Abstract: Objective To prepare a novel lipsome of polyethylene glycol packaged with epirubicin(EPI) liposomes, to explore the properties of the liposome and evaluate its antitumor activities. Methods Emulsion solvent evaporation method was used to prepare the liposome. The morphology of the liposome was observed by transmission electron microscope(TEM) and scanning electron microscope(SEM). The characteristics such as particle size, zeta potential, drug entrapment rate, stability and releasing property in vitro were studied. The anti-proliferation activities of EPI liposome and EPI against cancer cells were evaluated by MTT assay. The antitumor activity in vivo was assayed on S180 mouse model. Results The average particle size and the zeta potential of the liposome were (231.4±2.0) nm and (-20~30) mV, respectively, and the average entrapment efficiency was (53.14±4.85)%. This novel liposome improved the stability, slowed the releasing rate, enhanced the activity, increased the tolerance and extended dosing interval. Conclusion PEG and EPI formed a novel liposome capable of long-acting, plasma-stabile, pH-dependent release, and highly inhibitory effect against tumor growth.

Key words: polyethylene glycol(PEG), levo-poly lactic acid(PLLA), epirubicin, liposome, long-acting