九州大学学術情報リポジトリ
Kyushu University Institutional Repository
Surface modification of natural polysaccharide scaffolds by coating biotic nanofibers with its effects on epidermal cell morphology
ナゲンドラ, ラオ, スレッシュ, ラオ
http://hdl.handle.net/2324/2236297
出版情報：九州大学, 2018, 博士（農学）, 課程博士 バージョン：
権利関係：
Name ：Nagendra Rao Suresh Rao
Title ：Surface modification of natural polysaccharide scaffolds by coating biotic nanofibers with its effects on epidermal cell morphology
(
表皮細胞の形態変化を誘発するバイオナノファイバーによる多糖足場材料の表面改質)Category：Kou
Thesis Summary
The first chapter discusses about the properties of the stretched and non-stretched
cellulose, chitin and cellulose-chitin composites coated with bacterial cellulose and collagen nanofibers. The comparison between stretched and non-stretched cellulose, chitin and cellulose-chitin composites showed that the stretched samples possess better molecular orientation, strength and wettability. The coating of bacterial cellulose and collagen nanofibers covers the stretched samples and make the substrate rougher than the non-coated substrate.
Nanofiber coating also increased the strength of both stretched and non-stretched cellulose, chitin and cellulose-chitin composites though the stretched ones are stronger. Coating of stretched and non-stretched samples with bacterial cellulose resulted in an increase in the hydrophilicity. At the same time, coating with collagen nanofibers increased the hydrophobicity of the stretched and non-stretched samples. Nanofiber coating changed the surface properties such as surface morphology, material strength and surface wettability of the stretched and the non-stretched scaffolds. Since the stretched samples showed better characteristics compared to the non-stretched samples, stretched samples were used for the further cell culture studies.
The second chapter discusses about the effect of the number of coating cycles on the substrate, changing surface morphology and its influence on cell growth and morphology. The
physical properties of the scaffolds such as surface morphology, tensile strength, surface wettability is
dependent on the coating cycles. The increase in the number of coating cycles is directly proportional to the increase in the tensile strength. As the number of coating cycles increased, the nanofibers densely covered the scaffold surfaces. Coating with cellulose nanofibers switched the surface wettability of the scaffolds from hydrophobic to hydrophilic in the initial four coating cycles. After the 4th coating cycle, it became stable and remained as hydrophilic. In contrary, repeated coating with collagen nanofibers increased the hydrophobicity of the substrates. Cell culture done on the collagen nanofiber coated scaffolds showed an early stage of cell spreading proliferation and this shows the applications of modified scaffolds in epidermal cell regeneration. It also suggests the role of these modified scaffolds in the neo-organogenesis and 3D cell culture since collagen nanofiber coating supports cell proliferation, adherence and cell spreading. Studies done on cellulose, chitin, and cellulose-chitin composites after coating them with collagen nanofibers with one, three, and five coating cycles suggests that three-time coating is the best for human epidermal cell growth. The cell morphology and the cell growth was ideal in the three-time coated scaffolds. The number of attached/grown cells increased from one time coating to three time coating whereas the cell number got decreased from three time coating to five time coating. The cell size increased inappropriately after the 5th time coating.
ANOVA done between all the samples showed a significance of P<0.001. Concluding all these results, it is very much evident that the increase in the coating cycles have an influence in the scaffold surface morphology such as material strength and surface wettability, which has a direct influence on the human epidermal cell growth.
