Preparation Of Porous PLA/CA Nanofibers By Electrospinning And Application Of Tissue Engineering Scaffolds

With the continuous development of tissue engineering,the preparation of biological scaffolds is becoming more and more important.Because the tissue engineering scaffold can highly simulate the structure and composition according to the needs of the target,it provides a temporary matrix for the proliferation and growth of seed cells,and can smoothly transport the cells to specific parts of the human body.However,the existing technology still has insurmountable problems in the manufacture of high-performance biological scaffolds.Therefore,a three-dimensional porous biological scaffold was prepared by electrospinning in this thesis.Through a series of experiments,the effects and rules of the main process parameters on the preparation of high-performance biological scaffolds were revealed,and the optimal process parameters of porous polylactic acid（PLA）/ cellulose acetate（CA）fiber scaffolds were obtained.Then the prepared high-performance biological scaffolds were used in cell culture,and finally double-layer tubular fiber scaffolds were constructed.The specific research contents are as follows:（1）Porous PLA/CA fiber membrane was prepared by electrospinning.The morphology and fiber diameter of the scaffold were controlled by changing the process parameters in the spinning process,and the microstructure of the porous membrane was characterized by scanning electron microscope（SEM）.The effects and rules of various process parameters on the fiber diameter and porosity were analyzed and discussed,and the optimal process parameters were obtained.（2）The porous PLA/CA fiber membrane prepared under the optimum parameters was taken as the research object.The physical and chemical properties of composite nanofibers were studied by X-ray photoelectron spectroscopy（XPS）,infrared spectroscopy（FITR）,contact angle test,water absorption test,mechanical properties test and cytotoxicity test.（3）The fibrous membranes were modified using lysine（PDL）and then studied for their tissue engineering performance.The modified fiber was characterized by SEM and XPS,and its microstructure and chemical composition were analyzed.The growth of cells on fiber scaffolds was observed by SEM and MTT methods,and compared with unmodified fibers.The effects of solute composition,porous structure and modified coating on biological properties were analyzed（4）Using pure PLA fiber membrane as outer layer and porous PLA/CA fiber membrane as inner layer,double-layer tubular fiber scaffold was constructed by layer-bylayer winding.Its microstructure,water absorption,mechanical properties and biocompatibility were characterized.The feasibility of double-layer tubular fiber scaffold as tissue engineering scaffold was analyzed.