FIG. 4.

In vivo survival and biodistribution of MSCs. (A) DiR-labeled AdIGF-I-MSCs were systemically administered and monitored from 1 to 14 days later by fluorescence imaging (FI). At different survival times, tissues were removed and lungs, liver, and spleen were exposed to FI. Images represent the radiant efficiency. (B) Regions of interest calculated for the isolated liver, spleen, and lung and results were expressed as total radiant efficiency ([p/s]/[μW/cm²]). Note that MSC-derived signals were more abundantly found in the liver and peak at 1 day after cellular application and decrease thereafter. Animals with liver fibrosis receiving vehicle instead of MSCs showed no significant signals at 4 days after this treatment. *P<0.05; ^σσP<0.01; ^σσσσP<0.0001; * versus lung; ^σ versus spleen. (C) IGF-I protein levels in liver samples as measured by enzyme-linked immunosorbent assay (D) Representative images from green fluorescent protein (GFP)-immunostained sections at 1, 4, and 8 days after AdGFP-MSCs application or at 1 day after vehicle administration, as control. *^σP<0.05; **^σσP<0.01; ***^σσσP<0.001; * versus saline; ^σ versus AdGFP-MSCs. Scale bars: 50 μm.