Figure 6.

Relationships among Individual Cell pH, Uptake, and Gene Expression at 24 hr

(A–H) Representative scatterplots of DsRed⁺ (red) and DsRed⁻ (black/gray) populations of cells transfected with (A and E) bPEI w/w 2, (B and F) bPEI w/w 1, (C and G) PLL w/w 2, and (D and H) PLL w/w 1 qualitatively showed minimal correlation between gene expression and calculated pH. (I–N) To quantify correlation between variables, we calculated Pearson’s correlation coefficient (PCC) for each well for variables in the case of HEK293T (I–K) and GB319 (L–N). (I and L) PCC between pH and gene expression showed weak (0.2 < PCC < 0.4) correlation only in the case of HEK293T cells transfected with bPEI at w/w 1 and w/w 2, as well as GB319 cells with bPEI w/w 1. (J and M) pH and nanoparticle uptake showed weakly positive correlation only for GB319 cells transfected with bPEI w/w 2. (K and N) Nanoparticle uptake and gene expression showed weak correlation only for GB319 cells transfected with bPEI w/w 2 and PLL w/w 2. All errors bars show the mean ± SEM of four wells for PCC calculated for the cells in that well.