人類間質幹細胞之三維成骨分化與力學模擬

Three-dimensional Osteogenic Differentiation and Mechanical Simulation on Human Mesenchymal Stem Cells

薛孟維(Meng-Wei Hsueh)

指導教授 ： 鄭文雅 ； 林耿慧

國立交通大學/工學院/機械工程系所/碩士(2020年)

摘要

牽引力在間充質幹細胞（MSCs）分化扮演著重要的角色，而目前大多數牽引力相關研究著重二維細胞培養作討論。本研究在內部孔徑大小均一之三維組織支架中培養人類間質幹細胞（hMSCs），並在成骨分化刺激及不同孔洞大小（70、120與240 µm）條件下推估其牽引力。本研究發現經過14天培養，hMSCs在孔洞間形成網狀組織結構，並且造成孔洞變形。以共軛焦顯微鏡擷取變形影像，並以圖像分割計算形變量。接著，本研究建立之數值模型分為兩類，第一類為支架內部孔洞數值模型，藉以模擬內部孔洞受三軸方向等值應力之孔洞變形；第二類則為支架邊界孔洞數值模型，藉以模擬內部孔洞受三軸方向非等值應力之孔洞變形。本研究以有限元素法進行hMSCs於支架中施加牽引力之數值模擬，根據實驗中觀察到之形變估算牽引力。數值模擬結果發現孔洞直徑為70 µm時對應之牽引力最小，而240 µm時對應之牽引力最大。另外hMSCs在直徑為70 µm之孔洞中呈現最差的成骨分化結果，在120 µm孔洞中呈現最佳的成骨分化結果。

關鍵字

三維細胞培養 ； 間充質幹細胞 ； 成骨分化 ； 組織支架 ； 有限元素法 ； 牽引力

並列摘要

Traction force plays an important role in mesenchymal stem cells (MSCs) differentiation and yet most studies to measure traction force are carried out on two-dimensional cell culture. We cultured human mesenchymal stem cells (hMSCs) in 3D monodisperse foam scaffold and measured the traction force of hMSCs under osteogenic induction and at different pore diameters (70, 120, and 240 µm). We found after culturing in scaffolds for 14 days, hMSCs organize into network tissue structures through pores and deform scaffold pores. The deformation is imaged directly by confocal microscopy and measured by image segmentation. We further analyzed the deformation into two parts. The first part is isotropic decrease of the diameters of the interior scaffold pores and the second part is the anisotropic deformation along x, y, z-axis of the boundary pores. Based on the experimental results, we used finite element method to simulate the traction force of hMSCs in foam scaffolds to estimate the traction force from pore deformation. Numerical results reveal that the traction force in the 70 µm pore case is found to be minimum among the three cases and the one in the 240 µm pore case is the maximum, while hMSCs in 70 µm pore show the least osteogenesis and hMSCs in 120 µm pore show the strongest osteogenesis.

並列關鍵字

three-dimensional cell culture ； mesenchymal stem cells ； osteogenic differentiation ； cellular foam scaffolds ； finite element method ； traction force

參考文獻

1. Bateman, M.E., et al., The Effects of Endocrine Disruptors on Adipogenesis and Osteogenesis in Mesenchymal Stem Cells: A Review. Front Endocrinol (Lausanne), 2016. 7: p. 171.

2. Engler, A.J., et al., Matrix elasticity directs stem cell lineage specification. Cell, 2006. 126(4): p. 677-89.

3. Hollister, S.J., Porous scaffold design for tissue engineering. Nature Materials, 2005. 4(7): p. 518-524.

4. Barrilleaux, B., et al., Review: Ex Vivo Engineering of Living Tissues with Adult Stem Cells. Tissue Engineering, 2006. 12(11): p. 3007-3019.

5. Hsieh, W.T., et al., Matrix dimensionality and stiffness cooperatively regulate osteogenesis of mesenchymal stromal cells. Acta Biomater, 2016. 32: p. 210-222.