| Summary: | 碩士 === 國立中興大學 === 生醫工程研究所 === 105 === The aim of this study was to develop a porous chitosan scaffold with long-acting drug release as an artificial dressing to promote skin wound healing. The dressing was fabricated by first, pre-freezing at different temperatures (-20 and -80°C) for different periods of time, then freeze-drying to form porous chitosan scaffolds with different pore sizes. The chitosan scaffolds were then used to investigate the effect of the controlled release of fibroblast growth factor-basic (bFGF) and transforming growth factor-β1 (TGFβ1) on mouse fibroblast cells (L929) and bovine carotid endothelial cells (BEC). The biocompatibility of the prepared chitosan scaffold was confirmed with WST-1 proliferation and viability assay, which demonstrated that the material is suitable for cell growth. The results of this study show that the pore sizes of the porous scaffolds prepared by freeze-drying can change depending on the pre-freezing temperature and time via the formation of ice crystals. It was found that the pre-freezing temperature controls the initial pore sizes, but the final pore sizes are determined by the period of time in pre-freezing. In this study, the scaffolds with the largest pore size was found to be 153.25 ± 31.87 µm and scaffolds with the smallest pores to be 34.45 ± 9.40 µm. Through cell culture analysis, it was found that the concentration that increased proliferation of L929 cells for bFGF was 0.005 to 0.1 ng/mL and the concentration for TGFβ1 was 0.005 to 1 ng/mL. In addition, a concentration of 0.005 to 0.05 ng/mL enhanced proliferation in BEC, however, for TGFβ1 it was observed that a concentration of 0.01 to 10 ng/mL reduced its proliferation. Controlled drug release of the growth factors showed that the chitosan scaffolds with pore sizes of 153.25 ± 31.87 µm (Pore I) containing 3.75 ng of bFGF and scaffolds with pore sizes of 34.45 ± 9.40 µm (Pore II) containing 400 pg of TGFβ1 showed results similar to the cell culture analysis. Cell culture of the chitosan scaffold and growth factors show that 3.75 ng of bFGF in Pore I scaffolds can effectively promote L929 cell proliferation; while 400 pg of TGFβ1 in Pore II scaffolds can enhance the proliferation of L929 cells, but also inhibit BEC proliferation. It is proposed that the prepared chitosan scaffolds can form a multi-drug (bFGF and TGFβ1) release dressing, and will have the ability to control wound healing via regulating the proliferation of different cell types, in order to avoid cell hyperplasia.
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