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Title: Nanoporous Gold as a Neural Interface Coating: Effects of Topography, Surface Chemistry, and Feature Size

We report that designing neural interfaces that maintain close physical coupling of neurons to an electrode surface remains a major challenge for both implantable and in vitro neural recording electrode arrays. Typically, low-impedance nanostructured electrode coatings rely on chemical cues from pharmaceuticals or surface-immobilized peptides to suppress glial scar tissue formation over the electrode surface (astrogliosis), which is an obstacle to reliable neuron–electrode coupling. Nanoporous gold (np-Au), produced by an alloy corrosion process, is a promising candidate to reduce astrogliosis solely through topography by taking advantage of its tunable length scale. In the present in vitro study on np-Au’s interaction with cortical neuron–glia co-cultures, we demonstrate that the nanostructure of np-Au achieves close physical coupling of neurons by maintaining a high neuron-to-astrocyte surface coverage ratio. Atomic layer deposition-based surface modification was employed to decouple the effect of morphology from surface chemistry. Additionally, length scale effects were systematically studied by controlling the characteristic feature size of np-Au through variations in the dealloying conditions. In conclusion, our results show that np-Au nanotopography, not surface chemistry, reduces astrocyte surface coverage while maintaining high neuronal coverage and may enhance neuron–electrode coupling through nanostructure-mediated suppression of scar tissue formation.
 [1] ;  [2] ;  [2] ;  [3] ;  [3] ;  [2] ;  [4]
  1. Univ. of California, Davis, CA (United States). Dept. of Biomedical Engineering
  2. Univ. of California, Davis, CA (United States). Dept. of Molecular Biosciences
  3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  4. Univ. of California, Davis, CA (United States). Dept. of Electrical and Computer Engineering
Publication Date:
OSTI Identifier:
Grant/Contract Number:
AC52-07NA27344; 12-LR- 237197; DGE-1148897; T32-GM008799; U54 NS079202
Accepted Manuscript
Journal Name:
ACS Applied Materials and Interfaces
Additional Journal Information:
Journal Volume: 7; Journal Issue: 13; Journal ID: ISSN 1944-8244
American Chemical Society
Research Org:
Univ. of California, Davis, CA (United States)
Sponsoring Org:
Country of Publication:
United States
36 MATERIALS SCIENCE; neural electrode; nanostructure; cell−material interaction; nanoporous gold; neuron−astrocyte co-culture; nanotopography; multifunctional biomaterial; gliosis