Cellular Internalization Study Of Poly(Vinyldiaminotriazine)-based Hydrogen Bonding Type Gene Transfer System

Previously we successfully established poly(vinyldiaminotriazine) (PVDT)-based nonviral vectors which was capable of complexing plasmid DNA via hydrogen bonding with adenine-thymine base pairs. In this thesis, gel retarded electrophoresis was applied to confirm the formation of hydrogen bonding between these vectors complex and plasmid DNA. Zeta potentials and complex sizes of this system were further examined: data showed that PVDT-based polymer could cover surface charges of DNA resulting in slightly negative or neutral complexes. It was also found that the complex sizes were governed by two events- the aggregation induced by the instability of neutral particles, and much compact complexes produced by PVDT-based polymers. In study of cellular uptake, chlorpromazine and filipin III were used to inhibit clathrin- and caveolae- mediated endocytosis, respectively. The results indicated that PVDT-based systems were transported into cells via a non-clathrin, non-caveolae mediated endocytosis. This special process was studied by temperature inhibition and kinetics assays. It was revealed that such a pathway is characterized by 1) a more energy dependent process and 2) a much slow transfection-effective internalization.