SPECIFIC INHIBITORY EFFECT OF HYBRID LIPO SOMES ON THE GROWTH OF HYBRIDOMA CELLS IN-VITRO

Remarkably high inhibitory effects of the hybrid liposomes composed of L-alpha-dimyristoyl-phosphatidylcholine (DMPC) and polyoxyethylenealk yl ether (C-14(EO)(n), n = 6-8 and C-12(EO)(n), n = 8-12)) on the grow th of human lymphoma-human B-lymphocyte hybridoma (HF) cells in vitro were obtained. The hybrid liposomes composed of 90 mol% DMPC/10 mol% C -14(EO)(n) (n = 6-8) or C-12(EO)(n) (n = 8-12) were more fluid as comp ared with 90mol% DMPC/10 mol% C-14(EO)(4) or C-12(EO)(n) (n = 4, 23) h ybrid liposomes on the basis of fluorescence polarization measurements . These results suggest that the inhibitory effects of the hybrid lipo somes on the growth of HF cells should be related to the membrane flui dity. No toxicity to normal rats in vivo was observed in the experimen t using 90mol% DMPC/10mol% C-14(EO)(7) Or 90mol% DMPC/10 mol% C-12(EO) (12) hybrid liposomes.