| Strenosis, complete obstruction or tracheal defects may occur due to trauma, tumors, granulomatous disease and long-term endortracheal intubation. Primary end-to-end anastomosis is preferred in the reconstruction of tracheal defects less than 50-60mm in humans.A large variety of allografts, prosthesis, autogenous tissue and tissue-engineered trachea have been extensively tried to repair larger, circumferential tracheal defects, but not only limited success have been achieved experimentally and cillinically. Graft ischemia and immunorejection have hindered the success of tracheal allografts. Reconstruction with autogenous tissue have been found unsatisfactory due to inadequate airway function and poor sources. So this research is a great challenge and very up-dated.In recent years, the perfect integration and development of polymeric sciences and life science provide necessary substitute for restoring and improving the functions of the impaired tissues and organs. Polymeric biomaterials comprise mainly synthetic and natural materials. The former such as polymers are characteristic of certain mechanical strengths andprocessing properties, which can provide appropriate scaffolds for cell growth and tissue regeneration. Compared with the former. The latter possessing excellent biocompatibility and biodegradability play a crucial role in inducing and facilitating cell growth and tissue regeneration. If the two kinds of different materials above could be integrated properly, it would be a great innovation theoretically and technically in designing and prefabricating tracheal prosthesis.In this paper, biomaterials possessing excellent strength and elasticity were selected to prefabricate the mesh tube as a scaffold, whose inner lumen were coated by polymers and the exterior were laminated by bioactive materials. The polypropylene(PP),poly(latic-co-glcolicacid) were measured systematically by the use of the hole test, stiffness, elongation test, longitudinal support force and radial support force test respectively. Besides, this paper also discusses the relationships among the yarn diameters, the knitting destiny and coat process. Last but not the least, this paper takes advantage the theory of equation to choose out the best knitting parameters.According to the best knitting parameters, in this paper, the animal model of tracheal reconstruction has been made. The experimental reconstruction of the tracheal prosthesis had been performed. Dynamic observation the situation of the implanted tracheal prosthesis and the functional changes of tissue structure surrounding the prosthesispostoperatively so as to provide valuable scientific bases and technical feasibility in improving tracheal prosthesis.Based on above results, we conclude that this tracheal prosthesis made from composite biomaterials is characterized by excellent biocompatibility and bioactive properties in facilitating tissue regeneration and new bone formation. Furthermore, the newly prefabricated prosthesis with a biosynthetic structure integrate lots of advantages of the previous porous and non-porous artificial tracheas, which can be shown up under X-ray and posses significant superiority to prevent prosthetic dehiscence, dislocation, leakage, and mesh collapse. The animal model of tracheal reconstruction not only certainly represent the requirements of physicochemical and biomechanical properties of the prosthesis matching with the host and the healing processes of prosthesis incorporating with the host, but really reflect the occurrence and progression of postoperative complications. These excellent biomaterials may prove potential of the long-segment circumferential tracheal reconstruction which also appears very promising for the clinical application and provides us the reference for clinical research.Liu Yan(Textile Engineering) Supervised by: Senior Engineer Wang Wenzu... |
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