人類羊水來源的幹細胞是一種多能性胎細胞，其具有分化成三胚層以及各種專門細胞系的能力，在再生醫學與組織工程中，從羊水中取得的幹細胞將是一種更適合的幹細胞來源，然而幹細胞的一些特質，例如適當的分化和多能性的維持，不僅會受到細胞自己本身的影響，也會因為周遭微環境的不同而改變，另一方面而言，細胞的多能性與分化將會受到用來培養的生醫材料之生物線索(例如細胞外間質)以及物理線索(例如表面硬度)的不同而影響其命運，我們在這篇研究中，利用將羊水幹細胞培養在具有不同軟硬度的聚- (乙烯醇共衣康酸) 膜 (PVA-IA films) 接枝某些細胞外間質的寡肽，並將其與環狀肽 (Cyclic RGD)作結合來探討羊水幹細胞的多能性維持與分化能力。我們從測量多能性基因 (Oct4、Sox2、Naong) 的結果中發現，羊水幹細胞培養在較軟的PVA-IA films (19.6 百帕) 接枝細胞外間質寡肽會有較高的多能性表現，而羊水幹細胞培養在較硬的PVA-IA films膜 (30.4 百帕)接枝第一型膠原蛋白寡肽和環狀肽，其會比在相同硬度之下只接枝第一型膠原蛋白寡肽還要有更高的多能性表現。我們從羊水幹細胞培養在以PVA-IA films為基質的材料且培養於細胞成長培養液中意外的發現，擁有較高多能性表現的細胞也會同時表現較高的前期三胚層分化基因，從這項結果可說明羊水幹細胞是一種非勻相的細胞系，其細胞組態包含了具有高多能性的幹細胞以及容易分化的幹細胞。在所有的結果中可發現，用來培養的生醫材料之物理效應 (例如表面硬度) 與生物效應 (例如細胞外間質) 的確可用來調控幹細胞的多能性和分化能力。;Human amniotic fluid-derived stem cells (AFSCs) are pluripotent fetal cells capable of differentiating into multiple lineages, including representatives of the three embryonic germ layers. Stem cells which derived from human amniotic fluid may become a more suitable source of stem cells in regenerative medicine and tissue engineering. However, stem cell characteristics, such as proper differentiation and maintenance of pluripotency, are regulated not only by the stem cells themselves but also by their microenvironment. On the other hand, the stem cell fates of pluripotency and differentiation can influence by biological cues (i.e. extracellular matrix (ECM)) and physical cues (i.e. elasticity) of cell culture biomaterials. Here we investigated the maintenance of pluripotency and differentiation ability of AFSCs cultured on poly(vinylalcohol-co-itaconic acid), PVA-IA films grafted with several ECM-derived oligopeptides and combined with cyclic RGD having different elasticity. AFSCs cultured on soft PVA-IA films (19.6 kPa) grafted with ECM-derived oligopeptides showed high pluripotency, as assessed by the pluripotent gene expression (Oct4, Sox2, and Naong). AFSCs grow on stiff PVA-IA films (30.4 kPa) grafted with the combination of oligopeptides derived from collagen type I (oligoCOL) and cyclic RGD peptide showed higher pluripotency than that grafted with oligoCOL. Surprisingly, AFSCs cultured on PVA-IA films showed higher pluripotency also expressed higher level of early differentiation markers for three germ layers (Nestin, Runx2, Sox17) in expansion medium. This result suggests that AFSCs are heterogenous and that this population contains highly pluripotent stem cells and stem cells that can be easily differentiated. It is suggested that physical cues such as stiffness of culture biomaterials and biological cues such as ECM-derived peptides can guide pluripotency and differentiation ability of stem cells.
