响应面法优化虾青素-植物甾醇亚麻酸酯复合脂质体的制备工艺

Optimization of preparation process of liposomes co-encapsulating astaxanthin and phytosterol linolenic acid ester by response surface methodology

虾青素具有多种生理功能,为了改善其水溶性低、稳定性差导致的生物利用率不高等问题,同时,避免胆固醇的负面效应,以大豆磷脂为主要膜材,运用薄膜-超声法构建虾青素-植物甾醇亚麻酸酯复合脂质体。以复合脂质体包封率为考察指标,在单因素试验的基础上,通过Box-Behnken响应面法优化制备复合脂质体的工艺条件。结果表明:影响包封率的因素由主到次依次为植物甾醇亚麻酸酯与磷脂质量比、水相与有机相体积比、pH值;复合脂质体的最佳制备工艺条件为植物甾醇亚麻酸酯与磷脂质量比10%(磷脂200 mg)、磷酸盐缓冲液pH 7.4、吐温80用量100 mg、水相与有机相体积比4/1、磷脂与虾青素质量比50/1,在此条件下复合脂质体的包封率为(95.87±0.40)%,与理论值较为接近。优化制备复合脂质体的工艺条件为植物甾醇酯应用于负载脂溶性生物活性物质的脂质体的构建提供了理论依据和新思路。

Astaxanthin has various physiological functions, including anti-oxidant, anti-cancer, anti-inflammatory, and so on. However, the applications of astaxanthin are considerably limited in food, medicine, and cosmetics field, because of its low water solubility, instability, and poor bioavailability. Astaxanthin-loaded liposomes prepared with the utilization of soy phospholipids and cholesterol can effectively improve the water solubility, stability, and antioxidant activity of astaxanthin. However, excessive cholesterol is a major cause of diseases such as coronary heart disease and atherosclerosis. As a result, to enhance the water solubility, stability and bioavailability of astaxanthin and to avoid the negative effects of cholesterol, liposomes co-encapsulating astaxanthin and phytosterol linolenic acid ester were prepared by employing a thin-film ultrasound method with the utilization of soy phospholipids and phytosterol linolenic acid ester. On the basis of single factor experiments, the optimal preparation conditions of complex liposomes were obtained using the Box-Behnken center combination test and response surface analysis method with encapsulation efficiency as an indicator. The results showed that the influence factors on encapsulation efficiency was in this order: mass ratio of phytosterol linolenic acid ester to phospholipids > volume ratio of water phase to organic phase > pH value of phosphate buffer solution. The optimum conditions for preparing liposomes co-encapsulating astaxanthin and phytosterol linolenic acid ester were as follows: the mass ratio of phytosterol linolenic acid ester to phospholipids was 10%(200 mg phospholipids), pH value of phosphate buffer solution was 7.4, Tween 80 dosage was 100 mg, the volume ratio of water phase to organic phase was 4∶ 1, and the mass ratio of phospholipids to astaxanthin was 50∶ 1. Under the optimum conditions, the encapsulation efficiency of liposomes co-encapsulating astaxanthin and phytosterol linolenic acid ester was(95.87±0.40)%, which is close to the theoretical value. These results provide a theoretical basis and new ideas for the application of phytosterol esters in lipid bioactive substances-loaded liposomes.