Dendritic α,ε-poly(L-lysine)s as delivery agents for antisense oligonucleotides

`Purpose. To evaluate the potential use of dendritic alpha,epsilon-poly(L-lysine)s ( DPL) for the efficient cellular delivery of antisense oligonucleotides. Methods. A series of dendritic alpha, epsilon-polylysines of various generations were prepared. Their physical properties and the ability to form complex with oligonucleotide were investigated by polyacrylamide gel electrophoresis, capillary zone electrophoresis (CZE), agarose gel electrophoresis, fluorescence titration and atomic force microscopy (AFM). The efficiency to deliver oligonucleotide to HeLa cells, stably transfected with plasmid pLuc/ 705, was evaluated by using antisense splicing correction assay and confocal microscopy. Results. DPLs formed the complexes with antisense oligonucleotide with modest cytotoxicity. The charge ratio of oligonucleotide to DPL and the size (generation) of DPLs were all critical variables for the antisense effect. Compared to low generation DPLs, high generation DPLs were more effective in delivering oligonucleotide into cells. Conclusions. High generation DPL-oligonucleotide complexes were moderately effective for delivery antisense oligonucleotide. The complex formation provides a promise for in vivo therapeutic application of DPLs or their derivatives in the delivery of gene or oligonucleotide.