Determination of Qu.
(A) HPLC analysis of Qu in MCF-7/ADR cells.
MCF-7/ADR cells were incubated with Qu (50 μM) or Qu-SS-Gcc
LNPs (50 μM) for 3 or 8 h: (a) determination of free Qu; (b,
c) determination of intracellular Qu after treatment with Qu-SS-Gcc
LNPs for 3 and 8 h, respectively; and (d, e) determination of intracellular
Qu after treatment with Qu for 3 and 8 h, respectively. (B) Amount
of intracellular Qu after incubation with Qu (50 μM) or Qu-SS-Gcc
LNPs (50 μM) in different conditions for 6, 12, or 24 h (upper)
and amount of intracellular Qu-SS-Gcc LNPs (50 μM) in different
conditions for 6, 12, or 24 h (lower). (C) Rh-123 efflux of the MCF-7/ADR
cells after treatment with MS SLNs (50 μM), Qu (50 μM),
Qu-SS-Gcc LNPs (50 μM), or verapamil (20 μM) for 3 or
8 h. The error bars in the graphs represent the standard deviation
(n = 3).