替诺福韦阳离子脂质体的制备及其对人体肝细胞SMMC-7721摄取和细胞毒性研究

目的:研究替诺福韦阳离子脂质体的制备及其促进肝实质细胞摄取的情况和细胞毒性作用。方法:采用叔丁醇冻干法制备替诺福韦阳离子脂质体,测定其包封率及理化性质;以SMMC-7721细胞为模型,研究脂质体对肝实质细胞摄取替诺福韦的促进作用,MTT法检测不同条件下载药脂质体对细胞的毒性情况。结果:制备的脂质体包封率为(88.3±1.6)%,粒径为(278.4±67.6)nm,Zeta电势为(31±5)mV;经半乳糖基及PEG修饰的脂质体较游离药物进入肝实质细胞的浓度明显升高,且时间延长;当替诺福韦脂质体、脂质浓度分别为7.5、30μg·mL-1时,细胞存活率在80%以上,毒性较小。结论:所制备的阳离子脂质体具有显著增加细胞摄取替诺福韦和保护替诺福韦的作用,有望成为抗病毒药物如替诺福韦等的高效传递系统。

Effect of Cationic Liposome Formulation on Human Carcinoma Hepatic SMMC-7721 Cells' Uptake of Tenofovir and Cytotoxicity

OBJECTIVE:To investigate the effect of liposome formulation in promoting hepatocytes' uptake of tenofovir and cytotoxic effect. METHODS: The tenofovir cationic liposomes were prepared by tert-butyl lyophilization, and its encapsulation efficiency and physico-chemical property were determined. Using human hepatic carcinoma cells SMMC-7721 as a model to investigate the effect of liposome formulation in promoting hepatocytes' uptake of tenofovir. MTT assays were used to examine the toxicity of tenofovir cationic liposomes in different conditions. RESULTS: The prepared tenofovir cationic liposomes had an encapsulation efficiency of (88.3±1.6)%, a size distribution of (278.4±67.6)nm and a Zeta potential of (31±5)mV. The results showed that the liposome formulations containing galactose and PEG modifying lipids resulted in significantly higher and prolonged drug accumulation inside cells as compared with free drugs. The cell survival rates were above 80% when the tenofovir liposome was at a concentration of 7.5μg·mL-1 and lipids at a concentration of 30μg·mL-1, and little toxicity was noted. CONCLUSION: The prepared cationic liposome can greatly enhance hepatocytes' uptake and protection of tenofovir, which is expected to become a highly effective drug delivery system of antiviral drugs such as tenofovir etc.