How transient alterations of organelles in mammalian cells submitted to electric field may explain some aspects of gene electrotransfer process.

Electric pulses can be used to transiently permeabilize the cell plasma membrane. This method is nowadays employed as a safe and efficient means to deliver therapeutic molecules into target cells and tissues. Despite the large bulk of literature on this topic, there is a lack of knowledge about the mechanism(s) of molecule delivery.

Cholesterol implications in plasmid DNA electrotransfer: Evidence for the involvement of endocytotic pathways.

The delivery of therapeutic molecules such as plasmid DNA in cells and tissues by means of electric fields holds great promise for anticancer treatment. To allow for their therapeutic action, the molecules have first to traverse the cell membrane. The mechanisms by which the electrotransferred pDNA interacts with and crosses the plasma membrane are not yet fully explained.

New insights in the visualization of membrane permeabilization and DNA/membrane interaction of cells submitted to electric pulses.

Electropermeabilization designates the use of electric pulses to overcome the barrier of the cell membrane. This physical method is used to transfer anticancer drugs or genes into living cells. Its mechanism remains to be elucidated.

Polynorbornene polycationic polymers as gene transfer agents. Influence of the counterion for in vitro transfection.

Polycationic derivatives of polynorbornene with different non-cytotoxic counterions, have been prepared by organometallic polymerization of methyleneammonium norbornene and subsequent exchange of the counterion. In this paper the effect of the counterion on the polycationic polymer binding onto plasmid DNA was studied via different ethidium bromide assays, heparin displacement and protection against degradation by DNAse. According to the nature of the counterions and consequently the size of the polymer particles, their complexation with the DNA led to aggregates with variable binding affinity for the plasmid.

Effect of electric field vectoriality on electrically mediated gene delivery in mammalian cells.

Electropermeabilization is a nonviral method used to transfer genes into living cells. Up to now, the mechanism is still to be elucidated. Since cell permeabilization, a prerequired for gene transfection, is triggerred by electric field, its characteristics should depend on its vectorial properties.

Kinetic mechanism for the formation of the presynaptic complex of the bacterial recombinase RecA.

RecA protein from Escherichia coli catalyzes DNA strand exchange during homologous recombination in a reaction that requires nucleoside triphosphate cofactor. In the first step of this reaction RecA protein polymerizes on single-stranded DNA to form a filament with a stoichiometry of three nucleotides/RecA monomer called the presynaptic complex. We have used fluorescence anisotropy of a fluorescein-labeled oligonucleotide to investigate presynaptic complex formation.