Figure 4.

Buffer effect on PBAE polyplex NP transfection efficacy. Buffers from six salts were prepared at 25 mM osmolarity and pH values of 4, 5, 6 and 7 and used to make PBAE 4–4-6 nanoparticles compared against the historical buffer of pH 5 sodium acetate (NaAc) shown as the hatched bar. Several buffers showed promising increases in transfection efficacy in (A) HEK293T and (B) MDA-MB-231 cells with effectively no difference in cytotoxicity (C,D). To assess the influence of buffer pH on transfection, we performed a Tukey-corrected matched comparisons one-way ANOVA across all buffer conditions with respect to pH to demonstrate that pH 4 and pH 5 buffers were statistically the most effective buffers among all groups with significantly greater transfection than pH 7 buffers. Bars show mean ± SEM of four wells.