FIG. 2.

Photosensitizer (PS) uptake profile within the 3D model. (a) Uptake of TMPyP PS by hNDF cultured in two-dimensional (2D) and 3D was determined through fluorescence emission normalized with the protein content (N=2, n=3). (b) The individual cellular content of TMPyP PS was evaluated by flow cytometry. Shown are TMPyP-positive cells (red) and -negative cells (green). FI, relative fluorescence intensity, is reported in arbitrary units (N=3, n=3). (c) Data from flow cytometry in (b) were quantified. Specifically, drug incorporation and mean fluorescence in 3D cultures were analyzed and plotted as percentages relative to 2D cultures. Moreover, total TMPyP uptake was also expressed as percentage number of positive cells multiplied by their mean fluorescence. (d) Confocal microscopy images of living hNDF in 2D and 3D after TMPyP incubation were registered before and after irradiation. All images correspond to the overlay of the TMPyP fluorescence signal (green, false color) and nuclei staining (blue) (N=2, n=2). All experiments were performed with 100 μM TMPyP. Scale bars (d) 20 μm. Error bars (a) and (c): standard deviation (SD) **p<0.01, ***p<0.001. Color images available online at www.liebertpub.com/tea