Biomedicine Nanowires as Needles to Poke Molecules into Cells A simple method may solve the problem of getting stuff into cells. by Courtney Humphries January 12, 2010 Sponsored by Beds of vertical silicone nanowires can act as a method for delivering molecules into cells. In this falsely colored scanning electron micrograph, a connective-tissue cell rests on these tiny spikes, which impale the membrane and allow direct access into the cell. A microscopic image of a cell with the structural protein tubulin tagged in fluorescent green is grown on a bed of nanowires, labeled with magenta (left). Viewing the cell without the wires shows the holes in its membrane where the nanowires have penetrated. Cells growing on the nanowires appear to behave normally; these rat neurons even form connections. The nanowires can be coated with various types of molecules to deliver them into cells. Here, the wires were used to deliver a gene encoding an orange-red fluorescent protein into human cells. Silicon nanowires can deliver a variety of different molecules at the same time. Here, a fluorescent protein (green) and a small RNA molecule (magenta) have been simultaneously, and yet distinctly, administered to cultured cells in a checkered pattern. Arraying different molecules, alone or in combination, makes it possible to perform parallel screens.