Efficient gene transfection in the neurotypic cells by star-shaped polymer consisting of β-cyclodextrin core and poly(amidoamine) dendron arms

In order to develop the effective vectors that had high gene transfection capability and low cytotoxicity in the neuronal cells, we tested the star-shaped polymer consisting of β-cyclodextrin core and poly(amidoamine) (PAMAM) dendron arms [β-CD-(D3)7] as the vector to transfect the human neuroblastoma SH-SY5Y cells. The physicochemical properties of the β-CD-(D3)7/plasmid DNA (pDNA) complexes were characterized by using gel electrophoresis, dynamic light scattering, transmission electron microscopy and zeta-potential experiments. Among the human neuroblastoma SH-SY5Y cells, β-CD-(D3)7/pDNA complex demonstrated a lower toxicity compared to those of PAMAM (G = 4, with an ethylenediamine core)/pDNA complex. When the N/P ratio was over 20, it was observed that PAMAM had a faster increment in toxicity compared to β-CD-(D3)7. Fluorescent image, confocal microscopy image and flow cytometry showed that β-CD-(D3)7/pDNA complexes had significantly higher transgene activity than that of PAMAM/pDNA complexes. For example, the transfection efficiency was 20% and 7.5% for β-CD-(D3)7/pDNA and PAMAM/pDNA complexes, respectively. These results indicated that β-CD-(D3)7 might be a promising candidate for neurotypic cells gene delivery with the characteristics of good biocompatibility, relatively high gene transfection capability and potential in vivo gene delivery ability.