RGD修饰紫杉醇脂质体的制备及其肺癌靶向治疗研究

目的:制备RGD修饰载紫杉醇(paclitaxel,PTX)脂质体(RGDLP-PTX),研究其理化性质,并探究其肺癌靶向治疗作用。方法:采用薄膜分散法制备RGDLP-PTX。荧光分光光度法研究A549细胞和NCI-H446细胞对普通脂质体(LP)和RGD修饰脂质体(RGDLP)的摄取效率。噻唑蓝实验研究不同紫杉醇浓度对A549细胞和NCI-H446细胞的细胞毒性;流式细胞仪检测RGDLP-PTX对A549细胞和NCI-H446细胞的凋亡诱导作用。用A549细胞构建肺癌裸鼠异位肿瘤模型,研究RGDLP-PTX的体内抗肿瘤作用。结果:RGDLP-PTX的粒径为(106.3±15.2)nm,电位为(6.23±2.2)mV;A549细胞对RGDLP-PTX的摄取效率是LP-PTX的4.4倍,差异有统计学意义(P<0.01);NCI-H446细胞对RGDLP-PTX的摄取效率是LP-PTX的3.8倍,差异有统计学意义(P<0.01);RGDLP-PTX对A549细胞和NCI-H446细胞的增殖抑制率具有浓度依赖性;在相同紫杉醇浓度下,RGDLP-PTX对A549细胞和NCI-H446细胞的增殖抑制率显著强于LP-PTX和游离紫杉醇,差异有统计学意义(P<0.01);RGDLP-PTX,LP-PTX和游离紫杉醇诱导肺癌A549细胞的凋亡率分别为48.3%,27.4%和35.5%,与生理盐水组比较,差异有统计学意义(P<0.01);NCI-H446细胞凋亡率分别为41.3%,22.8%和34.1%,与生理盐水组比较,差异有统计学意义(P<0.01)。RGDLP-PTX,LP-PTX和游离紫杉醇对肺癌肿瘤的抑制率分别为69.3%,47.5%和24.4%,差异有统计学意义(P<0.01)。结论:RGD修饰载紫杉醇脂质体能够高效抑制肺癌细胞的增殖和肿瘤的生长,是一种有效的肺癌靶向给药系统。

Preparation of RGD modified paclitaxel loaded liposomes and its targeted therapy against lung cancer

OBJECTIVE To prepare RGD modified paclitaxel loaded liposome (RGDLP-PTX), study its physicochemical property and its targeted therapy against lung cancer.METHODS RGDLP-PTX was prepared by thin-film methods. The fluorescence spectrophotometry was used to value the uptake efficiency of liposomes by A549 cells and NCI-H446 cells. MTT assay was used to evaluate anti-proliferative efficiency of RGDLP-PTX, LP-PTX and free PTX. Flow cytometry was used to detect the cell induced apoptosis by liposomes. The anti-tumor effects of RGDLP-PTX were evaluated in tumor bearing nude mice.RESULTS The particle size of RGDLP-PTX was (106.3±15.2)nm and the zeta potential was (6.23±2.2)mV. RGDLP-PTX uptake by A549 cells and NCI-H446 cells was 4.4 and 3.8 time higher than that of LP-PTX. The anti-proliferation rate of A549 cells and NCI-H446 cells increased with paclitaxel concentration. The RGDLP-PTX showed higher anti- proliferation efficiency than LP-PTX and free PTX at the same concentration of PTX. A549 cell apoptosis rates induced by RGDLP-PTX, LP-PTX and free PTX were 48.3%, 27.4% and 35.5% (P<0.01). The NCI-H446 cell apoptosis rates induced by RGDLP-PTX, LP-PTX and free PTX were 41.3%,22.8% and 34.1% (P<0.01). The tumor inhibition rates of RGDLP-PTX, LP-PTX and free PTX were 69.3%, 47.5% and 24.4% in vivo (P<0.01).CONCLUSION RGD modified paclitaxel loaded liposome can efficiently inhibit the proliferation of lung cancer cells and tumor growth, which may be an effective lung targeting drug delivery system.