Comparison of the In Vitro and In Vivo Electrochemical Performance of Bionic Electrodes
The electrochemical performance of platinum electrodes was assessed in vitro and in vivo to determine the impact of electrode implantation and the relevance of in vitro testing in predicting in vivo behaviour. A significant change in electrochemical response was seen after electrode polarisation. As...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-01-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/13/1/103 |
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| author | Alexander R. Harris Carrie Newbold Dimitra Stathopoulos Paul Carter Robert Cowan Gordon G. Wallace |
| author_facet | Alexander R. Harris Carrie Newbold Dimitra Stathopoulos Paul Carter Robert Cowan Gordon G. Wallace |
| author_sort | Alexander R. Harris |
| collection | DOAJ |
| description | The electrochemical performance of platinum electrodes was assessed in vitro and in vivo to determine the impact of electrode implantation and the relevance of in vitro testing in predicting in vivo behaviour. A significant change in electrochemical response was seen after electrode polarisation. As a result, initial in vitro measurements were poor predictors of subsequent measurements performed in vitro or in vivo. Charge storage capacity and charge density measurements from initial voltammetric measurements were not correlated with subsequent measurements. Electrode implantation also affected the electrochemical impedance. The typically reported impedance at 1 kHz was a very poor predictor of electrode performance. Lower frequencies were significantly more dependent on electrode properties, while higher frequencies were dependent on solution properties. Stronger correlations in impedance at low frequencies were seen between in vitro and in vivo measurements after electrode activation had occurred. Implanting the electrode increased the resistance of the electrochemical circuit, with bone having a higher resistivity than soft tissue. In contrast, protein fouling and fibrous tissue formation had a minimal impact on electrochemical response. In vivo electrochemical measurements also typically use a quasi-reference electrode, may operate in a 2-electrode system, and suffer from uncompensated resistance. The impact of these experimental conditions on electrochemical performance and the relevance of in vitro electrode assessment is discussed. Recommended in vitro testing protocols for assessing bionic electrodes are presented. |
| first_indexed | 2024-03-10T00:54:56Z |
| format | Article |
| id | doaj.art-8bf872afe02b452486bb8d7f961921c1 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-10T00:54:56Z |
| publishDate | 2022-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-8bf872afe02b452486bb8d7f961921c12023-11-23T14:44:59ZengMDPI AGMicromachines2072-666X2022-01-0113110310.3390/mi13010103Comparison of the In Vitro and In Vivo Electrochemical Performance of Bionic ElectrodesAlexander R. Harris0Carrie Newbold1Dimitra Stathopoulos2Paul Carter3Robert Cowan4Gordon G. Wallace5Aikenhead Centre for Medical Discovery, ARC Centre of Excellence for Electromaterials Science, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne 3010, AustraliaDepartment of Otolaryngology, University of Melbourne, 32 Gisborne Street, Melbourne 3002, AustraliaDepartment of Otolaryngology, University of Melbourne, 32 Gisborne Street, Melbourne 3002, AustraliaCochlear Ltd., 1 University Avenue, Sydney 2109, AustraliaDepartment of Audiology & Speech Pathology, University of Melbourne, 550 Swanston Street, Melbourne 3010, AustraliaARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, Wollongong 2522, AustraliaThe electrochemical performance of platinum electrodes was assessed in vitro and in vivo to determine the impact of electrode implantation and the relevance of in vitro testing in predicting in vivo behaviour. A significant change in electrochemical response was seen after electrode polarisation. As a result, initial in vitro measurements were poor predictors of subsequent measurements performed in vitro or in vivo. Charge storage capacity and charge density measurements from initial voltammetric measurements were not correlated with subsequent measurements. Electrode implantation also affected the electrochemical impedance. The typically reported impedance at 1 kHz was a very poor predictor of electrode performance. Lower frequencies were significantly more dependent on electrode properties, while higher frequencies were dependent on solution properties. Stronger correlations in impedance at low frequencies were seen between in vitro and in vivo measurements after electrode activation had occurred. Implanting the electrode increased the resistance of the electrochemical circuit, with bone having a higher resistivity than soft tissue. In contrast, protein fouling and fibrous tissue formation had a minimal impact on electrochemical response. In vivo electrochemical measurements also typically use a quasi-reference electrode, may operate in a 2-electrode system, and suffer from uncompensated resistance. The impact of these experimental conditions on electrochemical performance and the relevance of in vitro electrode assessment is discussed. Recommended in vitro testing protocols for assessing bionic electrodes are presented.https://www.mdpi.com/2072-666X/13/1/103electrochemistryelectrochemical impedance spectroscopyanimal modelbionicselectrodetesting protocol |
| spellingShingle | Alexander R. Harris Carrie Newbold Dimitra Stathopoulos Paul Carter Robert Cowan Gordon G. Wallace Comparison of the In Vitro and In Vivo Electrochemical Performance of Bionic Electrodes Micromachines electrochemistry electrochemical impedance spectroscopy animal model bionics electrode testing protocol |
| title | Comparison of the In Vitro and In Vivo Electrochemical Performance of Bionic Electrodes |
| title_full | Comparison of the In Vitro and In Vivo Electrochemical Performance of Bionic Electrodes |
| title_fullStr | Comparison of the In Vitro and In Vivo Electrochemical Performance of Bionic Electrodes |
| title_full_unstemmed | Comparison of the In Vitro and In Vivo Electrochemical Performance of Bionic Electrodes |
| title_short | Comparison of the In Vitro and In Vivo Electrochemical Performance of Bionic Electrodes |
| title_sort | comparison of the in vitro and in vivo electrochemical performance of bionic electrodes |
| topic | electrochemistry electrochemical impedance spectroscopy animal model bionics electrode testing protocol |
| url | https://www.mdpi.com/2072-666X/13/1/103 |
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