Self Assembled Nanostructures of Triblock Co-polymer and Plasmid DNA for Gene Delivery

H.K. Daima, S. Shankar, P.R. Selvakannan, S.K. Bhargava, V. Bansal
RMIT University, AU

Keywords: tri-block copolymer, gene delivery, transformation


In present work, we have used tri-block copolymer (PEO-PPO-PEO) as a non-viral vector to deliver plasmid DNA (pDNA). Green fluorescence protein (GFP) plasmid DNA was used as a model plasmid DNA. Addition of pDNA to the aqueous solution of triblock co-polymer, led to the formation of self assembled polymer-pDNA complex. Mixtures of different weight ratios of polymer and pDNA have been made to screen the optimum ratio to achieve high transformation. Formation of polymer-pDNA complex was conformed from the gel electrophoresis studies. DNA transformation studies were carried using wild type E. coli DH5α as model microorganism. We have observed high pDNA transformation and our results revealed that the biocompatible tri-block copolymer is an appropriate candidate for non-viral DNA transfer and it alleviates the drawbacks of the conventional cationic vectors/DNA complexes. Self assembled structures between the pDNA and polymer were studied using TEM, XPS and FTIR techniques in order to understand the nature of interaction between the pDNA and the polymer. We have observed that those interactions and vesicle formation are purely electrostatic, which is required for the pDNA release in the cell cytoplasm.