PEGylated lipoplexes: Preparation Protocols affecting DNA condensation and cell Transfection efficiency

The inclusion of poly(ethylene glycol) monolaurate in liposomes formulated with dimyristoyl-sn-glycero-3-phosphocholine and certain cationic gemini surfactants improves their capability of condensing DNA into a psi phase and transfecting it into cells. Both the condensation, observed by circular dichroism, and the transfection efficiency are strongly effected by the protocol of inclusion of the polymer in the formulations. The highest transfection efficiency is observed in correspondence of the highest extent of DNA condensation.