Figure 3.

Cellular uptake and viability analysis after various treatments. (A) CLSM and (B) flow cytometry analyses of the internalization of D@PNE by 4T1 cells after 2 h of incubation at pH 7.4 or pH 6.5. The nucleus in Figure A was stained blue with 4',6-diamidino-2-phenylindole (DAPI). The scale bar in Figure A is 20 µm. (C) Viability of NIH-3T3 cells cultured with PNE for 24 h. The viability of (D) 4T1, (E) A549, and (F) B16 cells incubated with D@PNE was determined at pH 7.4 or pH 6.5 for 24 h; *p < 0.05, **p < 0.01, ***p < 0.001.