Figure 3.

Morphological analysis of hNLCs cultured with Fe₃O₄NPs. Representative micrographs, by phase-contrast microscopy, of hNLCs after 3 (a) and 8 (b) days of culture in neurogenic medium with increasing Fe₃O₄NPs concentrations (5–50 μg/mL). No morphological changes were induced by Fe₃O₄NPs exposure in hNLCs at day 3 and 8 of transdifferentiation. However, a cell density decrease was observed from 25 μg/mL Fe₃O₄NPs at both time points considered. Brownish aggregates/agglomerates of Fe₃O₄NPs were observed in culture medium and intracellularly. White arrows indicate Fe₃O₄NP aggregates/agglomerates, orange heads indicate intracellular nanoparticles. Scale bar: 100 μm.