Quantification of cytotoxicity
of CPP-ELPBC drug carriers.
(A) Cytotoxicity of CPP-ELPBC carriers appended with BH3
peptide drug was evaluated by a modified cell survival assay. HeLa
cells were incubated with Arg5-ELPBC-cBH3, Arg8-ELPBC-cBH3, or ELPBC-cBH3 with cleavable
peptide drug cargo for 1 h at 37 or 42 °C. HeLa cells were also
incubated with controls including Arg8-ELPBC-BH3 with noncleavable peptide drug cargo and free BH3 peptide alone.
Cells were washed and returned to complete media for 24 h before cell
survival was quantified by MTS assay. *Indicates p < 0.005 between thermal conditions (two-way ANOVA, Bonferroni
posthoc test for multiple comparisons). (B) Induction of apoptosis
was evaluated by quantification of caspase-3 activity. Caspase-3 activity
was quantified in HeLa cell lysates after treatment with ELPBC-cBH3, Arg5-ELPBC-cBH3, Arg8-ELPBC-cBH3, or free BH3 peptide for 1 h at 37 or 42 °C. *Indicates p < 0.01 between thermal conditions (two-way ANOVA, Bonferroni
posthoc test for multiple comparisons). Data represents mean of three
experiments ± SEM.