| Summary: | 碩士 === 元智大學 === 化學工程與材料科學學系 === 103 === Polyhydroxyalkanoates (PHAs) is a microbial production of biodegradable plastics, which has special biodegradation and biocompatibility, so PHAs has considered in potential applications in the tissue engineering. The scaffold is made of PHAs except with biocompatibility, and the function of guiding the cell ingrowth in organism, also can be made according to the demand of the different specific degradation rates of PHAs, provides cells mechanical support, and ultimately degradation products of non-toxic products. The purpose of this study is to investigate the experimental parameters of producing PHAs scaffold. It has two parts in this thesis.
First, scaffold materials using poly (3- hydroxybutyrate) P3HB and poly (3-hydroxybutyrate -co- 3-hydroxyvalerate)，P3HBV). Two kinds of processes were adopted, solvent-casting and electrospinning method to prepare different properties of materials. In addition, modify the scaffold surface with polyethylenimine graft to enhance the biocompatibility of the PHAs scaffold.
Based on the mechanical test, the solvent-casting film tends to rigid and brittle. However, the electrospinning film tends to soft and flexible. The electrospun film is relatively hydrophobic. The results of thermal property tests show that the onset temperature and temperature with maximal weight loss rate for P3HB were higher than those for P3HBV. In the meanwhile, the glass transition and melting temperatures for P3HB were higher 5 oC than these for P3HBV. This result apparently demonstrated the P3HB has better thermal stability to apply in the polymer processing and tissue engineering.
Second, use the scaffolds made from the first part to cultivate NIH-3T3 cell for biocompatible test by means of fluorescence stain, WST-1 and MTT assay to explore the relationship between biomaterials and cell diagram. Furthermore, compare biocompatibility of the scaffold produced by solution-casting and electrospinning processes, in order to obtain the optimal operational conditions of preparing scaffold.
For biocompatibility, the images of fluorescence stain showed that the number of cell on the electrospun film was more than that on solvent-casting film. This result indicated the surface roughness and pore size of electrospinning scaffold were suitable for cell attachment and proliferation. By WST-1 quantitative analysis, the cell culture on the P3HB electrospun scaffold was the best one, and second was P3HBV electrospun scaffold. The number of cell on P3HB electrospun scaffold could reach around 60% of TCPS at 7 day.
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