Chen Dandan, Li Qiong, Meng Zihui, Guo Lei, Tang Ying, Liu Zhihe, Yin Shengyan, Qin Weiping, Yuan Zhen, Zhang Xuanjun, Wu Changfeng
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, Jilin 130012, China.
Department of Hepatobiliary-Pancreatic Surgery, China-Japan Union Hospital, Jilin University, Changchun, Jilin 130033, China.
Theranostics. 2017 Apr 10;7(7):1820-1834. doi: 10.7150/thno.18614. eCollection 2017.
Stem cell therapy holds promise for treatment of intractable diseases and injured organs. For clinical translation, it is pivotal to understand the homing, engraftment, and differentiation processes of stem cells in a living body. Here we report near-infrared (NIR) fluorescent semiconductor polymer dots (Pdots) for bright labeling and tracking of human mesenchymal stem cells (MSCs). The Pdots exhibit narrow-band emission at 775 nm with a quantum yield of 22%, among the highest value for various NIR probes. The Pdots together with a cell penetrating peptide are able to track stem cells over two weeks without disturbing their multipotent properties, as confirmed by the analyses on cell proliferation, differentiation, stem-cell markers, and immunophenotyping. The in vivo cell tracking was demonstrated in a liver-resection mouse model, which indicated that the Pdot-labeled MSCs after tail-vein transplantation were initially trapped in lung, gradually migrated to the injured liver, and then proliferated into cell clusters. Liver-function analysis and histological examination revealed that the inflammation induced by liver resection was apparently decreased after stem cell transplantation. With the bright labeling, superior biocompatibility, and long-term tracking performance, the Pdot probes are promising for stem cell research and regenerative medicine.
干细胞疗法为治疗疑难疾病和受损器官带来了希望。对于临床转化而言，了解干细胞在活体中的归巢、植入和分化过程至关重要。在此，我们报告了用于对人间充质干细胞（MSC）进行明亮标记和追踪的近红外（NIR）荧光半导体聚合物点（Pdot）。这些Pdot在775nm处呈现窄带发射，量子产率为22%，在各种近红外探针中处于最高值之列。Pdot与细胞穿透肽一起能够在两周多的时间里追踪干细胞，且不会干扰其多能特性，这一点已通过对细胞增殖、分化、干细胞标志物和免疫表型分析得到证实。在肝切除小鼠模型中展示了体内细胞追踪情况，结果表明尾静脉移植后用Pdot标记的MSC最初被困在肺部，随后逐渐迁移至受损肝脏，然后增殖形成细胞簇。肝功能分析和组织学检查显示，干细胞移植后肝切除所诱导的炎症明显减轻。凭借明亮的标记、卓越的生物相容性和长期追踪性能，Pdot探针在干细胞研究和再生医学方面具有广阔前景。
