TY - JOUR

T1 - A silicone fiber coating as approach for the reduction of fibroblast growth on implant electrodes

AU - Dencker, Folke

AU - Dreyer, Lutz

AU - Müller, Dietrich

AU - Zernetsch, Holger

AU - Paasche, Gerrit

AU - Sindelar, Ralf

AU - Glasmacher, Birgit

N1 - Publisher Copyright: © 2016 Wiley Periodicals, Inc. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.

PY - 2017/11

Y1 - 2017/11

N2 - In cochlear implant (CI) patients, an increase in electrode impedance due to fibrotic encapsulation is frequently observed. Several attempts have been proposed to reduce fibroblast growth at the electrode contacts, but none proved to be satisfactory so far. Here, a silicone fiber coating of the electrode contacts is presented that provides a complex micro-scale surface topography and increases hydrophobicity to inhibit fibroblast growth and adhesion. A silicone fiber electrospinning process was developed to create a thin and porous fiber mesh. Fiber coatings were applied on graphite specimen holders, glass cover slips and CI electrode contacts. For characterization of the coating's pore distribution, water contact angle and electrical impedance were analyzed. Cytotoxicity and in vitro fibroblast growth were evaluated to assess biological efficacy of the coatings. It could be shown that the silicone fiber mesh itself had only minor influence on electrode impedance. A uniform, hydrophobic fiber coating could be achieved that decreased fibroblast growth without showing toxic effects. Finally, CI electrode contacts were successfully coated in order to present this promising approach for a long-term improvement of CI electrodes. We are one of the first groups that could successfully adapt the electrospinning technique on the utilization of silicone. Silicone was chosen because of its high hydrophobicity, chemical stability and excellent biocompatibility and as it is one of the biomaterials already used in CIs.

AB - In cochlear implant (CI) patients, an increase in electrode impedance due to fibrotic encapsulation is frequently observed. Several attempts have been proposed to reduce fibroblast growth at the electrode contacts, but none proved to be satisfactory so far. Here, a silicone fiber coating of the electrode contacts is presented that provides a complex micro-scale surface topography and increases hydrophobicity to inhibit fibroblast growth and adhesion. A silicone fiber electrospinning process was developed to create a thin and porous fiber mesh. Fiber coatings were applied on graphite specimen holders, glass cover slips and CI electrode contacts. For characterization of the coating's pore distribution, water contact angle and electrical impedance were analyzed. Cytotoxicity and in vitro fibroblast growth were evaluated to assess biological efficacy of the coatings. It could be shown that the silicone fiber mesh itself had only minor influence on electrode impedance. A uniform, hydrophobic fiber coating could be achieved that decreased fibroblast growth without showing toxic effects. Finally, CI electrode contacts were successfully coated in order to present this promising approach for a long-term improvement of CI electrodes. We are one of the first groups that could successfully adapt the electrospinning technique on the utilization of silicone. Silicone was chosen because of its high hydrophobicity, chemical stability and excellent biocompatibility and as it is one of the biomaterials already used in CIs.

KW - cochlear implant

KW - electrospinning

KW - silicone fiber

UR - http://www.scopus.com/inward/record.url?scp=84990180469&partnerID=8YFLogxK

U2 - 10.1002/jbm.b.33798

DO - 10.1002/jbm.b.33798

M3 - Article

C2 - 27701814

AN - SCOPUS:84990180469

VL - 105

SP - 2574

EP - 2580

JO - Journal of Biomedical Materials Research - Part B Applied Biomaterials

JF - Journal of Biomedical Materials Research - Part B Applied Biomaterials

SN - 1552-4973

IS - 8

ER -