The Preparation And Comparison Of Decellularized Nerve Scaffold Of Tissue Engineering

Spinal cord injury(SCI) is a serious nervous system injury. As the nerve cells do not have renewable, it is difficult to restore nerve damage as the normal connecting structure. Proliferation of glial cells leads to the formation of glial scar, which blocks nerve cells regeneration processes through the damage area. The functional recovery after spinal cord injury is extremely limited, which has become serious problem in treatment of spinal cord injury. There are many kinds of treatments aimed at spinal cord injury, such as drug, exercise therapy, cell transplantation, cytokine therapy, gene therapy, and so on. With the development of research in recent years, tissue engineering for spinal cord injury becomes a hot topic. Due to spontaneous axons and myelin sheath after spinal cord injury is extremely limited, tissue engineering transplant therapy can not only provide seed cells for the axon regeneration, but also can provide a good living environment for seed cells function reconstruction.Tissue engineering is first formally proposed and determined by the U.S. National Science Foundation. It is a science that applied the principle of cell biology, biological materials and engineering, research and development to repair or improve the human damage to the structure and function of tissues or organs of the biological activity. The basic strategy of tissue engineering is to build a biologically active implants implanted in the body to replace or repair of spinal cord injury. Due to the deficiencies of the ability to penetrate nerve regeneration, nerve regeneration will stop once the the growth of the body encounter, and mesenchymal cells will fill the defect space, hindering both ends of the nerve injury docking after nerve disconnected. Scaffold as a bridge body can establish contact with spinal cord injury which supply to provide direction and guidance tube suitable micro-environment for nerve fiber regeneration and spinal cord injury recovery. The choice of scaffold materials for tissue engineering in treatment of spinal cord injury has been a key element. It becomes the research focus of scholars in recent years, however the research is still controversial.To integrate tissue engineering concepts into strategies to repair spinal cord injury (SCI) has been a hotspot in recent years. The choice of scaffolding material is crucial to tissue engineering. Recently, decellularized nerve scaffold becomes a central concern due to its peculiar superiority. In this study, the decellularized nerve scaffold was prepared with three different methods and a comparison was made to acquire an ideal scaffold materials. All sciatic nerves fromSprague-Dawley (SD) rats were randomly divided into four groups:A:normal control group, B:TritonX-100 with sodium deoxycholate group, C:TritonX-100 with enzyme group and D:freezing-thawing with enzyme group. Histology and transmission electron microscope were exploited to evaluate the effect of removing cells and immunological histological chemistry was exploited to evaluate immunogenicity. Meanwhile the mechanical properties were evaluated by mechanics index. Hematoxylin and eosin (HE) staining and electron microscopic examinations reveal that the cell components and myelin sheaths are the least in the freezing-thawing with enzyme group. Immunohistochemistry shows that the immunogenicity is lower in group B, C, and D than the control group, and the group D has the lowest immunogenicity. Mechanical testing shows that there is no significant difference after acellular processing. Sciatic nerve, cellextracted by freezing-thawing with enzyme, could obtain the ideal scaffold materials which has no cells and myelin sheaths. In addition, the decellularized nerve scaffold has no immunogenicity and the mechanical property of normal sciatic nerve is preserved.