Distribution of hUCMSCs in Balb/c nude mice

Objective To study the distribution of hUCMSCs in Balb/c nude mice. Methods DiR was employed to label hUCMSCs. The growth of labeled hUCMSCs in vitro was evaluated by MTT method. The phenotype of labeled hUCMSCs was evaluated by flow cytometer. The osteogenesis, adipogenesis and chondrogenesis capabilities were tested by differentiation induction. The distribution of labeled hUCMSCs was observed by living imaging. LSD t-test was employed to analysis the difference of proliferations between DiR-labeled and non-labeled hUCMSCs. Results The absorbance has no difference between DiR-labeled and non-labeled hUCMSCs determined by MTT method in 0, 24, 48, 72, 96 and 120 hours. DiR labeling has no effect on growth, phenotype, osteogenesis, adipogenesis or chondrogenesis capability of hUCMSCs. The fluorescence was observed in lung rapidly after intravenous injection of hUCMSCs labeled by DiR. And then, the fluorescence shifted to liver and spleen from lung. Finally, the fluorescence was seen in liver, spleen and lung. The fluorescence density decreased slowly, but still exited in liver, spleen and lung at 4 weeks. Conclusion DiR labeling has no effect on growth, phenotype, osteogenesis, adipogenesis or chondrogenesis capability of hUCMSCs. The fluorescence was seen in lung immediately after injection of hUCMSCs labeled by DiR, then in liver and spleen, mainly in liver, spleen and lung, the first pass effect was observed. Key words: Mesenchymal stem cells; Distribution; Home; Living imaging