Figure 5.

Spectral area analysis by IQ mapping of 989–1185 cm⁻¹ region of astrocytes and neurons exposed to SiO₂-NPs. The spectral region of 989–1185 cm⁻¹ that includes specific spectral bands related to nucleic acids is presented for astrocytes (a–f) and neurons (g–l). A sample of cells treated with SiO₂-NPs for 24 h was dispersed on a gold-coated slide. The three-dimensional image is presented in the x, y, and z axes, and the area presented as a gradient of color indicates a decrease (from blue) or increase (red) in the spectral signal. For astrocytes, a decrease in the signal was seen at 1 µg/mL (b) and 10 µg/mL (c) SiO₂-NPs compared to the control (a). Recovery of the signal at 25–100 µg/mL SiO₂-NPs (d–f) was detected. In neurons, the signal decreased at 1 µg/mL (h) and 100 µg/mL (l); on the contrary, at 10–50 µg/mL (i–k), the signal increased compared to control (g). The image is representative of four independent experiments with three technical replicates.