叶酸靶向载紫杉醇磷脂-聚合物杂化纳米粒的制备及其体外细胞评价

Preparation and in vitro evaluation of folate-targeted lipid-polymer hybrid nanoparticles loaded with paclitaxel

目的制备具有叶酸靶向性的载紫杉醇磷脂-聚合物杂化纳米粒（FIN-FLPNPs），并研究其对乳腺癌细胞EMT-6的细胞毒性及体外细胞吞噬。方法以聚己内酯-聚乙二醇-聚己内酯（PCL-PEG-PCL）、二硬脂酰基磷脂酰乙醇胺-甲氧基聚乙二醇（DSPE-mPEG2000）和叶酸偶联的磷脂（Folate—PEG（2000）-DSPE）为药物载体，通过薄膜水化法自组装制备PTX-FLPNPs，并对其进行表征；使用激光扫描共聚焦显微镜观察比较叶酸受体高表达的乳腺癌细胞EMT-6对叶酸靶向及无靶向杂化纳米粒的吞噬作用；采用MTS法研究PTX．FLPNPs对EMT．6细胞的细胞毒性。结果成功制备了PTX-FLPNPs，其呈球形，粒径均匀，具有明显的“核-壳”结构。投药量为30％的PTX-FLPNPs的平均粒径为（279．9±8．7）nm，多分散系数为0．173±0．021，Zeta电位为（-17．5±1．1）mv，载药量为（27．36±0．91）％，包封率为（91．16±1．12）％。细胞吞噬实验表明，叶酸受体高表达的EMT-6细胞对叶酸靶向的杂化纳米粒的吞噬作用明显强于无靶向的杂化纳米粒（P〈0．05）。细胞毒性实验结果表明，PTX-FLPNPs的细胞毒性低于紫杉醇注射剂，且对肿瘤细胞的抑制效果优于无靶向的杂化纳米粒。结论VFX-FLPNPs具有较高载药量及包封率，粒径均匀，可通过主动靶向作用介导肿瘤细胞内吞，并增加药物在肿瘤细胞内的浓度，是-种能有效抑制肿瘤的靶向载药纳米制剂。

Objective To prepare folate-targeted lipid-polymer hybrid nanoparticles loaded with paclitaxel （PTX-FLPNPs）, evaluate its in vitro cellular uptake and cytotoxicity. Methods PTX-FLPNPs composed of PCL- PEG-PCL, DSPE-mPEG2000 and Folate-PEG（2000）-DSPE were prepared by thin-film hydration method, and characterized in terms of morphology, particle size and size distribution, drug loading and encapsulation efficiency. The uptake efficiency of FLPNPs in breast carcinoma cells EMT-6 was evaluated by confoeal laser scanning microscopy. The cytotoxicity of PTX-FLPNPs against EMT-6 cells was determined by MTS assay. Results FFX- FLPNPs showed spherical core-shell morphology with narrow size distribution. The PTX-FLPNPs with 30% drug- loading content were found as spherical shape with average particle diameter of （279.9±8.7） nm, polydispersity index of （0.173±0.021）, Zeta potential of （-17.5±1.1） mV, drug loading of （27.36±0.91）% and encapsulation efficiency of （91.16±1.12）%. Tile internalization efficiency of FLPNPs was obviously higher that of LPNPs in EMT-6 cells which overexpress folate receptor （P〈0.05）. The cytotoxie effect of FFX-loaded FLPNPs was lower than that of PTX injection, but higher than that of PTX-loaded LPNPs （without folate conjugation）. Conclusions The PTX-FLPNPs exhibits high drug-loading content and drug encapsulating efficiency, uniform size with narrow size distribution, high internalization efficiency in EMT6 cells by active targeting-mediated endocytosis. The FFX-FLPNPs would be a promising nanosized drug formulation for tumor-targeted therapy.