Information Technology Reference
In-Depth Information
Figure 8.10
Fluorescent micrographs of CHO cells expressing a vertically aligned
carbon nanofiber (VACNF)-delivered green fluorescent protein (GFP) gene. (a) Time-
lapse images of GFP-expressing cells from (top) spotted (nonspecifically adsorbed
plasmid) nanofibers, and (bottom) nanofibers with covalently linked plasmid. The
spotted samples tend to produce colonies of cells from initial transfectants, whereas
the covalently linked samples tend to maintain a constant number of GFP-expressing
cells. (b) A time-lapse sequence of a typical cell division on a covalently linked plas-
mid VACNF array indicating that the plasmid DNA is not segregated to progeny cells.
Within 1 day after cell division, no fluorescence is observed from the daughter cell
not retained on the nanofiber. (c) Brightfield image demonstrates that the daughter
cell still resides adjacent to the mother cell. This division and subsequent loss of GFP
expression in the daughter cells for covalently linked plasmid VACNF samples leads
to a constant number of GFP-expressing cells over long periods of time, as indicated
in the lower two panels of part a.
VACNFs provide the means to elevate cellular matrices above the substrate,
enhancing diffusion of molecular species while still providing electrical and
electrochemical interconnectivity with the suspended matrix (Figure 8.12).
CONCLUSIONS
The successful incorporation of whole cells as functional elements in microscale
and nanoscale devices requires a unique environment that fosters continued cell
viability and provides for information transport between the synthetic and bio-
logical substrates. There has been significant progress in this area from many
investigators, including the integrated circuit-based approach and the numerous
