星点设计-效应面法优化pH值响应及线粒体靶向双功能金丝桃苷脂质体的处方及其体外评价

目的 优化线粒体靶向金丝桃苷脂质体（DLD/Hyp-Lip）制备的最佳处方，并研究研究其在胎牛血清中的稳定性及体外释放行为，考察其线粒体靶向性。方法 采用薄膜分散法制备DLD/Hyp-Lip，以包封率和载药量为考察指标进行单因素实验，考察磷脂总量与金丝桃苷（hyperoside，Hyp）用量比、二硬脂酰磷脂酰乙醇胺-聚乙二醇（DSPE-PEG）与DLD用量比等条件对DLD/Hyp-Lip的影响，结合星点设计-效应面法优化DLD/Hyp-Lip处方。使用透射电子显微镜和粒径仪观察测定脂质体粒子外观、平均粒径和Zeta电位，采用血清稳定性实验和体外释药、线粒体靶向性对该载药系统进行评价。结果 DLD/Hyp-Lip最佳处方为磷脂总量和金丝桃苷用量比为12.50：1，磷脂总量与胆固醇用量比为6.00：1，DSPE-PEG与DLD用量比为3：5；测得金丝桃苷包封率为（95.57±0.56）%，载药量为（8.55±0.57）%。所制备的DLD/Hyp-Lip外观良好，平均粒径为（124.9±3.4）nm，Zeta电位为（-6.2±1.9）mV；在胎牛血清中性状稳定，在体外释放介质中24 h累积释放量达到40%。线粒体靶向实验表明DLD/Hyp-Lip可以促进药物聚集在线粒体部位。结论 采用此方法能够精准有效的优化DLD/Hyp-Lip的制备工艺，该方法操作简单方便，可以用于DLD/Hyp-Lip制备与处方的优化，制备的DLD/Hyp-Lip包封率高，粒径小，分布均匀，且具有良好的缓释作用，为DLD/Hyp-Lip的进一步体内研究奠定了基础。载金丝桃苷的DLD/Hyp-Lip具有良好的肝癌细胞线粒体靶向性，是一种潜在高效的肝癌细胞线粒体靶向给药系统。

Optimization of pH response and mitochondrial targeting bifunctional hyperoside liposomes by central composite design response surface methodology and its in vitro evaluation

Objective To optimize preparation of mitochondrial targeting hyperoside liposomes (DLD/Hyp-Lip), and study its stability in fetal bovine serum, in vitro release behavior and mitochondrial targeting. Methods DLD/Hyp-lip was prepared by film dispersion method. Single factor experiment was carried out with entrapment efficiency and drug loading as indexes to investigate the effects of the ratio of phospholipids to hyperoside (Hyp) and DSPE-PEG (distearoyl phosphoethanolamine-polyethylene glycol) to DLD on DLD/Hyp-Lip. The formulation of DLD/Hyp-Lip was further optimized by central composite design response surface methodology. The appearance, size and potential of liposomes were observed by transmission electron microscope and particle size analyzer. The stability and drug release rate of liposomes in fetal bovine serum were evaluated by serum stability test and in vitro drug release test. The drug delivery system was evaluated by mitochondrial targeting. Results The optimal formula of DLD/Hyp-Lip was as follows:the ratio of total phospholipids to hyperoside was 12.50:1, the ratio of total phospholipids to cholesterol was 6.00:1, and the dosage ratio of DSPE-PEG to DLD was 3:5, the encapsulation efficiency was (95.57±0.56)%, the drug loading was (8.55±0.57)%. The prepared liposomes had good appearance, the particle size of the lip was (124.9±3.4) nm, and the potential was (-6.2±1.9) mV. It was stable in fetal bovine serum and accumulated in vitro release medium for 24 h. Mitochondrial targeting experiments showed that DLD/Hyp-Lip could promote the accumulation of drugs in the mitochondria. Conclusion This method is simple and convenient, and can accurately and effectively optimize the preparation process of DLD/Hyp-Lip. The prepared DLD/Hyp-Lip has high encapsulation efficiency, small particle size, uniform distribution and good sustained-release effect, which lays the foundation for further in vivo research of DLD/Hyp-Lip. DLD/Hyp-Lip with hyperoside has good mitochondrial targeting of liver cancer cells and is a potentially efficient mitochondrial targeted drug delivery system for liver cancer cells.