中文摘要：

目的制备壳聚糖修饰的聚乳酸-羟基乙酸纳米粒（CS-PLGA NPs）并研究其体外细胞摄取情况。方法采用单乳化溶剂挥发法制备包载香豆素6的CS-PLGA NPs并对其粒径、电位及其表面形态进行表征;采用CCK-8细胞活性检测法测定其细胞毒性;在倒置荧光显微镜下观察纳米粒浓度对细胞摄取的影响。结果制备了带正电荷（＋18.47 m V）的香豆素6 CS-PLGA NPs,其粒径为248.8nm,多分散系数为0.182,粒径分布均匀;透射电镜下观察纳米粒类似球形,大小较均匀、边缘清晰。体外细胞试验显示其在浓度32 mg/m L以下无细胞毒性,细胞摄取呈现浓度依赖性,且纳米粒多分布在核周围或进入核内。结论初步建立了带正电荷的壳聚糖修饰的PLGA纳米粒系统,为其作为基因或药物递送载体提供实验依据。

英文摘要：

Objective： To investigate the preparation and in vitro cellular uptake of polylactic/glycolicacid nanoparticles surface-modified by chitosan（CS-PLGA NPs）. Methods： CS-PLGA NPs were prepared by the emulsion/solvent evaporation method and the particle size, surface charge and morphology of the NPs were determined. The cytotoxicity was measured using CCK-8 assay and the cellular uptake was observed in an inverted fluorescence microscope. Results： Coumarin-6 labeled CS-PLGA NPs preparated had a positively charge（＋18.47 m V） and an uniform particle size about 248.8 nm with a PDI of 0.182. The TEM observation showed the CS-PLGA NPs were relatively uniform and sharp-edged aspheric. In vitro tests suggested that the NPs concentration up to 32 mg/m L were non-cytotoxic, and its cellular uptake displayed concentration-dependent manner with a location around or into the nucleus. Conclusion： We successfully established a system of CS-PLGA NPs with positively charge, which could enter L929 cells and adsorbed to the nucleus or made its way into the nucleus, providing a theoretical basis as gene or drug delivery vector.