Gene delivery to tumor cells by cationic polymeric nanovectors coupled to folic acid and the cell-penetrating peptide octaarginine.

Target ligand folic acid (FA) and cell-penetrating peptide octaarginine (R8) were coupled with the gene vectors (PEI(600)-CyD, PC) composed of β-cyclodextrin (β-CyD) and low-molecular-weight polyethylenimine (PEI, Mw 600) to form nanovectors for highly efficient gene delivery to tumor cells. The resultant ternary nanocomplexes of FA-PC/R8-PC/pDNA produced excellent gene transfaction abilities in the folate receptor (FR)-positive tumor cells in vitro and in vivo. The FR-mediated endocytosis and the R8-mediated transmembrane functionality together contributed to the high transfection levels. This study provides a promising means to produce gene nanovectors for in vivo applications.