title: Porous silicon as a potential electrode material in a nerve repair setting: Tissue reactions.
abstract: We compared porous silicon (pSi) with smooth Si as chip-implant surfaces in a nerve regeneration setting. Silicon chips can be used for recording neural activity and are potential nerve interface devices. A silicon chip with one smooth and one porous side inserted into a tube was used to bridge a 5 mm defect in rat sciatic nerve. Six or 12 weeks later, new nerve structures surrounded by a perineurium-like capsule had formed on each side of the chip. The number of regenerated nerve fibers did not differ on either side of the chip as shown by immunostaining for neurofilaments. However, the capsule that had formed in contact with the chip was significantly thinner on the porous side than on the smooth side. Cellular protrusions had formed on the pSi side and the regenerated nerve tissue was found to attach firmly to this surface, while the tissue was hardly attached to the smooth silicon surface. We conclude that a pSi surface, due to its large surface area, diminished inflammatory response and firm adhesion to the tissue, should be a good material for the development of new implantable electronic nerve devices.
authors.affiliation: Nano Neuro Research Center, Lund University, Sweden. per_fredrik.johansson@cob.lu.se
authors.forename: Fredrik
authors.initials: F
authors.lastname: Johansson
authors.forename: Lars
authors.initials: L
authors.lastname: Wallman
authors.forename: Nils
authors.initials: N
authors.lastname: Danielsen
authors.forename: Jens
authors.initials: J
authors.lastname: Schouenborg
authors.forename: Martin
authors.initials: M
authors.lastname: Kanje
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000009:adverse effects / Q000737:chemistry*; D004599:Electric Stimulation Therapy / Q000295:instrumentation*; D004567:Electrodes, Implanted / Q000009:adverse effects*; D005240:Feasibility Studies; D005260:Female; D008839:Microelectrodes / Q000009:adverse effects; D009416:Nerve Regeneration; D016062:Porosity; D051381:Rats; D017207:Rats, Sprague-Dawley; D020426:Sciatic Neuropathy / Q000209:etiology* / Q000473:pathology*; D012825:Silicon / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D012825:Silicon