Figure 5.

Ion reconstruction of a 3D depth profile (depth layer numbers: 50–250) of one single HaCaT cell exposed to Al₂O₃ NMs for 24 h. The images show the top-down view of the outline of a cell of a depth profile. The translucent blue outline was reconstructed based on the C₃H₈N⁺ signal that originates from intracellular amino acids. (a) Control cells exposed to Al₂O₃ NMs only (red color); and corresponding intracellular localization of Al₂O₃ NM agglomerates (e). (b) Cells treated with retinol and Al₂O₃ NMs (red); and corresponding intracellular localization of Al₂O₃ NM agglomerates (f). (c) Cells treated with low vitamin D3 and Al₂O₃ NMs (red); and corresponding intracellular localization of Al₂O₃ NM agglomerates (g). (d) Cells treated with high vitamin D3 and Al₂O₃ NMs (red); and corresponding intracellular localization of Al₂O₃ NM agglomerates (h).