Study Of Repairing Spinal Cord Injury Using Novel Pre-vascularized Nerve Tube

Objective:Study on the effect of repairing spinal cord injury(SCI)in rat using novel pre-vascularized cell sheets tube,aiming to provide better solution to SCI.Methods:1)Fabrication of novel pre-vascularized cell sheets tube:Rabbit bone marrow mesenchymal stem cells(MSCs)were isolated and cultured using whole bone marrow adherence method;MTT assay was performed to observe the cell growth curve;The multiple differentiation potential of MSCs was detected,including adipogenesis,osteogenesis and the ability of differentiation into neuron-like cells;After culturing MSCs of high density for 5 days,human umbilical vein endothelial cells(HUVECs)were seeded on the surface of MSCs,which were cultured for another 5 days to obtain pre-vascularized cell sheets;Pre-vascularized cell sheets tuber could be obtained by combing the pre-vascularized cell sheets with tubular scaffold and culturing them for 10 days;The characteristics of pre-vascularized cell sheets tuber were detected with HE staining,scanning electron microscopy(SEM)and CD31,Collagen I and Fibronectin immunofluorescence staining.2)Repairing SCI in rat using novel pre-vascularized cell sheets tube:SCI models were built in rats;Novel pre-vascularized cell sheets tubes were implanted in the SCI rat;BBB scores were graded each week after implantation;Spinal Cord specimens were obtained at the time point of 2,8 weeks after implantation,and they were detected by HE staining and CD31,Tuj-1,GFAP immunofluorescence staining.Results and Conclusion:1)Novel pre-vascularized cell sheets tube was fabricated successfully.The isolated MSCs had the potential of adipogenesis,osteogenesis and the ability of differentiation into neuron-like cells.Cell growth curve showed"S" type.Extracellular matrix of novel pre-vascularized cell sheets tube was rich in CD31,Collagen I and Fibronectin.Its surface was rough,and microvascular structures can be observed on it;2)The application of novel pre-vascularized cell sheets tube on SCI rat can get better functional and tissular repair effects.2 weeks after implantation,BBB score of novel pre-vascularized cell sheets tube group was obviously higher than that of blank group(P<0.05),4 weeks after implantation,BBB score of novel pre-vascularized cell sheets tube group was obviously higher than that of pure cell sheets tube group(P<0.05).Immunofluorescence showed that:2 weeks after implantation,the expression of Tuj-1 in novel pre-vascularized cell sheets tube group was slightly higher than the other two groups.8 weeks after implantation,the expression of Tuj-1 in novel pre-vascularized cell sheets tube group was obviously higher than the other two groups.The expression of GFAP in the blank group is higher than the other two groups.So the application of novel pre-vascularized cell sheets tube on SCI rat can promote functional and tissular repair.