Fig. 1

NP cells and NPc-exo isolation and characterization. (A) Representative magnetic resonance images (MRI) of idiopathic scoliosis and degenerated IVD. (B) Representative confocal images for F4/80 (green) and iNOS (M1 macrophage marker) (red). The nucleus was counterstained with DAPI (blue). (C) Quantitative analysis showed the number of iNOS positive cells were significantly increased in IVDD group. (D) Expression of Aggrecan and Col2A1 was shown in the two groups by immunohistochemistry. (E) Quantitative analysis showed that the expression of Aggrecan and Col2A1 were significantly decreased in IVDD group. (F) Representative images of the percentage of CD86 (M1 macrophage marker) positive cells in NP tissues from different IVD grade groups detected by flow cytometry analysis. (G) Schematic illustration of NPc-exo isolation using differential centrifugation. (H) Typical image of NPc-exo was captured by transmission electron microscopy (TEM). Scale bar = 200 nm. (I) Particle size distribution of NPc-exo was examined by nanoparticle trafficking analysis (NTA). (J) Western blot analysis of CD9, CD63 and TSG101 markers. (K) The M0 macrophages were incubated with PKH26-labeled dNPc-exo and observed. The red fluorescence proved cellular internalization of dNPc-exo into M0 macrophages. Scale bar = 10 μm. The data are expressed as the mean ± SEM. n = 3. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001