Complexation d'ADN par des polynorbornènes polycationiques, application au transfert de gènes

Non-viral systems for gene transfection are essentially based on DNA complexation into particles by electrostatic interaction between polycationic polymers. In this context, polycationic derivatives of polynorbornene with different counterions (chloride, acetate, lactobionate), have been prepared by organometallic polymerization. According to the nature of the counterion, their complexation with the DNA led to aggregates with variable binding affinity for the plasmid. The transfection efficiency was compared, on the basis of reporter gene expression, in cells in culture. The nature of the counterion affects gene delivery, and the results obtained with the polynorbornene methyleneammonium lactobionate and acetate are particularly encouraging. Finally, a new family of polycationic polynorbornene as amphiphilic counterions have been prepared. These polymers form stable latexes in water with an amphilic sugar corona, and are able to bind and efficiently complex the DNA in very small aggregates.