Tracking gene expression after DNA delivery using spatially indexed nanofiber Arrays

The penetration and residence of vertically aligned carbon nanofibers (VACNF) within live cell matrices is demonstrated upon substrates that incorporate spatially registered indices to facilitate temporal tracking of individual cells. Penetration of DNA-modified carbon nanofibers into live cells using this platform provides efficient delivery and expression of exogenous genes, similar to "microinjection "-styled methods, but on a massively parallel basis. Spatially registered indices on the substrate allow one to conveniently locate individual cells, facilitating temporal tracking of gene expression events. We describe fabrication and use of this gene delivery platform which consists of arrays of individual carbon nanofibers at 5-mum pitch within numerically indexed, 100-mum square grid patterns. Fabrication of these devices on silicon substrates enables mass production of 100 devices (5 mm(2)) per wafer, with each device providing over 800,000 nanofiber-based "needles" for cellular impalement and gene delivery applications.