Fig. 2

Intracellular-uptake analysis. a. The cells were treated with various BBR formulations at an equivalent BBR concentration of 1 μg mL⁻¹ for 3 h, respectively, at 37 °C in 5% CO₂. Left: representative fluorescent images of BBR in HepG2 cells visualized using CLSM (Carl Zeiss, Germany); right: representative flow cytometry diagram of BBR in HepG2 cells. b The cells were treated with BBR-S or BBR-CTA-Mic for 1, 4, or 8 h, respectively. Representative fluorescent images of BBR in HepG2 cells visualized using CLSM. c HepG2 cells were pre-incubated with BBR-S or BBR-CTA-Mic accompanied with P-gp siRNA or mismatch siRNA (mm RNA) (50 nM) for 8 h. Cells were washed with PBS twice and incubated with fresh medium for another 4 h. Left: representative fluorescent images of BBR and P-gp in HepG2 cells visualized using C2t Nikon fluorescent microscope (Morrell, USA); middle: representative flow cytometry diagram of BBR deposition in HepG2 cells before and after dispel experiment. Right: representative flow cytometry diagram of P-gp expression in HepG2 cells before and after RNAi. The experiments were conducted in five times. Scale bars, 10 μm (a–c)