摘要:
The therapeutic application of artemisinin (ART) is restricted in application due to its poor water solubility and stability. In this study, the long-circulating liposomes (L-Lip) were constructed to improve the solubility and stability of ART. The preparation method, physicochemical properties, serum stability, in vitro release profile and cytotoxicity of the ART loaded long-circulating liposomes were investigated. Using the particle size and entrapment efficiency (EE) as the evaluation index, the preparation procedure was optimized by the Box-Behnken response surface design based on the single factor screening method. The ART loaded long-circulating liposomes were prepared by filming rehydration method, and evaluated with particle size and entrapment efficiency. The optimal formulation was as follows: lipid-cholesterol = 5.22∶1 (mass ratio), drug-lipid = 1∶23.15 (mass ratio), lipid concentration = 14.35 mg·mL-1, and molar percentage of mPEG = 2%. The morphology of L-Lip was uniformly spherical shape according to optimal formulation. The mean size and polydispersity index (PDI) were about (113.3 ± 4.7) nm and 0.227 ± 0.022 respectively, the zeta potential was (-12.9 ± 2.6) mV, and the entrapment efficiency (EE) of ART was (95.88 ± 4.8) %. The L-Lip had good stability at 4 °C for 15 days and the particle sizes did not exhibit significant variations in 50% rat plasma over 24 h at 37 °C. The in vitro release study of formulation showed a sustained release. Moreover, the cytotoxicity exhibited that blank liposomes were of great safety. Compared with the free ART, the liposome formulation achieved lower cytotoxicity at the high concentration. The L-Lip successfully prepared by a simple filmingrehydration method exhibited ideal physicochemical properties and were enhanced safety, which may sever as a promising nanoplatform for clinical application.%青蒿素(artemisinin, ART)由于溶解度差、稳定性低,限制了其应用.本研究采用长循环脂质体包裹青蒿素,增强其溶解度及稳定性.以粒径和包封率(entrapment efficiency, EE)等为评价指标,采用单因素试验及 Box-Behnken响应面设计试验优化处方,考察最优处方制备得到脂质体的外观形态、粒径分布、zeta电位、放置稳定性、血清稳定性、体外释放和细胞毒性作用.结果表明,载青蒿素长循环脂质体的最优处方为:磷脂与胆固醇的质量比为5.22∶1,青蒿素与磷脂的质量比为1∶23.15,磷脂浓度为14.35 mg·mL-1,DSPE-mPEG摩尔含量为2%.按优化后处方制备所得青蒿素长循环脂质体呈类球形,分布均匀,粒径为 (113.3 ± 4.7) nm,多分散系数(polydispersity index,PDI)为0.227 ± 0.022,zeta电位为(-12.9 ± 2.6) mV,包封率为 (95.88 ± 4.8)%,在4°C条件下放置15天稳定性良好,血清中24 h内无明显聚集.体外释放实验表明青蒿素长循环脂质体具有缓释作用;细胞毒性实验证实脂质体载体本身安全性较高,载药脂质体制剂在高浓度时的细胞毒性作用低于游离青蒿素.本研究表明,优化得到的青蒿素长循环脂质体具有简便的制备方法、适宜的理化性质和较高的安全性,具有广阔的临床应用前景.