Brain astrocyte cell taking up carbon nano-needles, SEM

False-coloured scanning electron microscope of an astrocyte cell (brown) in the process of taking up carbon nanotubes (green). Carbon nanotubes are allotropes of carbon with a cylindrical nanostructure which have been recently explored as drug delivery systems due to their 'nano-needle' characteristics. Diameter of the cell is approximately 20 micrometres.