Fig. 7

PEDF-sEVs effectively reduced PEDF degradation both in vitro and in vivo. A DiD-labelled sEVs and FITC-labelled PEDF were used to detect the distribution of PEDF and sEVs, respectively. PEDF-sEVs and a mixture of PEDF and sEVs without sonication were added to HRECs in culture. Representative confocal images show the cellular uptake of PEDF and sEVs in HRECs after 24 and 48 h; scale bar = 50 μm. B FITC fluorescence intensity in HRECs was measured by integrated density using the ImageJ software (n = 6/group). C PEDF-sEVs and a mixture were added to HRECs in culture. After 24 and 48 h, cells were collected for flow cytometry to analyse the cellular uptake efficiency of PEDF. D PEDF and PEDF-sEVs were added to HRECs in culture. After 6, 24, 48, and 72 h, the concentrations of PEDF in supernatants were measured using ELISA (n = 3/group). E Ocular distribution of PEDF and PEDF-sEVs in cryosections of OIR retinas on P13 and P17 after intravitreal injection on P12; scale bar = 50 μm. F FITC fluorescence intensity in cryosections of retinas was measured by integrated density using the ImageJ software (n = 6 mice/group; 3 sections per mouse, and at least 3 images per section were analysed and the values were averaged). The data are represented as mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. RGC: Retinal ganglion cell; IPL: inner plexiform layer; INL: inner nuclear layer; OPL: outer plexiform layer; ONL: outer nuclear layer; RPE: retinal pigment epithelium