| Scaffolds and its preparation technology is very important for tissue engineering. In order to improve the existing deficiency in electrospinning technology, this study mainly develops three new spinning technology and then explores the correlation between these technological parameters and the structure and properties of obtained materials to provide more choice of preparation strategy for tissue engineering materials.-Firstly, a kind of inclined plate electrostatic spinning device is developed to solve the problem of needle blockage and low yield in the process of electro-spinning. The Maxwell 14.0 is used to construct the simulation model of the inclined plate electrostatic spinning and conventional needle plate electrostatic spinning device to forecast the morphology of fiber membrane by comparison of the electric field distribution in space from two methods. The ordered PLGA fiber films are successfully prepared through optimizing various spinning parameters, which can be served as a new and efficient electrostatic spinning technology for preparation of tissue engineering scaffolds.The second spinning device developed in our study mainly uses the spray gun to produce a high speed airflow field through compressed gas, resulting in stretching effect on polymer droplet to form nanofiber. Comsol4.4 is used to simulate the airflow field in the space near the nozzle and then obtained the kinesiograph of polymer droplet in this space. According to the simulation results, we try to understand the principle of air spinning and predict the effects of different collecting distance on the fiber morphology. The results show that nanoscale fibers can be obtained by using airflow spinning and possess high porosity. The method exhibits more security due to no requirement of high voltage static electricity, and living cells show less damage in the process of mixed spinning.Third kind of spinning device developed in this paper is a small wet spinning one. The oriented polymer fiber membranes are prepared based on shear force produced by coagulation bath flow. Comsol4.4 is used to simulate the flow field formed by rotation of the coagulation bath, meanwhile, the flow condition in coagulation bath of PLGA solution with different injection speed is simulated by using two-phase model. The results show that the injection speed has an important effect on the fiber diameter, and excellent micron fiber membranes can be obtained by using wet spinning technology. It is also found that oriented fiber membranes can present different degradation characteristics through regulation of the proportions of PLGA/PC L sp inning solution. The wet spinning technology is suitable for preparation of many kinds of polymer fibers what electrostatic spinning cannot accomplish, and has advantage of simple allocation, no requirement of high voltage static, easily controlled parameters. This technique shows wide application prospects for the preparation of oriented biodegradable fiber membranes.In addition, three kinds of PLGA fiber membranes are prepared by using three spinning technologies developed in this study, and then loaded vancomycin through emulsion spinning and absorption respectively. The degradation property, drug loading and release characteristics and antimicrobial properties of PLGA fiber membrane are studied. The results show that those fibers obtained by wet spinning possess larger diameter, moderate porosity and longer degradation time. The drugloaded PLGA fiber membranes obtained by emulsion method has sustained release effect, while the membranes obtained by surface adsorption can display high concentration release in the short term. High efficiency antibacterial properties of wet spinning PLGA fiber membrane under low vancomycin concentration. The drugloaded PLGA fiber membrane s prepared by wet spinning can not only achieve high efficient antibacterial properties but also avoid high concentration of vancomycin due to initial burst. |
PDF Full Text Request