In Vitro Transfection Mediated by Dendrigraft Poly(L-lysines): The Effect of Structure and Molecule Size

Dendritic poly(L‐lysines) (DGL) constitute promising nanomaterials applicable as a nonviral gene‐delivery vector. In this study, we evaluate the transfection abilities of four DGL generations with special emphasis on the systematic description of the relationship of how generation (i.e., molecule size) affects the transfection efficacy. Using Hep2 cells, we demonstrated that the capability of unmodified DGL to deliver plasmid is of a magnitude lower than that of jetPEI. On the other hand, employing the Hep2 cell line stably transduced with eGFP, we observed that DGL G5 delivers the siRNA oligonucleotide with the same efficiency as Lipofectamine 2000. In further experiments, it was shown that DGL affords excellent ability to bind DNA, protect it against DNase I attack, and internalize it into cells. The relationship between the molecule size of dendrigraft poly(L‐lysines) (DGL) and their transfection abilities is described systematically. The DGL transfection capability for oligonucleotide is much higher than for plasmid, while generations G3, G4, and G5 are more effective transfection mediators in comparison with G2. A possible structure‐based explanation for the transfection behavior of DGL is given.