Abstract
The long-term stability of implanted micromachined neural probes is compromised due to the glial scar formation at the insertion site. In this study, we developed a novel nitrocellulose-based coating for the sustained local delivery of the anti-inflammatory drug dexamethasone, a synthetic glucocorticoid that effectively reduces inflammation in the CNS. In vitro dexamethasone release was observed over 16 days, with a relatively high release in the first three days and a slow, stable release thereafter. When Michigan neural recording probes coated with and without dexamethasone-loaded nitrocellulose coatings were implanted into the adult rat brains, immunohistochemical evidence shows a marked reduction of reactive astrocytes (GFAP), reactive microglia (ED1), and chondroitin sulfate proteoglycans (CS56) expression around the insertion site compared to uncoated probes. Impedance spectroscopy showed that the dexamethasone-loaded nitrocellulose coatings slightly reduce the magnitude of electrode impedance at the biologically relevant frequency of 1 kHz through an increase of capacitance. In vivo acute recordings demonstrate that extracellular recordings with coated probes are akin to non-coated probes and it is anticipated that with time, the coated probes will exhibit superior performance. In conclusion, we developed a novel nitrocellulose-based, drug releasing coating for neural electrodes that can effectively reduce scar tissue formation without adversely affecting the electrical performance of the electrodes.
Original language | English |
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Pages | 522-525 |
Number of pages | 4 |
DOIs | |
State | Published - 2005 |
Event | 2nd International IEEE EMBS Conference on Neural Engineering, 2005 - Arlington, VA, United States Duration: 16 Mar 2005 → 19 Mar 2005 |
Conference
Conference | 2nd International IEEE EMBS Conference on Neural Engineering, 2005 |
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Country/Territory | United States |
City | Arlington, VA |
Period | 16/03/05 → 19/03/05 |