载内皮抑素壳聚糖纳米粒联合顺铂对小鼠Lewis肺癌移植瘤的治疗作用

Preparation of endostatin-loaded chitosan nanoparticles and antitumor effect of the nanoparticles combined with cisplatin in Lewis lung cancer mice

目的制备载内皮抑素(endostain,ES)壳聚糖纳米粒(endostatin-loaded chitosan nanoparticles,ES-NPs),并探讨其联合顺铂(cisplatin,DDP)对小鼠Lewis肺癌模型的治疗作用。方法采用离子凝胶法制备ES-NPs,并对其形态及基本性质进行研究。建立小鼠Lewis肺癌皮下移植瘤模型,按随机数字表法分为对照组、ES组、DDP组、ES-NPs组、ES+DDP组、ES-NPs+DDP组。各组给药后,动态测量小鼠移植瘤体积,免疫组化检测移植瘤组织中微血管密度(microvessel density,MVD),ELISA检测小鼠血清中内皮抑素和VEGF水平。结果制备的ES-NPs具有合适的粒径和较高的包封率,在体外具有明显缓释性,7 d累积释放量达(60.22±2.58)%。当ES-NPs与DDP联合时,能明显抑制肺癌移植瘤生长,观察结束时,ES-NPs+DDP组的抑瘤率为76.47%,明显高于ES+DDP组及其余各组(P<0.05)。同时,免疫组化和ELISA检测结果证实了ES-NPs与DDP联合对肿瘤血管具有较强的抑制作用。结论内皮抑素纳米粒联用DDP可增强对小鼠Lewis肺癌移植瘤的抗瘤效果。

Objective To prepare endostatin-loaded chitosan nanopartieles （ES-NPs）, and investigate the antitumor effect of the nanoparticles combined with cisplatin （DDP） in Lewis Lung cancer mice. Methods ES-NPs were prepared with a simple ionic crosslinking method. The characterization of ES- NPs, including size distribution, zeta potential, loading efficiency, encapsulation efficiency and release behavior, was determined. Subcutaneous Lewis lung cancer xenograft model of C57BL/6J mice was established, and the mice were randomly divided into 6 groups ： control group （0.9% NaC1）, ES group, DDP group, ES-NPs group, ES ＋ DDP group, and ES-NPs ＋ DDP group. After drug administration, the volume of xenograft tumor in different groups was measured dynamically. The microvascular density （MVD） in xenograft tumor tissues was detected by immunohistochemical assay. The serum vascular endothelial growth factor （VEGF） and endostatin levels were determined by enzyme-linked immunosorbent assay （ELISA）. Results ES-NPs were successfully synthesized and had suitable size distribution and high encapsulation efficiency. The NPs were spherical and homogeneous in shape, and exhibited an ideal releasing profile in vitro. The tumor growth was significantly inhibited after treatment with ES-NPs combined with DDP. The tumor inhibitory rate was much higher in the ES-NPs ＋ DDP group than in the other groups （ P 〈 0.05 ）. Moreover, the results of immunohistochemical assay and ELISA confirmed that ES-NPs combined with DDP had strong effect on inhibiting tumor angiogenesis. Conclusion ES-NPs can overcome the shortcomings of free ES, such as short retention time in circulation, and can enhance antitumor efficacy of ES. When the nanoparticles are combined with DDP, the antitumor effect becomes stronger.