Quantification of Internalized Silica Nanoparticles via STED Microscopy

Table 3

Quantification of internalized SNP.

	Number of objects/cell	Number of objects/cell area (μm^−2)	Number of cells	Total number of objects	Mean intensity (a.u.)
Si-25-FD			21	2465
Si-85-FD			17	5742

Internalized SNPs were quantified by image segmentation of 3D stacks of whole A549 cells. The number of segmented objects in the NP channel is given per cell and per cell area. Also specified is the number of analyzed cells, the total number of objects found in all cells, and the mean fluorescence intensity (arbitrary units) of the objects. After exposition of cells to larger particles, a slightly higher number of objects were found inside the cells. The mean intensity values reflect the stronger fluorescence of the larger particles.