Manufacturing And Fundamental Research Of Polyurethane-Collagen Composite Auricle Framework

In plastic reconstruction surgeries, total auricular reconstruction for microtia is a challenge. The key point is the construction of a perfect framework. Presently autogenous costal sculpted cartilage and assembled MEDPOR are used widely. None of them can satisfy the need of patients. In this study an auricle framework is formed using fused deposition modeling method. A real like individuation human ear was obtained. On this basis, a polyurethane-collagen composite auricle framework was designed to improve its biocompatibility by combined with traditional method.The study includes two parts: research on rapid prototyping of auricle scaffold and fundamental research on improving biocompatibility of auricle scaffold. Research on rapid prototyping of auricle scaffold includes design of three-dimension reconstruction of auricle scaffold, develop of rapid prototyping system and optimize the process parameters of rapid prototyping. In fundamental research on improving biocompatibility of auricle scaffold, low temperature plasma on polyurethane surface, configuration design and forming technology of polyurethane-collagen composite auricle framework were performed. The main results of this study are as follows.In the course of ear reconstruction, a new ear model of auricle cartilage, auricle muscle and earlap was introduced. A more real and stronger ear was obtained. The operation of earlap transform and tragus reforger can be cut down. It is the first time to built ear model with external ear canal. This ear model forms a real like ear. This model is in favor of the scaffold fixation and can avoid the closure again of external ear canal.The result of animal experiment indicated that: in the start of ear scaffold implant, the inflammations appeared, in the following the inflammations disappeared gradually and contour of ear become clearly. It is similar to human ear. It shows that the polyurethane ear scaffold has a good histocompatibility. And the ear shape is not changed. It proved that the mechanics performances of ear scaffold are satisfied.In this study, the surface of polyurethane was modified by low temperature plasma with ammonia. The surface becomes roughness. Much oxygen elements and nitrogen elements are introduced in the scaffold surface, and some functional groups such as carbonyl groups and amidogen groups were exposed on the surface, which enhanced hydrophilic property of polyurethane. The cell culture experiments proved that the structure and the properties of the modified materials enhanced the cell adhesion and growth. This modified method can be spread to other polymeric biomaterials.A new forming process including of rapid prototyping and traditional method was designed to build polyurethane-collagen composite auricle framework. In this auricle framework, polyurethane forms macro-porous structures and collagen forms micro-porous structures. This composite auricle framework not only has a satisfied mechanics performance, but also its biocompatibility is improved greatly through cell culture experiments.