Fig. 3

The ability of EVs^−cl−NGF to target sites of inflammation and release NGF. A NGF fluorescence imaging in the injured spinal cord of different group mice after NGF, EVs^−cl−NGF and RVs^−cl−NGF injected by tail vein respectively, in different time points. B Fluorescence quantitative analysis of NGF inside injured spinal cord in different group mice at different time points. C The fluorescence imaging of the vital organs (heart, liver, spleen, lung and kidney) and spinal cord from different groups of mice at 12 h after tail vein injection. D Fluorescence quantitative analysis of spinal cord and kidney in different groups. E The concentration of NGF in plasma after injection of free NGF and EVs^−cl−NGF at different times. F, K Schematic diagram of the coculture and the uptake of primary macrophages and PC12 cells in different groups. G CLSM images of NGF uptake in PC12 cells cultivated at the upper level of the Transwell™ coculture system. H Flow cytometry analysis of NGF uptake by PC12 cells cultivated at the upper level of the Transwell™ coculture system. I Fluorescence quantitative statistical analysis of Figure G. J Fluorescence quantitative statistical analysis of Figure H. L CLSM images of NGF uptake in primary M1 macrophages cultivated at the lower level of the Transwell™ coculture system. M Flow cytometry analysis of the uptake of NGF by primary M1 macrophages cultivated at the lower level of the Transwell™ coculture system. N Fluorescence quantitative statistical analysis of Figure L. O Fluorescence quantitative statistical analysis of Figure M. Data presented the mean ± SD (n = 6 per group) (*P < 0.05, **P < 0.01, ***P < 0.001 and ns: not significant)