Figure 2: Sites of accumulation of huMSCs in vivo in TBI rats. (A) Live imaging of the primary organs of experimental rats. (B, C) The average fluorescence intensity in the brain, liver and lung in the In Situ (B) and Tail Vein (C) groups. Data are expressed as the mean ± SD (n = 5 rats at each time point). #P < 0.05, ##P < 0.01, vs. TBI group (one-way analysis of variance followed by least significant difference test). (D, E) CD29 (red, stained by CoraLite594) immunoreactivity in CFSE-labeled huMSCs in brain tissue (immunofluorescence staining, original magnification 200×, scale bars: 100 μm). CD29 and CFSE co-labeled huMSCs were identified in the In Situ group on days 1, 3 and 7 (D) in the brain lesions. A few CFSE-labeled huMSCs in the Tail Vein group were also observed in the brain lesions on days 1 and 3 (E). CFSE: Carboxyfluorescein succinimidyl ester; CON: TBI group; DAPI: 4′,6-diamidine-2′-phenylindole dihydrochloride; huMSCs: human umbilical cord mesenchymal stem cells; TBI: traumatic brain injury.