Fig. 8.

In vivo retention and distribution of exosomes after local and systemic injection. a Nude mice with bone defects on right distal femurs were created. (i) For exosomes retention, Cy5.5 labelled exosomes were treated by local injection on both sides, and the retention of exosomes was imaged by IVIS Imaging System at 6, 24 and 48 h. (ii) For exosome distribution, Cy5.5 labelled exosomes were treated by intravenously injected through the tail vein, and distribution of exosomes in different organs was imaged at 48 h. b, c The retention of exosomes was imaged after local injection and performed quantitative analysis of fluorescent intensities at injection sites, n = 3. d, e Femurs and tibias of both sides in MSC-BMP2-Exo and MSC-Exo groups were excised at 48 h after exosome injection visualized by biofluorescence imaging, and performed quantitative analysis of fluorescent intensities at injection sites, n = 3. f, g Biodistribution of Cy5.5 labelled MSC-BMP2-Exo in major organs (heart, liver, spleen, lung, kidney, and femur) was visualized at 48 h after intravenously injection, and performed quantitative analysis of fluorescent intensities, n = 3. Bone defect was made on right distal femurs, and mice without bone defect was compared. *p < 0.05, **p < 0.01, ***p < 0.001