title: Assessment of biocompatibility of chronically implanted polyimide and platinum intrafascicular electrodes.
abstract: Longitudinal intrafascicular electrodes (LIFEs) are electrodes designed to be placed inside the peripheral nerve to improve stimulation selectivity and to increase the recording signal-to-noise ratio. We evaluated the functional and morphological effects of either Pt wire LIFEs or polyimide-based thin-film LIFEs implanted in the rat sciatic nerve for 3 mo. The newly designed thin-film LIFEs are more flexible, can be micromachined and allow placement of more active electrode sites than conventional Pt LIFEs. Functional results at 1 mo indicated an initial decline in the nerve conduction velocity and in the amplitude of muscle responses, which recovered during the following 2 mo towards normal values. Morphological results showed that both types of LIFEs induced a mild scar response and a focal but chronic inflammatory reaction, which were limited to a small area around the electrode placed in the nerve. Both types of LIFEs can be considered biocompatible and cause reversible, minimal nerve damage.
authors.affiliation: Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autónoma de Barcelona, E08193 Bellaterra, Spain.
authors.forename: Natalia
authors.initials: N
authors.lastname: Lago
authors.forename: Ken
authors.initials: K
authors.lastname: Yoshida
authors.forename: Klaus P
authors.initials: KP
authors.lastname: Koch
authors.forename: Xavier
authors.initials: X
authors.lastname: Navarro
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001672:Biocompatible Materials / Q000009:adverse effects / Q000737:chemistry; D004567:Electrodes, Implanted / Q000009:adverse effects*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D000071938:Fasciotomy; D005549:Foreign-Body Reaction / Q000209:etiology* / Q000473:pathology; D009443:Neuritis / Q000209:etiology* / Q000473:pathology; D010984:Platinum / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012117:Resins, Synthetic / Q000009:adverse effects*; D012584:Sciatic Nerve / Q000502:physiology*
chemical_list: D001672:Biocompatible Materials; D012117:Resins, Synthetic; C029945:polyimide resin; D010984:Platinum