Figure 4. (A) Quantification of cellular uptake and apoptosis of different shaped PSiO₂ by flow cytometry analysis of different prepared PSiO₂ nanoparticles: sphere-shaped, NS (100 nm), short rod-shaped, NSR (240 nm) and long rod-shaped, NLR (450 nm). (B) Quantitative measurement (fluorescence) of particle numbers in cells (data are presented as mean ± s.d; statistical significance for the comparison of the number of internalized particles between different shaped particles, **p < 0.1). (C) Influence of different concentrations of shaped nanoparticles on early apoptosis of A375 cells. Reprinted with permission from reference 77.