title: In vivo effects of L1 coating on inflammation and neuronal health at the electrode-tissue interface in rat spinal cord and dorsal root ganglion.
abstract: The spinal cord (SC) and dorsal root ganglion (DRG) are target implantation regions for neural prosthetics, but the tissue-electrode interface in these regions is not well-studied. To improve understanding of these locations, the tissue reactions around implanted electrodes were characterized. L1, an adhesion molecule shown to maintain neuronal density and reduce gliosis in brain tissue, was then evaluated in SC and DRG implants. Following L1 immobilization onto neural electrodes, the bioactivities of the coatings were verified in vitro using neuron, astrocyte and microglia cultures. Non-modified and L1-coated electrodes were implanted into adult rats for 1 or 4 weeks. Hematoxylin and eosin staining along with cell-type specific antibodies were used to characterize the tissue response. In the SC and DRG, cells aggregated at the electrode-tissue interface. Microglia staining was more intense around the implant site and decreased with distance from the interface. Neurofilament staining in both locations decreased or was absent around the implant, compared with surrounding tissue. With L1, neurofilament staining was significantly increased while neuronal cell death decreased. These results indicate that L1-modified electrodes may result in an improved chronic neural interface and will be evaluated in recording and stimulation studies.
authors: Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, USA.
authors: C L
authors: CL
authors: Kolarcik
authors: D
authors: D
authors: Bourbeau
authors: E
authors: E
authors: Azemi
authors: E
authors: E
authors: Rost
authors: L
authors: L
authors: Zhang
authors: C F
authors: CF
authors: Lagenaur
authors: D J
authors: DJ
authors: Weber
authors: X T
authors: XT
authors: Cui
mesh_terms: D000818:Animals; D034961:Antigens, Nuclear / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D002448:Cell Adhesion / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D004567:Electrodes, Implanted; D005727:Ganglia, Spinal / Q000187:drug effects / Q000201:enzymology / Q000473:pathology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007249:Inflammation / Q000473:pathology*; D008840:Microfilament Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D039842:Neural Cell Adhesion Molecule L1 / Q000494:pharmacology*; D016900:Neurofilament Proteins / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000187:drug effects / Q000473:pathology*; D013194:Staining and Labeling; D013499:Surface Properties / Q000187:drug effects; D014746:Vimentin / Q000378:metabolism
chemical_list: C100745:Aif1 protein, rat; D034961:Antigens, Nuclear; D002135:Calcium-Binding Proteins; D020099:Coated Materials, Biocompatible; D005904:Glial Fibrillary Acidic Protein; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D039842:Neural Cell Adhesion Molecule L1; D016900:Neurofilament Proteins; C546339:Rbfox3 protein, rat; D014746:Vimentin; C051774:neurofilament protein H; D053148:Caspase 3