Conducting polymers grown in hydrogel scaffolds coated on neural prosthetic devices.

The conducting polymer polypyrrole (PPy) was electrochemically grown on hydrogel scaffolds deposited on the surface of microfabricated neural prosthetic devices. It is shown that the pyrrole monomer can be grown vertically through the hydrogel layer up to the surface without affecting the adjacent sites on the probes. The electrochemical properties of the conducting polymer-modified hydrogels were studied by impedance spectroscopy and cyclic voltammetry. It is also found that the conducting polymers could still be readily grown through the hydrogel after the microstructure is disrupted by freeze drying. Impedance measurements at the biologically important frequency of 1 kHz showed that the minimum impedance of this polymer-modified hydrogel was 7 kOmega. This is much lower than the minimum impedance of polypyrrole film ( approximately 100 kOmega).

[1]  Rachel Williams,et al.  A preliminary assessment of poly(pyrrole) in nerve guide studies , 1994 .

[2]  L. Shapiro,et al.  Novel alginate sponges for cell culture and transplantation. , 1997, Biomaterials.

[3]  Kinam Park,et al.  Hydrogels and Biodegradable Polymers for Bioapplications , 1996 .

[4]  M. A. Johnson,et al.  Chronic recording of regenerating VIIIth nerve axons with a sieve electrode. , 2000, Journal of neurophysiology.

[5]  W. Rutten.  Selective electrical interfaces with the nervous system. , 2002, Annual review of biomedical engineering.

[6]  S. B. Brummer,et al.  Activated Ir: An Electrode Suitable for Reversible Charge Injection in Saline Solution , 1983 .

[7]  Olle Inganäs,et al.  Polymer Hydrogel Microelectrodes for Neural Communication , 2002 .

[8]  David J. Anderson,et al.  Electrochemical deposition and characterization of conducting polymer polypyrrole/PSS on multichannel neural probes , 2001 .

[9]  T. Stieglitz,et al.  Micromachined, Polyimide-Based Devices for Flexible Neural Interfaces , 2000 .

[10]  R. Stein,et al.  Stable long-term recordings from cat peripheral nerves , 1977, Brain Research.

[11]  Philip N. Bartlett,et al.  Mesoporous Platinum Films from Lyotropic Liquid Crystalline Phases , 1997 .

[12]  J. Hetke,et al.  Surface modification of neural recording electrodes with conducting polymer/biomolecule blends. , 2001, Journal of biomedical materials research.

[13]  K. Miller,et al.  Modelling of Brain Tissue Mechanical Properties: Bi–Phasic Versus Single–Phase Approach , 1998 .

[14]  O. Inganäs,et al.  Conducting Polymer Hydrogels as 3D Electrodes: Applications for Supercapacitors , 1999 .

[15]  B. C. Kim,et al.  Electroformation of conducting polymers in a hydrogel support matrix , 2000 .

[16]  John R. Reynolds,et al.  Use of Conducting Electroactive Polymers for Drug Delivery and Sensing of Bioactive Molecules. A Redox Chemistry Approach , 2000 .

[17]  David J. Anderson,et al.  Surgical Implantation and Biocompatibility of Central Nervous System Auditory Prostheses , 1989, The Annals of otology, rhinology, and laryngology.

[18]  Michael Freemantle,et al.  The Endless Polymer Science Frontier , 2000 .

[19]  N Wisniewski,et al.  Characterization of implantable biosensor membrane biofouling , 2000, Fresenius' journal of analytical chemistry.

[20]  R. Hoch,et al.  High power electrochemical capacitors based on carbon nanotube electrodes , 1997 .

[21]  Chronic electrode-brain interface modeled with FEM , 1999, Proceedings of the First Joint BMES/EMBS Conference. 1999 IEEE Engineering in Medicine and Biology 21st Annual Conference and the 1999 Annual Fall Meeting of the Biomedical Engineering Society (Cat. N.

[22]  G G Wallace,et al.  Polypyrrole-heparin composites as stimulus-responsive substrates for endothelial cell growth. , 1999, Journal of biomedical materials research.

[23]  R Langer,et al.  Stimulation of neurite outgrowth using an electrically conducting polymer. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[24]  Gordon G. Wallace,et al.  Integration of biocomponents with synthetic structures: use of conducting polymer polyelectrolyte composites , 1996, Smart Structures.

[25]  D. F. Williams,et al.  Biomaterials Science: An Introduction to Materials in Medicine, Buddy D. Ratner (Ed.). Academic Press (2004), (864pp., $95/£49.99), ISBN: 0-12-582463-7 , 2005 .

[26]  Geoffrey M. Spinks,et al.  Conductive Electroactive Polymers: Intelligent Materials Systems , 1997 .

[27]  David C. Martin,et al.  Impedance spectroscopy of protein polymer modified silicon micromachined probes , 1999 .

[28]  Processing and characterization of protein polymer thin films for surface modification of neural prosthetic devices. , 1997 .

[29]  Christopher R. Lowe,et al.  Enzyme entrapment in electrically conducting polymers. Immobilisation of glucose oxidase in polypyrrole and its application in amperometric glucose sensors , 1986 .

[30]  Wang Yongbin,et al.  Theoretical and experimental studies of conducting polymer polyaniline / electrolyte interface by impedance spectroscopy , 1993 .