Novel cationic lipidic peptide dendrimer vectors - In vitro gene delivery

Cationic lipidic dendrimers with a well-defined diameter and a precise numb er of terminal amines (from eight to thirty-two groups) were synthesised us ing a solid support. The application of dendrimers with widely varied geome tries in gene delivery has been studied by estimating transfection efficien cy of members of the series, with variable branch length, position of attac hment of lipid, the presence of a sugar unit and presence of a nuclear loca lization signal peptide. The transfection activity of the products was assa yed in vitro on Cos-7 (fibroblast) cells. Dendrimers (1a and 1b) displayed high transfection activities. Results indicated that the presence of more a mino groups on the surface of the the dendrimers could enhance gene deliver y. A primary physiocochemical characterization of the DNA/lipid complexes d emonstrated the amount of dendrimers with eight transfection of 2.5 mu g pl asmid(10 ug/ml for the dendrimers with eight free amino terminals and 5 and 2.5 mu g/ml for the dendrimers with sixteen and thirty-two free amino term inals, respectively).