POLY 558 |
| Polyelectrolyte complexes of nucleic acids and polycations (polyplexes) are investigated as promising delivery vectors for a variety of nucleic acid therapeutics. Polyplexes capable of responding to environmental changes or stimuli by altering their properties and behavior promise a significant improvement of the efficacy of the delivery process. One of the suitable micro-environmental features is a redox potential gradient existing between extracellular environment and various subcellular organelles. The existence of such redox gradient can be exploited by incorporating disulfide bonds into the structure of polycations to provide the polyplexes with a capability to release the therapeutic cargo selectively in the subcellular reducing space. The focus of this paper is the synthesis of peptide and non-peptide reducible polycations (RPC) and their use in delivery of DNA and RNA. Our studies demonstrate that reducible polycations can be readily synthesized by an oxidative polycondensation. Polyplexes sensitive to redox potential gradients can be formulated as promising gene delivery vectors using the RPCs. In comparison with control polyethylenimine, only minimum toxic effects of RPCs are observed on the metabolic activity and membrane integrity of human endothelial cells. Synthetic strategy and biological properties, including toxicity and transfection activity, of the RPCs will be presented and the potential of these polymers in gene delivery discussed. |
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7th International Biorelated Polymers Symposium
8:30 AM-12:40 PM, Wednesday, 13 September 2006 San Francisco Marriott -- Salon 14/15, Oral
Division of Polymer Chemistry |