Figure 1

Identification of MSC and MSC-Exo. (A) Immunophenotypes of the cultured hMSCs were examined by flow cytometry. The vast majority of cells (>90%) were positive for CD29, CD90, but few cells (<0.5%) expressed CD34, CD45. (B) The hMSCs were maintained in specific induction media for 3 weeks, and the induced cells were then stained by oil red O to indicate adipocytes (B1), von Kossa for osteocytes (B2). For endothelial cell identification, the cells were firstly incubated with antibodies against vWF (B3), and then stained by secondary antibodies conjugated with Alexa Flour 647. (C) Micrographs of scanning electron microscopy of (C1) MSC-Exo and (C2) Fib-Exo show spheroid shaped vesicles at the diameter of about 40-100 nm. Scale bar = 200 nm. (D) Western blot analysis showed that both MSC-Exo and Fib-Exo express CD63, CD9 and CD81.