Comparison of cytotoxicity of synthesized CdSe QDs before and after SGF treatment utilizing MTT assay. (A) The Caco-2 cells were dosed with untreated synthesized CdSe QDs. (B) The Caco-2 cells were dosed with SGF-treated QDs. Data are expressed as the mean ± SE from three separate experiments using cells of different cultures. Statistically significant differences in relative viability between certain QD doses and all other doses of the same type of QDs are indicated by an asterisk (*) (p < 0.05). Statistically significant difference in cell relative viability between certain types of QDs and all other types of QDs within the same dose are indicated by a pound symbol (#) (p < 0.05).