title: Size-dependent long-term tissue response to biostable nanowires in the brain.
abstract: Nanostructured neural interfaces, comprising nanotubes or nanowires, have the potential to overcome the present hurdles of achieving stable communication with neuronal networks for long periods of time. This would have a strong impact on brain research. However, little information is available on the brain response to implanted high-aspect-ratio nanoparticles, which share morphological similarities with asbestos fibres. Here, we investigated the glial response and neuronal loss in the rat brain after implantation of biostable and structurally controlled nanowires of different lengths for a period up to one year post-surgery. Our results show that, as for lung and abdominal tissue, the brain is subject to a sustained, local inflammation when biostable and high-aspect-ratio nanoparticles of 5 μm or longer are present in the brain tissue. In addition, a significant loss of neurons was observed adjacent to the 10 μm nanowires after one year. Notably, the inflammatory response was restricted to a narrow zone around the nanowires and did not escalate between 12 weeks and one year. Furthermore, 2 μm nanowires did not cause significant inflammatory response nor significant loss of neurons nearby. The present results provide key information for the design of future neural implants based on nanomaterials.
authors.affiliation: Neuronano Research Center, Department of Experimental Medical Science, Medical Faculty, Lund University, BMCF10, Lund SE-221 84, Sweden.
authors.forename: Lina
authors.initials: L
authors.lastname: Gällentoft
authors.affiliation: Neuronano Research Center, Department of Experimental Medical Science, Medical Faculty, Lund University, BMCF10, Lund SE-221 84, Sweden.
authors.forename: Lina M E
authors.initials: LM
authors.lastname: Pettersson
authors.affiliation: Neuronano Research Center, Department of Experimental Medical Science, Medical Faculty, Lund University, BMCF10, Lund SE-221 84, Sweden.
authors.forename: Nils
authors.initials: N
authors.lastname: Danielsen
authors.affiliation: Neuronano Research Center, Department of Experimental Medical Science, Medical Faculty, Lund University, BMCF10, Lund SE-221 84, Sweden.
authors.forename: Jens
authors.initials: J
authors.lastname: Schouenborg
authors.affiliation: Neuronano Research Center, Department of Experimental Medical Science, Medical Faculty, Lund University, BMCF10, Lund SE-221 84, Sweden; Division of Solid State Physics, The Nanometer Structure Consortium, Lund University, Box 118, Lund SE-221 00, Sweden. Electronic address: Christelle.Prinz@ftf.lth.se.
authors.forename: Christelle N
authors.initials: CN
authors.lastname: Prinz
authors.affiliation: Neuronano Research Center, Department of Experimental Medical Science, Medical Faculty, Lund University, BMCF10, Lund SE-221 84, Sweden. Electronic address: Cecilia.Eriksson_Linsmeier@med.lu.se.
authors.forename: Cecilia Eriksson
authors.initials: CE
authors.lastname: Linsmeier
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000473:pathology; D001672:Biocompatible Materials / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects / Q000473:pathology*; D002452:Cell Count; D005260:Female; D007249:Inflammation / Q000473:pathology; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D017628:Microglia / Q000187:drug effects / Q000378:metabolism; D018613:Microscopy, Confocal; D053770:Nanowires / Q000648:ultrastructure; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D010316:Particle Size; D017207:Rats, Sprague-Dawley; D013535:Suspensions; D013997:Time Factors
chemical_list: D001672:Biocompatible Materials; D013535:Suspensions
keywords: Biocompatibility; Brain; Inflammation; Nanoparticle