| 摘要: | 目前治療疾病，除了一般的化學藥物治療，另一個較好的方案就是基因治療，而有效的基因治療必須依靠載體系統，良好的載體系統則必須具備較高的轉染能力及低的細胞毒性，這兩點重要之因素。本研究主要的目的是利用新開發之聚胺基甲酸酯基因載體對市面上常用的基因載體PEI25K進行物理性摻合修飾，並且評估其生物化學性質。首先本研究合成聚(酯-胺基甲酸酯) (PUE)，此共聚合物之主鏈含有胺基甲酸酯及酯類之官能基，而側鏈則帶有胺基。由動態光學散射儀測定，發現此型陽離子型高分子PUE可與DNA形成奈米級的複合體，粒徑大小為120-195 nm且帶正電。水解實驗中可得到PUE水解半衰期為35小時，從緩衝能力測試結果可得知此高分子上攜帶之二級胺，使緩衝能力曲線之斜率更接近PEI25K，由此可證實此高分子具有不錯之緩衝效率。最後利用COS-7細胞株與Hela細胞株進行毒性測試，並與PEI25K進行比較，得知其毒性比PEI25K更低。接著本研究藉由合成出之高分子PUE與市面上最常使用之基因載體PEI25K進行物理性摻合修飾，作為更新穎之基因載體，以250/1、200/1、150/1、100/1、75/1、50/1、25/1、10/1、5/1、1/1高分子摻合組成比例進行製備及研究，由實驗結果發現，經由物理摻合修飾過後之載體複合體，與DNA縮合之複合體粒徑大約為170nm，比單純的載體材料之粒徑更小，帶正電荷，且電荷介於兩個單純的基因載體之間，而從緩衝能力試驗中可看出，經由摻合修飾之複合體，緩衝能力並不會比單純的PEI25K差，細胞毒性更是因為PUE的修飾,變的更低。藉由物理摻合修飾之方法，可以在短時間內得到具有更小的粒徑，並且具有更低毒性之基因載體，藉此達到載體系統在能力上不足之問題。
In addition to chemotherapy, the current treatment of diseases .The effective gene therapy vector system must rely on good vector system which must have a high transfection capability and low cytotoxicity . The purpose of this study is develope a new gene vector containing cationic polyurethane and PEI25k, and to assess their biochemical properties. First, the study of poly (ester - polyurethane) (PUE), the total of polymer containing polyurethane and ester functional groups is based on the main chain and side chain with an amine. Measured by the dynamic optical scattering and found that this type of cationic polymer PUE with nanoscale DNA complex formation, particle size is 120-195 nm and positively charged. Hydrolysis, hydrolysis half-life of PUE available 35 hours, from the experiment results of this polymer buffer with good buffering capacities. Finally, COS-7 cells and HELA cell lines do toxicity compared with PEI25k, that the results with low toxicity. Then this study, we synthesized the polymer PUE and the market most commonly used gene vectors PEI25k blending the physical nature of modification, as more novel gene vector to 1 / 250, 1 / 200, 1 / 150, 1 / 100,1 / 50,1 / 25,1 / 10,1 / 5,1 / 1 polymer blend composition for preparation and study, the experimental results showed that after modification by physical blending of the vector, and condensation of DNA complex particle size about 170nm, more than a simple carrier particle size is small, with a positive charge, and between the two vectors between the ability to test from the buffer can be seen, through the modification of the complex blend, buffer capacity and will not be worse than the simple PEI25K, cytotoxicity is because of the modification of PUE, become lower. Modified by physical blending methods, can be obtained in a short time with a smaller particle size, and has lower toxicity of the gene vector, vector system to meet the deficiencies in capacity on the issue. |
