藍藻蛋白為一種非核醣體合成蛋白質存在於藍綠藻菌中，經由基因重組後利用大腸桿菌來生產藍藻蛋白，其結構為aspartic acid為骨架arginine與lysine為側鏈組成。明膠主要來源為動物的皮膚、骨骼與結締組織，由不同的胺基酸形成龐大且複雜的多肽分子再以不同方式排列形成三股螺旋。
藍藻蛋白與明膠皆具有良好的生物相容性，近幾十年明膠已廣泛利用於生醫材料上，而藍藻蛋白因機械性質較差還未被廣泛使用，本研究希望藉由戊二醛將明膠與藍藻蛋白薄膜進行交聯反應，提高藍藻蛋白的應用性。
首先將藍藻蛋白與明膠混合溶液於鐵氟龍片上風乾成膜後利用戊二醛進行交聯，將交聯過後的薄膜取下用萬能試驗機測試其機械性質，結果顯示隨著藍藻蛋白混合比例越高，其抗拉強度與伸長率有所下降。在膨脹率研究方面，將藍藻蛋白/明膠複合薄膜浸泡於37 ℃磷酸鹽緩衝溶液，測得其膨脹率隨著藍藻蛋白混合比例越高有下降趨勢，但仍保有一定膨脹率。最後以掃描式電子顯微鏡觀察薄膜表面，顯示出整體上薄膜表面完整且平坦，並沒有因為交聯或取膜過程中出現孔洞或明顯的裂痕。

Cyanophycin granule polypeptide (CGP) is a non-ribosomal protein found in cyanobacteria. CGP which is composed of aspartic acid (back bone), arginine and lysine (side chain) is produced with Escherichia coli through recombinant technology. Gelatin whose sources are animal skin ,bone and connective tissue is large and complex polypeptide of different amino acids, then arranged in different ways to form a triple helix.
Both of CGP and gelatin are well biocompatible. In recent decades, gelatin is widely used in biomaterials. However, CGP exhibits poor mechanical properties which limit its possible applications. In this study, to improve the applicability of CGP, we made CGP crosslink with gelatin by glutaraldehyde reaction.
In the beginning, we air-dried the mixed CGP/gelatin solution on teflon plate. After that we made the films crosslink with glutaraldehyde. The films were removed after crosslinking, and then we used universal test machine to test their mechanical properties. The result exhibits both tensile strength and elongation decreased with higher mixing ratio of CGP. In the swelling studies, the CGP/gelatin films were immersed in phosphate buffered saline at 37 ℃. We obtained the result that the swelling trend was downward with higher mixing ratio of CGP. Finally, using scanning electron microscopy to observe the surface morphology of the films, we found it smooth and homogeneous. They didn’t show cracks or holes when we removed the film froms teflon plate or during the crosslinking.

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