Porous PEDOT:PSS Particles and their Application as Tunable Cell Culture Substrate

Abstract

Due to its biocompatibility, electrical conductivity, and tissue‐like elasticity, poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) constitutes a highly promising material regarding the fabrication of smart cell culture substrates. However, until now, high‐throughput synthesis of pure PEDOT:PSS geometries was restricted to flat sheets and fibers. In this publication, the first microfluidic process for the synthesis of spherical, highly porous, pure PEDOT:PSS particles of adjustable material properties is presented. The particles are synthesized by the generation of PEDOT:PSS emulsion droplets within a 1‐octanol continuous phase and their subsequent coagulation and partial crystallization in an isopropanol (IPA)/sulfuric acid (SA) bath. The process allows to tailor central particle characteristics such as crystallinity, particle diameter, pore size as well as electrochemical and mechanical properties by simply adjusting the IPA:SA ratio during droplet coagulation. To demonstrate the applicability of PEDOT:PSS particles as potential cell culture substrate, cultivations of L929 mouse fibroblast cells and MRC‐5 human fibroblast cells are conducted. Both cell lines present exponential growth on PEDOT:PSS particles and reach confluency with cell viabilities above 95 vol.% on culture day 9. Single cell analysis could moreover reveal that mechanotransduction and cell infiltration can be controlled by the adjustment of particle crystallinity.

Highly Rectifying Water-Mediated Hydrogen Bond-Coupled Organic–Inorganic Interfaces

“…Airborne H 2 O molecules have been shown to passivate the surface-exposed SO 3 H groups and hinder their ionization . The PEDOT:PSS surface is mainly covered with the hydrophilic PSS chains, ,− and H 2 O molecules can form hydrogen bonds with the surface-exposed SO 3 H groups (Figure B). Accordingly, deionized water vapor is introduced to the argon chamber to bring the RH level to 10%.…”

Toward the Next Generation of Neural Iontronic Interfaces

“…From the material side, it is becoming evident that striving toward softer materials (in the 10-100 kPa range), such as hydrogels or viscoelastic materials, achieve tighter interaction with biological tissue. [42,[78][79][80][81] These materials bear the potential for lifelong implantation and continuous monitoring and interaction with the surrounding tissue by further displaying biomimetic (and conductive) tissue-like architectures, which can be achieved through innovative techniques such as additive manufacturing and bioprinting. However, it is still challenging to create devices with such materials with a high electrode count, as they are not compatible with standard microfabrication techniques and chemicals, thereby introducing many extra steps that make the processing highly manual and labor-intensive.…”

Tunable Conductive Hydrogel Scaffolds for Neural Cell Differentiation

“…compliant surfaces. [26][27][28] However, despite modifications of PE-DOT:PSS and PPy systems, including incorporation into a hydrogel matrix to provide better cell interfaces, these composites have limitations. The porous nature of these conductive hydrogels is minimal which results in limited ability for cells to integrate and migrate through the matrix.…”

“…[ 24,25 ] Now, poly(3,4‐ethylenedioxythiopene) is doped with PSS, or commonly known as PEDOT:PSS, and can be electrodeposited into small, confined microchannels for equally “fuzzy” but also more mechanically compliant surfaces. [ 26–28 ] However, despite modifications of PEDOT:PSS and PPy systems, including incorporation into a hydrogel matrix to provide better cell interfaces, these composites have limitations. The porous nature of these conductive hydrogels is minimal which results in limited ability for cells to integrate and migrate through the matrix.…”