目的 制备单甲氧基聚乙二醇5000-聚己内酯10000（mPEG5000-PCL10000）修饰的多西他赛（DTX）脂质体（DTXPLip），并初步评价其体外抗肿瘤活性。方法 采用薄膜分散-水化法制备DTX-Plip。以粒径、包封率（EE）、载药量（LC）为评价指标，通过单因素及正交试验优选DTX-PLip的最佳处方工艺；研究DTX-PLip的透射电镜微观形态、粒径、ζ电位、EE及LC；考察其在4℃放置21 d内的稳定性；采用透析法对DTX-PLip的体外释放特性进行研究；采用MTT法评估DTXPLip对小鼠乳腺癌4T1细胞的增殖抑制效应；通过体外细胞摄取实验，结合荧光显微镜观察与流式细胞术定量分析4T1细胞对DTX-PLip的摄取效率。结果 DTX-PLip最佳处方为mPEG5000-PCL10000用量150 mg，DTX用量8 mg，药脂比为1∶ 20，胆脂比为1∶ 5。透射电子显微镜图片显示DTX-PLip具封闭囊泡结构，平均粒径为（82.13±3.33） nm，ζ电位为（-15.70±3.86） mV； EE为（89.34±1.07）%，LC为（2.04±0.02）%；体外释放结果表明，DTX-PLip 72 h体外累积释放率为58%，具有一定的缓释性，4℃放置21 d内储存稳定；细胞毒实验结果表明DTX-PLip对4T1细胞的半数抑制浓度（IC50）值为（0.13±0.01） μg·mL^-1，均显著高于DTX溶液组和DTX脂质体（DTX-Lip）组（P＜0.001） ，具有良好的抗肿瘤活性；荧光显微镜观察结果表明DTX-PLip在各个时间平均荧光强度均显著高于DTX-Lip（P＜0.01），流式细胞术结果表明，与DTX-Lip相比，DTX-PLip细胞摄取量显著增加（P＜0.001）。结论 DTX-PLip表现出明显的缓释作用，能增强DTX的抗肿瘤效果。

Objective To prepare monomethoxy polyethylene glycol 5000- Polycaprolactone 10000 (mPEG5000-PCL10000) modified docetaxel (DTX) liposomes (DTX-PLip), preliminary evaluate the antitumor activity in vitro. Methods DTX-PLip was prepared by thin film dispersion-hydration method. The optimal prescription process of DTX-PLip was optimized by one-way and orthogonal tests using particle size, encapsulation efficiency (EE), and drug loading capacity (LC) as evaluation indexes, the transmission electron microscopy microstructure, particle size, ζ potential, EE, LC, and stability of the optimized DTX-PLip were investigated. The in vitro release characteristics of DTX-PLip were studied using dialysis method. MTT method was used to evaluate the inhibitory effect of DTX-PLip on the proliferation of mouse breast cancer 4T1 cells. Quantitative analysis of the uptake efficiency of DTX PLip by 4T1 cells was conducted through in vitro cell uptake experiments, combined with fluorescence microscopy observation and flow cytometry. Results The optimal formulation of DTX-PLip was mPEG5000-PCL10000 at 150 mg, DTX at 8 mg, with a drug-to-lipid ratio of 1∶20 and a bile-to-lipid ratio of 1∶5. Transmission electron microscopy images showed that DTX-PLip had a closed vesicular structure, with an average particle size of (82.13 ±3.33) nm and a ζ potential of (-15.70 ±3.86) mV. EE was (89.34 ±1.07)%, and LCwas (2.04 ±0.02)%. In vitro release results indicated that the cumulative release rate of DTX-PLip was 58% after 72 h, demonstrating a certain sustained-release property. It remained stable during storage at 4 ℃ for 21 d. The cytotoxicity assay results showed that the IC₅₀ value of DTX-PLip against 4T1 cells was (0.13 ±0.01) μg·mL^-1, which was significantly higher than that of the DTX solution group and the DTX-Lip group (P <0.001), indicating good anti-tumor activity. Fluorescence microscopy observations revealed that the average fluorescence intensity of DTX-PLip was significantly higher than that of DTX-Lip at each time point (P <0.01). Flow cytometry results indicated that the cellular uptake of DTX-PLip was significantly increased compared with DTX-Lip (P <0.001). Conclusion DTX-PLip demonstrated a significant sustained-release effect and could enhance the anti-tumor efficacy of DTX.

R979.1

河南省科技攻关项目（242102310563）；河南省科技攻关项目（ 232102310337）；新乡医学院三全学院生物与医药省级重点学科项目资助（ ZDXKXM019）；新乡医学院三全学院优秀青年教师培养计划（ SQ2023YQJH06）