Site-specific gene transfer with high efficiency onto a carbon nanotube-loaded electrode.

A transfection array, which is specifically developed for use in high-throughput analyses of genome functions by the over-expression or suppression of genes on a chip, is expected to become an important method for post-genome research. High efficiency of gene expression or suppression is indispensable for high-throughput analyses because the adherent cell number on a single spot decreases as the density of spots increases in the transfection array. We have studied an electro-stimulated pore formation on the cell membrane for gene delivery. Fine pores should be formed on the cell membrane to increase the efficiency of gene transfection without cell damage. Herein, we examined the electrode carrying chemically functionalized carbon nanotubes (CNTs) on the surface. The CNTs were loaded on a gold electrode with a self-assembled monolayer membrane by electrostatic interaction. Adsorbed plasmid DNA was transfected with higher efficiency into adherent cells on the CNT-loaded electrode than on an electrode without CNTs. This result may be due to the strong but fine field emission formed from the tips of the CNTs.