Fig. 7
A Schematic diagram of the plasmid constructs containing Lamp2b, CAP-EGFP-Lamp2b and CAP-Lamp2b, and the engineering exosomes derived from MSCsSC. B Transmission electron microscopy (TEM) analysis for the morphology of CAP-MSCsSC-Exos (Scale bar: 100 nm). C Nanoparticle tracking analysis (NTA) for measuring the size distribution and concentration of CAP-MSCsSC-Exos. D Western blot analysis of protein markers CD9, CD81, Alix, Tsg101, and Calnexin in whole cell lysates (WCLs) and purified exosomes including CAP-MSCsSC-Exos and MSCsSC-Exos. E Schematic illustration of rat chondrocytes and synovial cells co-culture assays. F Efficient delivery of miR-199a-3p into chondrocytes by CAP-EGFP-MSCsSC-Exos. Scale bar: 10 μm. G Specific delivery to chondrocytes instead of synovial cells by CAP-EGFP-MSCsSC-Exos. Scale bar: 10 μm. H The relative expression of miR-199a-3p in chondrocytes treated with different MSCsSC-Exos delivery systems was detected by RT-PCR. I The immunofluorescence analysis of COL2A1 and MMP-13 in chondrocytes of OA model treated with different MSCsSC-Exos delivery systems. n = 6 for each group. Scale bar: 10 μm. J Rat chondrocytes were infected with RFP-GFP-LC3 adenovirus and effects of different MSCsSC-Exos delivery systems on RFP-GFP- LC3 puncta. The numbers of RFP- and GFP-LC3 dots per cell were counted. n = 6 for each group. Scale bar: 10 μm. K Protein level of mTOR in chondrocytes of OA model treated with different MSCsSC-Exos delivery systems was examined by western blotting. * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.001, ns not significant