中文摘要：

目的以聚乳酸-羟基乙酸共聚物（PLGA）为材料,制备用于肿瘤化疗的甲氨蝶呤-聚乳酸-羟基乙酸共聚物（MTX-PLGA）纳米囊,并考察MTX-PLGA纳米囊的体外释放特性。方法采用复乳化-溶剂挥发法制备MTX-PLGA纳米囊,用透射电镜观察纳米囊的形态,并研究MTX-PLGA纳米囊的粒径、回收率、载药量、包封率、稳定性和体外释药。结果MTX-PLGA为圆整的类球形实体粒子,平均粒径为（161.2±6.7）nm,载药量为（4.23±0.77）%,包封率为（62.1±3.8）%,体外释药符合一级释放方程：ln（1-Y）=-0.004 1t-0.064 8（r=0.984 5）。结论采用复乳法-溶剂挥发法成功制备MTX-PLGA纳米囊,所制纳米囊具有明显缓释作用,是具有应用前景的新型化疗药物。

英文摘要：

OBJECTIVE To prepare （MTX） loaded nanocapsules using the biodegradable materials-poly （L-lactic-co-glycolic aeid） （PLGA） , and to study the release behavior of the nanocapsules in vitro. METHODS MTX loaded PLGA nanocapsules were made by double emulsion （W/O/W）-liquid drying process with poly （L-lactic-co-glycolie acid） （PLGA） as carrier materials. The mop- hology of the nanocapsules was observed by transmission electron microscope. The mean diameter, size distribution,recovery,drug loading,incorporation effieiency, stability and the drug release behavior were determined. RESULTS MTX loaded PLGA nanocapsules were spherical with the mean size of （161.2 ± 6. 7 ）nm, the drug loading of （4. 23 ± 0. 77 ）% and the encapsulation efficiency of （ 62. 1 ± 3.8） %. The in vitro release property were diseribed by the first order kinetics equation ： In （ 1 - Y） = - 0. 004 1 t - 0. 064 8 （ r = 0. 984 5）. CONCLUSION MTX can be encapsuled in PLGA nanocapsules which showed signifieant sustained release. The PL- GA nanocapsules are promising for loading MTX in anti-cancer drug delivery system.