海藻酸钠-壳聚糖表面修饰维生素C/β-胡萝卜素复合脂质体的制备

Preparation of Vitamin C/β-Carotene Composite Liposomes with Their Surfaces Modified by Sodium Alginate-Chitosan

摘要:

为了增强脂质体的稳定性，本研究将壳聚糖、海藻酸钠逐层修饰在维生素C（Vc）/β胡萝卜素（βC）复合脂质体（L）的表面，制备出了壳聚糖单层修饰脂质体（C-L）和海藻酸钠-壳聚糖双层修饰脂质体（S-C-L），并对三种脂质体的包埋率、粒度分布、微观形态、形成机理和贮藏稳定性进行了研究。结果表明，表面修饰前后，脂质体中活性成分的包埋率无显著变化，其中Vc的包埋率高于75%，βC的包埋率高于95%；动态光散射（DLS）和透射电子显微镜（TEM）结果表明，经表面修饰后，脂质体的z-平均粒径从250.1 nm增大到541.9 nm；Zeta-电位和傅里叶红外光谱（FT-IR）分析表明壳聚糖和海藻酸钠通过静电相互作用成功修饰在脂质体表面，不改变脂质体的内部结构；贮藏稳定性结果表明，C-L和S-C-L中Vc和βC的保留率在同一条件下要比L中Vc和βC的保留率约高2%~10%，说明脂质体经表面修饰后，其贮藏稳定性增强。

Abstract:

In order to enhance the stability of liposomes, the surface of Vitamin C (Vc)/β-carotene (βC) composite liposomes (L) were modified by chitosan and sodium alginate with layer-by-layer technique, to prepare monolayered chitosan liposomes (C-L) and bilayered sodium alginate-chitosan liposomes (S-C-L). The encapsulation efficiency, particle size distribution, microscopic morphology, formation mechanism and storage stability of the liposomes were studied. The results showed that there was no significant change in the encapsulation efficiency of the active components in the liposomes before and after a liposomal surface modification, with the encapsulation efficiency of Vc and βC higher than 75% and 95%, respectively. The results obtained dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed that after surface modification, the z-average particle size of liposomes increased from 250.1 nm to 541.9 nm. The Zeta-potential measurements and FT-IR analysis showed that chitosan and sodium alginate could successfully modify the surface of liposomes via electrostatic interactions, without changing the internal structure of the liposomes. The results of storage stability tests showed that the retention rates of Vc and βC in C-L and S-C-L were about 2%~10% higher than that of L under the same conditions, indicating that the storage stability of liposomes was enhanced after surface modification.