Fabrication And Characterization Of Three Dimensional Porous Biodegradable Polymer Scaffold For Tissue Engineering

The research on porous tissue engineering scaffold has been one of the major braches in tissue engineering field. Therefore, it has received considerable attention and many researchers have already focused on it due to its application as matrix of seeding cells and repairing the tissues. Ideally, these porous scaffolds should have the following characteristics:high porosity, an interconnected porous structure, nontoxic, biocompatible, and suitable mechanical strength. Therefore, How to fabricate the ideal three dimensional porous scaffolds is a front subject in the field of tissue engineering. The biodegradable polymer scaffolds have become the focal researcher of tissue engineering domain due to its outstanding advantage; for example, it would be resorbed by live tissue while guiding the cells growth.This dissertation pays attention on the technology, morphology, and property of biodegradable polymer scaffolds in the process of their forming. The novel porous biodegradable polymer scaffolds were manufactured with high porosity, interconnected, and three dimensional by choosing suitable technique, designing rational material formula, controlling pores morphology, porosity, water absorption, interconnectivity, and mechanical porosity. The main works are as follow:1, To fabricate the three dimensional porous PCL and PCL/HA scaffolds by injection molding/particulate leaching method. To control the pores morphology, porosity, water absorption, and mechanical porosity of the scaffold by varying the material formula. The leaching process of NaCl particular and the soluble polymer PEO inside the scaffold were observed. The mechanical porosity and biocompatible of three dimensional porous PCL and PCL/HA scaffold were compared. The result shows that the application of HA not only enhance the mechanical porosity of scaffold, but also promote the proliferation ability of cells.2,To fabricate the three dimensional porous PCL scaffolds by microcellular injection molding/particulate leaching. The morphology,static and dynamic mechanical properties, porosity, and water absorption of scaffold which formed by injection molding were compared with that of scaffold which fabricated by microcellular injection molding. The super critical N:not only used as physical blowing agent, but also used as plasticizer, which could decrease the viscosity of blend melt, resulting to easy to molded, as well as increasing the porosity of the PCL scaffold.3,To fabricate the three dimensional porous PCL scaffolds with double morphology of micro pores and channels by using chitosan fiber at the first time based on adopting injection molding technique,weak acid leaching method and novel material formula (PCL/PEO/NaCl/chitosan fiber). The addition of chitosan fiber not only formed the micro channel inside scaffold, but also increased the porosity and interconnectivity of scaffold. In addition, the effection of chitosan fiber content in blend on the morphology and mechanical property of PCL scaffold were studied.4,To fabricate the three dimensional highly porous chitosan/PLGA nario composite scaffolds with micro channels and nano-topography by combining unidirectional freeze drying and electrospinning technology. The chitosan/PLGA scaffold not only has nano-topography but also has bigger specific surface area and higher mechanical property compared with that of chitosan scaffold due to the addition of PLGA nano fiber. In addition, the effection of chitosan concentration and electrospinning time on the morphology and mechanical property of scaffold were investigated.5,The degradation mechanism and degradation rate of compression molding polyanhydrides samples were investigated. Moreover, the effection of processing temperature and the geometry of samples on the degradation rate were studied.