Skip to main content
. 2014 Mar 6;15(4):1491–1497. doi: 10.1021/bm5001026

Figure 3.

Figure 3

Cell-penetrating properties of polypeptides with quaternary phosphonium side chains. (A) Uptake level of fluorescein-labeled polypeptides in HeLa cells at different incubation time (n = 3). The polypeptide concentration was maintained constant at 20 μg/mL. (B) Uptake level of fluorescein-labeled PHLG-TEP in HeLa cells at 37 and 4 °C as monitored by flow cytometry. M1 and M2 phases corresponded to fluorescence-negative and positive cells, respectively. (C) CLSM images of HeLa cells incubated with fluorescein-labeled PHLG-TEP at 37 and 4 °C for 4 h (bar = 20 μm). (D) Uptake level of fluorescein-labeled PHLG-TEP in HeLa cells at 4 °C or in the presence of various endocytic inhibitors (n = 3). NS denotes no significant differences. (E) Cytotoxicity of polypeptides toward HeLa cells following 20 h treatment as determined by the MTT assay (n = 3).