| 초록 |
As a gene carrier, many polycationic polymer have been applied for gene therapy, because they form the complex with plasmid DNA. Comparing with other polycationic polymer, chitosan has many advantages such as biodegradability, biocompatibility and nontoxicity. Chitosan was first described as a delivery system for plasmids by Mumper et al. In this study, we revealed the effects of experimental conditions such as pH of medium and molecular weight of low molecualr water soluble chitosan (LMWSC) on the transfection efficiency of plasmid/chitosan complex. In pH 7.4, LMWSC with molecular weight of l0K and 20K formed complex with plasmid DNA at high charge ratio, above 1:10. But, when pH of medium is 6.0, they formed complex above 1:2. Generally, chitosan is more stable at the low pH, because pKa of primary amines in chitosan is around 6.3 ～ 6.4. Also, the similar pH dependence on the transfection efficiency was observed in serum-free medium. The transfection efficiency of LMWSC to 293T cells was significantly higher than that of naked DNA for all molecular weight. |
