Electrically active hydrogels based on PEDOT:PSS for neural cultures

Journal of Materials Chemistry C, vol. 14, pp. 648–659

Abstract

neural cell cultures. The hydrogels' matrix comprises a viscoelastic alginate primary network, interpenetrated by a secondary network formed by the neural cell-adhesive protein, laminin. Conducting poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) particles are embedded throughout the hydrogel matrix, serving as the electrically active filler phase. Oscillatory rheology confirmed the viscoelastic nature of the composite hydrogels, with storage and loss moduli in the range of 1-10 kPa, suitable for neural tissue interfacing. The hydrogels exhibited high optical transparency across the visible spectrum. At a wavelength of 500 nm, transmission exceeded 45% for 400 µm thick hydrogels and was further enhanced to over 60% by reducing the hydrogel thickness to 150 µm. We established a reproducible protocol for electrochemical impedance spectroscopy and cyclic voltammetry measurements, demonstrating that the incorporation of PEDOT:PSS significantly enhanced both conductivity and charge storage capacitance of hydrogel films. The alginate-laminin-PEDOT:PSS hydrogels demonstrated excellent operational stability, maintaining consistent electrochemical performance over 80 charging/discharging cycles and remaining structurally and functionally stable under cell culture conditions for over four weeks. Cortical neuron cultures derived from human induced pluripotent stem cells prove the stability and cytocompatibility of our proposed hydrogels for over 28 days in culture. Collectively, these results highlight the potential of electrically active hydrogels loaded with PEDOT:PSS as soft, bioelectronic interfaces for neural engineering applications.

Authors 5

1. Liwen Wang

   Delft University of Technology

   Affiliation as printed

   Department of Microelectronics, Faculty of Electrical Engineering, Computer Science and Mathematics, Delft University of Technology, Delft, the Netherlands

2. Yannick Hajee

   Radboud University Nijmegen · Radboud University Medical Center

   Affiliation as printed

   Regenerative Biomaterials–Dentistry, Research Institute for Medical Innovation, Radboud University Medical Center, Nijmegen, the Netherlands

3. Jean‐Philippe Frimat Aachen Department of Human Genetics

   Leiden University Medical Center

   Affiliation as printed

   Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands

4. Mani Diba

   Radboud University Nijmegen · Radboud University Medical Center

   Affiliation as printed

   Regenerative Biomaterials–Dentistry, Research Institute for Medical Innovation, Radboud University Medical Center, Nijmegen, the Netherlands

5. Achilleas Savva

   Delft University of Technology

   Affiliation as printed

   Department of Microelectronics, Faculty of Electrical Engineering, Computer Science and Mathematics, Delft University of Technology, Delft, the Netherlands