| 摘要: | 應用間葉幹細胞於軟骨修復一直是很重要的課題，至今也有大量的文獻發表。但是眾多文獻中，甚少探討幹細胞在分化與成長的過程如何與基材交互作用，亦或是一筆帶過。然而欲發展軟骨修復材料，瞭解細胞與基材間的影響是技術發展的關鍵。我們嘗試利用軟骨細胞的特性來發展間葉幹細胞往軟骨分化的基材。軟骨細胞的特性諸如：細胞呈現圓形於透明軟骨中，相較下，扁平的細胞存在纖維化的外層軟骨。另者，在二維培養時，軟骨細胞亦傾向扁平貼附於平面而失去特性表現。因此，我們推估細胞在材料表面的貼附行為，能影響軟骨細胞的特性。 所以，我們假設材料表面的黏附性能藉由改變細胞的貼附行為，而誘導間葉幹細胞往軟骨分化。因此，我們在材料表面上修飾抗貼附的分子，包括聚乙二醇以及雙離子性的碘丙酸。在不同程度的修飾之下，成功地控制了細胞的貼附量，及更進一步影響了貼附行為。我們透過觀察細胞的形貌發現，材料表面不同的化學修飾，直接影響了細胞的形貌與整體的行為。更藉由基因表現的分析得知，並且也呼應了細胞形貌的不同，貼附控制能促進間葉幹細胞往軟骨分化。 Mesenchymal stem cells (MSCs) being an alternative of chondrocytes is a serious issue for cartilage repair. Even though various researches contributed to the chondrogenetic materials, there were still specifically short discussion about the surface-to-cell interaction which could brought differentiation and proliferation. However, it’s important for developing chondrogenetic material. For this study, we thought chondrocyte-to-matrix physiology might model the strategy for the usage of MSCs for chondrogenesis. For example, at articular cartilage, chondrocytes are sphere-like in vivo of the hyaline cartilage, while flat in fibrocartilage around the bone tissue as via endochondral ossification. Similarly in vitro, the dedifferentiated chondrocytes flattened by binding exactly through integrins to substrate. Moreover, the mature chondrocytes tend to aggregate in vitro. In short, the adhesion to the matrix affects physiology of chondrocytes. Thus, we hypothesized that the adhesivity of the substrate might direct the differentiation of MSCs by transforming their adhesivity and naturally spreading morphology in 2-dimensional culture. Under this hypothesis, we modified type I collagen substrate by various amounts of non-adhesive PEG and zwitterions (iodopropionic acid, IPA) and produced surfaces of various adhesivities to affect MSCs. Through the different chemistry of surface, we would like to illustrate the interaction between cells to the matrix. The density of modification were determined by XPS, and results indicated concentration-dependent modification, following controlled the adhesion of cells. The cell morphologies were observed under optical microscope. The morphologies were distinguishingly different between the different modification that took advantages with the different surface chemistry. Most important of all, the differentiation to chondrocytes was determined by analyzing genes such as type II collagen, aggrecan, and Sox9 through RT-PCR. The results indicated that the surface adhesivity of substrate does affect the chondrogenesis of MSCs. |
