PEG-thiol修饰对金磁微粒胶体稳定性和抗吞噬能力的影响  

Impact of PEG-thiol modification on the colloidal stability and anti-phagocytic capacity of GoldMag nanoparticles

作　　者：龚明福[1] 杨华[1] 张松[1] 邹利光[1] 张冬[1] 舒通胜[1] 

机构地区：[1]第三军医大学新桥医院放射科,重庆400037

出　　处：《中国医学影像技术》2013年第7期1053-1057,共5页Chinese Journal of Medical Imaging Technology

基　　金：国家自然科学基金面上项目(81071197);国家"十二五"科技支撑计划课题项目子课题(2012BAI23B08-4)

摘　　要：目的探讨PEG-thiol修饰对GoldMag的磁学性能、体外悬浮稳定性和抗吞噬能力的影响。方法用PEG-thiol对GoldMag进行表面修饰,采用MR FSE序列T2W、GRE序列T2*W和T2mapping分别检测PEG-GoldMag和GoldMag的磁学性能;以Zeta电位仪检测两种纳米粒溶液的Zeta电位,紫外-可见光分光光度计检测两种纳米粒溶液不同时间点的吸光度,评估其悬浮稳定性。分别用两种纳米粒对小鼠单核巨噬细胞RAW 264.7进行体外标记,以普鲁士蓝染色检测两种纳米粒的细胞标记率,ICP-OES检测两种不同纳米粒标记的RAW 264.7细胞的细胞内铁含量,评估PEG修饰对GoldMag纳米粒体外抗吞噬能力的影响。结果GoldMag和PEG-GoldMag溶液的Zeta电位分别为-18.3mV和-39.5 mV。室温下静置100 min后,GoldMag和PEG-GoldMag溶液的相对吸光度分别为50%和88.5%;静置200min后两种溶液的相对吸光度分别为17%～18%和80%。两种纳米粒均能标记RAW 264.7细胞,GoldMag和PEG-GoldMag对RAW 264.7细胞的标记率分别为(85.3±2.1)%和(23.6±1.3)%。GoldMag和PEG-GoldMag标记的RAW264.7细胞的铁含量分别为(21.6±2.3)pg/细胞和(8.7±1.2)pg/细胞。在T2WI、T2*WI和T2mapping三种图像上,各浓度下PEG-GoldMag和GoldMag纳米粒凝胶的信号强度和T2值差异无统计学意义(P>0.05)。结论PEG-thiol修饰能显著改善GoldMag的悬浮稳定性和抗吞噬清除能力,且对其磁学性能无明显影响。Objective To investigate the impact of PEG-thiol modification on the magnetic property,colloidal stability and anti-phagocytic capacity of GoldMag nanoparticles in vitro.Methods GoldMag nanoparticles were modified using PEG-thiol,and the magnetic property of PEG-GoldMag and GodlMag were tested with FSE sequence T2WI,GRE sequence T2＊WI and T2 mapping.Zeta potential of the two nanoparticle solutions were tested with Zeta potential instrument,while the absorbance was tested with UV-visible spectrophotometer at different time points.Mouse monocyte-macrophage RAW 264.7 was labeled with GoldMag and PEG-GoldMag and stained with Prussian blue buffer in order to calculate the labeling rate.Intracellular iron content of the RAW 264.7 labeled with two different nanoparticles was measured with ICP-OES to assess the influence of PEG-thiol modification on anti-phagocytic capacity of GoldMag.Results The Zeta potential of GoldMag and PEG-GoldMag solution was-18.3 mV and-39.5 mV,respectively.After standing at room temperature for 100 min,the relative absorbance of GoldMag and PEG-GoldMag solution was 50% and 88.5%,respectively.When standing for 200 min,the relative absorbance of the two nanoparticle solutions dropped to 17%—18% and 80%,respectively.Prussian blue staining showed that both the two kinds of nanoparticles could label RAW 264.7 cells,and the label rate of GoldMag and PEG-GoldMag was（85.3±2.1）% and（23.6±1.3）%,respectively.The intracellular iron content of RAW 264.7 cells labeled with GoldMag and PEG-GoldMag was（21.6±2.3）pg/cell and（8.7±1.2）pg/cell,respectively.On T2WI,GRE T2＊WI and T2 mapping,the differences of signal intensity and T2 relaxation time between PEG-GoldMag and GoldMag nanoparticle solutions at various concentrations were not statistically significant（all P0.05）.Conclusion PEG-thiol modification can significantly improve the suspension stability and anti-phagocytic clearance capacity of GoldMag nanoparticles in vitro without obvious alteration of magnetic properties.

关 键 词：金磁微粒 巯基聚乙二醇 悬浮稳定性 抗吞噬能力 磁共振成像 

分 类 号：R445.2[医药卫生—影像医学与核医学] R-332[医药卫生—诊断学]