藍藻蛋白是由非核醣體合成的蛋白質，經由基因重組生產的藍藻蛋白在構造上以天門冬胺酸(aspartic acid)為骨架，在側鏈上接有精胺酸(arginine)以及離胺酸(lysine)；葡聚醣是由葡萄糖分子構成的多醣，具有良好的親水性以及生物相容性；硫化葡聚醣是具有生物可降解性和擁有類似於肝素(heparin)的生物相容性的聚陰離子，以醣類為骨架接有帶負電荷的硫酸基的高分子。本研究目的是以戊二醛進行交聯反應製備不同比例的藍藻蛋白-葡聚醣與藍藻蛋白-硫化葡聚醣3D的組織支架，期望組織支架擁有藍藻蛋白、葡聚醣和硫化葡聚醣的特性。
實驗將葡聚醣以及硫化葡聚醣做個別的修飾後，再以化學鍵結將兩個修飾過後高分子分別與藍藻蛋白接枝，形成更具生物相容性的高分子。將葡聚醣進行開環使其醛基的比例增加，以利後續與藍藻蛋白做接枝，並期望接枝率接近於10%；硫化葡聚醣則是讓其接上羧基，以利後續與藍藻蛋白做接枝，並對其做TNBSA (2,4,6 - Trinitrobenzene Sulfonic Acid assay)測定接枝情形；對兩者接枝材料進行MTT毒性測試。最後再以不同重量比混合，在96 well中以戊二醛進行交聯反應，形成3D的組織支架，對其進行探討。
實驗結果顯示，在葡聚醣-藍藻蛋白組別接枝率大約為10%；硫化葡聚醣-藍藻蛋白組別也利用TNBSA間接確認其接枝；在毒性測試方面，材料並無顯著的毒性；測量3D組織支架體積方面，發現在硫化葡聚醣-藍藻蛋白含量較多時，體積明顯的會比較小；由含水率可以觀察到，無論在哪種比例皆能在短時間內達到很龐大的含水率，從數據可以看出葡聚醣-藍藻蛋白對含水率的影響相較於葡聚醣-藍藻蛋白來的明顯；藉由Scanning electron microscope (SEM)觀察不同比例組織支架，可發現到不同比例形成的組織支架，表面與切面皆呈現孔洞型態。
綜上所述，所形成的3D組織支架具有良好親水性以及細胞遷入時適當的孔洞大小，期望未來投入細胞做觀察。

Cyanophycin, a non-ribosomal synthesis protein, can be produced by recombinant Escherichia coli. The polymer consists of a polyaspartic acid backbone with arginine and lysine as a side chain. Dextran is a polysaccharide composed by glucose molecules, and is capable of good hydrophilicity and biocompatibility. Dextran sulfate is capable of good biodegradability and it has biocompatible polyanion as heparin. Its structure is a polysaccharide which has negatively charged sulfate groups. In this study, we prepared differnet ratios of cyanophycin - dextran/ cyanophycin - dextran sulfate composite 3D scaffolds by cross-linking reaction with glutaraldehyde. We expect that scaffolds have their properties.
We modified the dextran and dextran sulfate by different method, and then the two polymers which had been modified were grafted with cyanophycin by chemical bonding in order to make more biocompatible polymer. We made the dextran have more aldehyde group in order to make it graft with cyanophycin. We except that the grafting ratio is up to 10%. We also made the dextran sulfate have carboxyl group in order to make it graft with cyanopycin. The graft information of cyanophycin - dextran sulfate was determind by TNBSA. We detected the toxicity of the two polymers (cyanophycin-dextran and cyanophycin dextran sulfate) by the MTT assay. Finally, we mixed cyanophycin-dextran and cyanophycin dextran sulfate in different weight ratio, and then the mixed polymer solution were cross-linked with glutaraldehyde to form 3D scaffold.
The result showed that the cyanophycin-dextran had the grafting ratio about 10%. We confirmed that the cyanophycin-dextran sulfate had grafted with each other. We had information that cyanophycin-dextran and cyanophycin-dextran sulfate was not toxic from MTT assay.
We measured the volume of 3D scaffolds which have different contain of cyanophycin-dextran and cyanophycin-dextran sulfate. The data showed that if cyanophycin-dextran sulfate contains large proportion in the scaffold, the volume will be relatively small. The swelling ratio of scaffolds showed that each scaffold had massive swelling ratio in short time and it also showed that cyanophycin-dextran had more influence than cyanophycin-dextran sulfate on the swelling ratio. The SEM data showed that both surface and cross section had pores.
In conclusion, the scaffold had good hydrophilicity. The scaffolds will be good for cells to migrate because of their proper pore size. We expect that it can use in cell culture.

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