叶黄素纳米脂质体的多聚赖氨酸修饰及其体外释放性能

采用亲水性阳离子多肽多聚赖氨酸(ε-poly-L-lysine,ε-PLL)通过静电吸附作用修饰叶黄素纳米脂质体(LUT-NLP),构建新型ε-PLL修饰纳米脂质体载运体系,提高对脂溶性叶黄素的包封和释放性能。采用反向溶剂法制备LUT-NLP,通过单因素试验和正交试验优化ε-PLL修饰LUT-NLP的工艺条件,并考察修饰前后LUT-NLP的结构特征和体外释放性能。结果表明:在ε-PLL用量0.08%、pH 6.0、修饰时间2.0 h时,叶黄素的包封率可达95.36%;动态光散射分析表明修饰后的脂质体平均粒径为(299.4±8.4) nm,多分散指数(PDI)降低(<0.3),膜电位升高;透射电子显微镜结果显示由于静电吸附作用,ε-PLL与脂质体表面结合形成保护包覆结构;体外释放性能评价结果显示,经ε-PLL修饰的LUT-NLP在胃肠液环境中对叶黄素的释放率显著升高。ε-PLL修饰可改善脂质体结构,增强对脂溶性叶黄素的包封效果和胃肠消化释放性能。

Polylysine modification of lutein nanoliposomes andits in vitro release performance

The lutein nanoliposomes (LUT-NLP) were modified with the hydrophilic cationic polypeptide (ε-poly-L-lysine,ε-PLL) by electrostatic adsorption to develop a new nanoliposome carrier system,in order to improve the encapsulation property and release performance of fat-soluble lutein. The nanoliposomes were prepared by anti-solvent method,and the optimal modification process of lutein nanoliposomes was explored by single factor experiment and orthogonal experiment,and the structural characteristics and in vitro release performance before and after modification were also investigated. The results showed that the optimal modification conditions were obtained as follows:ε-PLL dosage 0. 08%,pH 6. 0 and modification time 2. 0 h. Under these conditions, the encapsulation efficiency of the lutein nanoliposomes was 95. 36%. Dynamic light scattering (DLS)analysis demonstrated that the modified lutein nanoliposomes had an average size of (299. 4 ±8. 4) nm,a lower polydispersity index (PDI) (< 0. 3) and an increasing membrane potential compared with the lutein nanoliposomes. Transmission electron microscopy (TEM) images showed that due to electrostatic adsorption,ε-PLL combined with the liposome surface to form a protective coating structure. In vitro release experiments revealed that ε-PLL improved the lutein release from the nanoliposomes in gastrointestinal fluid conditions. Therefore,the modification with ε-PLL could improve the structure of lutein nanoliposomes and enhance the encapsulation effect of lutein,and their release in gastric and intestinal fluid environment was also improved.