Effect of Electrical Stimulation Conditions on Neural Stem Cells Differentiation on Cross-Linked PEDOT:PSS Films

Abstract

The ability to culture and differentiate neural stem cells (NSCs) to generate functional neural populations is attracting increasing attention due to its potential to enable cell-therapies to treat neurodegenerative diseases. Recent studies have shown that electrical stimulation improves neuronal differentiation of stem cells populations, highlighting the importance of the development of electroconductive biocompatible materials for NSC culture and differentiation for tissue engineering and regenerative medicine. Here, we report the use of the conjugated polymer poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS CLEVIOS P AI 4083) for the manufacture of conductive substrates. Two different protocols, using different cross-linkers (3-glycidyloxypropyl)trimethoxysilane (GOPS) and divinyl sulfone (DVS) were tested to enhance their stability in aqueous environments. Both cross-linking treatments influence PEDOT:PSS properties, namely conductivity and contact angle. However, only GOPS-cross-linked films demonstrated to maintain conductivity and thickness during their incubation in water for 15 days. GOPS-cross-linked films were used to culture ReNcell-VM under different electrical stimulation conditions (AC, DC, and pulsed DC electrical fields). The polymeric substrate exhibits adequate physicochemical properties to promote cell adhesion and growth, as assessed by Alamar Blue® assay, both with and without the application of electric fields. NSCs differentiation was studied by immunofluorescence and quantitative real-time polymerase chain reaction. This study demonstrates that the pulsed DC stimulation (1 V/cm for 12 days), is the most efficient at enhancing the differentiation of NSCs into neurons.

PEDOT:PSS-Coated Polybenzimidazole Electroconductive Nanofibers for Biomedical Applications

“…The PEDOT:PSS cross-linking solution used in this work was previously tested by Pires et al in the form of films, using slightly different annealing conditions, and showed a conductivity of 5.8 S·m −1 [ 16 ]. The conductivity obtained for a cross-linked PEDOT:PSS film deposited on glass using the new annealing conditions (150 °C, 2 min) is 500 S·m −1 , which is consistent with our most recent studies [ 45 ].…”

Modulation of the electrical double layer in metals and conducting polymers

“…Figure 1 a shows a typical setup used in the study of the EDL formed between PEDOT:PSS and an aqueous electrolyte. The PEDOT:PSS film was cross-linked to ensure its integrity upon contact with the aqueous solution 15 . The potential of the electrical double layer (EDL) was measured using open circuit potentiometry (OCP) in a three-electrode configuration, using an Ag/AgCl reference electrode and a platinum wire as the counter electrode.…”

“…1a), which are under the PEDOT:PSS contacting the electrolyte, or between the two outer contacts (+ 1 V or − 1 V). We note that, during the cell culture studies, the voltage was applied just at the container borders, outside the electrolyte, and was limited to 1 V. This limiting voltage was intended to avoid water electrolysis 14 , 15 .…”

“…The electrolyte container was prepared by 3D printing and the cross-linked PEDOT:PSS film, ca. 100 nm thick, was prepared as described previously 14 , 15 , using PEDOT:PSS CLEVIOS P AI 4083, from Heraeus, and 3-glycidyloxypropyl)trimethoxysilane (GOPS, Aldrich) as cross-linker. Silver and gold films were thermally evaporated on glass slides or glass slides with ITO stripes (after etching from ITO/glass substrates with diluted hydrogen chloride) in a vacuum evaporator (Edwards 306A).…”

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

“…Despite numerous reports of new conductive biomaterials for a variety of applications, relatively few studies have evaluated cultures of primary animal [5,16] or human [116,240,328,340,393] neural cells with conductive biomaterials and/or the effects of applied stimulation. As many studies appear to be done by materials scientists instead of neuroscientists, cell lines that are easy to obtain and culture, for example PC12 and SH-SY5Y cells derived from cancers, are commonly used.…”