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 (). Confidence intervals for pairwise ratios of IC50s, corrected for multiple comparisons, are summarized in Table 1.