Fig. 8
In vivo MR imaging (a) and fluorescence imaging (b) of nude mouse after subcutaneous injection of labeled and unlabeled human mesenchymal stem cells with MNP@SiO2(RITC)-PEG (1 = 1 × 105 unlabeled human mesenchymal stem cells for control, 2 = 1 × 106 labeled human mesenchymal stem cells, 3 = 1 × 105 labeled human mesenchymal stem cells). Labeled human mesenchymal stem cells are clearly seen as dark dot (arrow) in subcutaneous layer of nude mouse on axial scan of fast spin echo sequence. Fluorescent signal of subcutaneously injected human mesenchymal stem cells is detected at injection sites of labeled cells. Injection sites of unlabeled cells shows autofluorescence-induced artifact [69]