Figure 2.

Caveolae‐mediated uptake and trafficking. Cellular uptake of dual‐labeled CNPs in A) 4T1 or B) Caco‐2 cells pretreated with caveolae inhibitors, nystatin (10 × 10⁻⁶ m) or M‐CD (2.5 × 10⁻³ m), for 0.5 h at 37 °C. Dual‐labeled CNPs were incubated with the pretreated cells at 37 °C for 4 h at 7.5 µg mL⁻¹ FITC or 100 × 10⁻⁹ m Cy5. The fluorescence intensity was assayed by flow cytometry. ^# P < 0.001 versus control (n = 5). C) Colocalization of Cy5‐CNPs with FITC‐labeled F‐actin (green), Alexa Fluor 488‐labeled CTB (green), and Alexa Fluor 488‐labeled Cave‐1 (green). Yellow spots display the colocalization of CNPs with F‐actin, CTB, or Cave‐1. The 4T1 cells were incubated with CNPs for 4 h at 37 °C. The location of the FITC‐CNPs (10 µg mL⁻¹, D) or Cy5‐CNPs (100 × 10⁻⁹ m let‐7a, E) in lysosomes of 4T1 cells after incubation for 0.5, 2, and 4 h at 37 °C, respectively. Yellow spots indicate the colocalization of CNPs with lysosomes. The scale bar is 5 µm.