Study And Fabrication On Biodegradable Nerve Regeneration Conduits With Braided Structure And Working On It's Properties

Early in 19 century , the recovery of injured nerve lacking appropriate1 material made people to attempt conduit to recover the injured nerve .Recently ,a lot of people focusing on the study of nerve conduits ,because some scholars believe that , from the research during the recent 10 years ,nerve conduits are more suitable than general nerve anastomoses and nerve migration, especially the nerve regeneration chamber can provide a perfect "window" to study the micro circumstance of nerve regeneration .This article mainly discusses the fabrication and performance of braided conduits for nerve regeneration , comparing and analyzing the effect on injured nerve of different braided structure conduits through animal experiment .PGLA ,one biodegradable material ,is used to braid the conduits ,which integrates the merits of its two aggregate ingredients .It is easy to adjust degrading rate to match the regeneration period of the nerve by changing the proportion of the two ingredients .The conduits are fabricated enlacing 2.2 millimeter stainless steel on the braiding machine with 16 spindles using 2700 Tex yarns .Four conduits with different structures are braided: common braided structure, braided structure using braided ply yarn , braided structure with inserted reinforcing yarn and adding bridge-yarn structure ,the last two conduits are new attempts to look for good shape-keeping structure ,being able to lead the nerve to regenerate effectively.Through experiment and analyzing the changes of the thickness, rigidity ,tensile strength and the opening rate of the conduits caused by the different kinds of coating material ,the thickness of the coating andthe different braiding structures ,we investigate the physical and mechanical, properties of the braided conduits .The results show : the chitosan is easy to form the film structure on the surface of the conduits increasing the conduits'rigidity clearly ;the rigidity and opening rate of the braided structure with inserted reinforcing yarn are better than the others ,this will prevent the conduits collapsing and distorting effectively in the practical uses ,so we select conduits of this structure for animal experiment .The animal experiment is carried out in the First Hospital of Shanghai through renovating the injured nerve of the rats .Four projects are used in this experiment :the conduits coated with PGLA ,the conduits coated with chitosan , the conduits coated with chitosan adding bridge-yarn and self-nerve migration .After 12 weeks ,we observe and analyze the thickness of marrow theca ,the diameter of axone ,the density of regeneration nerve and then do electromyography and statistics analyzing ,finding out that the third conduits have the best recovering effects on the injured nerve , close to the self-nerve migration .The braided conduits is a new feasible method to recover the injured nerve proved by the experiment results .We are convinced that it will bring new breakthrough and referenced value to the fields of researching the nerve recovering .