碩士 / 國立臺灣科技大學 / 化學工程系 / 102 / Cyanophycin is a kind of biopolymers. By genetic recombination, the main chain of cyanophycin is aspartic acid, and the side chain is composed of arginine and lysine. The lysine contains primary amines, and allows chemical modifications. Branched polyethyleneimine (BPEI) is a cationic polymer, and has been extensively studied as a non-viral vector. However, as molecular weight increases and transfection efficiency is enhanced, PEI will produce high cytotoxicity.
In this study, cyanophycin was cross-linked with BPEI of different molecular weights by glucose. It was expected to mitigate cytotoxicity, maintain transfection efficiency, and eventually obtain an optimal mixing ratio and weight ratio. The results suggest that the optimal transfection efficiency occurs when the molar ratio of BPEI monomer and glucose equals to 1. Moreover, BPEI modified with cyanophycin can effectively mitigate cytotoxicity and maintain transfection efficiency which is close to the control group, BPEI25kDa, at the optimal ratio.
From the physical properties tests, the surface of vectors have positive zeta potentials, which are lower than the PEI25kDa. With the increases in molecular weight and the molar ratio of PEI in the vector, the surface zeta potential rises but the hydrodynamic size of the vector decreases. The vectors still retain 20-50% of nucleic acids under negatively charged conditions. Compared with the control group, the vectors increased the stability. Finally, from the results of protein delivery, both S-CGP/1PEI25kDa/1GC and S-CGP/4PEI25kDa/4GC have excellent efficiency. For future studies, changing the weight ratio of protein/polymer or using different proteins will extend the applications of the carrier.
| Identifer | oai:union.ndltd.org:TW/102NTUS5342091 |
| Date | January 2014 |
| Creators | Pei-Ying Lin, 林佩穎 |
| Contributors | Wen-Chi Tseng, 曾文祺 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 84 |
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