All-Organic Conductive Biomaterial as an Electroactive Cell Interface

Abstract

Various attractive materials are being used in bioelectronics recently. In this paper, hydroxymethyl-3,4-ethylenedioxythiophene (EDOT-OH) has been in situ integrated and polymerized on the surface of the regenerated silk fibroin (RSF) film to construct a biocompatible electrode. In order to improve the efficiency of in situ polymerization, sodium dodecyl sulfate (SDS) was adopted as surfactant to construct a well-organized and stable poly­(hydroxymethyl-3,4-ethylenedioxythiophene) (PEDOT-OH) coating, whereas ammonium persulfate was used as oxidant. The effects of dosages of surfactant and oxidant, initial pH value, and monomer concentration on the polymerization were studied. Under the optimal conditions, the RSF/PEDOT-OH film exhibited a square resistance of 3.28 × 105 Ω corresponding to a conductance of 6.1 × 10–3 S/cm. Scanning electron microscope images indicated that PEDOT-OH was deposited uniformly on the surface of the RSF film with SDS. Furthermore, Fourier transform infrared spectroscopy confirmed that interactions existed between the peptide linkages of silk fibroin (SF) macromolecules and PEDOT-OH. The RSF/PEDOT-OH film displayed favorable electrochemical stability, biocompatibility, and fastness. This study provides a feasible method to endow conductivity to RSF materials in various forms. In addition, the conductive layer and biocompatible silk substrate make the RSF/PEDOT-OH biomaterial highly suitable for potential applications in bioelectric devices, sensors, and tissue engineering.

Transparent Conductive Silk Film with a PEDOT–OH Nano Layer as an Electroactive Cell Interface

“…The chemical oxidative polymerization and deposition method has clear advantages in terms of mass production capabilities and is suitable for both conductive and insulative substrates. Products with strong adhesion could be fabricated through this method. , Furthermore, this method can be expanded to the 3D biomaterial substrates produced by various processes such as an RSF mat, sponge, and scaffold. Yet precise control of the PEDOT deposition is very difficult.…”

Engineering Tissues of the Central Nervous System: Interfacing Conductive Biomaterials with Neural Stem/Progenitor Cells

“…[369,396,397] Laponite, a synthetic nanoclay consisting of silicate nanoplatelets, has been explored by a number of groups as a bioink additive for its ability to impart conductivity and shear thinning properties desirable for 3D printing. [397][398][399] For example, laponite was dispersed in heparin hydrogels that were then evaluated in a spinal cord crush model (T9) in rats. [397] When also loaded with FGF-4 for release in vivo, laponite/heparin hydrogels improved tissue pathology and recovery of hindlimb function.…”

“…[367] For example, graphene-containing bioinks based on PU-PCL and PPy-PCL copolymers have been used to print viable cultures of embedded neural cells. [369,396,397] Laponite, a synthetic nanoclay consisting of silicate nanoplatelets, has been explored by a number of groups as a bioink additive for its ability to impart conductivity and shear thinning properties desirable for 3D printing. [397][398][399] For example, laponite was dispersed in heparin hydrogels that were then evaluated in a spinal cord crush model (T9) in rats.…”

“…[397][398][399] For example, laponite was dispersed in heparin hydrogels that were then evaluated in a spinal cord crush model (T9) in rats. [397] When also loaded with FGF-4 for release in vivo, laponite/heparin hydrogels improved tissue pathology and recovery of hindlimb function. In another report, laponite was doped into polyacrylamide and 3D printed into structures onto which PEDOT was subsequently polymerized.…”

“…For example, coating of regenerated silk fibroin with a conductive thiophene derivative, hydroxymethyl‐3,4‐ethylenedioxythiophene (EDOT‐OH), yielded maximum conductivity around 6 × 10 −3 S cm −1 and supported cultures of PC12 cells. [ 412 ] Thin 2D substrates, or films, enable researchers to easily assess material composite formulations and the effects of surface modifications on interfaced cells. In another example, a composite film of PLGA and graphene oxide was found to have good cytocompatibility when seeded with mouse E14 cortical NSCs.…”