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. 2010 May 28:3:8.
doi: 10.3389/fneng.2010.00008. eCollection 2010.

Biocompatibility of intracortical microelectrodes: current status and future prospects

Cristina Marin  1 , Eduardo Fernández
Affiliations

Biocompatibility of intracortical microelectrodes: current status and future prospects

Cristina Marin et al. Front Neuroeng. .

Abstract

Rehabilitation of sensory and/or motor functions in patients with neurological diseases is more and more dealing with artificial electrical stimulation and recording from populations of neurons using biocompatible chronic implants. As more and more patients have benefited from these approaches, the interest in neural interfaces has grown significantly. However an important problem reported with all available microelectrodes to date is long-term viability and biocompatibility. Therefore it is essential to understand the signals that lead to neuroglial activation and create a targeted intervention to control the response, reduce the adverse nature of the reactions and maintain an ideal environment for the brain-electrode interface. We discuss some of the exciting opportunities and challenges that lie in this intersection of neuroscience research, bioengineering, neurology and biomaterials.

Keywords: brain-machine interface; coating; glial scar; neural interface; neural prosthesis.

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Figures

Figure 1
Figure 1
Development of glial encapsulation on an intracortical microelectrode. (A) Acute neural injury caused by inserting a microelectrode into the brain cortex. Astrocytes and microglial cells become activated and migrate to the site of injury. (B) Chronic response showing a dense sheath around implanted probes, which contains fibroblasts, macrophages and astrocytes. (C,D) The reactive astrocytes, immunohistochemically labeled here for GFAP, encapsulate the neural probes forming a dense cellular sheath. Calibration bar = 50 μm.
Figure 2
Figure 2
Photomicrograph showing astrocytes (GFAP staining, red) and neurons (NeuN staining, green) around one microelectrode track (asterisk) following chronic implantation of a NeuroProbes multielectrode array in rabbit occipital cortex. Calibration bar = 50 μm.
Figure 3
Figure 3
Summary of optimum surface behavior for an implanted neural probe. (A) Surface of encapsulation and insulation material: adsorption of proteins and adhesion of fibroblast for good incorporation into the tissue, no reaction of macrophages. (B) Surface without electrodes: good contact to neurons and glial cells, no reaction of macrophages. (C) Surface of electrodes: attraction and good contact to neurons, no adhesion of fibroblasts, no macrophage reaction.
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References

    1. Agnew B. J., Duman J. G., Watson C. L., Coling D. E., Forte J. G. (1999). Cytological transformations associated with parietal cell stimulation: critical steps in the activation cascade. J. Cell. Sci. 112, 2639–2646 - PubMed
    1. Asplund M., Thaning E., Lundberg J., Sandberg-Nordqvist A. C., Kostyszyn B., Inganas O., von Holst H. (2009). Toxicity evaluation of PEDOT/biomolecular composites intended for neural communication electrodes. Biomed. Mater. 4, 45009. 10.1088/1748-6041/4/4/045009 - DOI - PubMed
    1. Azemi E., Stauffer W. R., Gostock M. S., Lagenaur C. F., Cui X. T. (2008). Surface immobilization of neural adhesion molecule L1 for improving the biocompatibility of chronic neural probes: in vitro characterization. Acta Biomater 4, 1208–1217 10.1016/j.actbio.2008.02.028 - DOI - PubMed
    1. Biran R., Martin D. C., Tresco P. A. (2005). Neuronal cell loss accompanies the brain tissue response to chronically implanted silicon microelectrode arrays. Exp. Neurol. 195, 115–126 10.1016/j.expneurol.2005.04.020 - DOI - PubMed
    1. Biran R., Martin D. C., Tresco P. A. (2007). The brain tissue response to implanted silicon microelectrode arrays is increased when the device is tethered to the skull. J. Biomed. Mater. Res. A. 82, 169–178 10.1002/jbm.a.31138 - DOI - PubMed