载量子点高分子光-声双模式成像剂制备及显像实验

摘要

Objective To prepare the quantum dots(QDs) (CdTe-MPA)-loaded polymer(lactic-coglycolic acid,PLGA) microbubbles(MBQDs@PLGA) as dual-modality imaging agent for both fluorescent and ultrasonic imaging ability.Methods The MBQDs@PLGA were generated by the double emulsion technique,then filling in C3F8 after freeze-drying.Confocal laser scanning microscope(CLSM) and transmission electron microscope(TEM) were used to confirm the load of quantum dots in the MBs.Fluorospectro photometer spectra of the MBQDs@PLGA were analyzed to demonstrate the fluorescent imaging ability and determine the encapsulation efficiency by using the regression equation.Imaging experiments was applied to validate the fluorescent and ultrasonic imaging ability of the MBQDs@PLGA both by imaging of the model in vitro and by imaging of ovarian tumor blood vessels of tumor-bearing nude mouse in vivo.Results At excitation 272 nm the MBQDs@PLGA peak of the emission spectrum was 549 nm,and the encapsulation efficiency was 54％.The average diameter of MBQDs@PLGA was (1.7 ±0.2)μm,CLSM and TEM results confirmed the QDs-loaded in MBQDs-PLGA.The imaging results of MBQDs@PLGA showed a dual-modality imaging ability both fluorescent and ultrasonic imaging.Conclusions MBQDs@PLGA present fluorescence-ultrasound dual mode imaging performance by the QDs embedding in polymer microbubbles,and explore a new development train of thought of multi-mode imaging agent.%目的 制备载量子点(QDs,CdTe-MPA)高分子乳酸羟基乙酸共聚物(PLGA)微气泡——荧光-超声双模式成像剂(MBQDs@PLGA).方法 双乳化-冷冻干燥充气法制备双模式成像剂MBQDs@PLGA并评价其显像性能,激光共聚焦显微镜(CLSM)、透射电镜(TEM)技术检测量子点装载及MBQDs@PLGA荧光成像稳定性,荧光分光光度计线性回归法计算量子点的包封率.体外模型成像、在体小动物荧光成像及超声造影增强成像(荷瘤裸鼠)评价MBQDs@PLGA显像.结果 在激发波长272 nm MBQDs@PLGA成像剂荧光发射光谱峰值为549 nm,量子点在微球中的装载率约为54％,平均粒径为(1.7±0.2)μm.体内、外成像结果表明MBQDs@PLGA有超声造影增强显像和荧光成像功能.结论 量子点包埋在高分子微泡内制得MBQDs@PLGA呈显荧光-超声双模式成像性能,为多模式成像剂研发开辟思路.