Multi-walled carbon nanotubes for plasmid delivery into Escherichia coli cells

Introduction of foreign genes into bacterial cells (transformation) is used for supplementing defective genes or providing additional biological functions. Transformation can be achieved using either chemical or physical methods, e.g., electroporation. Bulk electroporation offers several advantages over chemical methods, including high transformation efficiency, but its application is limited due to the high numbers of cells and plasmids needed as a result of the high death rate of cells during this process, and the difficulty in electroporating single cells. Synthetic inorganic gene nanocarriers have received limited attention in the transformation of bacterial cells. Here we present a plasmid delivery system based on water dispersible multi-walled carbon nanotubes (CNTs) that can simultaneously target the bacterial surface and deliver the plasmids into the cells via temporary nanochannels across the cell envelope. Transformation experiments performed on E. coli provide evidence for the high potential of CNTs for nanoscale cell electroporation.