Histocompatibility and in vivo signal throughput for PEDOT, PEDOP, P3MT, and polycarbazole electrodes

Abstract

Stimulation and recording of the in vivo electrical activity of neurons are critical functions in contemporary biomedical research and in treatment of patients with neurological disorders. The electrodes presently in use tend to exhibit short effective lifespans due to degradation of signal transmission resulting from the tissue response at the electrode-brain interface, and the signal throughput suffers most at the low frequencies relevant for biosignals. To overcome these limitations, new electrode designs to minimize tissue responses, including conducting polymers have been explored. Here we report the short-term histocompatibility and signal throughput results comparing platinum and conducting polymer modified platinum electrodes in a Sprague-Dawley rat model. Two of the polymers tested elicited significantly decreased astrocyte responses relative to platinum. These polymers also showed improved signal throughput at low frequencies and comparable signal to noise ratios during targeted intracranial electroencephalograms (EEG). These results suggest that conducting polymer electrodes may present viable alternatives to the metal electrodes that are currently in use.

Highly Stable Glassy Carbon Interfaces for Long-Term Neural Stimulation and Low-Noise Recording of Brain Activity

“…S4, and show no change before and after the implantation. This result further supports previous evidence on the suitability of PEDOT:PSS for neural interfaces37383940.…”

“…We compare, for the first time, biocompatibility, electrochemical properties and in vivo performance of thin-film MEAs fabricated with either GC or Pt, a biocompatible material traditionally used for neural interfaces, with particular focus on the long term stability. Furthermore, we compare GC and Pt as substrates for Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS), a highly conductive polymer with great chemical stability that is often used16182223353637383940 to improve electrochemical performances when electrode miniaturization41 and high-density spatial arrays are required. We believe that these wide spectra of in vitro and in vivo results demonstrate that GC electrodes offer a new and compelling material for neural recording and stimulation.…”

Optogenetic activation of superior colliculus neurons suppresses seizures originating in diverse brain networks

“…Power spectra were generated essentially as previously described (Forcelli et al, 2012b). The FFT size was 1024 with a Hamming window and 93.75% window overlap.…”

In vitro and in vivo evaluation of poly(3,4‐ethylenedioxythiophene)/poly(styrene sulfonate)/dopamine‐coated electrodes for dopamine delivery

“…One of the most biomedical applications of conducting polymers which have been explored is as biomaterial coatings for electronic biomedical devices . Previous studies have revealed that soft, low impedance, mechanically compliant, and biologically active coatings can be prepared by direct electrochemical deposition of conducting polymers, such as polypyrrole (PPy) and poly(3,4‐ethylenedioxythiophene) (PEDOT), on the electrode sites . Because these conducting polymers could facilitate efficient charge transport by increasing the surface area of the electrode and decreasing the electrical impedance between the metal electrode and living tissues, thus, using bioactive conducting polymers as electrode coatings, a great improvement of performance of electrodes implanted in tissues has been achieved .…”