中文摘要：

目的研究纳米四氧化三铁（Fe3O4）颗粒包裹不同外壳材料对宫颈癌细胞HeLa毒性的影响。方法通过无溶剂热分解法制备磁性纳米Fe3O4颗粒并分别使用聚乳酸一羟基乙酸共聚物（PLGA）和胆酸（CA）修饰的PLGA（CA-PLGA）星型共聚物包裹，对其进行验证表征后，使用激光共聚焦显微镜观察Heh细胞对纳米颗粒的摄取，并用噻唑蓝（MTY）法测定上述两种材料包裹的纳米Fe3O4颗粒对HeLa细胞的毒性作用。结果制备的单个纳米Fe3O4颗粒粒径约7nm，载Fe3O4的PLGA和CA-PLGA纳米颗粒均呈球状，粒径约200nm，理论载药量为10％。当Fe3O4纳米颗粒的质量浓度相同（25μg／m1）时，载Fe3O4的CA-PLGA纳米颗粒对HeLa细胞的毒性小于对应的PLGA纳米颗粒。结论CA-PLGA星型共聚物可降低磁性纳米Fe3O4。颗粒的细胞毒性，在生物体内具有广阔的应用前景。

英文摘要：

Objective To investigate the effects of magnetic iron-oxide （Fe3O4） nanoparticles with different skin materials on cytotoxicity against human cervix cancer HeLa cells. Methods The Fe3O4 nanoparticles were pre- pared by solvent-free dissolving method and then covered with poly（lactic-co-glycolic acid） （PLGA） and cholic acid （CA）-PLGA respectively. After the characterization, the uptake of nanoparticles by HeLa cells was observed by laser scanning confocal microscopy, and thiazolyl blue tetrazolium bromide （MTT） assay was used to assess the cytotoxcity of the Fe3O4-10aded nanoparticles against HeLa cells. Results The size of single Fe3O4 nanoparticle was about 7 nm. The Fe3O4-1oaded PLGA and CA-PLGA nanoparticles were spherical in shape under transmission electron micro- scope, around 200 nm in diameter, and the theoretical drug-loading capacity was 10%. At the same Fe3O4 nanoparti- cles concentration of 25 μg/ml, the Fe3O4-loaded CA-PLGA nanoparticles showed less toxicity than Fe3O4-1oaded PL- GA nanoparticles. Conclusions Star-shaped copolymer CA-PLGA is promising in decreasing cytotoxicity of mag- netic Fe3O4 nanopartieles and expanding its application in living organisms.