Assessment of biocompatibility of chronically implanted polyimide and platinum intrafascicular electrodes.
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.
Lago
Natalia
N
Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autónoma de Barcelona, E08193 Bellaterra, Spain.
Yoshida
Ken
K
Koch
Klaus P
KP
Navarro
Xavier
X
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*
D001672:Biocompatible Materials; D012117:Resins, Synthetic; C029945:polyimide resin; D010984:Platinum