Structure And Properties Of Braided Peripheral Nerve Regeneration Conduit

The regeneration and function recovery of peripheral nerve is one of the hottest issues in the field of neuroscience. Because of the characteristics of peripheral nerve anatomically and functionally, anastomosis cannot be achieved ideally in most cases. It is necessary to search some kinds of nerve substitute for the nerve repair. With the development of material science and molecular biology, more and more kinds of materials have come out over the past decade. Nowadays, the emphases of nerve repair research shift from nerve repair technology to nerve regeneration.The nerve regeneration conduits prefer to the tubes made by using biological material or other material, into which the defect nerve is put. Then the neural axons will regenerate from the proximal end to the distal end along the conduit. Following the development of the tissue engineering, the study of artificial nerve regeneration conduit comes to be the focus of the people's study.Braided nerve regeneration conduits are normally produced from biodegradable material poly (glycolide-co-L-lactide) (PGLA) using the braiding technology. It is one kind of conduits to repair the nerve defect. Previous studies have demonstrated that the braided PGLA conduits can promote nerve fiber regeneration and partial functional recovery when they are implanted to bridge 14mm rat injured sciatic nerves. However, slight buckling in some conduits was observed due to their low radial compressive resistance. It is evident that the mechanical properties of the conduits, especially their compressive properties in the radial direction, are very important factors, which can influence nerve regeneration. In addition, as one of basicallymechanical properties, the tensile properties are tested and analyzed.In this paper, the mechanical properties of the braided peripheral nerve regeneration conduits were studied to find the best producing factors. Besides, the compressive properties and the weight loss rate of the different conduits during in vivo degradation were discussed.The tensile properties and the compressive properties in the radial direction of different conduits were discussed. The influences of the producing factors, such as of material proportion, braided structure, braid angle, braiding machine spindle counts, yarn density, and coating treatment, on the mechanical properties were discussed. The mechanical testing results show that the properties of the conduits, made by PGLA 90/10 material, triaxial structure, braiding angle 60°, braiding yarn density 40.6tex, inserted reinforcing yarn density 23.2tex and coating treatment, is better.Considering the mechanical testing results, some conduits are taken into in vivo degradable test. During the in vivo degradation, the compressive properties in the radial direction, the maintenance capability of compressive properties, radical elastic recovery rate and the weight loss rate were tested. In addition, surfaces of the conduits were observed and analyzed. The result shows that the degradation of the conduit, made of PGLA (90/10) material, triaxial structure and coating treatment is better.