1. Platinum corrosion products from electrode contacts of human cochlear implants induce cell death in cell culture models
- Author
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Martin Durisin, Thomas Lenarz, Kirsten Wissel, Gian Luigi Angrisani, Nils Pütz, Jan Thieleke, and Gudrun Brandes
- Subjects
Respiratory chain ,Cell Culture Techniques ,lcsh:Medicine ,Metal Nanoparticles ,02 engineering and technology ,Endoplasmic Reticulum ,Biochemistry ,Mice ,0302 clinical medicine ,Medicine and Health Sciences ,Nanotechnology ,mitochondrion ,animal ,platinum ,Cytotoxicity ,lcsh:Science ,Energy-Producing Organelles ,Multidisciplinary ,cochlea prosthesis ,Cell Death ,Chemistry ,drug effect ,Chemical Reactions ,021001 nanoscience & nanotechnology ,Cochlear Implantation ,Mitochondria ,medicine.anatomical_structure ,Electrode ,Physical Sciences ,Cell lines ,Engineering and Technology ,Cellular Structures and Organelles ,0210 nano-technology ,Biological cultures ,Research Article ,Chemical Elements ,Cell type ,Programmed cell death ,Cell Physiology ,NIH 3T3 cell line ,Cell Survival ,Surgical and Invasive Medical Procedures ,Bioenergetics ,Endocytosis ,chemistry ,3T3 cells ,03 medical and health sciences ,Cell Line, Tumor ,medicine ,endocytosis ,Animals ,Humans ,ddc:610 ,human ,procedures ,cell culture technique ,Electrodes ,mouse ,metal nanoparticle ,corrosion ,Functional Electrical Stimulation ,lcsh:R ,tumor cell line ,Biology and Life Sciences ,Cell Biology ,Cell Cultures ,electrode ,Cell Metabolism ,Research and analysis methods ,Cochlear Implants ,Cell culture ,Biophysics ,NIH 3T3 Cells ,Nanoparticles ,lcsh:Q ,Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit ,030217 neurology & neurosurgery - Abstract
Despite the technological progress made with cochlear implants (CI), impedances and their diagnosis remain a focus of interest. Increases in impedance have been related to technical defects of the electrode as well as inflammatory and/or fibrosis along the electrode. Recent studies have demonstrated highly increased impedances as the result of corroded platinum (Pt) electrode contacts. This in vitro study examined the effects of Pt ions and compounds generated by corrosion of the electrode contacts of a human CI on cell metabolism. Since traces of solid Pt in surrounding cochlear tissues have been reported, the impact of commercially available Pt nanoparticles (Pt-NP, size 3 nm) on the cell culture model was also determined. For this purpose, the electrode contacts were electrically stimulated in a 0.5% aqueous NaCl solution for four weeks and the mass fraction of the platinum dissolute (Pt-Diss) was determined by mass spectrometry (ICP-MS). Metabolic activity of the murine fibroblasts (NIH 3T3) and the human neuroblastoma (SH-SY5Y) cells was determined using the WST-1 assay following exposure to Pt-Diss and Pt-NP. It was found that 5–50 μg/ml of the Pt-NP did not affect the viability of both cell types. In contrast, 100 μg/ml of the nanoparticles caused significant loss in metabolic activity. Furthermore, transmission electron microscopy (TEM) revealed mitochondrial swelling in both cell types indicating cytotoxicity. Additionally, TEM demonstrated internalized Pt-NP in NIH 3T3 cells in a concentration dependent manner, whereas endocytosis in SH-SY5Y cells was virtually absent. In comparison with the Pt-NP, the corrosion products (Pt-Diss) with concentrations between 1.64 μg/ml and 8.2 μg/ml induced cell death in both cell lines in a concentration dependent manner. TEM imaging revealed both mitochondrial disintegration and swelling of the endoplasmic reticulum, suggesting that Pt ions trigger cytotoxicity in both NIH 3T3 and SH-SY5Y cell lines by interacting with the respiratory chain.
- Published
- 2018
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