Enhanced nuclear gene delivery via integrating and streamlining intracellular pathway

The essential challenge of gene therapy is to develop safe and efficient vectors that escort genes to target sites. However, due to the cumbersome workflow of gene transfection into cells, successive gene loss occurs. This leads to considerable reductions in nuclear gene uptake, eventually causing low gene expression. Herein, we designed a gene vector named CA₃S₂ (C: N,N'-cystamine-bis-acrylamide [CBA], A: agmatine dihydrochloride [Agm], S: 4-(2-aminoethyl) benzenesulfonamide [ABS]) with excellent gene transfection ability. This vector can promote gene delivery to the nucleus via enhanced endoplasmic reticulum (ER) targeting through integrating and streamlining of the complex intracellular pathway. Briefly, ABS endowed CA₃S₂/DNA nanoparticles with not only a natural ER-targeting tendency attributed to the caveolae-mediated pathway but also direct receptor-binding capacity on the ER surface. Agm enabled CA₃S₂ to enhance lysosomal escape and nuclear uptake ability. The gene delivery efficiency of CA₃S₂ was significantly better than that of polyethyleneimine 25K (PEI 25K). Therefore, CA₃S₂ is a promising gene carrier, and the ER-targeting strategy involving intracellular pathway integration and streamlining has potential for gene therapy.