Recently, many studies on the three-dimensional (3D) fabrication of cells have been performed. Under these circumstances, it is indispensable to develop the imaging technologies and methodologies for noninvasive visualization of 3D cells fabricated. The objective of this study is to develop the labeling method of human induced pluripotent stem (iPS) cells-derived 3D cartilage tissue with gelatin nanospheres coincorporating three kinds of quantum dots (QD) and iron oxide nanoparticles (IONP) (GNS_QD+IONP). In this study, two labeling methods were performed. One is that a cartilage tissue was labeled directly by incubating with octaarginine (R8)-treated GNS_QD+IONP (direct labeling method). The other one is a “dissociation and labeling method.” First, the cartilage tissue was dissociated to cells in a single dispersed state. Then, the cells were incubated with R8-GNS_QD+IONP in a monolayer culture. Finally, the cells labeled were fabricated to 3D pellets or cell sheets. By the direct labeling method, only cells residing in the surrounding site of cartilage tissue were labeled. On the contrary, the 3D cartilage pellets and the cell sheets were homogenously labeled and maintained fluorescently visualized over 4 weeks. In addition, the cartilage properties were histologically detected even after the process of dissociation and labeling. Homogenous labeling and visualization of human iPS cells-derived 3D cartilage tissue was achieved by the dissociation and labeling method with GNS_QD+IONP.

中文翻译：

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明胶纳米球对人诱导的多能干细胞衍生的三维软骨组织的可视化。

近来，已经进行了关于电池的三维（3D）制造的许多研究。在这些情况下，必不可少的是开发用于非侵入式可视化制作的3D细胞的成像技术和方法。本研究的目的是开发明胶纳米球与人类诱导的多能干细胞（iPS）衍生的3D软骨组织的标记方法，明胶纳米球包含三种量子点（QD）和氧化铁纳米颗粒（IONP）（GNS _{QD + IONP}） 。在这项研究中，执行了两种标记方法。一种是通过与八精氨酸（R8）处理的GNS _{QD + IONP}一起孵育直接标记软骨组织（直接标记方法）。另一种是“解离和标记方法”。首先，将软骨组织以单一分散状态解离成细胞。然后，将细胞与R8-GNS _{QD + IONP}一起孵育在单层文化中。最后，将标记的细胞制成3D颗粒或细胞片。通过直接标记方法，仅标记位于软骨组织周围部位的细胞。相反，将3D软骨沉淀和细胞片同质标记并在4周内保持荧光可见。另外，即使在解离和标记过程之后，仍通过组织学检测软骨性质。通过GNS _{QD + IONP}的解离和标记方法，实现了人iPS细胞衍生的3D软骨组织的均匀标记和可视化。