Abstract: Octadecyl quaternized carboxymethyl chitosan(QACMC) was synthesized through carboxymethyl chitosan grafting with glycidyl octadecyl dimethylammonium chloride. Then, novel magnetic cationic polymeric liposomes(MCPL) formed from QACMC/cholesterol and Fe₃O₄ ferrofluid were prepared via Thin-Layer Evaporation. The structure and properties of all samples were characterized via TEM, DLS, VSM and FTIR. The results show that the superparamagnetic cationic polymeric liposomes were prepared successfully. It was stable in aqueous phase and had a high zeta potential of +38.22 mV. The average diameter of MCPL was about 15 nm and the saturation magnetization value of it was 28 A·m²/kg at 300 K. Vincristine as a kind of hydrophilic components was entrapped into its aqueous core. Vincristine encapsulation efficiency of MCPL was 93.1% and it exhibited a slow steady release of vincristine over two weeks at 37 ℃ in Tris-HCl(pH=7.4).

Key words: Quaternized chitosan, Fe₃O₄ ferrofluid, Polymeric liposomes, Magnetic liposomes