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Ramesh V, Rehbock C, Giera B, Karnes JJ, Forien JB, Angelov SD, Schwabe K, Krauss JK, Barcikowski S. Comparing Direct and Pulsed-Direct Current Electrophoretic Deposition on Neural Electrodes: Deposition Mechanism and Functional Influence. Langmuir 2021; 37:9724-9734. [PMID: 34357777 DOI: 10.1021/acs.langmuir.1c01081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Electrophoretic deposition (EPD) of platinum nanoparticles (PtNPs) on platinum-iridium (Pt-Ir) neural electrode surfaces is a promising strategy to tune the impedance of electrodes implanted for deep brain stimulation in various neurological disorders such as advanced Parkinson's disease and dystonia. However, previous results are contradicting as impedance reduction was observed on flat samples while in three-dimensional (3D) structures, an increase in impedance was observed. Hence, defined correlations between coating properties and impedance are to date not fully understood. In this work, the influence of direct current (DC) and pulsed-DC electric fields on NP deposition is systematically compared and clear correlations between surface coating homogeneity and in vitro impedance are established. The ligand-free NPs were synthesized via pulsed laser processing in liquid, yielding monomodal particle size distributions, verified by analytical disk centrifugation (ADC). Deposits formed were quantified by UV-vis supernatant analysis and further characterized by scanning electron microscopy (SEM) with semiautomated interparticle distance analyses. Our findings reveal that pulsed-DC electric fields yield more ordered surface coatings with a lower abundance of particle assemblates, while DC fields produce coatings with more pronounced aggregation. Impedance measurements further highlight that impedance of the corresponding electrodes is significantly reduced in the case of more ordered coatings realized by pulsed-DC depositions. We attribute this phenomenon to the higher active surface area of the adsorbed NPs in homogeneous coatings and the reduced particle-electrode electrical contact in NP assemblates. These results provide insight for the efficient EPD of bare metal NPs on micron-sized surfaces for biomedical applications in neuroscience and correlate coating homogeneity with in vitro functionality.
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Affiliation(s)
- Vaijayanthi Ramesh
- Technical Chemistry I, Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 45141 Essen, Germany
| | - Christoph Rehbock
- Technical Chemistry I, Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 45141 Essen, Germany
| | - Brian Giera
- Center for Engineered Materials and Manufacturing, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - John J Karnes
- Center for Engineered Materials and Manufacturing, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Jean-Baptiste Forien
- Center for Engineered Materials and Manufacturing, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Svilen D Angelov
- Department of Neurosurgery, Hannover Medical School, 30625 Hannover, Germany
| | - Kerstin Schwabe
- Department of Neurosurgery, Hannover Medical School, 30625 Hannover, Germany
| | - Joachim K Krauss
- Department of Neurosurgery, Hannover Medical School, 30625 Hannover, Germany
| | - Stephan Barcikowski
- Technical Chemistry I, Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 45141 Essen, Germany
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Nguyen T, Dierre B, Grasset F, Dumait N, Cordier S, Lemoine P, Renaud A, Fudouzi H, Ohashi N, Uchikoshi T. Electrophoretic Coating of Octahedral Molybdenum Metal Clusters for UV/NIR Light Screening. Coatings 2017; 7:114. [DOI: 10.3390/coatings7080114] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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