PEG修饰的紫草素纳米结构脂质载体的制备和体外评价

Preparation and in vitro evaluation of PEG-modified shikonin nanostructured lipid carrier

关键词:  紫草素  纳米结构脂质载体  MCF-7细胞

Key words:  shikonin  nanostructured lipid carrier  MCF-7 cell

摘要:

[目的] 制备一种有长循环效果的聚乙二醇（PEG）修饰的紫草素纳米结构脂质载体，并对其进行理化表征和体外抗肿瘤效果评价。[方法] 采用乳化蒸发-低温固化法制备紫草素纳米结构脂质载体，通过超速离心法检测包封率；通过粒径、多分散指数（PDI）、Zeta电位、透射电镜、差示扫描量热、X射线等对制剂进行表征。采用CCK-8法考察乳腺癌MCF-7细胞的活性，以香豆素-6和Hoechst 33342为荧光探针定量考察细胞摄取行为。[结果] PEG修饰的紫草素纳米结构脂质载体粒径为（19.68±1.25）nm，多分散指数为（0.28±0.68），Zeta电位为[-（20.27±1.27）]mV。平均包封率为98%，制剂外观圆整，分布均匀。紫草素以无定型物包载于制剂中。紫草素的抗肿瘤作用呈现浓度依赖性，中、高剂量的PEG修饰制剂组抗肿瘤活性明显高于未修饰制剂组和溶液组。细胞摄取实验结果与细胞毒性实验结果一致。[结论] 实验制备的PEG修饰的紫草素纳米结构脂质载体包封率较高，粒径小，体系稳定，具有良好的体外抗肿瘤和细胞摄取效果。

Abstract:

[Objective] A PEG-modified shikonin nanostructured lipid carrier with long circulation effect has been prepared, and its physicochemical characterization and anti-tumor effect were evaluated in vitro.[Methods] The shikonin nanostructured lipid carrier was prepared by emulsification evaporation-low temperature solidification method, and the encapsulation efficiency was measured by ultracentrifugation;the formulation was characterized by particle size, polydispersity index(PDI), Zeta potential, transmission electron microscope, differential scanning volume heat, X-ray, etc. The CCK-8 method was used to investigate the activity of breast cancer MCF-7 cells, and coumarin-6 and Hoechst 33342 were used as fluorescent probes to quantitatively investigate the cellular uptake.[Results] The particle size of the PEG-modified shikonin nanostructured lipid carrier was (19.68±1.25) nm, and the PDI was 0.28±0.68, and the Zeta potential was[-(20.27±1.27)] mV. The average encapsulation rate was 98%, and the preparation had a spherical appearance and uniform size distribution. Shikonin was contained in the formulation in an amorphous form. The anti-tumor effect of shikonin was concentration-dependent. The anti-tumor activity of the medium and high-dose PEG-modified preparation group was significantly higher than that of the unmodified preparation group and the solution group. The results of the cellular uptake experiment was consistent with the results of the cytotoxicity experiment.[Conclusion] The PEG-modified shikonin nanostructured lipid carrier has good encapsulation efficiency, small particle size, stable system, good anti-tumor and cell uptake effects in vitro.