Figure 3. DSPE-PEG_2k reduces cellular cholesterol in Npc1^−/− cells with a dose dependent response.

DSPE-PEG_2k micelles were assembled by thin film rehydration method. (A) TEM images of micelles show electron dense cores that are approximately 5 nm. (B) Schematic diagram of assembled DSPE-PEG_2k micelles has an electron dense hydrophobic core, with extended hydrophilic PEG head groups. (C) Npc1^−/− cells were exposed to different concentrations of DSPE-PEG_2k (0–500 μM), fixed and a dose dependent decrease in filipin fluorescence per cell was observed by high throuhgput screening. (D) Whole cell cholesterol (per mg protein), normalized to un-treated cells, also shows a dose dependent reduction in cholesterol when treated with DSPE-PEG_2k. Results were tested for statistical significance using one-way ANOVA with Tukey’s multiple comparison test. *P < 0.05, **P < 0.01, ***P < 0.001 and NS = not significant.