The intracellular distribution of nanoparticular drug delivery systems is very complex, but its investigation yields high potential for further development and optimization of these systems. In the following chapter, we introduce the application of fluorescent imaging techniques in order to highlight uptake and cellular processing of nanoparticular drug delivery systems (e.g., liposomal drug delivery systems). We selected a combination of different protocols for the staining of the most important endocytic compartments and organelles. The presented imaging systems are appropriate to detect liposomal drug delivery systems localized in these cellular structures.
