Abstract: Objective This study is to prepare a new type of chitosan nanoparticles (PEG/CS-EPI NPs), which contain epirubicin and modified by PEG, Furthermore, to investigate the anticancer activity of the NPs in vitro and in vivo. Methods The ionic gelation technique was employed to prepare the PEG/CS-EPI NPs and CS-EPI NPs. The particle size and morphology were determined respectively by laser scattering and transmission electron microscopy. The proliferation of nasopharyngeal carcinoma cells were detected by MTT assay in vitro; The mouse model of implantation murine sarcoma cells(S-180) were applied to evaluate the anticancer effectiveness of PEG/CS-EPI NPs and CS-EPI NPs in vivo. Results The PEG modified CS NPs prepared were discrete and uniform spheres with an average diameter of 322.1nm and the rates of drug loading and encapsulation is 13% and 74%, respectively. The results of the anticancer tests showed a sustained cytotoxicity of loading drug NPs on nasopharyngeal carcinoma cells in vitro and the stealth nanoparticles was more powerful than ordinary nanoparticles on the inhibitory potency in vivo. Conclution Stealth chitosan nanoparticles as compared with ordinary chitosan nanoparticles could be more suitable for the preparation of chemotherapy drug carriers.

Key words: Chitosan, epirubicin, stealth nanoparticles