Inhibition of rhodamine incorporation into human metastatic melanoma cells (M14#5), fibroblasts from a metastatic melanoma patient (Hs895Sk), and normal foreskin fibroblasts (BJ). Cells were initially treated with 0, 25, 50, or 100 μM exogenous α1(IV)1263-1277 THP for 30 min, followed by treatment with α1(IV)1263-1277 PA liposomes for 35 min. Relative quantification was performed as described in Materials and Methods. One hundred percent rhodamine incorporation was considered to be M14#5 melanoma cell treatment with PA liposomes for 35 min. All liposomes utilized DSPC as the primary lipid (see Table 1).