間葉幹細胞於不同交聯程度自癒性水膠之生長及硬骨分化研究

本研究目的在於系統性的評估不同交聯度自癒性水膠的性質，並探討間葉幹細胞 (Mesenchymal stem cells, MSCs) 培養於自癒性水膠內之生長情形與硬骨分化能力。將羥乙基脫乙醯殼多糖 (Glycol chitosan, GC) 與不同分子量和不同濃度的二苯甲醛封端之聚乙二醇 (Dibenzaldedehyde terminated poly(ethylene glycol), DF-PEG) 混合，所製備出的一系列水膠為 GC-DF2 2％、GC-DF2 4％、GC-DF2 6％、GC-DF4 2％、GC-DF4 4％、GC-DF4 6％、GC-DF6 2％、GC-DF6 4％和 GC-DF6 6％。結果顯示當 DF-PEG 分子量減少或濃度增加時，水膠的交聯度隨之增加，其中高交聯度之水膠會形成緊實結構並具備高孔洞率、所需交聯時間短、低溶脹率、較長的降解時間、低應變、高應力及高硬度等特性，且流變結果顯示所備製的水膠也具有自癒能力。在生物相容性部分， MSCs 培養於水膠內具有良好存活率及低毒性。交聯度提高細胞活性隨之提升，然而交聯度過高，導致水膠硬度太高，使得細胞活性下降。由鹼性磷酸酶檢測、鈣沉積及ALP、Col-1及OCN基因表現結果顯示增加水膠硬度可促進硬骨分化而PPARγ基因結果顯示減少水膠硬度促進脂肪分化。綜合上述結果，本研究備製之自癒性水膠具有生物相容性、生物可降解性且可促進硬骨分化之能力。

關鍵字

羥乙基脫乙醯殼多糖；二苯甲醛封端的聚乙二醇；自癒性水膠；間葉幹細胞；硬骨分化

並列摘要

This study aimed to systemically evaluate self-healed hydrogels with different crosslinking degrees for mesenchymal stem cells (MSCs) culture and osteogenic differentiation. Hydrogels were prepared by mixing glycol chitosan (GC) with dibenzaldehyde terminated poly (ethylene glycol) (DF-PEG) at different molecular weights and concentrations. The series of hydrogels prepared were GC-DF2 2%, GC-DF2 4%, GC-DF2 6%, GC-DF4 2%, GC-DF4 4%, GC-DF4 6%, GC-DF6 2%, GC-DF6 4%, and GC-DF6 6%. Result showed decreasing of DF-PEG molecular weight or increasing of DF-PEG concentration increased crosslinking degree of hydrogels. Hydrogels with higher crosslinking degrees led to more compact structure of hydrogels which had higher porosity, shorter gelation time, lower swelling ratio, slower degradation rate, lower strain and higher stress. The rheology results also showed the hydrogels exhibited self-healing ability. All of the hydrogels showed good cell proliferation and low cytotoxicity. Increased crosslinking degree of hydrogels increased cell viability. However, too high crosslinking degree caused high hydrogels stiffness which decreased cell viability. In osteogenic differentiation, alkaline phosphatase assay, calcium deposition and RT-PCR result of ALP, Col-1, OCN proved hydrogels with higher stiffness had better ability on osteogenic differentiation and PPARγ expression showed softer hydrogels promote better adipogenic differentiation. In summary, the hydrogels prepared were biocompatible, biodegradable, and able to promote osteogenic differentiation.

並列關鍵字

glycol chitosan ； DF-PEG ； hydrogel ； self-healing ； mesenchymal stem cel ； biocompatible ； osteogenic differentiation

參考文獻

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