Extended studies will be needed to evaluate the nanoES for longer-term implants,
although the major component of nanoES, SU-8, has demonstrated long-term
chronic biocompatibility suitable for in vivo recording [ 42 , 43 ].
Fig. 4.13 NanoES innervated synthetic neural tissue. 3D reconstructed confocal images of rat
hippocampal neurons after 2 week culture in Matrigel™on self-organized nanoES. Red (Alexa
Fluor®546): neuronalb-tubulin, yellow (rhodamine 6G): epoxy ribbons. The metal interconnects
are false-colored in blue, and are imaged in reflected light mode. White arrow highlights a neurite
passing through a ring-like structure supporting a nanowire FET. Dimensions inax: 317lm; y:
317 lm; z: 100lm; inbx: 127lm; y: 127lm; z: 68lm.c,dThe images were rotated from the
view shown in (b) approximately as follows: (left image) 90° about z-axis,−10° about y-axis;
(right image) 90° about z-axis, 100° about y-axis, 40° about x-axis. Together, these images show
unambiguously that neurites pass through the ring-like structures supporting individual nanowire
FETs
54 4 Three-Dimensional Macroporous Nanoelectronics...