VSE knjižnice (vzajemna bibliografsko-kataložna baza podatkov COBIB.SI)
  • TEM images of HepG2 spheroids exposed to magnetic Ferite-based Nanoparticles MxFe3-xO4 (M=Fe, Zn, Mn) for 24 and 96 hours [Elektronski vir] : version v1
    Morales Ovalle, Marco A. ...
    Nanosized spinel-type ferrites have gained recognition as a unique class of engineered nanomaterials with promising applications, but their safety profiles remain insufficiently explored. Although ... iron (Fe), zinc (Zn), and manganese (Mn) are biologically relevant elements, the use of Zn- and Mn-containing ferrite nanoparticles (NPs) in biomedical contexts demands careful (geno)toxicity evaluation. In this study, three ferrite NPs – γFe2O3 (FeNPs), Zn0.7Fe2.3O4 (ZnNPs), and Mn0.4Fe2.6O4 (MnNPs) – synthesised through a microwave-assisted polyol route, functionalized with citric acid to improve colloidal stability, were evaluated for their potential (geno)toxic effects in an advanced in vitro 3D cell model, HepG2 spheroids. To assess the spatial distribution of the tested NPs within the 3D cellular architecture of HepG2 spheroids, TEM analysis was performed after 24 and 96 hours of exposure. HepG2 spheroids were exposed to each NP type at a concentration of 50 µg/mL. Following incubation, spheroids were collected, gently washed with phosphate-buffered saline (PBS, pH 7.4) to remove unbound NP, and fixed in 2 % glutaraldehyde in 0.1 M phosphate buffer (PB, pH 7.2) for 2 hours at room temperature, followed by incubation in 1.5 % glutaraldehyde in 0.05 M PB at 4°C overnight. Post-fixation was carried out with 1% osmium tetroxide for 1 hour at room temperature, followed by dehydration through a graded ethanol series (30%, 50%, 70%, 90%, and absolute ethanol) and infiltration with epoxy resin. For cross-sectional analysis, resin-embedded spheroids were polymerised at 60 °C for 48 hours, and ultrathin sections (~70 nm) were obtained using an ultramicrotome. Sections were collected on copper grids and stained with uranyl acetate (2% aqueous) and lead citrate to enhance contrast. Imaging was performed using a Tecnai T20 transmission electron microscope (Thermo Fisher Scientific, USA) operated at 200 kV. For each sample and time point, at least three spheroids were analysed. Additionally, in one selected spheroid, a systematic series of TEM images was acquired along a straight linear trajectory across the section, beginning at one external edge of the spheroid and progressing through consecutive adjacent fields until reaching the opposite border, and then the images were composed into a single frame.
    Vrsta gradiva - raziskovalni podatki ; neleposlovje za odrasle
    Založništvo in izdelava - Genève : Zenodo, 2025
    Jezik - angleški
    COBISS.SI-ID - 266869251

    Povezava(-e):

    https://zenodo.org/records/15862860
    DOI

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