Protective effects of umbilical cord mesenchymal stem cell exosomes in a diabetic rat model through live retinal imaging

AIM:To assess the protective effect of human umbilical cord mesenchymal stem cell exosomes(hucMSC-Exs)in a diabetic rat model by using a variety of retinal bioassays.METHODS:hucMSCs were subjected to differential ultracentrifugation for the collection of exosomes,and transmission electron microscopy(TEM),nanoparticle tracking analysis(NTA)using a NanoSight analysis system and Western blotting(WB)were used to analyze the expression of surface marker proteins such as CD63,CD9 and Calnexin.Streptozotocin(STZ)was injected into the intraperitoneal cavity to establish a diabetic model.Rats were divided into a normal group,diabetic group and hucMSC-Ex group.Fundus fluorescein angiography(FFA),optical coherence tomography(OCT)and other live imaging methods were used to observe the fundus of the rats.Finally,the eyeballs of rats from each group were collected for hematoxylin-eosin(HE)staining to further analyze the retinal structure.RESULTS:Through TEM,NTA and WB,we successfully isolated hucMSC-Exs.Subsequent FFA and OCT confirmed that hucMSC-Exs effectively prevented early retinal vascular damage and thickening of the retina.Finally,HE staining of rat retinal sections revealed that exosomes effectively alleviated retinal structure disruption caused by diabetes.CONCLUSION:hucMSC-Exs have a protective effect on the retina in diabetic rat through FFA,OCT and HE staining.