Regulation of eukaryotic cell physiology using organic bioelectronics

Abstract: The field of organic bioelectronics deals with the implementation of conducting polymer science in biology and medicine. The purpose of this thesis was to develop organic bioelectronic devices for the regulation of eukaryotic cell physiology. The specific physiological concepts that the devices aimed to address were activation of voltage-gated ion channels, cellular mechanotransduction and cell adhesion. The conductive polymers that were used in these devices were polypyrrole and poly(3,4- ethylenedioxythiophene). These polymers are biocompatible which makes them suitable for studying cell physiology. Five devices are presented in the thesis. These are: a nano-fiber scaffold coated with a conducting polymer for electric cell stimulation with high charge transfer capacity, a microfabricated chip comprising microactuators for mechanical stimulation on a cellular level, a conducting polymer surface and a planar electrochemical transistor for control of cell adhesion, and finally a conducting polymer surface with self-disintegrating properties for non-invasive cell release. To evaluate the ability of these devices to address the key physiological concepts they were designed for. A number of cell lines with individual characteristics were chosen. Electric stimulation via conducting polymer coated nano-fibers was tested with a neuroblastoma cell line expressing voltage-operated Ca 2+ channels. A renal epithelial cell line was used to investigate the microactuator chip for mechanical cell stimulation. Renal epithelial cells were also used when investigating devices designed to regulate cell adhesion by interacting with extracellular serum proteins. A human bladder carcinoma cell line was used to examine the self-disintegrating polymer surface for non-invasive cell detachment of adherent cells. The results of the thesis show that it is possible to activate voltage-gated ion channels, induce stimuli that trigger cellular mechanotransduction, and control cell adhesion using organic bioelectronics.