| Abstract: | 隨著微創技術的日益普及，發展注射系統符合骨腔形狀和原位注射硬化聚合，吸引了莫大注意。 本研究室已成功使用溶膠凝膠法發展出快速硬化且具高生物活性的矽酸鈣骨泥(CSCs)。且添加不透 光劑之後，此骨泥的硬化時間約20分鐘，統計明顯低於根管治療常用的ProRoot三氧礦聚合物(~ 3 小 時)。然而，當以常用的陶瓷骨泥糊狀物植入骨缺損區，可能會因血液或其他液體而崩解或沖蝕，因此， 添加某些黏著提昇因子(如高分子)到骨泥以發展抗沖蝕材料避免崩解。而且，骨泥材料也要夠軟以便 塑造成不同形狀，填補到複雜的牙根或骨組織缺陷內。本三年計劃的主要目標為發展具骨形成性的抗 沖蝕CSCs，並與商品三氧礦聚合物、BoneSource磷酸鈣等產品比較，以求達成CSCs骨修補產品臨床目 標。 第一年計劃將經由各種材料基本分析及體外模擬測試比較透光性與不透光性CSCs 二種系統與商 品材料，並使製程參數最佳化。第二年將利用幹細胞與小鼠骨母細胞比較研究此具潛力的材料與商品 骨泥間之細胞增殖、分化及其骨形成等表現，並進一步探討CSCs 訊號傳遞路徑，作為新材料設計的 基石。最後一年著重於材料抗菌性及植入兔子大腿骨後之骨再生能力及吸收反應，植入1、3、6、12 月之後，使用電腦斷層與組織型態等分析。本三年計畫兼顧基礎研究及醫學應用，預期此三年的研究 結果在生醫材料開發及產業應用性上會有其顯著效能。
With the increasing popularity of minimally invasive techniques, to develop injectable systems that mould to the shape of a bone cavity and polymerize when injected in situ has attracted a great deal of attention. We have successfully developed quick-setting calcium silicate cements (CSCs) with high in vitro bioactivity using a sol-gel method. After the addition of radiopacifier, the radiopaque CSCs set within 20 min when mixed with water, which was significantly lower than that (~ 3 h) of ProRoot white-colored mineral trioxide aggregate (WMTA), which have been commonly used in endodontic treatment. The ceramic cements, when implanted as a paste that is just starting to set, tend to disintegrate and washout upon early contact with blood or other fluids. For this reason, a great attention has been paid to the anti-washout-cement that some cohesion promoters (polymers) were added to prevent this disintegration. Moreover, the cements may be soft enough to be molded into different shapes and extruded from a syringe, which is important to repair defects with complicated shapes in bones and roo-end. The purpose of this project is to develop anti-washout CSC systems with osteogenesis, and to compare with commercial WMTA and BoneSource calcium phosphate cement (CPC). Thus, to practice in clinical applications the potential materials for bone repair and/or filling applications may be achieved. The first-year objective will evaluate the physicochemical properties of anti-washout CSC systems with and without radiopacity, as compared to ProRoot WMTA and CPC, which can optimize the parameters. In the second year, we will study cell proliferation, differentiation, and bone formation of human mesenchymal stem cells and neonatal mouse calvaria osteoblasts between CSC, WMTA, and CPC. Additionally, the investigation of signal transduction pathway will be performed for further design of new materials. Finally, along with antibacterial activity, the in vivo bone-regenerative capacity and resorption of the cement specimens will be investigated in a rabbit femur defect model. After being implanted for 1, 3, 6 and 12 months, we will use microfocus computed tomography and histomorphometric analysis to investigate the osteogenic property and degradability of different cement systems. Combination of basic science and medical practice, pre-clinical results of this three-year research are expected to have a significant potency in the areas of biomaterials development and industry. |
