Extracellular vesicles derived from mesenchymal stem cells mediate extracellular matrix remodeling in osteoarthritis through the transport of microRNA-29a

Figure 1 Morphological observation of bone marrow-derived mesenchymal stem cells and identification of bone marrow-derived mesenchymal stem cells-exosomes. A: The bone marrow-derived mesenchymal stem cells (BMSCs) had a homogeneous spindle morphology; B: The BMSC-exosomes (Exos) were approximately 60–160 nm in diameter and had a sub-circular, typical teatoid appearance; C: The nanoparticle tracking analysis results showed that the concentration of BMSC-Exos was 3.43 × 10⁹/mL and their average particle size was 131.9 nm; D: The results of the western blotting assays showed that the expression of CD9, heat shock protein 70, and tumor necrosis factor-alpha-stimulated gene 101 was positive. Exo: Exosomes; HSP: Heat shock protein; TSG: Tumor necrosis factor-alpha-stimulated gene.