Figure 8: Cytotoxicity IC50s for doxorubicin-loaded vehicles and free DOX. Targeted and untargeted hybrid PLNs were incubated with osteosarcoma cell lines in comparison to free doxorubicin and conventional PEG-liposomal doxorubicin. Mean log IC50 for osteosarcoma cell lines shows that untargeted hybrid PLNs have a 6-fold increase in cytotoxicity over conventional liposomal formulation. ALCAM targeted hybrid PLNs (HPLN) show an additional 2-fold increase over untargeted HPLNS and 12-fold increase in cytotoxicity over conventional PEG-liposomal doxorubicin. Geometric mean IC50s were derived from seven, five, and three sets of MTT assay experiments in, respectively, the KHOS240s, HOS, and MNNG-HOS cell lines. Error bars correspond to 1 standard error for mean log (IC50). Within each cell line, differences among vehicles are highly significant ( 𝑃 < 0 . 0 0 0 1 ). Confidence intervals for pairwise ratios of IC50s, corrected for multiple comparisons, are summarized in Table 1.