title: Biocompatibility and charge injection property of iridium film formed by ion beam assisted deposition.
abstract: Iridium thin film formed by electron-beam evaporation with simultaneous bombardment of Ar ion beam was evaluated for a stimulating neural electrode. The electrochemical behavior of as-deposited Ir film on Ni-Ti sample was almost identical to bulk Ir by producing much higher open-circuit corrosion potential and much lower anodic current density than the uncoated Ni-Ti in both 1N sulfuric acid and saline solution. The charge injection capability of Ir film was compared with that of Pt electrode currently used mostly as a stimulating neural electrode. The charge density of Pt was small and unchanged with increasing number of activating cycles in 0.1M H(2)SO(4), whilst the Ir film continuously produced increases in charge density. The charge injection density of Ir film in physiological solution was higher for the more activated sample under the identical stimulating condition. Attachment and proliferation with PC12 cells on Ir-coated CP Ti without applying electrical stimulation was similar to the polished CP Ti. A network of neurons and extending axons were formed on Ir film.
authors.affiliation: Atomic Scale Surface Science Research Center, Yonsei University, 134 Shinchon-dong, Sudaemoon-ku, Seoul 120-749, South Korea. inseop@yonsei.ac.kr
authors.forename: In-Seop
authors.initials: IS
authors.lastname: Lee
authors.forename: Chung-Nam
authors.initials: CN
authors.lastname: Whang
authors.forename: Jong-Chul
authors.initials: JC
authors.lastname: Park
authors.forename: Dong-Hee
authors.initials: DH
authors.lastname: Lee
authors.forename: Won-Sun
authors.initials: WS
authors.lastname: Seo
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D004558:Electric Stimulation / Q000295:instrumentation* / Q000379:methods; D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods; D004563:Electrochemistry; D004567:Electrodes, Implanted; D004595:Electroplating / Q000379:methods*; D007495:Iridium / Q000737:chemistry* / Q000494:pharmacology; D008422:Materials Testing; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D016716:PC12 Cells; D051381:Rats; D055672:Static Electricity
chemical_list: D020099:Coated Materials, Biocompatible; D007495:Iridium