Objective To observe the survival of human umbilical cord derived mesenchymal stem cells (hUC-MSCs) after injection into the vitreous of rabbits,and the animal safety under those procedures.Methods Twentyseven pigmented rabbits were randomly divided into 3 groups (intravitreal injection 1 week group，2 weeks group and 4 weeks group)， each with 9 rabbits.For each animal the right eye was the experimental eye receiving hUCMSCs injection,while the left eye was the control eye receiving culture medium. The rabbit eyes were examined by slitlamp microscope, indirect ophthalmoscopy, fundus photography, fundus fluorescence angiography（FFA）and Tonopen tonometer before and after injection. hUCMSCs were labeled by CMDil in vitro, and their survival status was measured by confocal fluorescence microscopy, light microscope and transmission electron microscope at 4 weeks after injection. Results Four weeks after injection, a large number of the hUCMSCs were still alive in the vitreous cavity. The overall condition of those rabbits was good. The anterior segment and retina of experimental eyes were normal, without hyperfluorescence, hypofluorescence and leakage in the retina at 1,2 and 4 weeks after injection. There was no significant difference on IOP before and after injection at different time points (P＞0.05), and no obvious changes at cornea, anterior chamber angle,lens,retinal structure by.light microscope and transmission electron microscope examination.Conclusion hUC-MSCs can survive in the rabbit vitreous for four weeks；intravitreal injection of hUCMSCs was safe and feasible.
ObjectiveTo observe the protective effect of human umbilical cord blood stem cells (hUCBSC) transplantation on retinal ganglion cells (RGC) after optic nerve injury. Method48 adult Sprague-Dawley rats were randomly divided into group A and B, therefore 24 rats in each group. Calibrated optic nerve crush injury model was induced in the left eyes, the right eyes served as a control. Medicine was injected at seventh day after optic nerve injury. PBS was injected into the eyes of Group A rats by peribulbar injection. The hUCBSCs were injected into the eyes of Group B rats by peribulbar injection. Seven days before sacrifice, 5% fluorogold was injected into superior colliculi bilaterally. At 7, 14, 21, 28 days after labeled, retinal flat mounts were observed under fluorescence microscope and optical microscope to investigate the morphological and RGC changes in density during retinal degeneration. ResultsThe RGC number showed a tendency to decline gradually along with increases of the time in two groups, but the trend of decrease of Group B was evidently slower than that of Group A. The RGC number of the injury eye were less than the control eye in Group A and B (t=3.24, 3.15; P < 0.05). At 7, 14, 21, 28 days after labeled, the RGC number (t=4.78, 4.70, 3.98, 3.27; P < 0.05) and labeled RGC rate (t=4.39, 4.21, 4.36, 5.07; P < 0.05) in group B were more than those in group A. After optic nerve injury, there was karyopycnosis on ganglion cell layer of retina, thinning on each layer of retina, derangement of cell and decrease in RGC. There was different degree of the above change in different time after optic nerve injury. There were the swelling, the hemorrhage, derangement of spongiocyte and the denaturation like vacuole in the spot of optic nerve injury. Moreover, they were aggravating with increases of the time after optic nerve injury. There was no pathological changes in normal eyes. ConclusionThe hUCBSC can increase the survival rate of the RGC and can rescue and(or) restore the injujed RGC after transplanted into body of optic nerve crush rat model by peribulbar injection.