目的 制备及表征银杏内酯K（GK）聚乙二醇-聚乳酸-羟基乙酸共聚物纳米粒（GK-mPEG-PLGA-NPs），并评价其神经保护活性。方法 采用聚乙二醇-聚乳酸-羟基乙酸共聚物（PEG-PLGA-COOH）作为载体，复乳溶剂挥发法制备隐形纳米粒；HPLC法测定GK-mPEG-PLGA-NPs的包封率及载药量；动态光散射粒径仪和透射电镜测定GK-mPEG-PLGA-NPs的粒径分布、Zeta电位及表面形态；以pH 7.4磷酸盐缓冲溶液（PBS）作为释放介质，考察GK-mPEG-PLGA-NPs的体外释放行为；采用体外细胞实验，考察GK-mPEG-PLGA-NPs对H₂O₂诱导肾上腺嗜铬细胞瘤PC12细胞损伤的保护作用。结果 GK-mPEG-PLGA-NPs包封率和载药量分别为（83.40±2.85）%和（3.26±0.24）mg/g；GK-mPEG-PLGA-NPs平均粒径为（93.19±2.77）nm；Zeta电位为（-11.93±1.71）mV；60 h内GK-mPEG-PLGA-NPs累积释药量为（90.5±4.0）%。GK-mPEG-PLGA-NPs对H₂O₂诱导的PC12细胞存活率降低有明显的改善作用，对乳酸脱氢酶（LDH）释放具有抑制作用，但其保护作用明显弱于GK对PC12细胞作用。结论 GK-mPEG-PLGA-NPs体外释放具有缓释性行为，对H₂O₂诱导PC12细胞具有神经保护作用，表明GK-mPEG-PLGA-NPs具有应用前景，值得进一步研究。

Objective To prepare and characterize ginkgolide K-loaded mPEG-PLGA[poly (D, L-lactide-co-gly-colide)-block-poly (ethylene glycol)] polymer nanoparticles (GK-mPEG-PLGA-NPs) and to evaluate its neuroprotective effect on the H₂O₂-induced PC12 cells injury in vitro. Methods The PLGA-PEG-COOH polymer was selected as carrier and double emulsion solvent evaporation technique was employed to prepare the stealth nanoparticles. The encapsulation efficiency (EE) and drug load (DL) of GK-mPEG-PLGA-NPs were investigated by HPLC. The size distribution, zeta potential, and surface morphology of GK-mPEG-PLGA-NPs were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. The in vitro release of GK-mPEG-PLGA-NPs was examined using phosphate buffer solution (pH 7.4) as the releasing medium for 24 h. The H₂O₂-induced PC12 cells injury models was established for the investigation of the protective effect of GK-mPEG-PLGA-NPs on nerve cells in vitro. Results EE and DL of GK-mPEG-PLGA-NPs was (83.40 ±2.85)% and (3.26 ±0.24) mg/g, respectively. The average diameter of GK-mPEG-PLGA-NPs was (93.19 ±2.77) nm and zeta potential was (-11.93 ±1.71) mV. The cumulative rate of drug release was (90.5 ±4.0)% after 60 h in phosphate buffer solution. GK-mPEG-PLGA-NPs significantly inhibited the apoptosis of PC12 cells and the release of lactic dehydrogenase induced by H₂O₂. However, the protective action of GK-mPEG-PLGA-NPs on the H₂O₂-iduced PC12 cells injury was significantly weaker than that of GK. Conclusion Our results proved that GK-mPEG-PLGA-NPs had a sustained release behavior in vitro and the neuroprotective effect of GK-mPEG-PLGA-NPs on H₂O₂-induced PC12 cells, which indicates that GK-mPEG-PLGA-NPs has the prospect of application and deserves further research.

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国家自然科学基金资助项目（81403067）；浙江省中医管理局项目（2015ZB105）；浙江医药高等专科学校校级项目（ZPCSR2015008）；黑龙江省省属高等学校基本科研业务费科研项目（UNPYSCT-2017160.YSTSXK201849）