Biomedical Engineering Reference
Fig. 2 Bright-fi eld light microscopy images of glass coverslips coated with PEI ( a ), SWCNT-PEI
( b ), and AP-MWCNTs ( c ). Fluorescence images show live hippocampal neurons accumulating
calcein and grown on PEI ( d ), SWCNT-PEI ( e ), and AP-MWCNT ( f ). Arrows indicate growth
cones. Scale bar, 20 m m. ( g ) Drawing summarizing the effect of charge “dilution” on the neurite
outgrowth and branching. Neurons grown on SWCNT-PEI graft copolymer display neurite out-
growth and branching intermediate to those exhibited when grown on PEI and AP-MWCNTs.
Modifi ed from (Hu et al. 2005 )