Repairation Of Rat Sciatic Nerve Defect With Silk Microchannel Artificial Nerve

Peripheral nerve defect is a common disease in reconstructive surgery. For the repair of nerve rupture, surgical suture can be directly performed. For the repair of nerve defect with long distance, it is necessary to bridge the nerve graft between the end of the broken end ". At present, autologous nerve transplantation can achieve the best effect of repair, but the donor nerve source is limited and will lead to donor site morbidity, and its clinical application by limited; nerve allograft in addition to the above problem is still faced with immune response. Therefore, by autologous and allogeneic nerve graft in repair of peripheral nerve defects, in clinical application are subject to varying degrees of restrictions. Therefore, it is a way to solve this problem to repair the peripheral nerve defect with tissue engineering method.At present, artificial neural generally has two basic forms, i.e., hollow into the neural tube of tubular structure(nerve conduits) and internal has filled the nerve scaffold(nerve scaffold), people design nerve conduit’s original intention is to provide a relatively closed micro environment for axonal regeneration. The purpose of the use of the nerve scaffold may be to allow the filler to play a guiding role in axonal regeneration. For the structure of the nerve conduit, the main academic point of view, the need for a certain number of nerve tube wall in the design of the pore, in order to facilitate the process of nerve regeneration in the material exchange. At the same time, there is also a point of view that these pores will have a negative effect on the regeneration of axons. In the current study, the filler used in the nerve scaffold, from the morphological point of view, is mostly disordered. There is also a study of the preset micro channel within the nerve scaffold, but the number of these micro channels is no more than 30, with a diameter of 70-300 μm. The micro channel in terms of the number and the diameter of the set has certain blindness, because, if these microchannels is prepared as a branch of the sciatic nerve, then the number should in three or so, if it is for a single axon growth reserved, then the number of micro channel should the not less than 5000, because according to this topic in the observation group, transverse section of rat sciatic nerve axon number in the 5000 or so.Based on the above reasons, we designed 2 kinds of nerve conduits, that is, the tube wall with and without pores. In the nerve scaffold used in this experiment, we have designed not about 5000 micro channels. The main purpose of the study is to investigate whether the pore is necessary in the wall of the nerve conduit, and whether a large number of micro channels are beneficial to the regeneration of the axon.Silk is the main material used in this study. In this paper, the structure, in vivo and in vitro degradation of silk were also studied.The rat sciatic nerve defect of 10 mm in length was as animal model, respectively, were five kinds of neural transplantation program, i.e., the control group is(Autograft group),(Microchannl+Silk)group,(Microchannl+PLA+Silk) group,(Silk) group and(PLA+Silk)group. After transplantation, behavioral testing was performed at a series of time points.After the transplantation of neural, behavioral detection results show that nociceptive response and the static sciatic index(SSI), the microchannel tube wall without holes the repair effect of autologous nerve transplantation similar and significantly better than the rest of the three groups.Gastrocnemius muscle wet weight analysis showed that in the1,2,3,4 weeks after nerve transplantation, there were different degrees of atrophy in the gastrocnemius muscle of the experimental side of each group. Among them, the degree of atrophy of the autologous transplantation group was the least, and the shrinkage of the micro channel wall was slightly less than that of the other 3 groups. At 20 weeks after the transplantation, found that autologous transplantation group gastrocnemius muscle wet weight rate for 83.16% in the gastrocnemius wet weight rate recovery was the best, and autologous transplantation group compared,(Microchannl+PLA+Silk)group is better than(Microchannl+Silk)group is better than(PLA+Silk)group was better than(Silk) group.The results showed that the degradation of silk in vitro was the essence of the hydrolysis, and the effect of the enzyme was not significant. The degradation of silk in vivo is not a uniform process, and its degradation process should be related to the mobilization of cells.Sciatic nerve transplantation in rats with experimental results in this study suggest that the nerve conduit wall preset pores have a negative effect on the 10 mm deletion and repair of sciatic nerve in rats. The preset micro channel in the artificial neural internal, and have positive significance for the 10 mm deletion and repair of sciatic nerve in rats. The repair effect of micro channel wall is better than that of repairing peripheral nerve defect, which is a potential artificial nerve to repair peripheral nerve defect.