靶向荧光二氧化硅纳米粒子检测模型循环肿瘤细胞的实验研究

Targeted Fluorescent Silica Nanoparticles in Detection of Model Circulating Tumor Cells: An Experimental Study

目的制备靶向标记的Cy5.5掺杂的二氧化硅纳米粒子,并研究其用于检测模型循环肿瘤细胞的可行性。材料与方法通过反相微乳液法及碳二亚胺法制备靶向上皮细胞黏附分子(EpCAM)的荧光二氧化硅纳米粒子,检测其结构形态、平均粒径、zeta电位、化学结构等基本理化性质;采用激光共聚焦显微镜及流式细胞术检测其对模型循环肿瘤细胞(CTC)系(乳腺癌MCF-7细胞)特异靶向能力。结果成功制备了靶向标记的Cy5.5掺杂的二氧化硅纳米粒子,呈单分散粒径相对均一的球形形态,平均粒径为(128.52±4.10)nm,平均zeta电位为(-27.51±3.81)mV;紫外/可见光光谱及荧光光谱结果显示荧光染料Cy5.5掺杂入二氧化硅后并未改变其荧光性质;傅里叶红外光谱结果表明PEG成功修饰于荧光二氧化硅表面;激光共聚焦显微镜及流式细胞术提示制备的靶向荧光二氧化硅纳米粒子能特异地与模型循环肿瘤细胞结合。结论制备的靶向荧光二氧化硅纳米粒子具有良好的理化性质及特异靶向乳腺癌MCF-7细胞的能力,在检测CTC细胞群或具有低标记物表达的细胞等方面显示出极好的潜力。

Purpose To prepare targeted Cy5.5-doped silica nanoparticles(NPs),and to study its feasibility for detecting model circulating tumor cells.Materials and Methods Fluorescent silica NPs for targeting epithelial cell adhesion molecules(EpCAM)were prepared by the reverse microemulsion method and carbodiimide method.The physicochemical properties such as morphology,average particle size,zeta potential and chemical structure were detected.The ability to specifically target the model circulating tumor cell(CTC)line(breast cancer MCF-7 cells)was detected by laser confocal microscopy and flow cytometry.Results The targeted Cy5.5-doped silica NPs were successfully prepared and showed the spherical morphology of a relative uniform monodisperse particle size,with the mean particle size of(128.52±4.10)nm and the mean zeta potential of(-27.51±3.81)mV.The UV/visible spectroscopy and fluorescence spectroscopy showed that the fluorescent dye Cy5.5 doped with silica did not change its fluorescence properties.Fourier infrared spectroscopy displayed that PEG was successfully modified on the surface of fluorescent silica.Laser confocal microscopy and flow cytometry prompted that the prepared targeted fluorescent silica NPs can specifically bind to model circulating tumor cells.Conclusion The prepared fluorescent silica NPs have good physicochemical properties and ability to specifically target the breast cancer MCF-7 cells,showing excellent potential in detection of CTC cell masses or cells with low marker expression.