The inhibitory effects of hybrid liposomes composed of lipids having a variety of head groups (zwitterionic L-α-dimyristoylphosphatidylcholine (DMPC), anionic L-α-dimyristoylphosphatidylglycerol (DMPG), and cationic 1, 2-dimyristoyl-3-trimethylammonium propane (DMTAP)) and polyoxyethylene (10) dodecyl ether (C12(EO)10) on the growth of tumor cells (human lung carcinoma (RERF-LC-OK), human hepatoma (Hep-G2), human stomach tumor (GT3TKB)) in vitro were examined. The hybrid liposomes of DMPC/10 mol % C12(EO)10 and DMPG/10 mol % C12(EO)10 were fairly more effective for inhibiting the growth of all tumor cells employed in this study as compared with liposomes (DMPC and DMPG) or micelles (C12(EO)10). Especially, it is attractive that the highly specific inhibitory effect of the hybrid liposomes of DMPG/10 mol % C12(EO)10 without any antitumor drugs on the growth of RERF-LC-OK and GT3TKB was obtained for the first time.
