摘要
目的:设计脑胶质瘤靶向的Ag2S量子点及Ag2S-PEG量子点近红外二区成像探针,并比较修饰脑靶向肽Angiopep-2(ANG)前、后量子点通过体外血脑屏障及靶向脑胶质瘤细胞的能力。方法:Ag2S量子点及Ag2S-PEG量子点和脑靶向肽ANG经EDC和NHS介导,发生氨基和羧基的缩合反应进行连接。对Ag2S、Ag2S-ANG、Ag2S-PEG、Ag2S-PEG-ANG量子点的结构及粒径进行琼脂糖电泳、动态光散射及透射电镜等表征,并评价其对U87 MG和bEnd.3细胞的细胞毒性以及穿透体外血脑屏障的能力。结果:修饰ANG肽后的Ag2S-ANG、Ag2S-PEGANG量子点水合粒径较Ag2S、Ag2S-PEG增大,差异有统计学意义(P<0.05);表面Zeta电位正电性增强;在琼脂糖电泳中迁移距离变短。MTT实验发现,Ag2S、Ag2S-ANG、Ag2S-PEG、Ag2S-PEG-ANG四种量子点在100μg/mL以下对U87 MG和bEnd.3细胞的存活率没有影响。在体外血脑屏障模型中,Ag2S-ANG、Ag2S-PEG和Ag2S-PEG-ANG均能够穿过上层的bEnd.3细胞到达下层培养基中,而Ag2S-ANG被下层的U87 MG细胞摄取的量有较大提升,约是Ag2S量子点的6倍,差异有统计学意义(P<0.01)。结论:本研究成功构建了2种脑靶向硫化银量子点,其中Ag2S-ANG能够跨体外血脑屏障系统,靶向脑胶质瘤细胞,为进一步的体内脑靶向成像奠定了基础。
Objective:To design the brain targeted Ag2S and Ag2S-PEG quantum dots and evaluate the property of the modified quantum dots in crossing the in vitro blood-brain barrier.Methods:Ag2S was conjugated with Angiopep-2(Ag2S-ANG)and Ag2S-PEG was conjugated with Angiopep-2(Ag2S-PEG-ANG)through the condensation reaction of amino and carboxyl groups mediated by EDC and NHS.The structure and size of Ag2S,Ag2S-ANG,Ag2S-PEG,Ag2S-PEG-ANG were characterized by agarose electrophoresis,dynamic light scattering transmission,electron microscope(TEM).The property of four kinds of quantum dots across the blood-brain barrier was evaluated in vitro by using the in vitro blood-brain barrier model.The cytotoxicity of four kinds of materials on U87 MG and bEnd.3 cells was observed.Results:Ag2S-ANG and Ag2S-PEG-ANG had a shorter migration distance compared with Ag2S and Ag2S-PEG in the agarose gel electrophoresis.The hydrate particle size of Ag2S-ANG and Ag2S-PEG-ANG was respectively increased compared with Ag2S and Ag2S-PEG.And their Zeta potential exhibited electropositive reinforcement.From the TEM results,we founded that the partical size of Ag2S-ANG and Ag2S-PEG-ANG was bigger than Ag2S and Ag2S-PEG(P<0.05).Ag2S,Ag2S-ANG,Ag2SPEG,Ag2S-PEG-ANG QDs had no obvious cytotoxicity when the concentration was lower than 100μg/mL.In vitro blood-brain barrier cell model,Ag2S-ANG,Ag2S-PEG and Ag2S-PEG-ANG quantum dots could cross the bEnd.3 cells in the upper layer,especially when the uptake of Ag2S-ANG was 6 times that of Ag2S by U87 MG cells in the lower layer(P<0.01).Conclusion:Brain targeted Ag2S-ANG and Ag2S-PEG-ANG are synthesized successfully.Ag2S-ANG QDs exhibit excellent ability to cross the blood-brain barrier system in vitro and target glioma cells,which lays the foundations for further study of in vivo brain targeting imaging.
作者
徐毅
闫美玲
马继飞
赵芳菲
孙艳红
王丽华
高基民
XU Yi;YAN Meiling;MA Jifei;ZHAO Fangfei;SUN Yanhong;WANG Lihua;GAO Jimin(School of Laboratory Medicine and Life Sciences,Wenzhou Medical University,Wenzhou 325035,China;CAS Key Laboratory of Interfacial Physics and Technology,Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China)
出处
《温州医科大学学报》
CAS
2020年第3期206-211,216,共7页
Journal of Wenzhou Medical University
基金
国家自然科学基金资助项目(11575278,21675167,U1632125)
国家重点研发计划项目(2016YFA0400902)
放射医学与辐射防护国家重点实验室开放性项目(GZK1201813)。
