Education and Research Institute of Nanostructures and Biosystems, Saratov National Research State University, Saratov 410012, Russia.
Department of Molecular Biotechnology, Ghent University, Gent B-9000, Belgium.
Biotechnol J. 2018 Nov;13(11):e1800071. doi: 10.1002/biot.201800071. Epub 2018 Jul 10.
Porous calcium carbonate (CaCO ) vaterite particles are very attractive templates for the encapsulation of pharmaceuticals and for the construction of hollow polyelectrolyte capsules, sensors, and enzyme-catalyzed reactors. Although CaCO is biocompatible and biodegradable, little is known about the intercellular behavior and properties of vaterite particles in the cytoplasm of cells. In this work, the authors combine confocal Raman and fluorescent microscopy for the imaging of porous CaCO vaterite particles in HeLa cells to study the uptake and status of the particles inside the cells in real time. Analysis of the fluorescence images shows that the particles penetrated the plasma membrane 3 h after being added to the cell culture and that the internalization of the particles continued up to 48 h. The crystal structure of individual vaterite particles in the cytoplasm of HeLa cells did not obviously change for 144 h. For clusters of particles, however, the authors identify Raman spectroscopic signatures of the stable calcite phase after 72 h of incubation, confirming an ion-exchange mechanism of vaterite transformation to calcite. The results indicate that these imaging approach to examining inorganic particles in living cells may have theranostic applications.
多孔碳酸钙（CaCO 3 ）文石颗粒是封装药物和构建中空聚电解质胶囊、传感器和酶催化反应器的非常有吸引力的模板。尽管 CaCO 3 具有生物相容性和可生物降解性，但对于其在细胞细胞质中文石颗粒的细胞内行为和特性知之甚少。在这项工作中，作者结合共聚焦拉曼和荧光显微镜，实时研究 HeLa 细胞中多孔 CaCO 3 文石颗粒的摄取和状态。荧光图像分析表明，颗粒在添加到细胞培养物 3 小时后穿透质膜，并且颗粒的内化持续到 48 小时。HeLa 细胞质中单个文石颗粒的晶体结构在 144 小时内没有明显变化。然而，对于颗粒簇，作者在孵育 72 小时后鉴定出稳定方解石相的拉曼光谱特征，证实了文石向方解石转化的离子交换机制。研究结果表明，这种用于检查活细胞中无机颗粒的成像方法可能具有治疗应用。
