open access

https://doi.org/10.14943/doctoral.k13385

https://hdl.handle.net/2115/72354

組織工学のための生体材料足場としてのマルチチャンネルコラーゲンゲル（MCCG）

英語

2018-12-25

Hokkaido University

ii, 55p

Multi-channel collagen gel (MCCG) is prepared simply by dialyzing a phosphate buffer solution (gelation PBS) against collagen solution, and the phase separation of collagen solution yields a porous anisotropic hydrogel. The anisotropic property of the MCCG is supplied by the arrangement of collagen fibres parallel to the circumference of the channel lumen, and perpendicular to the axis of the channel. The aim of this dissertation was to explore the potential of MCCG as a biomaterial for tissue engineering. The MCCG presents a porous hydrogel scaffold onto which cells may be seeded or encapsulated within to achieve a 3D culture system. In chapter 3, these seeding methods were tested using single cells and cell spheroids, and it was observed that kidney epithelial cells adhered to the surface of the channels when seeded, but formed cysts with a hollow cavity when encapsulated within the collagen matrix. Furthermore, PC12 cells encapsulated in normal collagen gel (COL) extended more neurites and grew in larger aggregates compared to those in MCCG. These findings suggest that even though various methods have been proposed for 3D culture systems, there still exists differences that affect the way cells behave. Cell encapsulation techniques typically utilizes the concept of phase separation of a cell-containing polymer solution. In chapter 4, the movement of fluorescent particles, used as models of cells, in a phase-separating collagen solution was investigated. The formation of COL proceeds by nucleation and growth (NG) phase separation, while that of MCCG proceeds by spinodal decomposition (SD) phase separation, providing an opportunity to study both types of phase separation simultaneously. The particles were observed to move downwards in COL, and were homogeneously distributed. On the other hand, the particles in MCCG were observed to move mainly sideways and upwards, and were distributed in the collagen matrix region and not in the channels. It was found that the particles do not move in the same way as the phase-separating collagen, but rather is thought to be driven by the movement of water. The alignment of collagen fibres and the restriction of available collagen-rich regions by the presence of the channels in MCCG make it a prospect for neural tissue engineering, given that the guidance of neurite growth is an important criteria for neural guidance conduits. In chapter 5, the alignment of collagen fibres in MCCG was investigated, and it was shown that the extension of PC12 cell neurites were significantly guided in MCCG compared to COL. It was also suggested that the MCCGs prepared with different ionic concentrations in this study, though having different degrees of collagen fibre alignment, were all within the threshold fibre alignment range required for contact guidance of neurites. Overall, the simple experiments conducted in this dissertation point to the potential applications of MCCG as a scaffold in 3D culture systems and tissue engineering, as well as a tool for studying phase separation processes with relevance to the extracellular matrix (ECM), of which collagen is a major component. Nevertheless, further comprehensive studies are required to fully understand the intricate details about the properties of the MCCG and its formation mechanism.

2018-12-25

甲第13385号

博士(生命科学)

(主査) 教授 芳賀 永, 教授 黒川 孝幸, 助教 石原 誠一郎, 客員准教授 古澤 和也（福井工業大学 環境・食品科学科）

生命科学院（生命科学専攻）

博士論文

Version of Record