title: Nanocomposites of iridium oxide and conducting polymers as electroactive phases in biological media.
abstract: Much effort is currently devoted to implementing new materials in electrodes that will be used in the central nervous system, either for functional electrostimulation or for tests on nerve regeneration. Their main aim is to improve the charge capacity of the electrodes, while preventing damaging secondary reactions, such as peroxide formation, occurring while applying the electric field. Thus, hybrids may represent a new generation of materials. Two novel hybrid materials are synthesized using three known biocompatible materials tested in the neural system: polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) (PEDOT) and iridium oxide (IrO2). In particular, PPy-IrO2 and PEDOT-IrO2 hybrid nanocomposite materials are prepared by chemical polymerization in hydrothermal conditions, using IrO2 as oxidizing agent. The reaction yields a significant ordered new hybrid where the conducting polymer is formed around the IrO2 nanoparticles, encapsulating them. Scanning electron microscopy and backscattering techniques show the extent of the encapsulation. Both X-ray photoelectron and Fourier transform infrared spectroscopies identify the components of the phases, as well as the absence of impurities. Electrochemical properties of the final phases in powder and pellet form are evaluated by cyclic voltammetry. Biocompatibility is tested with MTT toxicity tests using primary cultures of cortical neurons grown in vitro for 6 and 9days.
authors.affiliation: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, E-08193, Bellaterra, Barcelona, Spain. Electronic address: jmoralvico@gmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Moral-Vico
authors.affiliation: Institut d'Investigacions Biomèdiques de Barcelona (IIBB-CSIC), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), CIBER de Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Sánchez-Redondo
authors.affiliation: Institut d'Investigacions Biomèdiques de Barcelona (IIBB-CSIC), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), CIBER de Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.
authors.forename: M P
authors.initials: MP
authors.lastname: Lichtenstein
authors.affiliation: Institut d'Investigacions Biomèdiques de Barcelona (IIBB-CSIC), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), CIBER de Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Suñol
authors.affiliation: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de la UAB, E-08193, Bellaterra, Barcelona, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Casañ-Pastor
mesh_terms: D000818:Animals; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry; D003470:Culture Media / Q000737:chemistry*; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods*; D007495:Iridium / Q000737:chemistry*; D051379:Mice; D053761:Nanocomposites / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology; D056951:Photoelectron Spectroscopy; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D003470:Culture Media; D011108:Polymers; D011758:Pyrroles; C121383:poly(3,4-ethylene dioxythiophene); C044458:iridium oxide; C067635:polypyrrole; D007495:Iridium
keywords: Conducting polymers; Cytotoxicity; Hybrid materials; Iridium oxide; Nanocomposites