茶皂素及槐糖脂对紫草素脂质纳米粒子形成和稳定性的影响

何洁; 彭盛峰; 张军兵; 刘伟

doi:10.13386/j.issn1002-0306.2023030169

茶皂素及槐糖脂对紫草素脂质纳米粒子形成和稳定性的影响

Effects of Saponin and Sophorolipid on the Formation and Stability of Shikonin Lipid Nanoparticles

摘要

摘要: 紫草素（Shikonin）是一种具有多种生理活性的疏水性天然色素，为了提高其水溶性、稳定性和生物利用率，开发天然表面活性剂修饰的紫草素脂质纳米粒子。本课题以卵磷脂为原料，采用pH驱动法制备紫草素脂质纳米粒子，通过添加茶皂素或槐糖脂，考察茶皂素或槐糖脂对紫草素脂质纳米粒子的形成以及不同环境稳定性的影响。实验结果表明，当卵磷脂与茶皂素（或槐糖脂）质量比为2:1时，茶皂素修饰的紫草素脂质纳米粒子（Saponin modified shikonin lipid nanoparticles，Sap-SLNP）的包封率达到99.01%，负载率达到5.06%，槐糖脂修饰的紫草素脂质纳米粒子（Sophorolipid modified shikonin lipid nanoparticles，Sop-SLNP）的包封率达到98.36%，负载率达到5.16%。两种天然表面活性剂修饰的紫草素脂质纳米粒子环境稳定性相近，热稳定性和光稳定性分别约是游离紫草素的2倍和1.6倍，在pH2~7以及离子浓度0~1000 mmol/L内依然保持较好的稳定性，经过反复冻融3次后粒径变化不大，包封率仍有85%左右，将近是无修饰脂质纳米粒子的2倍，并且经过4周储藏粒径基本不变，包封率仍有80%左右，约为无修饰脂质纳米粒子的1.7倍。此外紫草素的生物利用率显著提高，约是游离紫草素的3倍。

Abstract: Shikonin is a kind of hydrophobic natural pigment with various physiological activities. In order to improve its water solubility, stability and bioavailability, a natural surfactant modified shikonin lipid nanoparticles was developed. In this study, lecithin was used as raw material to prepare shikonin lipid nanoparticles by pH-driven method. The effects of saponin or sophorolipid on the formation and stability of shikonin lipid nanoparticles were investigated. When the mass ratio of lecithin to natural surfactant was 2:1, the encapsulation rate and the loading rate of saponin modified shikonin lipid nanoparticles (Sap-SLNP) reached to 99.01% and 5.06%, respectively. For sophorolipid modified shikonin lipid nanoparticles (Sop-SLNP), the encapsulation rate and the loading rate were 98.36% and 5.16%, respectively. The environmental stability of shikonin lipid nanoparticles modified by two kinds of natural surfactants were similar. The shikonin retention rate of Sap-SLNP and Sop-SLNP after thermal treatment and light irradiation were about 2 times and 1.6 times of free shikonin, respectively. And they maintained good stability without any significant changes at pH range of 2~7 and ion concentration of 0~1000 mmol/L. After repeated freeze-thaw three times, the particle size of Sap-SLNP and Sop-SLNP showed no significant changes and the encapsulation rate was around 85%, which was nearly twice to that of unmodified lipid nanoparticles. After 4 weeks of storage, the particle size of Sap-SLNP and Sop-SLNP remained unchanged, and the encapsulation rate was about 80%, which was about 1.7 times that of the unmodified lipid nanoparticles. Moreover, the bioavailability of shikonin in Sap-SLNP and Sop-SLNP was significantly improved, which was about three times that of free shikonin.