[In vivo tracking of PKH26-labeled human umbilical cord mesenchymal stem cells after transplantation into rats with liver cirrhosis].

Objective: To observe the in vivo migration of human umbilical cord mesenchymal stem cells (hUCMSCs) labeled with the PKH26 red fluorescent dye after transplantation into rats with liver cirrhosis.
Methods: Frozen hUCMSCs were resuscitated and labeled with PKH26. Labeling efficiency and fluorescent maintenance time of the PKH26-1abeled cells were measured. Morphology of the labeled and unlabeled (control) cells was observed by microscopy. The cell growth curve was determined using the MTT method. The PKH26-1abeled hUCMSCs were transplanted via tail vein injection into healthy (control) rats and rats with liver cirrhosis. Migration of the PKH26-1abeled hUCMSCs observed 48 h later in frozen liver sections under a fluorescence microscope.
Results: The labeling ratio of PKH26 to hUCMSCs was 100%. Growth of the labeled cells was good. The cell morphology was not significantly different between the labeled and unlabeled cells; all cells were long and spindle-like. Cell proliferation was not impacted significantly by labeling.Fluorescence was maintained for at least 20 days, as detected by in vitro analysis. After transplantation into the rats, the PKH26-1abeled hUCMSCs were mainly distributed in the area surrounding the portal vein, the blood vessels, and the false lobule of the cirrhotic liver; a small amount ofhUCMSCs were present in the spleen and lung.
Conclusion: PKH26 is an ideal fluorescent dye to label hUCMSCs. The PKH26 labeling technique can be used to study the migration of hUCMSCs in cirrhotic liver.