Abstract
Electrodes implanted in the brain or spinal cord trigger the activation of resident astrocytes. In their reactive state, astrocytes surrounding the electrode form a glial scar, compromising the ability of the electrode to interface with the surrounding neural tissue. One approach to reduce the inhibiting scar tissue is to incorporate nanoarchitecture on the surface of the implanted materials to modify the astrocytic response. The incorporated nanoarchitecture changes both the surface characteristics and the material properties of the implant interface. We investigated the response of rat cortical astrocytes to nanoporous anodic aluminum oxide (AAO) surfaces. Astrocytes were seeded onto nonporous aluminum control surfaces and AAO surfaces with average nanopore diameters of 20 and 90 nm. The surfaces were characterized by assessing their nanomorphology, hydrophobicity, surface chemistry, mechanical properties, and surface roughness. For cell response characterization, calcein-based viability and adhesion studies were performed. Plasmid-assisted vinculin live cell imaging was done to characterize focal adhesion number and distribution. Immunocytochemistry was used to assess glial fibrillary acidic protein (GFAP) expression. We found that astrocyte adhesion was significantly higher on small pore surfaces compared to large pore surfaces. Astrocytes produced more focal adhesions (FA) and distributed these FA peripherally when cultured on small pore samples compared to the other groups. Astrocyte GFAP expression was lower when astrocytes were cultured on surfaces with small nanopores compared to the control and large pore surfaces. These results indicate that unique surface nano porosities influence astrocyte adhesion and subsequent cellular response. The reduction in GFAP immunoreactivity exhibited by the smaller pore surfaces can improve the long-term performance of the implanted neurodevices, thus making them credible candidates as a coating material for neural implants.
Recommended Citation
D. Ganguly et al., "Specific Nanoporous Geometries on Anodized Alumina Surfaces Influence Astrocyte Adhesion and Glial Fibrillary Acidic Protein Immunoreactivity Levels," ACS Biomaterials Science and Engineering, vol. 4, no. 1, pp. 128 - 141, American Chemical Society, Jan 2018.
The definitive version is available at https://doi.org/10.1021/acsbiomaterials.7b00760
Department(s)
Chemical and Biochemical Engineering
Keywords and Phrases
alumina; astrocyte; cell adhesion; glial scar; nanopores; neural interface
International Standard Serial Number (ISSN)
2373-9878
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2025 American Chemical Society, All rights reserved.
Publication Date
08 Jan 2018
Comments
National Institutes of Health, Grant 1150125