Theranostics 2017; 7(7):1820-1834. doi:10.7150/thno.18614

Research Paper

Bright Polymer Dots Tracking Stem Cell Engraftment and Migration to Injured Mouse Liver

Dandan Chen1, Qiong Li1, Zihui Meng2, Lei Guo2, Ying Tang1, Zhihe Liu1, Shengyan Yin1, Weiping Qin1, Zhen Yuan3, Xuanjun Zhang3, Changfeng Wu1✉

1. State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun, Jilin 130012, China;
2. Department of Hepatobiliary-Pancreatic Surgery, China-Japan Union Hospital, Jilin University, Changchun, Jilin 130033, China;
3. Faculty of Health Science, University of Macau, Taipa, Macau SAR China.


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.

Keywords: semiconductor polymer dot, near-infrared fluorescence, stem cells, cell tracking, in vivo imaging.

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) license ( See for full terms and conditions.
How to cite this article:
Chen D, Li Q, Meng Z, Guo L, Tang Y, Liu Z, Yin S, Qin W, Yuan Z, Zhang X, Wu C. Bright Polymer Dots Tracking Stem Cell Engraftment and Migration to Injured Mouse Liver. Theranostics 2017; 7(7):1820-1834. doi:10.7150/thno.18614. Available from