver of PEG-GNP treated mice, such as fatty acid synthase ( Fas ) and stearoyl coenzyme A desaturase 1 ( Scd1 ), was observed in our previous research, which would also play an important role in the variation of lipid contents.…”

Green Silver Nanoparticles Promote Inflammation Shutdown in Human Leukemic Monocytes

“…Ag is known to have a sharp and strong plasmon resonance peak [4], showing high toxicity in cancer cells [5][6][7], extensively demonstrated in vitro [8] as well as antibacterial and antimycotic features [9,10]. However, the application of Ag NPs in clinical trials is often hindered by the activation of the inflammatory response [11]; in general, this occurs because the foreign material is recognized as an antigen [12]. Ideally, the NPs should not trigger the immune response in living organisms, when they are used as vectors or therapeutic agents [13].…”