Figure 10.

TEM micrographs of high-pressure frozen HeLa cells treated with high concentrations of SiNPs for 2 h, stained with OsO₄ and uranyl acetate. Particle concentrations are c = 3400 µg·mL⁻¹ for SiNP-22 (A,B), c = 3000 µg·mL⁻¹ for SiNP-12 (C,D) and c = 3000 µg·mL⁻¹ (E,F) for SiNP-7. The upper images are bright field micrographs using a pseudocolor for Si containing areas as extracted from energy filtered TEM micrographs. The bottom row (B,D,F) displays the corresponding STEM micrographs with enhanced contrast, clarifying the particle enclosing membranes.