Control of Neural Stem Cell Adhesion and Density by an Electronic Polymer Surface Switch

Abstract

Adhesion is an essential parameter for stem cells. It regulates the overall cell density along the carrying surface, which further dictates the differentiation scheme of stem cells toward a more matured and specified population as well as tissue. Electronic control of the seeding density of neural stem cells (c17.2) is here reported. Thin electrode films of poly(3,4-ethylenedioxythiophene) (PEDOT):Tosylate were manufactured along the floor of cell growth dishes. As the oxidation state of the conjugated polymer electrodes was controlled, the seeding density could be varied by a factor of 2. Along the oxidized PEDOT:Tosylate-electrodes, a relatively lower density of, and less tightly bonded, human serum albumin (HSA) was observed as compared to reduced electrodes. We found that this favors adhesion of the specific stem cells studied. Surface analysis experiments, such as photoelectron spectroscopy, and water contact angle measurements, were carried out to investigate the mechanisms responsible for the electronic control of the seeding density of the c17.2 neural stem cells. Further, our findings may provide an opening for electronic control of stem cell differentiation.

Quantifying fibronectin adhesion with nanoscale spatial resolution on glycosaminoglycan doped polypyrrole using Atomic Force Microscopy

“…It was found that the amount of protein adsorption decreased 18,19 but had a greater propensity to adopt a more unfolded conformation 20 along the gradient toward the positive bias end of increased cell adhesion. A similar effect was observed with neural stem cells on a PEDOT:tosylate electrode with a 2-fold increase in cell adhesion on the oxidized polymer even though the protein adsorption was lower compared to the reduced polymer 21 .…”

“…surface potential and conductivity) 29,30 , that have been shown to display nanoscale lateral variation are expected to amplify variations in the conformation and adhesion of individual proteins across the polymer surface. Whilst the above studies have focused on conformation 17,20,21 , the FN-polymer interfacial forces are also interest as they play an important role in force-dependent signal transduction processes such as cellular forces exerted on FN through cell receptors and intracellular proteins to regulate cell function.…”

Applications of conducting polymers and their issues in biomedical engineering

“…This work proved that cell adhesion and proliferation can be controlled by electrochemical modulation of surface parameters. Electrochemically active polymers were also explored as the surface switch material to regulate surface wetting (Salto et al 2008). Electrochemical switching in polymers is expected to affect the strength and the density of dipoles and the binding characteristics of doping ions.…”

Nano-fiber scaffold electrodes based on PEDOT for cell stimulation

“…Planar electronically active cell seeding surfaces based on conjugated polymers have been used to control the cell adhesion and proliferation of various cell systems [11][12][13]. In addition, these materials have been successfully utilized to induce and record signalling in neurons [3,[14][15][16].…”