組織工程之構成要素包含支架、細胞以及調控細胞生長之訊息，相關研究多致?於如何使細胞容 ?在支架上貼附、遷移及分化，其中，支架的表面性質將扮演十分重要的角色。本研究以明膠及氫氧 基磷灰石製作成骨支架材?，透過化學法與生物結合法進?骨生長因子之固定，藉此促進幹細胞在材 ?上生長，進一步有效分化成骨母細胞。首先使用EDC/NHS 將?白素(avidin)以共價鍵鍵結在材?表 面，再?用?白素與生物素(biotin)的生物結合作用，使骨生長因子第二型骨形成蛋白(type II bone morphogenetic protein,BMP-2)在???於化學環境之下，穩定的固定在材?表面，保存原有的生物活 性，接著種植骨髓間質幹細胞於材?中進?體外評估，使用掃描式電子顯微鏡(scanning electron microscope, SEM)評估細胞貼附生長的情況，並以鹼性磷酸?活性分析(ALP activity assay)和骨鈣素 (osteocalcin)表現?評估幹細胞分化情況。初步實驗顯示以?白素與生物素之結合系統可有效將BMP-2 固定在材?上。
Three elements of Tissue Engineering is cells, scaffolds and signals. Surface characteristizations of scaffolds play an important role to facilitate cell adhesion, migration and differentiation. In this study, we prepared gelatin and surface-modified hydroxyapatite to make bone scaffolds. The surface modification is performed by the methods of covalence and non-covalence to immobilize biomolecules on scaffolds. Avidin as a medium, is immobilized on scaffolds surface by a chemical reaction of EDC/NHS. Then, biotin-conjugated growth factor is added and combined with immobilized avidin. BMP-2 is not only effectively immobilized on scaffolds surface, but also maintained bioreactive while it is excluded from the exposure of chemical environment. Otherwise, an experimental evaluation was adopted for seeding mesenchymal stem cells on scaffolds. We examined the growth and attachment of the cell by SEM, and observed the differentiation of the cell by ALP assay and osteocalcin expression. The research confirms that Avidin-Biotin system can effectively immobilize BMP-2 on the scaffold.
