Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/3511
標題: The effect of ultrasound and dynamic conditions on the neocartilage formation in tissue-engineering scaffolds
超音波刺激與動態培養對組織工程支架體外再生組織形成之影響
作者: 郭霽慶
Kuo, Chi-Ching
關鍵字: cartilage repair;軟骨修復;articular cartilage tissue engineering;type II collagen;RGD;sodium hyaluronate;bioreactor;ultrasound;關節軟骨組織工程;第二型膠原蛋白;RGD;透明質酸鈉;生物反應器;超音波
出版社: 化學工程學系
摘要: 
本研究是以組織工程技術來發展軟骨修復的方法。在實驗設計中,分為新材料與新改質物應用在軟骨組織工程支架的研究,以及將成人或小豬關節軟骨細胞植入聚酯類高分子支架中,以靜置培養、超音波刺激與動態生物反應器培養後進行再生組織的比較。
在新材料(聚丁烯丁二酯)的評估中,此材料的HC細胞相容性與PLLA相近,加上支架製備簡易與成本低廉,未來可以應用於需要較慢降解速率的硬骨修復上。
在新改質物方面,以透明質酸鈉加入已經用第II型膠原蛋白與CBD-RGD改質的支架,發現能夠促進HC生長與分泌基質。
在HC 3D支架體外培養實驗中,發現超音波刺激系統與旋轉式(Rotator)生物反應器皆能夠促進細胞生長與分泌基質,尤其是旋轉式生物反應器。
在PC 3D支架體外培養實驗中,發現旋轉式(Rotator)生物反應器能夠使得細胞於支架中分布均勻,且促進細胞生長與分泌基質,維持細胞形態,幫助基質排列規則而增強機械性質,達到功能接近真實組織的再生軟骨組織。迴轉振盪式(Shaker)生物反應器則因提供一不當的紊流(turbulent flow)使得細胞產生大量的NO.自由基,造成細胞生長抑制與減少基質合成。靜置培養的控制組細胞則只長於支架外圍,使得質傳效果不佳而促使支架中央pH值過低加速支架材料降解,最後導致再生組織的機械性質不佳。
綜合上述,旋轉式(Rotator)生物反應器對於AP6+CII支架,能夠成功培育出具功能性的再生組織,是一個最佳的體外培養模式。

Tissue engineering technique has been broadly explored in recent years to repair the damaged cartilage. In this study, new materials and modification of the scaffolds were tested; more importantly, the effect of ultrasound and dynamic culture conditions (bioreactors) on the neocartilage formation in tissue engineering scaffolds were examined.
Polybutylene succinate was found to possess some excellent characters, including similar biocompatibility to poly(L-lactide), easy process for scaffold fabrication as well as low cost. Although its degradation time was longer, the previous characters could still make it a good candidate for bone tissue engineering.
Regarding surface modification, sodium hyaluronate, type II collagen and CBD-RGD (a recombinant RGD-containg protein), when used together, can promote the growth of human articular chondrocytes, and increase the production of extracellular matrix (ECM).
Chondrogenesis in 3D scaffolds were studied under controlled in vitro conditions. The chondrocytes harvested from adult human knee articular cartilage were seeded onto our biodegradable composite scaffolds and cultivated in vitro. After being incubated for several weeks, the chondrocytes grew well and produced more ECM in those constructs either stimulated with ultrasound or cultured in the rotating-type bioreactor, especially for the latter.
The chondrocytes harvested from baby porcine knee articular cartilage were seeded into scaffolds and cultivated in static condition, the shaking-type bioreactor or the rotating-type bioreactor. It was demonstrated that the rotating-type bioreactor could promote the growth of chondrocytes, help to maintain their phenotype and increase the production of extracellular matrix (ECM). In addition, the constructs grown in such condition had several interesting features. The chondrocytes were enclosed in lacunae-like structure and distributed uniformly in the scaffolds. The constructs contained largest amount of ECM compared to the others and had a dynamic compression modulus similar to that of the real porcine cartilage. On the other hand, in the shaking-type bioreactor, chondrocytes produced high amount of NO. which inhibited their growth. In the static condition, chondrocytes grew toward the outer layer of the cell-polymer constructs. That may cause a low pH value in the middle of the constructs which led further to high degradation rate of the scaffold as well as the weaker neocartilage.
In conclusion, the functional neocartilage could be successly regenerated by culturing human and porcine chondrocytes in the scaffolds using the rotating-type bioreactor. Ultrasound also showed a positive effect.
URI: http://hdl.handle.net/11455/3511
Appears in Collections:化學工程學系所

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