Characterisation of plasmid DNA conjugates as a basis for their processing

Plasmid DNA complexes have been used by several research groups for gene th erapy applications and have given promising results during preliminary clin ical trials. However, their eventual adoption for the treatment of a wide r ange of genetic diseases requires considerable progress with regards to car rier formulation and processing.,Amongst the key parameters that are known to be important and need further elucidation are the size and surface charg e of the conjugates and the binding efficiency of the carrier to the DNA. The present study has focused on two synthetic carriers with different form ulation and charge characteristics, both of which have been recommended in the literature as having the potential to deliver genes to target cells. Th ese were a cationic lipid (DC-chol/DOPE) and a polylysine-condensed anionic liposome (OA/DOPE/Chol). Conjugate size, zeta potential, stability and bin ding efficiency were measured for conjugates of DNA plasmids of molecular w eights between 6.9 kb and 29 kb. Plasmids were condensed by polylysine of t wo different molecular weights with or without cationic lipids.