Drug efflux inhibition phenomenon evaluated
by Rh123 dye exclusion
assay. (A) Cancer cells were treated for 24 h with 10 nM PTX or 10
nM PPNPs and incubated with Rh123 for 30 min before visualizing them
under a microscope to obtain representative images. Rh123 showed more
accumulation in treatment groups of PPNPs, indicating P-gp and drug
export inhibition in this treatment group. (B) Mean fluorescence intensity
in an FL1 channel (488 excitation, blue laser, 530 ± 15 nm, FITC/GFP)
was measured for treatment groups. PPNPs showed increased fluorescence
in both PanCa cells as compared to 10 nM PTX treatment, indicating
that PTX in solution gets effluxed because of P-gp. Data are presented
as the mean ± SEM (n = 3). *p < 0.05 and #p < 0.05 represent
the significant value compared to the control and PTX, respectively.