目的 构建转铁蛋白（Tf）和叶酸（FA）双重修饰的薏苡仁油-雷公藤红素微乳（transferrin and folic acid modified coix seed oil-tripterine microemulsion，Tf/FA-CT-MEs），提高其体外靶向抗肿瘤能力。方法 采用经典缩合法制备叶酸-聚乙二醇400（FA-PEG 400），通过FT-IR与¹H-NMR进行结构表征，并连同Tf共同作为靶配体；以薏苡仁油为油相，包埋难溶性抗肿瘤药物雷公藤红素，水滴定法制备Tf/FA-CT-MEs等制剂并表征其理化性质；以异硫氰酸荧光素（FITC）为荧光探针，通过流式细胞仪定量比较MCF-7（Tf/FA受体双过表达）和A549（仅Tf受体过表达）细胞对微乳的摄取量。同时考察微乳抑制细胞增殖作用和诱导细胞凋亡的能力。结果 合成并表征了FA-PEG 400，作为制剂靶配体制备了Tf/FA-CT-MEs等制剂；Tf/FA-CT-MEs外观圆整，平均粒径为（52.52±0.11）nm，多分散指数（PDI）为0.124±0.019，Zeta电位为（-21.50±1.70）mV，且具有较好的体外稳定性。细胞实验表明，Tf/FA-CT-MEs对MCF-7细胞和A549细胞的半数抑制浓度（IC₅₀）分别为0.77、0.85 μmol/L；4 h细胞摄取荧光强度分别为2 782.33±131.77、2 762.91±23.18；诱导MCF-7细胞凋亡率为（70.60±6.92）%。结论 Tf/FA-CT-MEs在体外干预Tf/FA受体双过表达细胞系时，体外靶向抗肿瘤作用明显增强，此类双靶修饰策略为提高中药纳米制剂针对特定肿瘤细胞的靶向性研究提供依据。

Objective A transferrin and folic acid co-modified Coicis Semen oil-tripterine microemulsion (Tf/FA-CT-MEs) was developed to improve the tumor targeting and thereby enhance the in vitro antitumor efficacy. Methods FA-PEG 400 was synthesized by classic condensation and together with transferrin as targeting ligands. The structures were characterized by FT-IR and H-NMR. Tf/FA-CT-MEs were prepared by aqueous titration method using Coicis Semen oil as oil phase, followed by anchoring Tf on the surface of prepared particles mentioned-above in aqueous environment. The physiochemical properties and morphology were detected by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. The A549 and MCF-7 cellular uptake of various microemulsions was detected through employing fluorescein isothiocyanate (FITC) as a fluorescence probe. The in vitro antitumor efficacy of the microemulsions against A549 and MCF-7 cells were determined by MTT assay and cell apoptosis kit. Results FA-PEG 400 was synthesized and characterized as a target ligand. The Tf/FA-CT-MEs with spherical shape had a small droplet size (52.52 ±0.11) nm, narrow polydispersion index (PDI, 0.124 ±0.019), and negative Zeta potential (-21.50 ±1.70) mV, respectively, with good in vitro stability. In in vitro antitumor efficacy, the half proliferation inhibitory concentration (IC₅₀) of Tf/FA-CT-MEs was 0.77 μmol/L on MCF-7 cell model and 0.85 μmol/L on A549 cell model. The cellular uptake results suggested that the fluorescence intensity of MCF-7 and A549 cells was 2 782.33 ±131.77 and 2 762.91 ±23.18 for 4 h, respectively. Besides, (70.60 ±6.92)% of MCF-7 cells were induced to apoptosis by Tf/FA-CT-MEs. Conclusion Tf/FA-CT-MEs could improve in vitro targeting and cytotoxicity toward MCF-7 cells. This study suggests that the modification with dul-targeted ligands could be a promising strategy for developing tumor-specific nanomedicines.

国家自然科学基金资助项目（81673606，81373979，81503264）