Figure 1

Kinetics of cellular uptake of Nile Red encapsulated in nanoparticles (●) or dissolved in medium (▲) or PBS (■). The cellular uptake was measured by FCM and is expressed as the percentage of Nile Red-positive cells (a) or median fluorescence intensity normalised to autofluorescence (b). Each data point is the mean of 2–5 independent measurements. Bars indicate the standard deviation. The R² values of the regression curves ranged from 0.73 to 0.99, and p-values were less than 0.014. CLSM images of cells incubated with Nile Red in medium (c, d, e) or Nile Red in nanoparticles (f, g, h) after 0 min (c, f), 5 min (d, g), and 60 min (e, h) of incubation. Scale bars are 10 μm. Nile Red was excited at 488 nm, and fluorescence was detected at 520–700 nm. CLSM images were recorded every min for 1 h. The average mean Nile Red fluorescence intensities from cells (n= 5-11) at each time point with standard deviation at every 5^th min are shown (i). The mean intensity of each cell was determined by drawing regions of interest around each cell.