基于亚甲基蓝二氧化硅纳米颗粒的细胞与活体成像

采用反相微乳液法,制备了以亚甲基蓝为内核材料的亚甲基蓝二氧化硅纳米颗粒,通过优化亚甲基蓝的包裹浓度获得荧光信号较强的纳米颗粒,并初步考察了其用于He-la细胞标记与体内示踪的可行性.通过MTT实验考察了颗粒对细胞的毒性影响以及较为适宜的标记细胞的浓度,结果表明:当颗粒浓度为1mg/mL时,细胞的存活率仍有80%左右.利用激光共聚焦显微镜考察了Hela细胞对颗粒的吞噬情况以及颗粒在细胞内的分布情况,结果表明,该颗粒能被Hela细胞吞噬且主要分布在溶酶体内.活体荧光成像结果显示,尾静脉注射该颗粒后,裸鼠全身都发射出近红外荧光信号,随着血液的循环,颗粒慢慢聚集在肝脏等器官中.以上结果表明,包裹亚甲基蓝的二氧化硅纳米颗粒可以用于细胞的标记和体内示踪成像.

Methylene Blue Doped Silica Nanoparticles for Cell Labeling and in Vivo Fluorescence Imaging

Methylene blue (MB) doped silica nanoparticles (MB-SiNPs) were synthesized in the water-in-oil microemulsion. By optimizing the concentration of MB doped in the silica matrix, the near-infrared fluorescent MB-SiNPs with strong fluorescence were obtained. Then, the feasibility of MB-SiNPs for cell labeling and tracking in vivo was studied. The cell viability assay of Hela cells in the presence of MB-SiNPs was performed by using MTT assay, and the result indicated that, as the concentration of MB-SiNPs was 1 mg/mL in medium, the cell survival percentage was 80%. The distribution of MB-SiNPs in Hela cells was assessed by laser scanning confocal microscopy, and the result showed that MB-SiNPs entered cells easily and mainly located in lysosomes. In vivo fluorescence imaging of MB-SiNPs after tail vein intravenous injection showed that the whole body of the mice emitted NIR fluorescence and most of the MB-SiNPs were accumulated in some organs, such as liver and spleen. All the results demonstrated that MB-SiNPs could be used for cell labeling and in vivo imaging.